Induction of labor versus expectant management in patients with idiopathic polyhydramnios

OBJECTIVE

To evaluate whether induction of labor is associated with lower risk of cesarean section compared to expectant management in patients with isolated polyhydramnios.

STUDY DESIGN

This is a single-center, retrospective cohort study of patients with pregnancies complicated by idiopathic polyhydramnios, documented between 34 and 38 weeks gestation, who were delivered between July 2012 and February 2020. The primary outcome was cesarean delivery. Secondary outcomes included chorioamnionitis, endometritis, postpartum hemorrhage, preeclampsia/gestational hypertension, and composite neonatal morbidity.

RESULTS

There were 194 patients included with idiopathic polyhydramnios - 115 underwent induction and 79 patients were expectantly managed. Planned induction was associated with a lower rate of CD compared with expectant management but did not meet statistical significance (19.1 % vs 30.4 %, aOR 0.51, 95 % CI 0.24, 1.05). A similar effect was seen when stratifying for parity: both nulliparous (9.1 % vs 16.3 %, aOR 0.59, 95 % CI 0.17, 1.98) and multiparous (32.7 % vs 47.2 %, aOR 0.45, 95 % CI 0.18, 1.15) patients had a lower CD rate when there was a planned induction, though neither group met statistical significance. No differences in maternal or fetal secondary outcomes were identified (chorioamnionitis, endometritis, postpartum hemorrhage, preeclampsia/gestational hypertension, composite neonatal morbidity).

CONCLUSION

Lower rates of cesarean section were associated with labor induction for patients with isolated polyhydramnios, but confidence intervals did not reach statistical significance.

Traction vs no traction in Foley catheter use for induction of labor: a systematic review and meta-analysis of randomized trials

OBJECTIVE

Intracervical Foley catheter is a safe and effective method for cervical ripening. There are a variety of ways to modify this ripening method, including adding traction or tension to the catheter. The utility of this practice is uncertain. The aim of this systematic review and meta-analysis of randomized controlled trials was to investigate whether the placement of traction vs no traction on a Foley catheter during cervical ripening decreases total time from induction to delivery.

DATA SOURCES

Electronic sources include MEDLINE, Scopus, ClinicalTrials.gov, the International Prospective Register of Systematic Reviews, SciELO, the Cochrane Central Register of Controlled Trials, and Google Scholar from inception through June 2020.

STUDY ELIGIBILITY CRITERIA

Randomized trials comparing Foley catheter with traction (ie, intervention) vs Foley catheter without traction (ie, control) for cervical ripening were included in the meta-analysis. All types of traction were analyzed (weighted, taped to thigh) and whether the traction was placed only initially at Foley catheter placement or repeated throughout the ripening process.

METHODS

The primary outcome was the mean time from induction to delivery in hours. Meta-analysis was performed using the random-effects model of DerSimonian and Laird to produce summary treatment effects in terms of mean difference with 95% confidence interval. Heterogeneity was measured using I-squared (Higgins I²).

RESULTS

Three trials including 790 singleton gestations were identified as relevant and included in the systematic review. Women randomized to traction on the Foley balloon had a similar time from induction to delivery compared with no traction (mean difference, 0.25; confidence interval, -0.78 to 1.27). No significant differences were found in the secondary outcomes. There was no difference in cesarean delivery between groups (relative risk, 0.94; 95% confidence interval, 0.74-1.19). Foley catheter expulsion was faster in the tension group (mean difference, -3.74; 95% confidence interval, -6.29 to -1.19) CONCLUSION: Adding traction to an intracervical Foley catheter during cervical ripening does not decrease time to delivery.

