Risk factors associated with adverse maternal outcomes following intrapartum cesarean birth: a secondary analysis of the WHO global survey on maternal and perinatal health, 2004–2008

Certain woman-level, obstetric-level, and available facility-level risk factors are associated with a greater likelihood of adverse maternal outcomes following an intrapartum cesarean birth. The modifiable factors could be targeted for interventions to reduce adverse maternal outcomes of intrapartum cesarean birth.

Cesarean birth rates are increasing gobally [1]. This increase in cesarean birth rates is due, in part, to the performance of medically unnecessary cesareans [2]. Cesarean birth can be a life-saving procedure for mothers and babies, but it can also be associated with maternal morbidity and mortality [3]. Cesarean birth can potentially result in longer hospitalization and neonatal respiratory complications [4]. Compared with cesarean births conducted before the onset of labor, women are at the greatest risk of harm from cesarean birth when it is performed during labor, which is variably described as an unplanned, intrapartum, or emergency cesarean birth [5]. This is often due to lack of availability of anesthetic and surgical workforce and availability of supplies such as oxygen, anesthesia, and bloodbanks [6]. In order to mitigate the risks of adverse outcomes, cesarean birth should be used at the right time, for the right indications, and with appropriate surgical technique [7].

Given that cesarean birth rates are increasing globally, identifying actionable, modifiable risk factors associated with adverse maternal outcomes following intrapartum cesarean birth may help prevent some maternal morbidity and mortality related to this procedure [5]. We conducted a secondary analysis of the WHO Global Survey on Maternal and Perinatal Health dataset in order to compare women from low- and middle-income countries who gave birth by intrapartum cesarean and experienced an adverse maternal outcome, to women who experienced an intrapartum cesarean birth without having an adverse outcome [8]. Our aim was to identify any modifiable risk factors associated with a composite adverse maternal outcome following intrapartum cesarean birth to determine if there are any target areas that might improve pregnancy outcomes in this population.

In this analysis of 29,516 women who underwent intrapartum cesarean birth in 22 countries in Africa, Asia, and Latin America, factors independently associated with the composite adverse maternal outcome following intrapartum cesarean included women being medically or obstetrically high risk or having a maternal, obstetric, or no other indication for cesarean birth. Factors associated with a reduction in the composite outcome were giving birth in a country of medium or high Human Development Index of the country in which the woman delivered, having had at least four antenatal care visits, and having a breech or other malpresenting fetus compared to cephalic. We hypothesize that our result related to malpresentation represents the fact that most women with non-cephalic fetuses were likely delivered by pre-labor cesarean birth, and only those with very advanced, spontaneous labor delivered vaginally with overall good outcomes.

A potential target for modifying risk associated with intrapartum cesarean birth is attendance at antenatal care. Our analysis suggests that four or more antenatal care visits during pregnancy is associated with 40% fewer adverse outcomes in women who experienced an intrapartum cesarean birth. Though antenatal attendance has previously shown an association with cesarean birth, we could not find other analyses suggesting that increased antenatal care attendance reduces adverse maternal outcomes of intrapartum cesarean birth [18]. This suggests the possibility that this variable is confounded by another variable or may reflect that women with preterm birth attend less antenatal visits. However, researchers in the United States have suggested that improving recovery after cesarean birth does begin in early antenatal care [19]. WHO has recently published recommendations that women have at least eight antenatal contacts during the course of pregnancy to improve outcomes, which might have an impact on this composite outcome, but we have no evidence of this potential effect [20, 21].

Improving maternal outcomes of intrapartum cesarean birth could involve triaging women during antepartum care to assess their need for specialized care as another potential strategy to improve outcomes. Women with obstetric complications of pregnancy (i.e. hypertensive disorders or suspected fetal growth impairment), who were shown to have an increased risk of maternal adverse outcomes, might benefit from additional prenatal management, a more skilled antenatal care provider, or management by a high-risk service in labor [22]. Specialty clinics and risk scoring have been previously explored as methods to meet the needs of subpopulations of women with special antepartum needs [23, 24]. As such, we hypothesize that optimizing management or prevention of these obstetric and medical issues, and recommending specific birth planning that takes current or potential complications into account, may improve maternal outcomes in the event an intrapartum cesarean birth occurs.

