Skip to main content
Erschienen in: BMC Pregnancy and Childbirth 1/2021

Open Access 01.12.2021 | Research

Are birth outcomes in low risk birth cohorts related to hospital birth volumes? A systematic review

verfasst von: Felix Walther, Denise Kuester, Anja Bieber, Jürgen Malzahn, Mario Rüdiger, Jochen Schmitt

Erschienen in: BMC Pregnancy and Childbirth | Ausgabe 1/2021

Abstract

Background

There is convincing evidence that birth in hospitals with high birth volumes increases the chance of healthy survival in high-risk infants. However, it is unclear whether this is true also for low risk infants. The aim of this systematic review was to analyze effects of hospital’s birth volume on mortality, mode of delivery, readmissions, complications and subsequent developmental delays in all births or predefined low risk birth cohorts. The search strategy included EMBASE and Medline supplemented by citing and cited literature of included studies and expert panel highlighting additional literature, published between January/2000 and February/2020. We included studies which were published in English or German language reporting effects of birth volumes on mortality in term or all births in countries with neonatal mortality < 5/1000. We undertook a double-independent title-abstract- and full-text screening and extraction of study characteristics, critical appraisal and outcomes in a qualitative evidence synthesis.

Results

13 retrospective studies with mostly acceptable quality were included. Heterogeneous volume-thresholds, risk adjustments, outcomes and populations hindered a meta-analysis. Qualitatively, four of six studies reported significantly higher perinatal mortality in lower birth volume hospitals. Volume-outcome effects on neonatal mortality (n = 7), stillbirths (n = 3), maternal mortality (n = 1), caesarean sections (n = 2), maternal (n = 1) and neonatal complications (n = 1) were inconclusive.

Conclusion

Analyzed studies indicate higher rates of perinatal mortality for low risk birth in hospitals with low birth volumes. Due to heterogeneity of studies, data synthesis was complicated and a meta-analysis was not possible. Therefore international core outcome sets should be defined and implemented in perinatal registries.

Systematic review registration

PROSPERO: CRD42018095289
Hinweise

Supplementary Information

The online version contains supplementary material available at https://​doi.​org/​10.​1186/​s12884-021-03988-y.
Mario Rüdiger and Jochen Schmitt contributed equally to this work.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Abkürzungen
AUS
Australia
B-A
Before-After-Design
BMI
Body mass index
BW
Birth weight
CA
Canada
CI
Confidence interval
CS
Caesarean sections
d
Days
DM
Diabetes mellitus
FIN
Finland
GER
Germany
GA
Gestational age
h
Hospital
HIV
Humane immunodeficiency virus
NICU
Neonatal intensive care unit
NO
Norway
OR
Odds ratio
sv. morb
Severe morbidity
RR
Relative risk
p.a
Per anno
POR
Portugal
SCD
Sudden cardiac death
SIDS
Sudden infant death syndrome
SWE
Sweden
SLE
Systemic lupus erythematosus
UH
University hospital
wk
Week
UK
United Kingdom
US
United States

Background

Several studies have shown mortality of high-risk-infants can be reduced if these infants are treated in highly equipped neonatal intensive or intermediate care units [1]. Therefore, different levels of care have been introduced for treatment of pregnant women and their newborns in relation to the medical condition. For each level certain requirements in terms of infrastructure, staffing, equipment and qualifications are defined. If a centre does not fulfill these requirements, a specialized care is usually not allowed [2, 3]. Since experience of the care team is likely to be also of advantage, it could be assumed that infants will benefit from hospitals with high annual birth volume. That assumption is supported by our recent systematic review, showing for very low birth weight infants an improved maternal and neonatal outcome in centers with higher birth volumes in high-risk births [4].
Important other risk factors for pregnancy and birth complications are higher maternal age, comorbidities (e.g. placenta praevia, pre-existing or gestational diabetes) or smoking. These factors are likely to increase the risks for maternal or neonatal adverse events [510]. Currently, appropriate management of these risks is still being discussed [1115]. In order to better study the impact of different interventionson on subsequent outcome, a homogenous definition of birth outcomes is needed and core outcome sets (COS) are currently developed [5, 6]. COS are multilaterally consented and standardized sets of outcomes which should be reported in clinical trials to guarantee comparabilityIn recent years, COS have been increasingly developed and registered for perinatal and maternal care [16], like gestational diabetes [17], preterm birth [18], maternity care [19], neonatal medicine [20] or pregnancy and childbirth [21]. However, currently there are no COS available to study the impact of birth volume on outcome of low risk pregnancies. For both this reason and since birth complications are difficult to predict in low risk pregnancies, it remains unknown whether women with a low risk pregnancy could also benefit from care in hospitals with higher birth volumes.
The aim of this systematic review was to summarize and critically appraise the impact of hospital case volume on mortality and morbidity in low risk birth cohorts.

Methods

We conducted this systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Checklist [22] and registered the review protocol (CRD42018095289) in the International Prospective Register of Systematic Reviews [23]. The original search strategy (Additional file 1) and review was designed to identify studies on the effects of either perinatal regionalization or hospital birth volume on infant and maternal outcomes. Here we report on the results of volume-outcome-relationships.

Eligibility criteria, information sources, search strategy

Inclusion and exclusion criteria (Table 1) addressed population, intervention, comparison, outcome and study type (PICOS). Interventions/ expositions included volume effect estimates on mortality as primary outcome and secondarily on caesarean sections, readmissions, birth complications, developmental delays (outcome) in all births or a pre-defined low risk birth cohort (population). In order to ensure comparability and current status of obstetric care, observational or interventional studies (study type) from countries with neonatal mortality rates below 5 per 1000 births (UN Child mortality report) that were published in English or German language after 01/01/2000 were included [24].
Table 1
PICO-Scheme
 
Inclusion criteria
Exclusion criteria
POPULATION
all births, term/ normal birth weight birth or low risk birth in a nationwide setting with < 5/1000 neonatal deaths
Preterm birth, low birth weight birth, other risk-selections (e.g. gestational diabetes, multiple births)
EXPOSITION
comparison of different hospital birth volumes or -sizes
No comparison of different hospital birth volumes or -sizes
COMPARISON
other birth volumes
No comparator provided
OUTCOME
Primary Outcome: Maternal or infant mortality
Secondary Outcomes: Caesarean sections, readmissions, birth complications, developmental delays
No measurement of maternal or infant mortality
STUDY TYPE
Observational and interventional studies
Descriptive studies, systematic reviews

Study selection

We systematically searched Medline and EMBASE on 18/04/2018 and on 26/02/2020. The search strategy included a combination of free text words and database-specific subject-headings (Additional file 1) using Ovid interface. We used Endnote X7 for the creation of the literature database and the removal of duplicates. Two authors (FW, AB) independently screened titles/ abstracts and full texts for eligibility. Additionally, an expert panel (MR, JM, Rainer Rossi) highlighted missing relevant papers. After full-text-screening, we conducted a hand search including forward (citing literature) and backward (cited literature) screening of included studies. Discrepancies during screening, extraction or quality assessment were solved by consulting of another reviewer (JS). For interpretation of reliability, we applied the prevalence-adjusted bias-adjusted kappa (PABAK). The advantage of PABAK in contrast to Kappa value is the consideration of the high class imbalance [25].

Data extraction and data synthesis

We predefined a data extraction form in MS Excel including study charateristics (e.g. population, period, country) and outcomes (e.g. definition, exposing/ referencing annual volume, result, estimator) was used. One reviewer extracted (FW) and a second (DK) verified the results resolving discrepancies by consensus or consulting a third reviewer (JS). To decide whether individual studies can be pooled in a meta-analysis, we reviewed methodological quality, comparability of the study contexts (population, outcomes, volume-thresholds and risk adjustment) and statistical heterogeneity. If studies were considered as not comparable, a qualitative synthesis followed.

Critical appraisal process

Two independent reviewers (FW, DK) performed the quality assessment using the Methodology Checklist for Cohort studies of the Scottish Intercollegiate Guidelines Network (SIGN). This checklist contains 14 items with a final quality rating of the studies in "high quality", "acceptable" and "inacceptable" [26]. Methodological explanations and definitions in the context of the application of the checklist are presented in Additional file 2.

Patient and public involvement

No patient involved.

Results

Study selection

After screening of 7955 records 13 studies met our predefinded eligibility criteria were included in the systematic review (Fig. 1) [2739]. Additional file 3 contains the reasons for exclusion of the remaining 30 full texts [4069]. The high prevalence and bias adjusted Kappa (PABAK) (Fig. 1) in both title-abstract and full-text-screnning suggests no systematic differences between the raters.