Failure to Detect SARS-CoV-2 RNA in the Air During Active Labor in Mothers Who Recently Tested Positive

The risk of potential SARS-CoV-2 transmission by infected mothers during labor and delivery has not been investigated in-depth. This work collected air samples close to (respiratory droplets) and more distant from (aerosol generation) unvaccinated patients who had previously tested positive for SARS-CoV-2 during labor within 5 days of a positive test. All but one of the patients wore masks during the delivery, and delivery was carried out in either birthing or negative pressure isolation rooms. Our work failed to detect SARS-CoV-2 RNA in any air samples for all of the six patients who gave birth vaginally, despite validation of the limit of detection of the samplers. In sum, this brief report provides initial evidence that the risk of airborne transmission of SARS-CoV-2 during labor may be mitigated by the use of masks and high ventilation rates common in many modern U.S. medical facilities; however more work is needed to fully evaluate the risk of SARS-CoV-2 transmission during labor and maternal pushing.

Vaginal progesterone vs intramuscular 17-hydroxyprogesterone caproate for prevention of recurrent preterm birth: a randomized controlled trial

BACKGROUND

Preterm birth is the leading cause of neonatal morbidity and mortality, and previous preterm birth is one of the strongest risk factors for preterm birth. National and international obstetrical societies have different recommendations regarding progesterone formulation for the prevention of recurrent preterm birth.

OBJECTIVE

This study aimed to determine whether vaginal progesterone is superior to 17-hydroxyprogesterone caproate in the prevention of recurrent preterm birth in patients with singleton pregnancies who had a previous spontaneous preterm birth.

STUDY DESIGN

This was an open-label multicenter pragmatic randomized controlled trial at 5 US centers of patients with singleton pregnancies at <24 weeks of gestation who had a previous spontaneous preterm birth randomized 1:1 to either 200 mg vaginal progesterone suppository nightly or 250 mg intramuscular 17-hydroxyprogesterone caproate weekly from 16 to 36 weeks of gestation. Based on the estimated recurrent preterm birth rate of 36% with 17-hydroxyprogesterone caproate, 95 participants were needed in each arm to detect a 50% reduction in preterm birth rate with vaginal progesterone, with 80% power and 2-sided alpha of 0.05. The primary outcome was preterm birth at <37 weeks of gestation. Prespecified secondary outcomes included preterm birth at <34 and <28 weeks of gestation, mean gestational age at delivery, neonatal morbidity and mortality, and measures of adherence. Analysis was by intention to treat. The chi-square test and Student t test were used as appropriate. P<.05 was considered significant.

RESULTS

Overall, 205 participants were randomized; 94 participants in the vaginal progesterone group and 94 participants in 17-hydroxyprogesterone caproate group were included. Although gestational age at enrollment was similar, those assigned to vaginal progesterone initiated therapy earlier (16.9±1.4 vs 17.8±2.5 weeks; P=.001). Overall continuation of assigned formulation until delivery was similar (73% vs 69%; P=.61). There was no significant difference in preterm birth at <37 (31% vs 38%; P=.28; relative risk, 0.81 [95% confidence interval, 0.54-1.20]), <34 (9.6% vs 14.9%; P=.26; relative risk, 0.64 [95% confidence interval, 0.29-1.41]), or <28 (1.1% vs 4.3%; P=.37; relative risk, 0.25 [95% confidence interval, 0.03-2.20]) weeks of gestation. Participants in the vaginal progesterone group had a later mean gestational age at delivery than participants in the 17-hydroxyprogesterone caproate group (37.36±2.72 vs 36.34±4.10 weeks; mean difference, 1.02 [95% confidence interval, 0.01-2.01]; P=.047).

CONCLUSION

Vaginal progesterone did not reduce the risk of recurrent preterm birth by 50% compared with 17-OHPC; however, vaginal progesterone may lead to increased latency to delivery. This trial was underpowered to detect a smaller, but still clinically significant, difference in the efficacy of preterm birth prevention. Patient factors that impact adherence and ability to obtain medication in a timely fashion should be included in counseling on progesterone selection.

Clinical and economic evaluation of a proteomic biomarker preterm birth risk predictor: cost-effectiveness modeling of prenatal interventions applied to predicted higher-risk pregnancies within a large and diverse cohort

OBJECTIVES

Preterm birth occurs in more than 10% of U.S. births and is the leading cause of U.S. neonatal deaths, with estimated annual costs exceeding $25 billion USD. Using real-world data, we modeled the potential clinical and economic utility of a prematurity-reduction program comprising screening in a racially and ethnically diverse population with a validated proteomic biomarker risk predictor, followed by case management with or without pharmacological treatment.

