Faculty Bibliography

OBJECTIVE:The aim of this systematic review and metaanalysis was to determine the efficacy and safety of cervical ripening agents in the second trimester of pregnancy in patients with previous cesarean delivery. STUDY DESIGN/METHODS:Data sources were PubMed, EMBASE, CINAHL, LILACS, Google Scholar, and clinicaltrials.gov (1983 through 2015). Eligibility criteria were cohort or cross-sectional studies that reported on efficacy and safety of cervical ripening agents in patients with previous cesarean delivery. Efficacy was determined based on the proportion of patients achieving vaginal delivery and vaginal delivery within 24 hours following administration of a cervical ripening agent. Safety was assessed by the risk of uterine rupture and complications such as retained placental products, blood transfusion requirement, and endometritis, when available, as secondary outcomes. Of the 176 studies identified, 38 met the inclusion criteria. Of these, 17 studies were descriptive and 21 studies compared the efficacy and safety of cervical ripening agents between patients with previous cesarean and those with no previous cesarean. From included studies, we abstracted data on cervical ripening agents and estimated the pooled risk differences and risk ratios with 95% confidence intervals. To account for between-study heterogeneity, we estimated risk ratios based on underlying random effects analyses. Publication bias was assessed via funnel plots and across-study heterogeneity was assessed based on the I(2) measure. RESULTS:The most commonly used agent was PGE1. In descriptive studies, PGE1 was associated with a vaginal delivery rate of 96.8%, of which 76.3% occurred within 24 hours, uterine rupture in 0.8%, retained placenta in 10.8%, and endometritis in 3.9% in patients with ≥1 cesarean. In comparative studies, the use of PGE1, PGE2, and mechanical methods (laminaria and dilation and curettage) were equally efficacious in achieving vaginal delivery between patients with and without prior cesarean (risk ratio, 0.99, and 95% confidence interval, 0.98-1.00; risk ratio, 1.00, and 95% confidence interval, 0.98-1.02; and risk ratio, 1.00, and 95% confidence interval, 0.98-1.01; respectively). In patients with history of ≥1 cesarean the use of PGE1 was associated with higher risk of uterine rupture (risk ratio, 6.57; 95% confidence interval, 2.21-19.52) and retained placenta (risk ratio, 1.21; 95% confidence interval, 1.03-1.43) compared to women without a prior cesarean. However, the risk of uterine rupture among women with history of only 1 cesarean (0.47%) was not statistically significant (risk ratio, 2.36; 95% confidence interval, 0.39-14.32), whereas among those with history of ≥2 cesareans (2.5%) was increased as compared to those with no previous cesarean (0.08%) (risk ratio, 17.55; 95% confidence interval, 3.00-102.8). Funnel plots did not demonstrate any clear evidence of publication bias. Across-study heterogeneity ranged from 0-81%. CONCLUSION/CONCLUSIONS:This systematic review and metaanalysis provides evidence that PGE1, PGE2, and mechanical methods are efficacious for achieving vaginal delivery in women with previous cesarean delivery. The use of prostaglandin PGE1 in the second trimester was not associated with significantly increased risk for uterine rupture among women with only 1 cesarean; however, this risk was substantially increased among women with ≥2 cesareans although the absolute risk appeared to be relatively small.

BACKGROUND: The rising cesarean birth rate has drawn attention to risks associated with repeat cesarean birth. Prevention of adhesions with adhesion barriers has been promoted as a way to decrease operative difficulty. However, robust data demonstrating effectiveness of such interventions are lacking. OBJECTIVE: We report data from a multicenter trial designed to evaluate the short-term safety and effectiveness of a modified sodium hyaluronic acid (HA)-carboxymethylcellulose (CMC) absorbable adhesion barrier for reduction of adhesions following cesarean delivery. STUDY DESIGN: Patients who underwent primary or repeat cesarean delivery were included in this multicenter, single-blinded (patient), randomized controlled trial. Patients were randomized into either HA-CMC (N = 380) or no treatment (N = 373). No other modifications to their treatment were part of the protocol. Short-term safety data were collected following randomization. The location and density of adhesions (primary outcome) were assessed at their subsequent delivery using a validated tool, which can also be used to derive an adhesion score that ranges from 0-12. RESULTS: No differences in baseline characteristics, postoperative course, or incidence of complications between the groups following randomization were noted. Eighty patients from the HA-CMC group and 92 controls returned for subsequent deliveries. Adhesions in any location were reported in 75.6% of the HA-CMC group and 75.9% of the controls (P = .99). There was no significant difference in the median adhesion score; 2 (range 0-10) for the HA-CMC group vs 2 (range 0-8) for the control group (P = .65). One third of the HA-CMC patients met the definition for severe adhesions (adhesion score >4) compared to 15.5% in the control group (P = .052). There were no significant differences in the time from incision to delivery (P = .56). Uterine dehiscence in the next pregnancy was reported in 2 patients in HA-CMC group vs 1 in the control group (P = .60). CONCLUSION: Although we did not identify any short-term safety concerns, HA-CMC adhesion barrier applied at cesarean delivery did not reduce adhesion formation at the subsequent cesarean delivery.