Study characteristics

Table 2 shows the characteristics of included studies. The observation period varied between 29 years (1967–1996) [33] and one year [35, 39]. The earliest observation started in 1967 [33] and the latest ended 2012 [39]. All of the included studies used cross-sectional designs to analyse retrospective cohorts in perinatal registers (Additional file 4). The studies were conducted in Finland [30, 32, 34], the United States [28, 35, 39], Sweden [27], Norway [33], Germany, [29] the United Kingdom, [31] Australia, [36] the Netherlands [70] and Canada [37]. The analyzed populations consist of either all births [27, 28, 30, 31, 3335, 37, 39] and/ or a predefined low risk population [29, 32, 34, 36, 38] excluding e.g. low birth weight or multiple births. Annual volumes and its comparators were set differently in terms of group sizes and defining births [27, 2933, 36, 39] or deliveries/ pregnancies respectively women giving birth [28, 34, 35, 37, 38] as basis for the calculation. While “birth” refer to the neonate, “delivery” describes the mother who is giving birth. Due to multiple pregnancies, number of deliveries is usually lower than the number of births. Unfortunately, not all studies reported both numbers, but Table 2 shows the different annual volumes in the included studies. In addition to the different annual volumes, maximum, [29, 33, 3639] minimum [35] and mean quantities [27, 28, 34] as well as university clinics (UH) [30, 32] were used as reference volumes. The analyzed outcomes included stillbirths, [31, 32, 34] perinatal/ early [29, 30, 32, 34, 37, 38] and neonatal mortality, [27, 31, 3336, 39] birth by caesarean section [30, 36] and composite outcomes like perinatal adverse outcome [38] or maternal morbidity/ mortality [37]. Six out of thirtheen studies did not solely focus on volume-outcome relationship, but analyzed influence of geographic accessibility [37], birth at night hours [38], staffing [31], availability of facilities [31], on call arrangements [32], or birth at weekday/ weekend [39].
Table 2
Characteristics of included studies
Study
Period
Country
Birth population
Grouped annual hospital volume
Outcomes
Outcome definition
Finnstrom et al. 2006[27]
1985–1999
SWE
births: all singletons (n = 1.538.814)
 < 500, 500–999, 1000–2499 (ref.), ≥ 2500
1) neonatal mortality
1) ≤ 27d
Friedman et al. 2016[28]
1998–2010
US
women: all hospital (n = 50.433.539)
50, 1000 (ref.), 1500, 2250
1) maternal mortality
2) maternal complications
1) failure to rescue
2) severe morbidity1
Heller et al. 2002[29]
1990–1999
GER
births: BW > 2500 g (n = 582.655);
 ≤ 500, 501–1000, 1001–1500, > 1500 (ref.)
1) Early-neonatal death
1) ≤ 7d
Hemminki et al. 2011[30]
1991–2008
FIN
births: all (n = 474.419) + BW > 2499 g in non-UH
 < 750, 750–1499, ≥ 1500, UH (ref.)
1) perinatal mortality
2) CS
1) ≤ 7d
Joyce et al. 2004[31]
1994–1996
UK
births: all (n = 540.834)
N/A: Volume entered the analysis as continuous variable
1) stand. stillbirth rates
2) stand. neonatal mortality
1) > 24 wk GA
2) ≤ 28d
Karalis et al. 2016[32]
2005–2009
FIN
births: low risk2 (n = 276.066)
births: ≤ 999, 1000–1999, ≥ 2000, UH (ref.)
1) stillbirths
2) early neonatal death
1) Intrapartum: undefined
2) undefined
Moster et al. 2001[33]
1967–1996
NO
births: all (n = 1.650.852)
 ≤ 100, 101–500, 501–1000, 1001–2000, 2001–3000, > 3000 (ref.)
1) neonatal mortality
1) ≤ 28d
Pyykonen et al. 2014[34]
2006–2010
FIN
women: all3 (n = 290.288) + low risk4 (n = 276.287)
 < 1000, 1000–2999 (ref.), < 3000
1) perinatal mortality
2) neonatal mortality
3) early neonatal mortality
4) stillbirths
1) stillbirth + death ≤ 7d
2) ≤ 28d
3) ≤ 7d
4) ≥ 22wk GA
Snowden et al. 2012[35]
2006
US
women: all (n = 527.617), low risk5
Urban: ≤ 50–1199 (ref.), 1200–2399, 2400–3599; ≥ 3600
Rural: 50–599 (ref.) 600–1699; ≥ 1700
1) neonatal mortality
1) undefined
Tracy et al. 2006[36]
1999–2001
AUS
births: low risk/ term6 (n = 331.147)
 < 100, 100–500, 501–1000, 1001–2000, > 2001 (ref.)
1) neonatal mortality
2) CS (labour)
3) Overall CS
1) ≤ 28d
de Graaf et al. 2010[38]
2000–2006
NEL
women: singleton (n = 655.961)
 < 750, 750–999, 1000–1249, 1250–1499, 1500–1749, ≥ 1750 (ref.)
1) perinatal mortality
2) neonatal complications
1) ≤ 7d
2) Perinatal adverse outcome7
Restrepo et al. 2018[39]
2012
US
births: live 20–44 wk GA (n = 32.140)
N/A: Volume entered the analysis as continu-ous variable
1) neonatal mortality
1) ≤ 28d
Aubrey-Brassler et al. 2019[37]
2006–2009
CA
women: all (n = 820.761)/
births: all (n = 827.504)
No services usually; 1–49; 50–99; 100–199; 200–499; 500–999; 1000–2499, > 2500 (ref.)
1) perinatal mortality
2) maternal complications
1) Death […]8
2) Maternal Morbidity & Mortality9
Notes:
1: heart/ renal/ respiratory failure, acute myocardial infarction, liver disease, disseminated intravascular coagulation, coma, delirium, puerperal cerebrovascular disorders, pulmonary edema or embolism, sepsis, shock, status asthmaticus, status epilepticus
2; Exclusion: Low BW, multiple pregnancy, antepartum stillbirth, out-of-hospital birth, major congenital anomalies, birth defects
3: Exclusion: birth in university hospital, length of stay > 7d
4: Exclusion: birth in university hospital, length of stay > 7d, multiple pregnancy, pre-/postterm birth
5: Exclusion: preterm birth, low BW
6: Exclusion: Low BW, multiple pregnancy, preterm, age, complications
7: intrapartum death, death ≤ 7d, 5-min Apgar < 7, NICU transfer
8: sudden infant death syndrome, sudden cardiac death, stillbirth (GA ≤ 20 wk), in-hospital death liveborn neonate
9: Eclampsia, Previa with hemorrhage abruption, Intrapartum + postpartum hemorrhage + transfusion or hysterectomy, Rupture of uterus before or during labor, Obstetric shock, Sepsis, Other complications of obstetric procedures, Obstetric embolism, Cardiovascular disease, Acute renal failure, Death, obstetric or unspecified, Neurologic disease, Hematologic disease, Respiratory disease, Diabetic ketoacidosis, Peritonitis or parametritis, Toxic liver disease or hepatic failure, Canadian Classification of Health Interventions, Assisted ventilation or resuscitation, Dialysis, Hysterectomy, Evacuation of incisional hemato-ma, Repair of bladder, urethra or intestine, Embolization or ligation of pelvic vessels or suturing of uterus, Blood transfusion

Results of the critical appraisal

Table 3 shows in detail that most of the included studies (12 out of 13 studies) fulfilled the majority of the queried items leading to an “acceptable” quality [2732, 3439]. Quality of one study was rated as “unacceptable” due to lack of comparability (missing baseline-tables, item 1.2) of the investigated groups [33].
Table 3
Detailed results of sign—quality assessment for cohort studies
Item
Description
Finnstrom et al. 2006 [27]
Friedman et al. 2016 [28]
Heller et al. 2002 [29]
Hemminki et al. 2011 [30]
Joyce et al. 2004 [31]
Karalis et al. 2017 [32]
Moster et al. 2001 [33]
Pyykonen et al. 2014 [34]
Snowden et al. 2012 [35]
Tracy et al. 2006 [36]
de Graaf et al. 2010 [38]
Restrepo et al. 2018 [39]
Aubrey-brassler et al. 2019[37]
1.1
appropriate and clearly focused question
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
1.2
illustrated comparability between studied groups
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
1.3
number of asked people (prospective studies)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1.4
Likelihood that some eligible subjects might have the outcome at the time of enrolment is assessed and taken into account in the analysis
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1.5
Drop-Out rate (prospective studies)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1.6
Comparison between full and lost-to-follow-up participants (prospective studies)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1.7
Clearly defined outcomes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
1.8
Assessment of outcome blinded to exposure status
No
No
No
No
No
No
No
No
No
No
No
No
No
1.9
When blinding impossible, recognition that knowledge of exposure status could have influenced assessment
No
No
No
No
No
No
No
No
No
No
No
No
No
1.10
reliable measurement of exposure
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
1.11
from other sources is used to demonstrate that the method of outcome assessment is valid and reliable (clearly defined primary outcomes)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1.12
Exposure level or prognostic factor is assessed more than once (prospective studies)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1.13
confounders identifed and adequately taken into account for analysis
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
1.14
confidence intervals provided
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
No
Yes
2.1
Overall rating
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Unacceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Acceptable
Due to the retrospective design and other methodological reasons, some items were not applicable:
  • number of participants (item 1.3)
  • outcome already present before start of study (item 1.4)
  • drop-out (item 1.5)
  • comparison between full and lost to follow-up (item 1.6) and
  • multiple measured exposure levels (item 1.12).
None of the studies fulfilled the criteria for blinding (item 1.8) and critical recognition of limited possibilities of blinding (item 1.9) in cohort studies. An externally demonstrated validity (item 1.11) and reliability (item 1.10) of the assessed outcomes was not applicable due mortality, caesarean sections or other clinical outcomes are not subjective measures.
We originally planned to perform a meta-analysis but were unable to conduct it due to definitional heterogeneities in the included studies. Additional file 5 provides a tabular overview of heterogeneities identified between the outcomes analyzed. Five studies were excluded from a pooled estimate due to singular report of the outcome maternal mortality, [28] maternal morbidity/ mortality, [37] neonatal complications, [38] missing adjustments [34, 35] and the singular use of risk ratios as estimator, [31] 99% confidence intervals [36] or pearson correlation coefficients [39]. The remaining results for the outcomes stillbirth, [32, 34] perinatal/ early neonatal mortality, [29, 30, 32, 37, 38] neonatal mortality [27, 33, 39] and caesarean sections [30] were not comparable due to heterogeneously defined adjustment variables, populations (all births vs. predefined low risks), outcomes (e.g. undefined vs. defined) and volume-thresholds. Consequently, we summarized the results qualitatively.