METHODS

The ACCORDANT microsimulation model used individual patient data from a prespecified, randomly selected sub-cohort (N = 847) of a multicenter, observational study of U.S. subjects receiving standard obstetric care with masked risk predictor assessment (TREETOP; NCT02787213). All subjects were included in three arms across 500 simulated trials: standard of care (SoC, control); risk predictor/case management comprising increased outreach, education and specialist care (RP-CM, active); and multimodal management (risk predictor/case management with pharmacological treatment) (RP-MM, active). In the active arms, only subjects stratified as higher risk by the predictor were modeled as receiving the intervention, whereas lower-risk subjects received standard care. Higher-risk subjects' gestational ages at birth were shifted based on published efficacies, and dependent outcomes, calibrated using national datasets, were changed accordingly. Subjects otherwise retained their original TREETOP outcomes. Arms were compared using survival analysis for neonatal and maternal hospital length of stay, bootstrap intervals for neonatal cost, and Fisher's exact test for neonatal morbidity/mortality (significance, p < .05).

RESULTS

The model predicted improvements for all outcomes. RP-CM decreased neonatal and maternal hospital stay by 19% (p = .029) and 8.5% (p = .001), respectively; neonatal costs' point estimate by 16% (p = .098); and moderate-to-severe neonatal morbidity/mortality by 29% (p = .025). RP-MM strengthened observed reductions and significance. Point estimates of benefit did not differ by race/ethnicity.

CONCLUSIONS

Modeled evaluation of a biomarker-based test-and-treat strategy in a diverse population predicts clinically and economically meaningful improvements in neonatal and maternal outcomes.

Physical examination-indicated cerclage in twin pregnancy: a randomized controlled trial

BACKGROUND

Women with twin pregnancies and a dilated cervix in the second trimester are at increased risk of pregnancy loss and early preterm birth; there is currently no proven therapy to prevent preterm birth in this group of women.

OBJECTIVE

This study aimed to determine whether physical examination-indicated cerclage reduces the incidence of preterm birth in women with a diagnosis of twin pregnancies and asymptomatic cervical dilation before 24 weeks of gestation.

STUDY DESIGN

Multicenter, parallel group, open-label, randomized controlled trial of women with twin pregnancies and asymptomatic cervical dilation of 1 to 5 cm between 16 weeks 0/7 days of gestation and 23 weeks 6/7 days of gestation were enrolled from July 2015 to July 2019 in 8 centers. Eligible women were randomized in a 1:1 ratio into either cerclage or no cerclage groups. We excluded women with monochorionic-monoamniotic twin pregnancy, selective fetal growth restriction, twin-twin transfusion syndrome, major fetal malformation, known genetic anomaly, placenta previa, signs of labor, or clinical chorioamnionitis. The primary outcome was the incidence of preterm birth at <34 weeks of gestation. Secondary outcomes were preterm births at <32, <28, and <24 weeks of gestation, interval from diagnosis to delivery, and perinatal mortality. Data were analyzed by intention-to-treat methods.

