OBSTETRICSDiagnosis of Subclinical Amniotic Fluid Infection Prior to Rescue Cerclage Using Gram Stain and Glucose Tests: An Individual Patient Meta-Analysis
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INTRODUCTION
Cervical insufficiency during the second trimester of pregnancy increases the risk of preterm delivery and presents a management challenge.1., 2., 3. While a rescue/emergency cerclage in the absence of clinical chorioamnionitis can potentially prolong pregnancy, the success of this intervention depends largely on the absence of subclinical infection.3., 4., 5., 6., 7., 8., 9., 10. In the presence of microbial invasion of the amniotic cavity, cervical cerclage can lead to increased maternal
METHODS
We used data available in the published literature, specifically using studies with individual-level information about amniotic fluid Gram stain, glucose concentration, and culture results following a second trimester amniocentesis. Additional criteria for study selection included those based on homogenous populations with preterm labour and intact membranes. Two studies satisfied these conditions: the first study13 included 168 consecutive patients, and the second study included 120 patients.16
RESULTS
The study population included 288 women who underwent amniocentesis during the second trimester to detect MIAC. The overall prevalence of culture confirmed MIAC was 11.8% (34/288). The test results for the Gram stain, glucose, and amniotic fluid culture tests are presented in Figure 1. The sensitivity and specificity of the Gram stain test were 65% and 99%, respectively, and the positive and negative predictive values were 92% and 95%, respectively (Table 1). The sensitivity of the glucose
DISCUSSION
Our study showed that the amniotic fluid Gram stain and glucose concentration tests diagnosed microbial infection of the amniotic cavity with reasonable accuracy when used singly or in combination. These tests provide a substantial advantage over no testing for diagnosing subclinical infection. For example, if used to aid clinical decision-making before rescue cerclage, Gram stain testing alone would identify 65% of women with MIAC and deny intervention to only 8% of women (92% of whom would
CONCLUSION
Our study showed that the use of Gram stain and glucose testing, either singly or in combination, can help diagnose subclinical MIAC; this may be, for instance, in women with cervical insufficiency considering a rescue cerclage. Details of test performance dictate whether a single test or both tests in combination is preferable. The choice of specific test or the specific combination of the two tests to be used depends on the value placed on detecting all cases of MIAC versus keeping
ACKNOWLEDGEMENTS
This study was supported by a Canadian Institutes of Health Research Team grant in severe maternal morbidity (MAH-115445). Yasser Sabr is supported by a scholar award from the King Saud University, Saudi Arabia. K.S. Joseph holds a Canadian Institutes of Health Research Chair in maternal, fetal and infant health services research and is also supported by the Child and Family Research Institute.
REFERENCES (28)
- et al.
Evidence for the clinical management of chorioamnionitis
(2012) - et al.
Microbial invasion of the amniotic cavity in patients with suspected cervical incompetence: prevalence and clinical significance
Am J Obstet Gynecol
(1992) - et al.
Amniocentesis for selection before rescue cerclage
Obstet Gynecol
(2000) - et al.
Bacteriology of amniotic fluid in women with suspected cervical insufficiency
J Obstet Gyneacol Can
(2008) - et al.
Evaluation of rapid diagnostic tests in the detection of microbial invasion of the amniotic cavity
Am J Obstet Gynecol
(1992) - et al.
Amniotic fluid glucose concentration: a rapid and simple method for the detection of amniotic fluid infection in preterm labor
Am J Obstet Gynecol
(1990) - et al.
The diagnostic and prognostic value of amniotic fluid white blood cell count, glucose, interleukin-6, and Gram stain in patients with preterm labor and intact membranes
Am J Obstet Gynecol
(1993) - et al.
Interleukin-6, but not relaxin, predicts outcome of rescue cerclage in women with cervical incompetence
Am J Obstet Gynecol
(2004) - et al.
Evaluating rapid diagnostic test of intra-amniotic infection: Gram stain, amniotic fluid glucose level, and amniotic fluid to serum glucose ratio
Am J Obstet Gynecol
(1998) - et al.
The effect of second-trimester antibiotics therapy on the rate of preterm birth
J Obstet Gynaecol Can
(2007)
Impact of subclinical chorioamnionitis on maternal and neonatal outcomes
Acta Obst Gynecol
Emergent cervical cerclage: Predictors of success or failure
J Matern Fetal Med
A randomized trial of cerclage vs. 17 alpha-hydroxyprogesterone caproate for treatment of short cervix
J Perinat Med
Cited by (31)
The role of intraamniotic inflammation in threatened midtrimester miscarriage
2022, American Journal of Obstetrics and GynecologyCitation Excerpt :Intrauterine and intraamniotic infection and/or inflammation have been implicated in midtrimester miscarriages indicated in case reports and case series based on the results of autopsies or placental histopathologic examinations.19–26 Moreover, a growing body of evidence suggests that intraamniotic infection and inflammation are major factors in cervical insufficiency—a cause of midtrimester miscarriage.27–35 A subset of patients with threatened midtrimester miscarriage show an increase in uterine contractility as the main symptom.
Optimization and validation of two multiplex qPCR assays for the rapid detection of microorganisms commonly invading the amniotic cavity
2022, Journal of Reproductive ImmunologyCitation Excerpt :This could be particularly useful for women with potential intraamniotic infection, preterm labor, preterm prelabor rupture of the membranes, or chorioamnionitis (Romero et al., 2014a). Moreover, these assays are applicable to other complications of pregnancy, including the diagnosis of subclinical amniotic fluid infection prior to rescue cerclage (Romero et al., 1992a; Lisonkova et al., 2014), as well as informing of the potential for early-onset neonatal sepsis in cases of preterm labor or membrane rupture (Stoll et al., 2011; Wang et al., 2013). They also provide the ability to rapidly determine the burden of specific microbial taxa within the amniotic cavity and compare it to clinical indicators, thus informing clinicians of the likelihood of adverse pregnancy outcomes thereby allowing for development of prevention and treatment strategies to circumvent microbial-induced pregnancy complications.
Physical examination–indicated cerclage in twin pregnancy: a randomized controlled trial
2020, American Journal of Obstetrics and GynecologyCitation Excerpt :In our trial, amniocentesis was not mandatory as IRB found it coercive; only 4 of 30 participants (13.3%) agreed to perform the procedure. Assessment of amniotic fluid Gram stain or amount of glucose in patients before physical examination–indicated cerclage has indicated a positive predictive value of 47% and a negative predictive value of 98% for intrauterine infection.35 Amniotic fluid culture is considered the gold standard for diagnosis of infection, but cultures take several days for final results to arrive and therefore limit the utility in clinical decision making.
Development and validation of a multivariable prediction model of spontaneous preterm delivery and microbial invasion of the amniotic cavity in women with preterm labor
2020, American Journal of Obstetrics and GynecologyEvidence that antibiotic administration is effective in the treatment of a subset of patients with intra-amniotic infection/inflammation presenting with cervical insufficiency
2019, American Journal of Obstetrics and GynecologyCitation Excerpt :The patient with group B Streptococcus carried the pregnancy to term, suggesting a therapeutic value for antibiotic administration.20 Subsequent studies have shown that microorganisms are present in the amniotic cavity in 8–52% of patients with cervical insufficiency.20–27 For example, in a study including 33 patients with cervical insufficiency, 51.5% (17/33) had a positive amniotic fluid culture for microorganisms.21
Competing Interests: None declared.