Effects of annual volume on neonatal outcomes

Stillbirth was evaluated in three studies [31, 32, 34] and defined as fetal death prior to 22 [34] or 24 [31] weeks of gestation or remained undefined [32]. For hospitals with medium-sized birth volumes (1000–1999 p.a.) stillbirth odds ratio was significantly higher when compared with university hospitals [32]. Similar effects were found for hospitals with birth volumes between 1000–2999, when compared with high birth volumes (≥ 3000 p.a.) [34]. However, taking all data together there was no clear volume effect on the rate of stilbirths (Fig. 2).
Perinatal or early neonatal mortality has been defined as death within the first 7 days of life [29, 30, 34, 38] or as a combined outcome [34, 37]. One study did not provide a specific definitio [32]. Results were always adjusted, except for one study [34]. Whereas two studies did not report a significant volume-effect, [32, 38] four studies showed significantly higher rates of perinatal/ early neonatal mortality in hospitals with low (≤ 1000) [29, 30, 34, 37] or very low (≤ 500) [29, 37] birth volumes (Fig. 2) for either low risk (term infants with birthweight > 2499 g) [29, 34] or all births [30, 37].
Neonatal mortality was defined as 28-day-, [31, 3336, 39] or 27-day-mortality [27] in order to analyze all [31, 3336, 39] and/or low risk births [27, 3436]. The majority of the studies undertook adjustments [27, 31, 33, 36]. As illustrated in Fig. 3 five [27, 33, 35, 36, 39] out of seven studies reported significant volume effect estimates with neonatal mortality being higher in hospitals with lower [33] or higher annual birth volumes [27, 35, 36, 39]. The remaining two studies reported non-significant volume-outcome effects [31, 34].
The study from Moster et al. reported higher neonatal mortality rates in hospitals with low birth volumes however, was lacking comparability between groups due to missing baseline-table and thus, quality was rated “unacceptable” [33]. In conclusion, methodically limitations hinder conclusive statements regarding the effect of birth volume on neonatal mortality.
Neonatal complications were reported in one study as a combined outcome (“perinatal adverse outcome”) including stillbirths, death ≤ 7 days, 5-min Apgar < 7 and a transfer to a neonatal intensive care unit in singleton births. Non-monotonous, significantly higher odds ratios of neonatal complications were reported for units with 750–999 and 1500–1749 births (Fig. 3) compared to at least 1750 births per anno [38].

Effects of annual birth volume on maternal outcomes

Adjusted maternal mortality was reported as failing attempts to resuscitate women with severe complications during birth [28]. The volume-outcome relationships were reported to be non-monotonous in general with lower and higher relative risks of maternal mortality in lower (50) and higher annual birth volumes (≥ 2250–7500) [28].
Adjusted maternal complications were reported in two studies as a combined outcome consisting of maternal mortality and different morbidy outcomes in all births [28, 37]. In a Canadian study the odds ratio were reported to be significantly higher in hospitals with ≤ 1000 births p.a [37]. However, a study from the US reported non-monotonous results with higher risk ratios in hospitals with high (2500) and low (50) annual birth volumes. Without providing results, the relative risks of maternal complications remained higher with a further increase in birth volume [28]. In conclusion, no conclusive statement regarding the impact of birth volume on maternal complication is possible due to contradicting study results as shown in Fig. 4.
An adjusted rate of delivery via caesarean section was reported in two studies [30, 36]. Hemminki et al. reported a significantly higher rate of caesarean sections in “small-hospital-areas” with less than 750 births per year compared to “capital areas” [30]. In contrast, Tracy et al. reported a significantly lower rate of caesarean sections in hospitals with ≤ 500 births [36]. Thus, contradicting study results do not allow conclusions regarding volume-effects on mode of delivery (Fig. 4).
In summary, most studies suggested a volume-outcome relationship on perinatal / early neonatal mortality and however reported either insignificant, non-monotonous or conflicting results regarding volume effects on the remaining outcomes.

Discussion

This systematic review on the effects of hospital case volume on the safety and outcomes of infants classified as being on low risk births has tremendous public health impact, as births of children are so frequent and such an important life event. There is evidence already for high risk births and many other conditions such as preterm birth [1, 23], pediatric intensive care [71] or pediatric heart surgery [72] that hospitals with more experience and higher case numbers provide better healthcare indicated by better health outcomes of patients being treated there. We therefore speculated that higher birth volumes of hospitals were also related to better outcomes in births of low risk or all infants. These studies reported on mortality (stillbirths, perinatal, neonatal, maternal), morbidity (neonatal, maternal) and mode of delivery. Readmissions and developmental delays were not reported. Initially, a pooled estimate was intended. Heterogenities within the definitions and presentations of characteristics led to the decision not to perform a pooled estimate. Therefore, the results were synthesized qualitatively focusing on volume-outcome in general and especially in terms of lower annual birth volumes (≤ 1000). The heterogeneous results reported by two studies in different groups were not discussed by the study authors [30, 34] but might be caused by effect modifications.
While a possible effect of volume on early neonatal mortality was found to be consistent when statistical significance was reached, the influence of birth volume on other outcomes was less consistent. The reason for these inconsistencies has to be discussed. It could be assumed, that inconsistencies can be explained at a systemic level reflecting differences between national health care systems with variations in budgeting, access, geographical and historical conditions. One study included in this review showed differences of caesarean sections in dependence to hospital birth volume [36]. Several explanations could be discussed. It is possible that this could be an effect of perinatal regionalization treating high risk pregnancies in high birth volume hospitals leading into the need of surgical birth interventions. On the other hand, the appropriateness and need for the indication of e.g. epidural anesthesia was also discussed with reference to hospital ownership [15]. However, to further analyze the sensitive topic of appropriateness, qualitative research with primary data is needed. Due to the lack of detail information and data quality, routine data must be used with caution in order to avoid over- or misinterpretation [73].
With respect to a risk appropriate care, perinatal regionalization policies vary in terms of general organization, obligation and practice [2, 3]. At the provider level birth/delivery volumes may be only one covariate between several others such as time of birth, [38, 39, 70] personnel and material resources, [31, 32, 74] work environment [75] or qualifications [76] influencing the outcome of newborns indicated by studies included in this review.
Despite of lower early neonatal mortality in hospitals with high annual birth volume, closure of low volume institutions has to be considered very carefully, since reults have been discussed controversially. Some studies suggest a higher rate of unplanned out-of-hospital births [77] and an increased rate of neonatal mortality and stillbirths immediately after closures [58]. Furthermore, an increased rate of adverse birth outcomes [78] and higher stress/ anxiety levels of pregnant women were reported in large rural landscapes with long distances to access perinatal care [79]. Other studies report significantly lower rates of stillbirths and neonatal mortality in both rural and urban regions after closing maternity units [41].
The heterogeneous definitions identified in this and other systematic reviews [80] support the need for a standardized terminology of outcomes, populations and volume-thresholds. The definition of core-outcome sets (COS) would help to overcome that issue. The uniform terminology enables the design of comparable studies and forms the basis for the development of an international perinatal register. A homogeneously created perinatal register would allow individual patient data meta-analyses providing promising results as it has been shown for other indications [81, 82].
Overall most (12/13) of the included studies showed an “acceptable” quality as it is the highest rating for retrospective studies [26]. One study lacked an illustrated comparability of the study groups that led to “unacceptable” quality as it strongly limits transparency. None of the studies blinded the assesors nor was a report of non-blinding included. Nevertheless, we considered the studies as meaningful for interpretation because the assessed outcomes are difficult to manipulate and therefore the lack of blinding seems to be a minor weakness.

Strengths and Limitations

This is the first systematic review explicitly assessing birth volume effects on neonatal outcome in low risk births. The review used transparent methods (independent screening, search strategy), was officially registered, is based on two major databases (combined with extensive hand search and expert panel for highlighting relevant literature) and followed common critical appraisal requirements of systematic reviews determined by AMSTAR 2 [83]. The high inter-rater-reliability ensures comprehensibility. The time and national restriction in the inclusion criteria could be interpreted as a limitation. However, it is well known that international comparisons must take into account the efficacy of health care systems [84, 85]. Thus, we used neonatal mortality rates as an indicator of this efficacy. With respect to the time restriction starting with publication in 2000, this review considered the decline of neonatal mortality and the development of perinatal care in since 1990 [86]. On the other hand, some of the studies have long past study periods (1967–2012) and intervals (1 to 29 years), indicating that the publication date did not work perfectly well as a delimiter to represent only current perinatal care. Almost every study showed an “acceptable” quality with retrospectively collected routine or register data.