RESULTS

After an interim analysis was performed, the Data and Safety Monitoring Board recommended stopping the trial because of a significant decrease in perinatal mortality in the cerclage group. We randomized 34 women, with 4 women being excluded because of expired informed consent. A total of 17 women were randomized to physical examination-indicated cerclage and 13 women to no cerclage. Whereas 4 women randomized to cerclage did not receive the surgical procedure, no women in the no cerclage group received cerclage. Maternal demographics were not significantly different. All women in the cerclage group also received indomethacin and antibiotics. When comparing the cerclage group vs the no cerclage group, the incidence of preterm birth was significantly decreased as follows: preterm birth at <34 weeks of gestation, 12 of 17 women (70%) vs 13 of 13 women (100%) (risk ratio, 0.71; 95% confidence interval, 0.52-0.96); preterm birth at <32 weeks of gestation, 11 of 17 women (64.7%) vs 13 of 13 women (100%) (risk ratio, 0.65; 95% confidence interval, 0.46-0.92); preterm birth at <28 weeks of gestation, 7 of 17 women (41%) vs 11 of 13 women (84%) (risk ratio, 0.49; 95% confidence interval, 0.26-0.89); and preterm birth at <24 weeks of gestation, 5 of 17 women (30%) vs 11 of 13 women (84%) (risk ratio, 0.35; 95% confidence interval, 0.16-0.75). The mean gestational age at delivery was 29.05±1.7 vs 22.5±3.9 weeks (P<.01), respectively; the mean interval from diagnosis of cervical dilation to delivery was 8.3±5.8 vs 2.9±3.0 weeks (P=.02), respectively. Perinatal mortality was also significantly reduced in the cerclage group compared with the no cerclage group as follows: 6 of 34 women (17.6%) vs 20 of 26 women (77%) (risk ratio, 0.22; 95% confidence interval, 0.1-0.5), respectively.

CONCLUSION

In women with twin pregnancies and asymptomatic cervical dilation before 24 weeks of gestation, a combination of physical examination-indicated cerclage, indomethacin, and antibiotics significantly decreased preterm birth at all evaluated gestational ages. Most importantly, cerclage in this population was associated with a 50% decrease in early preterm birth at <28 weeks of gestation and with a 78% decrease in perinatal mortality.

Combination of Foley and prostaglandins versus Foley and oxytocin for cervical ripening: a network meta-analysis

BACKGROUND

Trial and meta-analysis data revealed a reduction in time to delivery for Foley and prostaglandins or Foley and oxytocin vs Foley alone. However, there are limited data for the comparison of the 2 combination methods against each other.

OBJECTIVE

This study aimed to determine whether Foley and prostaglandins or Foley and oxytocin decrease the time to vaginal delivery using a network meta-analysis.

STUDY DESIGN

A network meta-analysis (PROSPERO CRD42018081948) was performed comparing Foley and prostaglandins (prostaglandin E1 or prostaglandin E2) vs Foley and oxytocin for cervical ripening. Foley alone and prostaglandins alone were used as nodes for indirect comparison. Database searches were performed from inception to March 2020 with data abstracted from published manuscripts. Eligibility criteria included randomized trials comparing Foley and oxytocin with Foley and prostaglandins (misoprostol or dinoprostone). Trials that compared Foley catheter or prostaglandins with a combination of Foley and prostaglandins or Foley and concurrent oxytocin were also included. Nulliparous and multiparous women were analyzed together. Foley catheters of any catheter material or size and >24 weeks' gestational age with a live fetus were included. Quasi-randomized, cohorts, and other combination methods for cervical ripening were not included. Prostaglandin E1 and prostaglandin E2 combined methods were analyzed separately in a planned subanalysis. The primary outcome was the mean time from induction to vaginal delivery in hours. Secondary outcomes included time from induction to delivery, delivery within 24 hours, cesarean delivery, chorioamnionitis, endometritis, epidural use, tachysystole, postpartum hemorrhage, meconium, neonatal intensive care unit admission, and 5-minute appearance, pulse, grimace, activity, and respiration score of <7. Data were analyzed as a network meta-analysis using multivariate meta-regression.

RESULTS

A total of 30 randomized controlled trials with a total of 6465 women were considered eligible for inclusion in this network meta-analysis. When compared with Foley alone, the use of Foley-oxytocin reduced the time to vaginal delivery by 4.2 hours (mean duration, -4.2 hours; 95% confidence interval, -6.5 to -1.9). Foley-prostaglandins reduced the time to vaginal delivery compared with Foley but did not meet statistical significance (mean duration, -2.9 hours; 95% confidence interval, -5.7 to 0.0; P=.05). When compared head-to-head, there was no difference in the time to vaginal delivery between Foley-prostaglandins and Foley-oxytocin (mean duration, 1.3 hours; 95% confidence interval, -2.0 to 4.7). There was no difference in the rate of cesarean delivery, chorioamnionitis, epidural, tachysystole, postpartum hemorrhage, meconium, neonatal intensive care unit admissions, or 5-minute appearance, pulse, grimace, activity, and respiration score of <7 for Foley-prostaglandins vs Foley-oxytocin, although the rate of endometritis was high for Foley-prostaglandins. In the subanalysis by prostaglandin type, there was no difference in the time to vaginal delivery for Foley-misoprostol vs Foley-dinoprostone vs Foley-oxytocin. However, Foley-dinoprostone had a definite trend toward longer time to all deliveries compared with that of both Foley-misoprostol and Foley-oxytocin (P=.05).