Our definition of obstetrically high risk included women with hypertension in pregnancy, pre-eclampsia, eclampsia, or have suspected fetal growth impairment, with other high risk variables (history of cesarean birth, number of gestations, fetal presentation) entered separately into the model. The WHO, in addition to a number of other organizations such as the American College of Obstetricians and Gynecologists, have published guidelines for managing hypertension in pregnancy as hypertensive disorders are a contributor to maternal mortality [25‐28]. Additionally, women referred during the course of labor also had an increased risk of the composite adverse outcome. WHO, in its guidelines on respectful maternity care during labor and childbirth, specifically notes that delivery of high-quality care requires timely and appropriate referral in labor when complications are encountered, through improved infrastructure and established referral pathways [20, 29, 30].

Finally, our analysis found that among women with a maternal or obstetric indication for intrapartum cesarean birth, as compared to cases where the indication was reported as “elective” (see Table 1 for definition), women were more likely to experience the composite adverse outcome. Compared to these cases, women that experience emergency cesarean birth have been shown to have worse maternal and fetal/neonatal outcomes [31, 32]. That being said, cesarean birth should be provided at the right time, for appropriate reasons, and with high-quality technique [7]. It is a major abdominal surgery that can in itself result in adverse outcomes, and can be quite expensive to deliver, so it should only be provided when medically necessary [1‐3, 33, 34]. Indication for cesarean birth is a modifiable risk factor in that it can be modified to promote best obstetric practices. Guidelines for prevention of primary cesarean birth have been produced to assist in the decision-making process to proceed to cesarean birth [35, 36].

The limitations of this study include the fact that the data were collected 10 years ago and that unmeasured facility, sociodemographic, or obstetric variables may confound the results. Due to the large amount of missingness for some maternal outcome variables (intrapartum and postpartum blood transfusion, internal iliac artery ligation, and postpartum urogenital fistula) they were not included in the definition of the composite outcome, although we ideally would have wanted to include them. Additionally, 16% of BMI data was missing, and while the weight parameter was meant to reflect the most recently recorded weight of a woman, the time of collection could vary. We also note that the criteria for definition of the various morbidities was according to local practices and the methodology of the survey did not impose any specific definition, which makes interpretation of some the results more challenging. For example, the collecting agency did not specify criteria for ICU admittance. We noted in our initial analysis that the component of the composite outcome that accounted for the most adverse outcomes was ICU admission. This was a subjective parameter in the data set as each hospital had its own admittance criteria. We ran a histogram of days in the ICU and found that most women were only admitted to the ICU for 1 day (data not shown); we hypothesized this was the result of it being common practice in some settings where the only hospital location capable of monitoring a post-operative patient is the ICU. In order to try to refine the definition to include only those women who had severe morbidity and were not just in the ICU for monitoring, we adjusted the definition to stays of greater than or equal to 2 days.

A previous paper observed the association of cesarean birth, considering indication, with maternal and perinatal outcomes in Asian populations from this dataset [10]. Our analysis adds to this prior analysis by evaluating the association of additional, potentially modifiable risk factors with a composite adverse maternal outcome following intrapartum cesarean birth in the entire dataset. Other strengths of this analysis are the use of a large data set, the collection of multiple variables potentially associated with the outcome, the fact that the survey was designed to assess method of birth, and that the multi-country data were collected using a standard approach/protocol/measurement tool and abstracted from routine medical records [9].

We found reduced adverse maternal outcomes following intrapartum cesarean birth associated with women giving birth in medium or high human development index countries and those who attended ≥ 4 antenatal visits. Maternal adverse outcomes of intrapartum cesarean birth were increased in medically and obstetrically high risk women and those with a maternal or obstetric indication for cesarean birth.