Conclusion

The aim of that review was originally to investigate volume-outcome associations in a comparatively low-risk birth cohort. With the exception of 7-day mortality, the review revealed heterogeneous results and major differences in the conception and definitions of the included studies.The qualitative synthesis of the studies indicated increased rates of early neonatal mortality (< 7d) in hospitals with birth volumes below 1000 or 500 births per anno when statistical significance was given. With respect to stillbirths, neonatal mortality, maternal mortality, caesarean section and neonatal and maternal complications the studies included reported inconclusive or insignificant results. Referring to the heterogeneously conducted study concepts in terms of assessed populations, volume-thresholds and outcomes, we recommend the development and use of internationally consented core-outcome sets to provide a homogenous definitional basis in future studies. A uniform terminology would enable a homogenously conceived internationally birth register for individual patient data meta analyses. Based on these data, strengths and weaknesses of different perinatal settings could be investigated using a common terminology of population, volume and outcome.

Acknowledgements

We would like to thank Peter Hellmund for his help in creating the Figures 2, 3 and 4 and Rainer Rossi for serving as an expert to highlight possible relevant literature.

Declarations

N/A
N/A

Competing interests

The authors declare that they have no competing interests.
Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://​creativecommons.​org/​licenses/​by/​4.​0/​. The Creative Commons Public Domain Dedication waiver (http://​creativecommons.​org/​publicdomain/​zero/​1.​0/​) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Literatur
1.
Zurück zum Zitat Lasswell SM, Barfield WD, Rochat RW, Blackmon L. Perinatal regionalization for very low-birth-weight and very preterm infants a meta-analysis. JAMA. 2010;304(9):992–1000.PubMedCrossRef Lasswell SM, Barfield WD, Rochat RW, Blackmon L. Perinatal regionalization for very low-birth-weight and very preterm infants a meta-analysis. JAMA. 2010;304(9):992–1000.PubMedCrossRef
2.
Zurück zum Zitat Zeitlin J, Papiernik E, Breart G. Regionalization of perinatal care in Europe. Semin Neonatol. 2004;9(2):99–110.PubMedCrossRef Zeitlin J, Papiernik E, Breart G. Regionalization of perinatal care in Europe. Semin Neonatol. 2004;9(2):99–110.PubMedCrossRef
3.
Zurück zum Zitat Kunz SN, Phibbs CS, Profit J. The changing landscape of perinatal regionalization. Semin Perinatol. 2020;44(4):151241. Kunz SN, Phibbs CS, Profit J. The changing landscape of perinatal regionalization. Semin Perinatol. 2020;44(4):151241.
4.
Zurück zum Zitat Walther F, Küster DB, Bieber A, Rüdiger M, Malzahn J, Schmitt J, Deckert S. Impact of regionalisation and case-volume on neonatal and perinatal mortality: an umbrella review. BMJ Open. 2020;10(9):e037135. Walther F, Küster DB, Bieber A, Rüdiger M, Malzahn J, Schmitt J, Deckert S. Impact of regionalisation and case-volume on neonatal and perinatal mortality: an umbrella review. BMJ Open. 2020;10(9):e037135.
5.
Zurück zum Zitat Gravett MG, Rubens CE, Nunes TM. the GRG: Global report on preterm birth and stillbirth (2 of 7): discovery science. BMC Pregnancy Childbirth. 2010;10(1):S2.PubMedPubMedCentralCrossRef Gravett MG, Rubens CE, Nunes TM. the GRG: Global report on preterm birth and stillbirth (2 of 7): discovery science. BMC Pregnancy Childbirth. 2010;10(1):S2.PubMedPubMedCentralCrossRef
6.
Zurück zum Zitat Lawn JE, Gravett MG, Nunes TM, Rubens CE, Stanton C. the GRG: Global report on preterm birth and stillbirth (1 of 7): definitions, description of the burden and opportunities to improve data. BMC Pregnancy Childbirth. 2010;10(1):S1.PubMedPubMedCentralCrossRef Lawn JE, Gravett MG, Nunes TM, Rubens CE, Stanton C. the GRG: Global report on preterm birth and stillbirth (1 of 7): definitions, description of the burden and opportunities to improve data. BMC Pregnancy Childbirth. 2010;10(1):S1.PubMedPubMedCentralCrossRef
7.
Zurück zum Zitat Jolly M, Sebire N, Harris J, Robinson S, Regan L. The risks associated with pregnancy in women aged 35 years or older. Hum Reprod. 2000;15(11):2433–7.PubMedCrossRef Jolly M, Sebire N, Harris J, Robinson S, Regan L. The risks associated with pregnancy in women aged 35 years or older. Hum Reprod. 2000;15(11):2433–7.PubMedCrossRef
8.
Zurück zum Zitat Lawn JE, Cousens S, Zupan J. 4 million neonatal deaths: when? Where? Why? Lancet. 2005;365(9462):891–900.PubMedCrossRef Lawn JE, Cousens S, Zupan J. 4 million neonatal deaths: when? Where? Why? Lancet. 2005;365(9462):891–900.PubMedCrossRef
9.
Zurück zum Zitat Luke B, Brown MB. Elevated risks of pregnancy complications and adverse outcomes with increasing maternal age. Hum Reprod. 2007;22(5):1264–72.PubMedCrossRef Luke B, Brown MB. Elevated risks of pregnancy complications and adverse outcomes with increasing maternal age. Hum Reprod. 2007;22(5):1264–72.PubMedCrossRef
10.
Zurück zum Zitat Ronsmans C, Graham WJ. Maternal mortality: who, when, where, and why. Lancet. 2006;368(9542):1189–200.PubMedCrossRef Ronsmans C, Graham WJ. Maternal mortality: who, when, where, and why. Lancet. 2006;368(9542):1189–200.PubMedCrossRef
12.
Zurück zum Zitat Jordan RG, Murphy PA. Risk Assessment and Risk Distortion: Finding the Balance. J Midwifery Womens Health. 2009;54(3):191–200.PubMedCrossRef Jordan RG, Murphy PA. Risk Assessment and Risk Distortion: Finding the Balance. J Midwifery Womens Health. 2009;54(3):191–200.PubMedCrossRef
13.
Zurück zum Zitat Simpson KR. Minimizing Unnecessary Interventions During Labor and Birth. MCN Am J Maternal/Child Nurs. 2017;42(4):240. Simpson KR. Minimizing Unnecessary Interventions During Labor and Birth. MCN Am J Maternal/Child Nurs. 2017;42(4):240.
14.
Zurück zum Zitat Simpson KR, Thorman KE. Obstetric “Conveniences”: Elective Induction of Labor, Cesarean Birth on Demand, and Other Potentially Unnecessary Interventions. J Perinatal Neonatal Nurs. 2005;19(2):134–44. Simpson KR, Thorman KE. Obstetric “Conveniences”: Elective Induction of Labor, Cesarean Birth on Demand, and Other Potentially Unnecessary Interventions. J Perinatal Neonatal Nurs. 2005;19(2):134–44.
15.
Zurück zum Zitat Tracy SK, Tracy MB. Costing the cascade: estimating the cost of increased obstetric intervention in childbirth using population data. BJOG Int J Obstetr Gynaecol. 2003;110(8):717–24. Tracy SK, Tracy MB. Costing the cascade: estimating the cost of increased obstetric intervention in childbirth using population data. BJOG Int J Obstetr Gynaecol. 2003;110(8):717–24.
16.
Zurück zum Zitat Duffy JMN, Rolph R, Gale C, Hirsch M, Khan KS, Ziebland S, McManus RJ, On behalf of the International Collaboration to Harmonise Outcomes in P-e. Core outcome sets in women's and newborn health: a systematic review. BJOG Int J Obstetr Gynaecol. 2017;124(10):1481–9. Duffy JMN, Rolph R, Gale C, Hirsch M, Khan KS, Ziebland S, McManus RJ, On behalf of the International Collaboration to Harmonise Outcomes in P-e. Core outcome sets in women's and newborn health: a systematic review. BJOG Int J Obstetr Gynaecol. 2017;124(10):1481–9.
17.
Zurück zum Zitat Egan AM, Galjaard S, Maresh MJA, Loeken MR, Napoli A, Anastasiou E, Noctor E, de Valk HW, van Poppel M, Todd M, et al. A core outcome set for studies evaluating the effectiveness of prepregnancy care for women with pregestational diabetes. Diabetologia. 2017;60(7):1190–6.PubMedPubMedCentralCrossRef Egan AM, Galjaard S, Maresh MJA, Loeken MR, Napoli A, Anastasiou E, Noctor E, de Valk HW, van Poppel M, Todd M, et al. A core outcome set for studies evaluating the effectiveness of prepregnancy care for women with pregestational diabetes. Diabetologia. 2017;60(7):1190–6.PubMedPubMedCentralCrossRef
18.
Zurück zum Zitat van 't Hooft J, Duffy JM, Daly M, Williamson PR, Meher S, Thom E, Saade GR, Alfirevic Z, Mol BW, Khan KS. A Core Outcome Set for Evaluation of Interventions to Prevent Preterm Birth. Obstet Gynecol. 2016;127(1):49–58. van 't Hooft J, Duffy JM, Daly M, Williamson PR, Meher S, Thom E, Saade GR, Alfirevic Z, Mol BW, Khan KS. A Core Outcome Set for Evaluation of Interventions to Prevent Preterm Birth. Obstet Gynecol. 2016;127(1):49–58.
19.
Zurück zum Zitat Devane D, Begley CM, Clarke M, Horey D, Oboyle C. Evaluating Maternity Care: A Core Set of Outcome Measures. Birth. 2007;34(2):164–72.PubMedCrossRef Devane D, Begley CM, Clarke M, Horey D, Oboyle C. Evaluating Maternity Care: A Core Set of Outcome Measures. Birth. 2007;34(2):164–72.PubMedCrossRef
20.
Zurück zum Zitat Webbe J, Brunton G, Ali S, Duffy JMN, Modi N, Gale C. Developing, implementing and disseminating a core outcome set for neonatal medicine. BMJ Paediatrics Open. 2017;1(1):e000048. Webbe J, Brunton G, Ali S, Duffy JMN, Modi N, Gale C. Developing, implementing and disseminating a core outcome set for neonatal medicine. BMJ Paediatrics Open. 2017;1(1):e000048.
21.
Zurück zum Zitat Nijagal MA, Wissig S, Stowell C, Olson E, Amer-Wahlin I, Bonsel G, Brooks A, Coleman M, Devi Karalasingam S, Duffy JMN, et al. Standardized outcome measures for pregnancy and childbirth, an ICHOM proposal. BMC Health Serv Res. 2018;18(1):953–953.PubMedPubMedCentralCrossRef Nijagal MA, Wissig S, Stowell C, Olson E, Amer-Wahlin I, Bonsel G, Brooks A, Coleman M, Devi Karalasingam S, Duffy JMN, et al. Standardized outcome measures for pregnancy and childbirth, an ICHOM proposal. BMC Health Serv Res. 2018;18(1):953–953.PubMedPubMedCentralCrossRef