CONCLUSION

Time to vaginal delivery was similar when comparing Foley with combined misoprostol, combined dinoprostone, and combined oxytocin. Dinoprostone comparisons are limited by small sample size but suggest longer time to delivery compared with Foley and misoprostol or oxytocin. No significant differences were observed in maternal or neonatal adverse events except for endometritis, but this was limited by the sample size, varied reporting of studies used in the indirect comparisons, and definitions of infectious morbidity use in the studies.

Impact of the ACOG guideline regarding low-dose aspirin for prevention of superimposed preeclampsia in women with chronic hypertension

BACKGROUND

Patients with chronic hypertension are at increased risk for superimposed preeclampsia. The 2016 American College of Obstetricians and Gynecologists guideline recommended initiating 81 mg of daily aspirin for all pregnant women with chronic hypertension to prevent superimposed preeclampsia.

OBJECTIVE

(1) To evaluate the rates of implementation of the 2016 American College of Obstetricians and Gynecologists guideline over time; and (2) to evaluate the effectiveness of aspirin for the prevention of superimposed preeclampsia and other adverse maternal and neonatal outcomes in women with chronic hypertension before and after this guideline.

STUDY DESIGN

This is a retrospective study of women with chronic hypertension who delivered at Thomas Jefferson University Hospital from January 2014 through June 2018. This cohort of women with chronic hypertension was divided into 2 groups, before and after the American College of Obstetricians and Gynecologists recommendation published in September 2016. Daily 81 mg of aspirin was initiated between 12 and 16 weeks. We excluded multiple gestations and incomplete records. The primary outcome was incidence of superimposed preeclampsia, and secondary outcomes were incidence of superimposed preeclampsia with or without severe features, small for gestational age, and preterm birth <37 weeks. Subgroup analysis based on risk stratification was evaluated in women with chronic hypertension requiring antihypertensive medication, history of preeclampsia, and pregestational diabetes.

RESULTS

We identified 457 pregnant women with chronic hypertension, 203 in the post-American College of Obstetricians and Gynecologists group and 254 in the pre-American College of Obstetricians and Gynecologists group. Aspirin 81 mg was offered to 142 (70%) in the post-American College of Obstetricians and Gynecologists group and 18 (7.0%) in the pre-American College of Obstetricians and Gynecologists group. Maternal demographics were not significantly different. The overall incidence of superimposed preeclampsia was not significantly different: 87 (34.3%) vs 72 (35.5%), P=.79, in the pre- and post-American College of Obstetricians and Gynecologists guideline groups, respectively. Superimposed preeclampsia with severe features significantly increased: 32 (12.6%) vs 9 (4.4%), P<.01, whereas superimposed preeclampsia without severe features significantly decreased: 55 (21.7%) vs 63 (31.0%), P=.03. There were no significant differences in small for gestational age neonates or preterm birth <37 weeks incidences between groups. There were no significant differences in the subgroup analysis based on the severity of chronic hypertension requiring antihypertensive medication, history of preeclampsia, or pregestational diabetes.

CONCLUSION

After the adoption of the American College of Obstetricians and Gynecologists guidelines in 70% of the cohort, superimposed preeclampsia, small for gestational age, and preterm birth were not significantly decreased after implementation of aspirin 81 mg initiated between 12 and 16 weeks of gestation.