BACKGROUND: Midtrimester ultrasound is a valuable method for identifying asymptomatic women at risk for spontaneous preterm delivery (PTD). However, response to various treatments (cerclage, progestogen) has been variable in the clinical setting. It remains unclear how other biomarkers may be used to guide intervention strategies. OBJECTIVE: We applied an amniotic fluid inflammatory scoring system to determine if the degree of inflammation is associated with intervention efficacy in patients with midtrimester short cervix. STUDY DESIGN: Women carrying a singleton fetus between 16-24 weeks' gestation with a short cervix (/=8) or low (score <8) risk for inflammation. Gestational age at delivery was compared for each intervention and risk score status. Risk of delivering as a function of the remaining gestation was evaluated using modified Cox proportional hazards models with incorporation of methods to account for both left and right truncation bias. RESULTS: Ninety patients were included: 24 were in the nonintervention control group, 51 received cerclage, and 15 received 17OHP-C. Inflammation status at time of sampling influenced the efficacy of the treatment (P < .001). Compared to the nonintervention control group, in patients with low inflammation (score < 8), both cerclage (adjusted hazard ratio [HR], 2.86; 95% confidence interval [CI], 1.28-6.37) and 17OHP-C (HR, 3.11; 95% CI, 1.04-9.30) were associated with increased hazard of PTD. In contrast, in patients with high inflammation (score >/=8) both cerclage (HR, 0.22; 95% CI, 0.08-0.65) and 17OHP-C (HR, 0.20; 95% CI, 0.05-0.81) were associated with lower hazard of delivering preterm. CONCLUSION: Cerclage placement or administration of 17OHP-C therapy for midtrimester short cervix for PTD prevention appears beneficial only in the subset of patients with high inflammation. Knowledge of the amniotic fluid inflammatory status may aid in guiding the appropriate therapy for women presenting with midtrimester short cervix who are at increased risk of PTD.

BACKGROUND:Placental abruption traditionally is defined as the premature separation of the implanted placenta before the delivery of the fetus. The existing clinical criteria of severity rely exclusively on fetal (fetal distress or fetal death) and maternal complications without consideration of neonatal or preterm delivery-related complications. However, two-thirds of abruption cases are accompanied by fetal or neonatal complications, including preterm delivery. A clinically meaningful classification for abruption therefore should include not only maternal complications but also adverse fetal and neonatal outcomes that include intrauterine growth restriction and preterm delivery. OBJECTIVES/OBJECTIVE:The purpose of this study was to define severe placental abruption and to compare serious maternal morbidity profiles of such cases with all other cases of abruption (ie, mild abruption) and nonabruption cases. STUDY DESIGN/METHODS:We performed a retrospective cohort analysis using the Premier database of hospitalizations that resulted in singleton births in the United States between 2006 and 2012 (n = 27,796,465). Severe abruption was defined as abruption accompanied by at least 1 of the following events: maternal (disseminated intravascular coagulation, hypovolemic shock, blood transfusion, hysterectomy, renal failure, or in-hospital death), fetal (nonreassuring fetal status, intrauterine growth restriction, or fetal death), or neonatal (neonatal death, preterm delivery or small for gestational age) complications. Abruption cases that did not qualify as being severe were classified as mild abruption cases. The morbidity profile included amniotic fluid embolism, pulmonary edema, acute respiratory or heart failure, acute myocardial infarction, cardiomyopathy, puerperal cerebrovascular disorders, or coma. Associations were expressed as rate ratios with 95% confidence intervals that were derived from fitting log-linear Poisson regression models. RESULTS:The overall prevalence rate of abruption was 9.6 per 1000, of which two-thirds of cases were classified as being severe (6.5 per 1000). Serious maternal complications occurred in 15.4, 33.3, and 141.7 per 10,000 among nonabruption cases and mild and severe abruption cases, respectively. In comparison with no abruption, the rate ratio for serious maternal complications were 1.52 (95% confidence interval, 1.35-1.72) and 4.29 (95% confidence interval, 4.11-4.47) in women with mild and severe placental abruption, respectively. Rate ratios for the individual complications were 2- to 7-fold higher among severe abruption cases. Furthermore, the rate ratios for serious maternal complications among severe abruption cases compared with mild abruption cases was 3.47 (95% confidence interval, 3.05-3.95). This association was considerably stronger for virtually all maternal complications among cases with severe abruption compared with mild abruption. Annual rates of mild and severe abruption were fairly constant during the study period. Although the maternal complication rate among non-abruption births was stable from 2006-2012, the rate of complications among mild abruption cases dropped from 2006-2008 and then leveled off thereafter. In contrast, the rate of serious complications among severe abruption cases remained fairly stable from 2006-2010 and increased sharply thereafter. CONCLUSIONS:Severe abruption was associated with a distinctively higher morbidity risk profile compared with the other 2 groups. The clinical characteristics and morbidity profile of mild abruption were more similar to those of women without an abruption. These findings suggest that the definition of severe placental abruption based on the proposed specific criteria is clinically relevant and may facilitate epidemiologic and genetic research.