22.
Zurück zum Zitat Moher D, Liberati A, Tetzlaff J, Altman DG, The Prisma Group. Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLOS Med. 2009;6(7):e1000097. Moher D, Liberati A, Tetzlaff J, Altman DG, The Prisma Group. Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLOS Med. 2009;6(7):e1000097.
24.
Zurück zum Zitat UN Interagency Group for Child Mortality Estimation: Levels and Trends in Child Mortality Report. 2017;2017:36. UN Interagency Group for Child Mortality Estimation: Levels and Trends in Child Mortality Report. 2017;2017:36.
25.
Zurück zum Zitat Byrt T, Bishop J, Carlin JB. Bias, prevalence and kappa. J Clin Epidemiol. 1993;46(5):423–9.PubMedCrossRef Byrt T, Bishop J, Carlin JB. Bias, prevalence and kappa. J Clin Epidemiol. 1993;46(5):423–9.PubMedCrossRef
27.
Zurück zum Zitat Finnstrom O, Berg G, Norman A, Otterblad Olausson P. Size of delivery unit and neonatal outcome in Sweden. A catchment area analysis. Acta Obstetricia et Gynecologica Scand. 2006;85(1):63–67. Finnstrom O, Berg G, Norman A, Otterblad Olausson P. Size of delivery unit and neonatal outcome in Sweden. A catchment area analysis. Acta Obstetricia et Gynecologica Scand. 2006;85(1):63–67.
28.
Zurück zum Zitat Friedman AM, Ananth CV, Huang Y, D’Alton ME, Wright JD. Hospital delivery volume, severe obstetrical morbidity, and failure to rescue. Am J Obstet Gynecol. 2016;215(6):795.e791–795.e714. Friedman AM, Ananth CV, Huang Y, D’Alton ME, Wright JD. Hospital delivery volume, severe obstetrical morbidity, and failure to rescue. Am J Obstet Gynecol. 2016;215(6):795.e791–795.e714.
29.
Zurück zum Zitat Heller G, Richardson DK, Schnell R, Misselwitz B, Kunzel W, Schmidt S. Are we regionalized enough? Early-neonatal deaths in low-risk births by the size of delivery units in Hesse, Germany 1990–1999. Int J Epidemiol. 2002;31(5):1061–8.PubMedCrossRef Heller G, Richardson DK, Schnell R, Misselwitz B, Kunzel W, Schmidt S. Are we regionalized enough? Early-neonatal deaths in low-risk births by the size of delivery units in Hesse, Germany 1990–1999. Int J Epidemiol. 2002;31(5):1061–8.PubMedCrossRef
30.
Zurück zum Zitat Hemminki E, Heino A, Gissler M. Should births be centralised in higher level hospitals? Experiences from regionalised health care in Finland. BJOG Int J Obstetr Gynaecol. 2011;118(10):1186–95.CrossRef Hemminki E, Heino A, Gissler M. Should births be centralised in higher level hospitals? Experiences from regionalised health care in Finland. BJOG Int J Obstetr Gynaecol. 2011;118(10):1186–95.CrossRef
31.
Zurück zum Zitat Joyce R, Webb R, Peacock JL. Associations between perinatal interventions and hospital stillbirth rates and neonatal mortality. Arch Dis Child Fetal Neonatal Ed. 2004;89(1):F51-56.PubMedPubMedCentralCrossRef Joyce R, Webb R, Peacock JL. Associations between perinatal interventions and hospital stillbirth rates and neonatal mortality. Arch Dis Child Fetal Neonatal Ed. 2004;89(1):F51-56.PubMedPubMedCentralCrossRef
32.
Zurück zum Zitat Karalis E, Gissler M, Tapper A-M, Ulander V-M. Effect of hospital size and on-call arrangements on intrapartum and early neonatal mortality among low-risk newborns in Finland. Eur J Obstet Gynecol Reprod Biol. 2016;198:116–9.PubMedCrossRef Karalis E, Gissler M, Tapper A-M, Ulander V-M. Effect of hospital size and on-call arrangements on intrapartum and early neonatal mortality among low-risk newborns in Finland. Eur J Obstet Gynecol Reprod Biol. 2016;198:116–9.PubMedCrossRef
33.
Zurück zum Zitat Moster D, Lie RT, Markestad T. Neonatal mortality rates in communities with small maternity units compared with those having larger maternity units. BJOG Int J Obstetr Gynaecol. 2001;108(9):904–9.CrossRef Moster D, Lie RT, Markestad T. Neonatal mortality rates in communities with small maternity units compared with those having larger maternity units. BJOG Int J Obstetr Gynaecol. 2001;108(9):904–9.CrossRef
34.
Zurück zum Zitat Pyykonen A, Gissler M, Jakobsson M, Petaja J, Tapper AM. Determining obstetric patient safety indicators: the differences in neonatal outcome measures between different-sized delivery units. BJOG Int J Obstetr Gynaecol. 2014;121(4):430–7.CrossRef Pyykonen A, Gissler M, Jakobsson M, Petaja J, Tapper AM. Determining obstetric patient safety indicators: the differences in neonatal outcome measures between different-sized delivery units. BJOG Int J Obstetr Gynaecol. 2014;121(4):430–7.CrossRef
35.
Zurück zum Zitat Snowden JM, Cheng YW, Kontgis CP, Caughey AB. The association between hospital obstetric volume and perinatal outcomes in California. Am J Obstet Gynecol. 2012;207(6):478.e471-477.CrossRef Snowden JM, Cheng YW, Kontgis CP, Caughey AB. The association between hospital obstetric volume and perinatal outcomes in California. Am J Obstet Gynecol. 2012;207(6):478.e471-477.CrossRef
36.
Zurück zum Zitat Tracy SK, Sullivan E, Dahlen H, Black D, Wang YA, Tracy MB. Does size matter? A population-based study of birth in lower volume maternity hospitals for low risk women. BJOG Int J Obstetr Gynaecol. 2006;113(1):86–96.CrossRef Tracy SK, Sullivan E, Dahlen H, Black D, Wang YA, Tracy MB. Does size matter? A population-based study of birth in lower volume maternity hospitals for low risk women. BJOG Int J Obstetr Gynaecol. 2006;113(1):86–96.CrossRef
37.
Zurück zum Zitat Aubrey-Bassler FK, Cullen RM, Simms A, Asghari S, Crane J, Wang PP, Godwin M. Population-based cohort study of hospital delivery volume, geographic accessibility, and obstetric outcomes. Int J Gynecol Obstet. 2019;146(1):95–102.CrossRef Aubrey-Bassler FK, Cullen RM, Simms A, Asghari S, Crane J, Wang PP, Godwin M. Population-based cohort study of hospital delivery volume, geographic accessibility, and obstetric outcomes. Int J Gynecol Obstet. 2019;146(1):95–102.CrossRef
38.
Zurück zum Zitat de Graaf JP, Ravelli ACJ, Visser GHA, Hukkelhoven C, Tong WH, Bonsel GJ, Steegers EAP. Increased adverse perinatal outcome of hospital delivery at night. BJOG Int J Obstetr Gynaecol. 2010;117(9):1098–107.CrossRef de Graaf JP, Ravelli ACJ, Visser GHA, Hukkelhoven C, Tong WH, Bonsel GJ, Steegers EAP. Increased adverse perinatal outcome of hospital delivery at night. BJOG Int J Obstetr Gynaecol. 2010;117(9):1098–107.CrossRef
39.
Zurück zum Zitat Restrepo E, Hamilton P, Liu F, Mancuso P. Relationships Among Neonatal Mortality, Hospital Volume, Weekday Demand, and Weekend Birth. Can J Nurs Res. 2018;50(2):64–71. Restrepo E, Hamilton P, Liu F, Mancuso P. Relationships Among Neonatal Mortality, Hospital Volume, Weekday Demand, and Weekend Birth. Can J Nurs Res. 2018;50(2):64–71.
40.
Zurück zum Zitat Adams N, Tudehope D, Gibbons KS, Flenady V. Perinatal mortality disparities between public care and private obstetrician-led care: a propensity score analysis. BJOG Int J Obstetr Gynaecol. 2018;125(2):149–58.CrossRef Adams N, Tudehope D, Gibbons KS, Flenady V. Perinatal mortality disparities between public care and private obstetrician-led care: a propensity score analysis. BJOG Int J Obstetr Gynaecol. 2018;125(2):149–58.CrossRef
41.
Zurück zum Zitat Allen VM, Jilwah N, Joseph KS, Dodds L, O'Connell CM, Luther ER, Fahey TJ, Attenborough R, Allen AC. The influence of hospital closures in Nova Scotia on perinatal outcomes. JOGC. 2004;26(12):1077–85. Allen VM, Jilwah N, Joseph KS, Dodds L, O'Connell CM, Luther ER, Fahey TJ, Attenborough R, Allen AC. The influence of hospital closures in Nova Scotia on perinatal outcomes. JOGC. 2004;26(12):1077–85.
42.
Zurück zum Zitat Badheka A, Rampa S, Wang T, Nalliah R, Caplin J, Allareddy V. Neonatal infections in Hospitals: Nationwide prevalence and outcomes. Crit Care Med. 2019;47(Supplement 1):808. Badheka A, Rampa S, Wang T, Nalliah R, Caplin J, Allareddy V. Neonatal infections in Hospitals: Nationwide prevalence and outcomes. Crit Care Med. 2019;47(Supplement 1):808.
43.
Zurück zum Zitat Clapp MA, James KE, Bates SV, Kaimal AJ. Patient and Hospital Factors Associated With Unexpected Newborn Complications Among Term Neonates in US Hospitals. JAMA Network Open. 2020;3(2):e1919498. Clapp MA, James KE, Bates SV, Kaimal AJ. Patient and Hospital Factors Associated With Unexpected Newborn Complications Among Term Neonates in US Hospitals. JAMA Network Open. 2020;3(2):e1919498.
44.
Zurück zum Zitat Engjom H, Morken NH, Hoydal E, Norheim OF, Klungsoyr K. Obstetric health system structure and perinatal outcomes in Norway. Int J Gynecol Obstet. 2015;131(SUPPL. 5):E487–8. Engjom H, Morken NH, Hoydal E, Norheim OF, Klungsoyr K. Obstetric health system structure and perinatal outcomes in Norway. Int J Gynecol Obstet. 2015;131(SUPPL. 5):E487–8.
45.
Zurück zum Zitat Engjom H, Moster D, Morken NH, Hoydahl E, Norheim OF, Klungsoyr K. Perinatal mortality and health system structure in Norway-a population-based registry study. BJOG Int J Obstetr Gynaecol. 2016;123(Supplement 2):11. Engjom H, Moster D, Morken NH, Hoydahl E, Norheim OF, Klungsoyr K. Perinatal mortality and health system structure in Norway-a population-based registry study. BJOG Int J Obstetr Gynaecol. 2016;123(Supplement 2):11.
46.