Evidence-based labor management: induction of labor (part 2)

Induction of labor is indicated for many obstetrical, maternal, and fetal indications. Induction can be offered for pregnancy at 39 weeks' gestation. No prediction method is considered sensitive or specific enough to determine the incidence of cesarean delivery after induction. A combination of 60- to 80-mL single-balloon Foley catheter for 12 hours and either 25-μg oral misoprostol initially, followed by 25 μg every 2-4 hours, or 50 μg every 4-6 hours (if no more than 3 contractions per 10 minutes or previous uterine surgery), or oxytocin infusion should be recommended for induction of labor. Adding membrane stripping at the beginning of induction should be considered. Once 5-6 cm of cervical dilation is achieved during the induction of labor, consideration can be given to discontinue oxytocin infusion if in use at that time and adequate contractions are present. Induction with oxytocin immediately (as soon as feasible) or up to 12 hours of term prelabor rupture of membranes if labor is not evident is recommended. Outpatient Foley ripening can be considered for low-risk women. Cesarean delivery should not be performed before 15 hours of oxytocin infusion and amniotomy if feasible and ideally after 18-24 hours of oxytocin infusion.

Performance of a proteomic preterm delivery predictor in a large independent prospective cohort

BACKGROUND

Preterm birth remains a common and devastating complication of pregnancy. There remains a need for effective and accurate screening methods for preterm birth. Using a proteomic approach, we previously discovered and validated (Proteomic Assessment of Preterm Risk study, NCT01371019) a preterm birth predictor comprising a ratio of insulin-like growth factor-binding protein 4 to sex hormone-binding globulin.

OBJECTIVE

To determine the performance of the ratio of insulin-like growth factor-binding protein 4 to sex hormone-binding globulin to predict both spontaneous and medically indicated very preterm births, in an independent cohort distinct from the one in which it was developed.

STUDY DESIGN

This was a prospective observational study (Multicenter Assessment of a Spontaneous Preterm Birth Risk Predictor, NCT02787213) at 18 sites in the United States. Women had blood drawn at 17^0/7 to 21^6/7 weeks' gestation. For confirmation, we planned to analyze a randomly selected subgroup of women having blood drawn between 19^1/7 and 20^6/7 weeks' gestation, with the results of the remaining study participants blinded for future validation studies. Serum from participants was analyzed by mass spectrometry. Neonatal morbidity and mortality were analyzed using a composite score by a method from the PREGNANT trial (NCT00615550, Hassan et al). Scores of 0-3 reflect increasing numbers of morbidities or length of neonatal intensive care unit stay, and 4 represents perinatal mortality.

RESULTS

A total of 5011 women were enrolled, with 847 included in this planned substudy analysis. There were 9 preterm birth cases at <32^0/7 weeks' gestation and 838 noncases at ≥32^0/7 weeks' gestation; 21 of 847 infants had neonatal composite morbidity and mortality index scores of ≥3, and 4 of 21 had a score of 4. The ratio of insulin-like growth factor-binding protein 4 to sex hormone-binding globulin ratio was substantially higher in both preterm births at <32^0/7 weeks' gestation and there were more severe neonatal outcomes. The ratio of insulin-like growth factor-binding protein 4 to sex hormone-binding globulin ratio was significantly predictive of birth at <32^0/7 weeks' gestation (area under the receiver operating characteristic curve, 0.71; 95% confidence interval, 0.55-0.87; P=.016). Stratification by body mass index, optimized in the previous validation study (22<body mass index≤37 kg/m²), resulted in an area under the receiver operating characteristic curve of 0.76 (95% confidence interval, 0.59-0.93; P=.023). The ratio of insulin-like growth factor-binding protein 4 to sex hormone-binding globulin ratio predicted neonatal outcomes with respective area under the receiver operating characteristic curve of 0.67 (95% confidence interval, 0.57-0.77; P=.005) and 0.78 (95% confidence interval, 0.63-0.93; P=.026) for neonatal composite morbidity and mortality scores of ≥3 or 4. In addition, the ratio of insulin-like growth factor-binding protein 4 to sex hormone binding globulin significantly stratified neonates with increased length of hospital stay (log rank P=.023).