Zurück zum Zitat Filipovic-Grcic B, Kniewald H, Rodin U, Grizelj R, Stipanovic-Kastelic J, Ninkovic D, Gveric-Ahmetasevic S, Stanojevic M, Furlan IA, Peter B, et al. Patterns of newborns' deaths to discharge from hospital in Croatia in the year 2011. Gynaecologia et Perinatologia. 2012;21(SUUPL.1):150–6. Filipovic-Grcic B, Kniewald H, Rodin U, Grizelj R, Stipanovic-Kastelic J, Ninkovic D, Gveric-Ahmetasevic S, Stanojevic M, Furlan IA, Peter B, et al. Patterns of newborns' deaths to discharge from hospital in Croatia in the year 2011. Gynaecologia et Perinatologia. 2012;21(SUUPL.1):150–6.
47.
Zurück zum Zitat Grytten J, Monkerud L, Skau I, Sorensen R. Regionalization and local hospital closure in Norwegian maternity care–the effect on neonatal and infant mortality. Health Serv Res. 2014;49(4):1184–204.PubMedPubMedCentralCrossRef Grytten J, Monkerud L, Skau I, Sorensen R. Regionalization and local hospital closure in Norwegian maternity care–the effect on neonatal and infant mortality. Health Serv Res. 2014;49(4):1184–204.PubMedPubMedCentralCrossRef
48.
Zurück zum Zitat Heller G, Schnell R, Richardson DK, Misselwitz B, Schmidt S. [Assessing the impact of delivery unit size on neonatal survival: estimation of potentially avoidable deaths in Hessen, Germany, 1990–2000]. Hat die Grosse der Geburtsklinik Einfluss auf das neonatale Uberleben? Schatzung von "vermeidbaren" Todesfallen in Hessen 1990–2000. 2003;128(13):657–62. Heller G, Schnell R, Richardson DK, Misselwitz B, Schmidt S. [Assessing the impact of delivery unit size on neonatal survival: estimation of potentially avoidable deaths in Hessen, Germany, 1990–2000]. Hat die Grosse der Geburtsklinik Einfluss auf das neonatale Uberleben? Schatzung von "vermeidbaren" Todesfallen in Hessen 1990–2000. 2003;128(13):657–62.
49.
Zurück zum Zitat Homer CSE, Thornton C, Scarf VL, Ellwood DA, Oats JJN, Foureur MJ, Sibbritt D, McLachlan HL, Forster DA, Dahlen HG. Birthplace in New South Wales, Australia: an analysis of perinatal outcomes using routinely collected data. BMC Pregnancy Childbirth. 2014;14:206.PubMedPubMedCentralCrossRef Homer CSE, Thornton C, Scarf VL, Ellwood DA, Oats JJN, Foureur MJ, Sibbritt D, McLachlan HL, Forster DA, Dahlen HG. Birthplace in New South Wales, Australia: an analysis of perinatal outcomes using routinely collected data. BMC Pregnancy Childbirth. 2014;14:206.PubMedPubMedCentralCrossRef
50.
Zurück zum Zitat Hughes S, Zweifler JA, Garza A, Stanich MA. Trends in rural and urban deliveries and vaginal births: California 1998–2002. J Rural Health. 2008;24(4):416–22.PubMedCrossRef Hughes S, Zweifler JA, Garza A, Stanich MA. Trends in rural and urban deliveries and vaginal births: California 1998–2002. J Rural Health. 2008;24(4):416–22.PubMedCrossRef
51.
Zurück zum Zitat Hurtado Suazo JA, Demestre Guasch X, Garcia Reymundo M, Ginovart Galiana G, Gimenez A, Calvo Aguilar MJ, Trincado Aguinagalde MJ, Fernandez Colomer B. Comparison of perinatal data between a cohort of Spanish late preterm babies and another of term newborns. J Perinatal Med. 2015;43(SUPPL. 1). Hurtado Suazo JA, Demestre Guasch X, Garcia Reymundo M, Ginovart Galiana G, Gimenez A, Calvo Aguilar MJ, Trincado Aguinagalde MJ, Fernandez Colomer B. Comparison of perinatal data between a cohort of Spanish late preterm babies and another of term newborns. J Perinatal Med. 2015;43(SUPPL. 1).
52.
Zurück zum Zitat Iglesias S, Bott N, Ellehoj E, Yee J, Jennissen B, Bunnah T, Schopflocher D. Outcomes of maternity care services in Alberta, 1999 and 2000: a population-based analysis. JOGC. 2005;27(9):855–63. Iglesias S, Bott N, Ellehoj E, Yee J, Jennissen B, Bunnah T, Schopflocher D. Outcomes of maternity care services in Alberta, 1999 and 2000: a population-based analysis. JOGC. 2005;27(9):855–63.
53.
Zurück zum Zitat Karalis E, Gissler M, Tapper AM, Ulander VM. Influence of time of delivery on risk of adverse neonatal outcome in different size of delivery units: a retrospective cohort study in Finland. J Maternal-Fetal Neonatal Med. 2019;32(10):1696–702. Karalis E, Gissler M, Tapper AM, Ulander VM. Influence of time of delivery on risk of adverse neonatal outcome in different size of delivery units: a retrospective cohort study in Finland. J Maternal-Fetal Neonatal Med. 2019;32(10):1696–702.
54.
Zurück zum Zitat Koch R, Gmyrek D, Vogtmann C. Risk adjusted assessment of quality of perinatal centers - results of perinatal/neonatal quality surveillance in Saxonia. Risikoadjustierte Qualitatsbeurteilung in Perinatalzentren ausgehend von der Perinatal- und Neonatalerhebung in Sachsen. 2005;209(6):210–8. Koch R, Gmyrek D, Vogtmann C. Risk adjusted assessment of quality of perinatal centers - results of perinatal/neonatal quality surveillance in Saxonia. Risikoadjustierte Qualitatsbeurteilung in Perinatalzentren ausgehend von der Perinatal- und Neonatalerhebung in Sachsen. 2005;209(6):210–8.
55.
Zurück zum Zitat Kozhimannil KB, Interrante JD, Henning-Smith C, Admon LK. Rural-Urban Differences In Severe Maternal Morbidity And Mortality In The US, 2007–15. Health affairs (Project Hope). 2019;38(12):2077–85.CrossRef Kozhimannil KB, Interrante JD, Henning-Smith C, Admon LK. Rural-Urban Differences In Severe Maternal Morbidity And Mortality In The US, 2007–15. Health affairs (Project Hope). 2019;38(12):2077–85.CrossRef
56.
Zurück zum Zitat Krzyzak M, Maslach D, Piotrowska K, Charkiweicz AE, Szpak A, Karczewski J. Perinatal mortality in urban and rural areas in Poland in 2002–2012. Przegl Epidemiol. 2014;68(4):675–9.PubMed Krzyzak M, Maslach D, Piotrowska K, Charkiweicz AE, Szpak A, Karczewski J. Perinatal mortality in urban and rural areas in Poland in 2002–2012. Przegl Epidemiol. 2014;68(4):675–9.PubMed
57.
Zurück zum Zitat Lesniczak B, Krasomski G, Rudnicka B, Piekarska E, Oszukowski P, Wozniak P. The perinatal mortality of fetuses and neonates in Poland in the years 1960–2010. Ginekologia i Poloznictwo. 2015;36(2):40–5. Lesniczak B, Krasomski G, Rudnicka B, Piekarska E, Oszukowski P, Wozniak P. The perinatal mortality of fetuses and neonates in Poland in the years 1960–2010. Ginekologia i Poloznictwo. 2015;36(2):40–5.
58.
Zurück zum Zitat Lorch SA, Srinivas SK, Ahlberg C, Small DS. The impact of obstetric unit closures on maternal and infant pregnancy outcomes. Health Serv Res. 2013;48(2 Pt 1):455–75.PubMedCrossRef Lorch SA, Srinivas SK, Ahlberg C, Small DS. The impact of obstetric unit closures on maternal and infant pregnancy outcomes. Health Serv Res. 2013;48(2 Pt 1):455–75.PubMedCrossRef
59.
Zurück zum Zitat Neto MT. Perinatal care in Portugal: effects of 15 years of a regionalized system. Acta Paediatrica. 2006;95(11):1349–52. Neto MT. Perinatal care in Portugal: effects of 15 years of a regionalized system. Acta Paediatrica. 2006;95(11):1349–52.
60.
Zurück zum Zitat Parazzini F, Cipriani S, Bulfoni G, Bulfoni C, Bellu R, Zanini R, Mosca F. Mode of delivery and level of neonatal care in Lombardy: a descriptive analysis according to volume of care. Ital J Pediatr. 2015;41:24.PubMedPubMedCentralCrossRef Parazzini F, Cipriani S, Bulfoni G, Bulfoni C, Bellu R, Zanini R, Mosca F. Mode of delivery and level of neonatal care in Lombardy: a descriptive analysis according to volume of care. Ital J Pediatr. 2015;41:24.PubMedPubMedCentralCrossRef
61.
Zurück zum Zitat Payne JC, Campbell MK, DaSilva O, Koval J. Perinatal mortality in term and preterm twin and singleton births. Twin Res. 2002;5(4):260–4.PubMedCrossRef Payne JC, Campbell MK, DaSilva O, Koval J. Perinatal mortality in term and preterm twin and singleton births. Twin Res. 2002;5(4):260–4.PubMedCrossRef
62.
Zurück zum Zitat Poeran J, Borsboom GJJM, de Graaf JP, Birnie E, Steegers EAP, Mackenbach JP, Bonsel GJ. Does centralisation of acute obstetric care reduce intrapartum and first-week mortality? An empirical study of over 1 million births in the Netherlands. Health Policy. 2014;117(1):28–38.PubMedCrossRef Poeran J, Borsboom GJJM, de Graaf JP, Birnie E, Steegers EAP, Mackenbach JP, Bonsel GJ. Does centralisation of acute obstetric care reduce intrapartum and first-week mortality? An empirical study of over 1 million births in the Netherlands. Health Policy. 2014;117(1):28–38.PubMedCrossRef
63.
Zurück zum Zitat Ravelli ACJ, Tromp M, van Huis M, Steegers EAP, Tamminga P, Eskes M, Bonsel GJ. Decreasing perinatal mortality in The Netherlands, 2000–2006: a record linkage study. J Epidemiol Community Health. 2009;63(9):761–5.PubMedCrossRef Ravelli ACJ, Tromp M, van Huis M, Steegers EAP, Tamminga P, Eskes M, Bonsel GJ. Decreasing perinatal mortality in The Netherlands, 2000–2006: a record linkage study. J Epidemiol Community Health. 2009;63(9):761–5.PubMedCrossRef
64.
Zurück zum Zitat Reid LD, Creanga AA. Severe maternal morbidity and related hospital quality measures in Maryland. J Perinatol. 2018;38(8):997–1008.PubMedCrossRef Reid LD, Creanga AA. Severe maternal morbidity and related hospital quality measures in Maryland. J Perinatol. 2018;38(8):997–1008.PubMedCrossRef
65.
Zurück zum Zitat Shuvalova MP, Yarotskaya EL, Pismenskaya TV, Dolgushina NV, Baibarina EN, Sukhikh GT. Maternity Care in Russia: Issues, Achievements, and Potential. JOGC. 2015;37(10):865–71. Shuvalova MP, Yarotskaya EL, Pismenskaya TV, Dolgushina NV, Baibarina EN, Sukhikh GT. Maternity Care in Russia: Issues, Achievements, and Potential. JOGC. 2015;37(10):865–71.
66.