CONCLUSION

We confirmed in an independent cohort the ratio of insulin-like growth factor-binding protein 4 to sex hormone-binding globulin ratio as a predictor of very preterm birth, with additional prediction of increased length of neonatal hospital stay and increased severity of adverse neonatal outcomes. Potential uses of the ratio of insulin-like growth factor-binding protein 4 to sex hormone-binding globulin predictor may be to risk stratify patients for implementation of preterm birth preventive strategies and direct patients to appropriate levels of care.

Azithromycin vs erythromycin for the management of preterm premature rupture of membranes

BACKGROUND

Preterm premature rupture of membranes complicates 2-3% of pregnancies. Many institutions have advocated for the use of azithromycin instead of erythromycin. This is secondary to national shortages of erythromycin, ease of administration, better side effect profile, and decreased cost of azithromycin as compared with erythromycin.

OBJECTIVE

The objective of the study was to evaluate whether there are differences in the latency from preterm premature rupture of membranes to delivery in patients treated with different dosing regimens of azithromycin vs erythromycin.

STUDY DESIGN

This is a multicenter, retrospective cohort of women with singleton pregnancies with confirmed rupture of membranes between 23⁰ and 33⁶ weeks from January 2010 to June 2015. Patients were excluded if there was a contraindication to expectant management of preterm premature rupture of membranes. Patients received 1 of 4 antibiotic regimens: (1) azithromycin 1000 mg per os once (azithromycin 1 day group); (2) azithromycin 500 mg per os once, followed by azithromycin 250 mg per os daily for 4 days (azithromycin 5 day group); (3) azithromycin 500 mg intravenously for 2 days, followed by azithromycin 500 mg per os daily for 5 days (azithromycin 7 day group); or (4) erythromycin intravenously for 2 days followed by erythromycin per os for 5 days (erythromycin group). The choice of macrolide was based on institutional policy and/or availability of antibiotics at the time of admission. In addition, all patients received ampicillin intravenously for 2 days followed by amoxicillin per os for 5 days. Primary outcome was latency from diagnosis of rupture of membranes to delivery. Secondary outcomes included clinical and histopathological chorioamnionitis and neonatal outcomes.

RESULTS

Four hundred fifty-three patients who met inclusion criteria were identified. Seventy-eight patients received azithromycin for 1 day, 191 patients received azithromycin for 5 days, 52 patients received azithromycin for 7 days, and 132 patients received erythromycin. Women who received the 5 day regimen were younger and less likely to be non-African American, have hypertension, have sexually transmitted infection, or experienced substance abuse. There was no statistical difference in median latency time of azithromycin 1 day (4.9 days, 95% confidence interval, 3.3-6.4), azithromycin 5 days (5.0, 95% confidence interval, 3.9-6.1), or azithromycin 7 days (4.9 days, 95% confidence interval, 2.8-7.0) when compared with erythromycin (5.1 days, 95% confidence interval, 3.9-6.4) after adjusting for demographic variables (P = .99). Clinical chorioamnionitis was not different between groups in the adjusted model. Respiratory distress syndrome was increased in the azithromycin 5 day group vs azithromycin 1 day vs erythromycin (44% vs. 29% and 29%, P = .005, respectively).

CONCLUSION

There was no difference in latency to delivery, incidence of chorioamnionitis, or neonatal outcomes when comparing different dosing regimens of the azithromycin with erythromycin, with the exception of respiratory distress syndrome being more common in the 5 day azithromycin group. Azithromycin could be considered as an alternative to erythromycin in the expectant management of preterm premature rupture of membranes if erythromycin is unavailable or contraindicated. There appears to be no additional benefit to an extended course of azithromycin beyond the single-day dosing, but final recommendations on dosing strategies should rely on clinical trials.

Blown out of proportion? Induction Foley balloon ruptures associated with overinflation

BACKGROUND

Larger volume Foley catheters are occasionally used for labor induction. In some instances the balloon is overinflated to obtain this volume. Neither the risk or rate of rupture are known for this practice.