Zurück zum Zitat Treurniet HF, Looman CW, van der Maas PJ, Mackenbach JP. Regional trend variations in infant mortality due to perinatal conditions in the Netherlands. Eur J Obstet Gynecol Reprod Biol. 2000;91(1):43–9.PubMedCrossRef Treurniet HF, Looman CW, van der Maas PJ, Mackenbach JP. Regional trend variations in infant mortality due to perinatal conditions in the Netherlands. Eur J Obstet Gynecol Reprod Biol. 2000;91(1):43–9.PubMedCrossRef
67.
Zurück zum Zitat Harvey SM, Oakley LP, Yoon J, Luck J. Coordinated Care Organizations: Neonatal and Infant Outcomes in Oregon. Med Care Res Rev. 2019;76(5):627–42.PubMedCrossRef Harvey SM, Oakley LP, Yoon J, Luck J. Coordinated Care Organizations: Neonatal and Infant Outcomes in Oregon. Med Care Res Rev. 2019;76(5):627–42.PubMedCrossRef
68.
Zurück zum Zitat Merlo J, Gerdtham U-G, Eckerlund I, Hakansson S, Otterblad-Olausson P, Pakkanen M, Lindqvist P-G. Hospital level of care and neonatal mortality in low- and high-risk deliveries: reassessing the question in Sweden by multilevel analysis. Med Care. 2005;43(11):1092–100.PubMedCrossRef Merlo J, Gerdtham U-G, Eckerlund I, Hakansson S, Otterblad-Olausson P, Pakkanen M, Lindqvist P-G. Hospital level of care and neonatal mortality in low- and high-risk deliveries: reassessing the question in Sweden by multilevel analysis. Med Care. 2005;43(11):1092–100.PubMedCrossRef
69.
Zurück zum Zitat Serenius F, Winbo I, Dahiquist G, Kallen B. Cause-specific stillbirth and neonatal death in Sweden: a catchment area-based analysis. Acta Paediatrica. 2001;90(9):1054–61. Serenius F, Winbo I, Dahiquist G, Kallen B. Cause-specific stillbirth and neonatal death in Sweden: a catchment area-based analysis. Acta Paediatrica. 2001;90(9):1054–61.
70.
Zurück zum Zitat de Graaf JP, Ravelli AC, Visser GH, Hukkelhoven C, Tong WH, Bonsel GJ, Steegers EA. Increased adverse perinatal outcome of hospital delivery at night. BJOG. 2010;117(9):1098–107.PubMedCrossRef de Graaf JP, Ravelli AC, Visser GH, Hukkelhoven C, Tong WH, Bonsel GJ, Steegers EA. Increased adverse perinatal outcome of hospital delivery at night. BJOG. 2010;117(9):1098–107.PubMedCrossRef
71.
Zurück zum Zitat Barbaro RP, Odetola FO, Kidwell KM, Paden ML, Bartlett RH, Davis MM, Annich GM. Association of hospital-level volume of extracorporeal membrane oxygenation cases and mortality. Analysis of the extracorporeal life support organization registry. Am J Respir Crit Care Med. 2015;191(8):894–901. Barbaro RP, Odetola FO, Kidwell KM, Paden ML, Bartlett RH, Davis MM, Annich GM. Association of hospital-level volume of extracorporeal membrane oxygenation cases and mortality. Analysis of the extracorporeal life support organization registry. Am J Respir Crit Care Med. 2015;191(8):894–901.
72.
Zurück zum Zitat Pasquali SK, Li JS, Burstein DS, Sheng S, O’Brien SM, Jacobs ML, Jaquiss RD, Peterson ED, Gaynor JW, Jacobs JP. Association of center volume with mortality and complications in pediatric heart surgery. Pediatrics. 2012;129(2):e370–376. Pasquali SK, Li JS, Burstein DS, Sheng S, O’Brien SM, Jacobs ML, Jaquiss RD, Peterson ED, Gaynor JW, Jacobs JP. Association of center volume with mortality and complications in pediatric heart surgery. Pediatrics. 2012;129(2):e370–376.
73.
Zurück zum Zitat Powell AE, Davies HTO, Thomson RG. Using routine comparative data to assess the quality of health care: understanding and avoiding common pitfalls. Qual Saf Health Care. 2003;12(2):122.PubMedPubMedCentralCrossRef Powell AE, Davies HTO, Thomson RG. Using routine comparative data to assess the quality of health care: understanding and avoiding common pitfalls. Qual Saf Health Care. 2003;12(2):122.PubMedPubMedCentralCrossRef
74.
Zurück zum Zitat Shah PS, Mirea L, Ng E, Solimano A, Lee SK. Association of unit size, resource utilization and occupancy with outcomes of preterm infants. J Perinatol. 2015;35(7):522–9.PubMedCrossRef Shah PS, Mirea L, Ng E, Solimano A, Lee SK. Association of unit size, resource utilization and occupancy with outcomes of preterm infants. J Perinatol. 2015;35(7):522–9.PubMedCrossRef
75.
Zurück zum Zitat Lake ET, Hallowell SG, Kutney-Lee A, Hatfield LA, Del Guidice M, Boxer BA, Ellis LN, Verica L, Aiken LH. Higher Quality of Care and Patient Safety Associated With Better NICU Work Environments. J Nurs Care Qual. 2016;31(1):24–32.PubMedPubMedCentralCrossRef Lake ET, Hallowell SG, Kutney-Lee A, Hatfield LA, Del Guidice M, Boxer BA, Ellis LN, Verica L, Aiken LH. Higher Quality of Care and Patient Safety Associated With Better NICU Work Environments. J Nurs Care Qual. 2016;31(1):24–32.PubMedPubMedCentralCrossRef
76.
Zurück zum Zitat Lake ET, Staiger D, Horbar J, Cheung R, Kenny MJ, Patrick T, Rogowski JA. Association between hospital recognition for nursing excellence and outcomes of very low-birth-weight infants. JAMA. 2012;307(16):1709–16.PubMedPubMedCentralCrossRef Lake ET, Staiger D, Horbar J, Cheung R, Kenny MJ, Patrick T, Rogowski JA. Association between hospital recognition for nursing excellence and outcomes of very low-birth-weight infants. JAMA. 2012;307(16):1709–16.PubMedPubMedCentralCrossRef
77.
Zurück zum Zitat Kozhimannil KB, Hung P, Henning-Smith C, Casey MM, Prasad S. Association Between Loss of Hospital-Based Obstetric Services and Birth Outcomes in Rural Counties in the United States. JAMA. 2018;319(12):1239–47.PubMedPubMedCentralCrossRef Kozhimannil KB, Hung P, Henning-Smith C, Casey MM, Prasad S. Association Between Loss of Hospital-Based Obstetric Services and Birth Outcomes in Rural Counties in the United States. JAMA. 2018;319(12):1239–47.PubMedPubMedCentralCrossRef
78.
Zurück zum Zitat Grzybowski S, Stoll K, Kornelsen J. Distance matters: a population based study examining access to maternity services for rural women. BMC Health Serv Res. 2011;11:147.PubMedPubMedCentralCrossRef Grzybowski S, Stoll K, Kornelsen J. Distance matters: a population based study examining access to maternity services for rural women. BMC Health Serv Res. 2011;11:147.PubMedPubMedCentralCrossRef
79.
Zurück zum Zitat Kornelsen J, Stoll K, Grzybowski S. Stress and anxiety associated with lack of access to maternity services for rural parturient women. Aust J Rural Health. 2011;19(1):9–14.PubMedCrossRef Kornelsen J, Stoll K, Grzybowski S. Stress and anxiety associated with lack of access to maternity services for rural parturient women. Aust J Rural Health. 2011;19(1):9–14.PubMedCrossRef
80.
Zurück zum Zitat McAteer JP, LaRiviere CA, Drugas GT, Abdullah F, Oldham KT, Goldin AB. Influence of surgeon experience, hospital volume, and specialty designation on outcomes in pediatric surgery: a systematic review. JAMA Pediatr. 2013;167(5):468–75.PubMedCrossRef McAteer JP, LaRiviere CA, Drugas GT, Abdullah F, Oldham KT, Goldin AB. Influence of surgeon experience, hospital volume, and specialty designation on outcomes in pediatric surgery: a systematic review. JAMA Pediatr. 2013;167(5):468–75.PubMedCrossRef
81.
Zurück zum Zitat Riley RD, Lambert PC, Abo-Zaid G. Meta-analysis of individual participant data: rationale, conduct, and reporting. BMJ. 2010;340:c221. Riley RD, Lambert PC, Abo-Zaid G. Meta-analysis of individual participant data: rationale, conduct, and reporting. BMJ. 2010;340:c221.
82.
Zurück zum Zitat Riley RD, Lambert PC, Staessen JA, Wang J, Gueyffier F, Thijs L, Boutitie F. Meta-analysis of continuous outcomes combining individual patient data and aggregate data. Stat Med. 2008;27(11):1870–93.PubMedCrossRef Riley RD, Lambert PC, Staessen JA, Wang J, Gueyffier F, Thijs L, Boutitie F. Meta-analysis of continuous outcomes combining individual patient data and aggregate data. Stat Med. 2008;27(11):1870–93.PubMedCrossRef
83.
Zurück zum Zitat Shea BJ, Reeves BC, Wells G, Thuku M, Hamel C, Moran J, Moher D, Tugwell P, Welch V, Kristjansson E, et al. AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. BMJ. 2017;358:j4008. Shea BJ, Reeves BC, Wells G, Thuku M, Hamel C, Moran J, Moher D, Tugwell P, Welch V, Kristjansson E, et al. AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. BMJ. 2017;358:j4008.
84.
Zurück zum Zitat McPherson K. International differences in medical care practices. Health Care Financ Rev. 1989;Spec No(Suppl):9–20. McPherson K. International differences in medical care practices. Health Care Financ Rev. 1989;Spec No(Suppl):9–20.
85.
Zurück zum Zitat Walt G, Shiffman J, Schneider H, Murray SF, Brugha R, Gilson L. “Doing” health policy analysis: methodological and conceptual reflections and challenges. Health Policy Plan. 2008;23(5):308–17. Walt G, Shiffman J, Schneider H, Murray SF, Brugha R, Gilson L. “Doing” health policy analysis: methodological and conceptual reflections and challenges. Health Policy Plan. 2008;23(5):308–17.
86.
Zurück zum Zitat Hug L, Alexander M, You D, Alkema L. National, regional, and global levels and trends in neonatal mortality between 1990 and 2017, with scenario-based projections to 2030: a systematic analysis. Lancet Glob Health. 2019;7(6):e710–20. Hug L, Alexander M, You D, Alkema L. National, regional, and global levels and trends in neonatal mortality between 1990 and 2017, with scenario-based projections to 2030: a systematic analysis. Lancet Glob Health. 2019;7(6):e710–20.
Metadaten
Titel
Are birth outcomes in low risk birth cohorts related to hospital birth volumes? A systematic review
verfasst von
Felix Walther
Denise Kuester
Anja Bieber
Jürgen Malzahn
Mario Rüdiger
Jochen Schmitt
Publikationsdatum
01.12.2021
Verlag
BioMed Central
Erschienen in
BMC Pregnancy and Childbirth / Ausgabe 1/2021
Elektronische ISSN: 1471-2393
DOI
https://doi.org/10.1186/s12884-021-03988-y