OBJECTIVE

The purpose of this study was to evaluate the use of overinflated Foley catheter balloons and the rate of rupture in prospective trials and to describe rupture events in our institutions.

STUDY DESIGN

Clinical trials and prospective cohorts were identified through a search of MEDLINE from 2000 through May 1, 2017; prospective studies were examined for the use of overinflated Foley catheters. Reports of overinflated balloons were then reviewed in detail to determine if rupture occurred and to record any reported maternal, neonatal, or gynecologic outcomes. Internal reports to the Obstetric Safety Report System were used to describe the local cases at our institutions.

RESULTS

We reviewed 296 abstracts. Seventeen prospective cohorts or randomized trials used larger balloon volumes (≥50 mL), of which 12 abstracts confirmed routine overinflation of the balloon. Within these studies, 19 patients who underwent cervical ripening with overinflated Foley catheters experienced balloon rupture during use. The incidence of rupture in these studies was 0.9%. No adverse maternal or fetal effects were noted. Internal safety reporting yielded an additional case. One gynecologic case was identified internally. The patient had an overinflated Foley catheter balloon used to tamponade excessive uterine bleeding after uterine evacuation. Balloon rupture was noted, and hysteroscopy was needed to remove fragments of the balloon.

CONCLUSION

Overinflation of Foley catheter balloons in obstetric and gynecologic applications may cause rupture. Because of possible underreporting, the extent of complications that may result from balloon rupture is unknown.

Increased single-balloon Foley catheter volume for induction of labor and time to delivery: a systematic review and meta-analysis

INTRODUCTION

Induction of labor is a common intervention. The objective was to investigate whether larger Foley catheter volumes for labor induction decrease the total time from induction to delivery.

MATERIAL AND METHODS

Randomized controlled trials comparing larger single-balloon volumes (60-80 mL) during Foley catheter cervical ripening with usual volume (30 mL) in women undergoing labor induction were identified by searching electronic databases (MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE, Scielo and the Cochrane Central Register of Controlled Trials) from inception through 2017. The primary outcome was mean time from induction to delivery in hours. Secondary outcomes included time from induction to vaginal delivery, delivery within 24 h, time to Foley expulsion, cesarean section, chorioamnionitis, epidural use, hemorrhage, meconium staining, and neonatal intensive care unit admission. Meta-analysis was performed using the random effects model of DerSimonian and Laird (PROSPERO CRD42017058885).

RESULTS

Seven randomized controlled trials including 1432 singleton gestations were included in the systematic review. Women randomized to larger volumes of balloon had a significantly shorter time from induction to delivery (mean difference 1.97 h, 95% CI -3.88 to -0.06). There was no difference in cesarean section between groups (16 vs. 18%, relative risk 0.84, 95% CI 0.6-1.17). A larger balloon volume was associated with a nonsignificant decrease in time from induction to delivery in multiparous (mean difference 2.67 h, 95% CI -6.1 to 0.76) and nulliparous women (mean difference 1.82 h, 95% CI -4.16 to 0.53).

CONCLUSION

Balloon volumes larger than 30 mL during Foley catheter induction reduce total time to delivery by approximately 2 h.

Why the United States preterm birth rate is declining

The preterm birth rate in the United States declined to 11.4% in 2013, the lowest level since 1997. Although the United States has one of the highest preterm birth rates in the developed world, we are improving this outcome and therefore improving the lives of thousands of infants. Demographic changes that may be responsible include a reduced teenage birth rate and fewer higher-order multiple births. Additionally, a public policy shift to prevent nonmedically indicated births at <39 weeks' gestation and smoking bans in several states have been associated with the reduced rate of preterm births. Last, interventions such as 17 hydroxyprogesterone caproate, vaginal progesterone, and the use of cerclage in selected populations probably are contributing to the reduction in preterm deliveries. However, a large portion of these births could still be prevented with greater access and implementation of our current interventions, the reduction of modifiable risk factors for preterm birth, and expanded reporting of outcomes and risk factors to facilitate research for both prevention and treatment.