Weitere Artikel der Ausgabe 1/2021

BMC Pregnancy and Childbirth 1/2021 Zur Ausgabe

Blutdrucksenkung könnte Uterusmyome verhindern

Frauen mit unbehandelter oder neu auftretender Hypertonie haben ein deutlich erhöhtes Risiko für Uterusmyome. Eine Therapie mit Antihypertensiva geht hingegen mit einer verringerten Inzidenz der gutartigen Tumoren einher.

Antikörper-Wirkstoff-Konjugat hält solide Tumoren in Schach

16.05.2024 Zielgerichtete Therapie Nachrichten

Trastuzumab deruxtecan scheint auch jenseits von Lungenkrebs gut gegen solide Tumoren mit HER2-Mutationen zu wirken. Dafür sprechen die Daten einer offenen Pan-Tumor-Studie.

Mammakarzinom: Senken Statine das krebsbedingte Sterberisiko?

15.05.2024 Mammakarzinom Nachrichten

Frauen mit lokalem oder metastasiertem Brustkrebs, die Statine einnehmen, haben eine niedrigere krebsspezifische Mortalität als Patientinnen, die dies nicht tun, legen neue Daten aus den USA nahe.

S3-Leitlinie zur unkomplizierten Zystitis: Auf Antibiotika verzichten?

15.05.2024 Harnwegsinfektionen Nachrichten

Welche Antibiotika darf man bei unkomplizierter Zystitis verwenden und wovon sollte man die Finger lassen? Welche pflanzlichen Präparate können helfen? Was taugt der zugelassene Impfstoff? Antworten vom Koordinator der frisch überarbeiteten S3-Leitlinie, Prof. Florian Wagenlehner.

Update Gynäkologie

Bestellen Sie unseren Fach-Newsletter und bleiben Sie gut informiert – ganz bequem per eMail.