Management of premature rupture of membranes at term: the need to correct a recurring mistake in articles, chapters, and recommendations of professional organizations

Optimal timing of labor induction after prelabor rupture of membranes at term: a secondary analysis of the TERMPROM study

BACKGROUND

In the case of prelabor rupture of membranes at term, the risk for neonatal and maternal infectious morbidity increases progressively with time from prelabor rupture of membranes. Although most studies identified a benefit associated with early induction within the first 24 hours following term prelabor rupture of membranes, there is currently no precise data regarding how early should induction be scheduled.

OBJECTIVE

This study aimed to identify the optimal timing of labor induction among women with term prelabor rupture of membranes by comparing the maternal and neonatal outcomes associated with labor induction with those of expectant management at any given 1-hour interval following prelabor rupture of membranes.

STUDY DESIGN

This was a secondary analysis of data from the TERMPROM trial, an international, multicenter, randomized clinical trial on immediate delivery vs expectant management of women with prelaor rupture of membranes at term (≥37+0/7 weeks' gestation). We considered all participants as a single cohort of women with term prelabor rupture of membranes, irrespective of the original randomized study group allocation. For each given 1-hour time interval within the first 36 hours following prelabor rupture of membranes, we compared the outcomes of subjects for whom labor induction was initiated during this interval with those of subjects managed expectantly at the same time interval. The primary neonatal outcome was a composite of neonatal infection and admission to the neonatal intensive care unit. The primary maternal outcomes included maternal infection (clinical chorioamnionitis or postpartum fever) and cesarean delivery.

RESULTS

Of the 4742 subjects who met the study criteria, 2622 underwent labor induction, and 2120 experienced a spontaneous onset of labor. The rates of the neonatal composite outcome, neonatal admission to intensive care unit, and maternal infection increased progressively with time after prelabor rupture of membranes. The risk for these outcomes was lower among women who underwent induction when compared with those managed expectantly within the first 15 to 20 hours after prelabor rupture of membranes without affecting the risk for cesarean delivery. In addition, women who underwent labor induction within the first 30 to 36 hours had a shorter prelabor rupture of membranes to delivery time and a shorter total maternal hospital stay when compared with those managed expectantly at the same time interval. Among women managed expectantly, less than two-thirds (64%; 1365/2120) experienced a spontaneous onset of labor within the first 24 hours following prelabor rupture of membranes.

CONCLUSION

These findings suggest that immediate labor induction seems to be the optimal management strategy to minimize neonatal and maternal morbidity in the setting of prelabor rupture of membranes at term gestations. In cases for which immediate induction is not feasible, labor induction remains the preferred option over expectant management if performed within the first 15 to 20 hours after prelabor rupture of membranes.

Perinatal maternal characteristics predict a high risk of neonatal asphyxia: A multi-center retrospective cohort study in China

Objective

This study aimed to identify various perinatal maternal characteristics that contributed to neonatal asphyxia (NA) in term and late-preterm newborns based on the data obtained from a Chinese birth registry cohort and to establish an effective model for predicting a high risk of asphyxia.

Method

We retrospectively reviewed and analyzed the birth database from July 1, 2016, to June 30, 2017, in the main economically developed regions of China. Asphyxia was defined as an Apgar score <7 at 5 min post-delivery with umbilical cord arterial blood pH < 7.2 in the infant born after 34weeks. We compared the perinatal maternal characteristics of the newborns who developed asphyxia (NA group, n = 1,152) and those who did not (no NA group, n = 86,393). Candidate predictors of NA were analyzed using multivariable logistic regression. Subsequently, a prediction model was developed and validated by an independent test group.

Result

Of the maternal characteristics, duration of PROM ≥ 48 h, a gestational week at birth <37, prolonged duration of labor, hypertensive disorder, nuchal cord, and birth weight <2,500 or ≥4,000 g, abnormal fetal heart rate, meconium-stained amniotic fluid, and placenta previa were included in the predicting model, which presented a good performance in external validation (c-statistic of 0.731).

Conclusion

Our model relied heavily on clinical predictors that may be determined before or during birth, and pregnant women at high risk of NA might be recognized earlier in pregnancy and childbirth using this methodology, allowing them to avoid being neglected and delayed. Future studies should be conducted to assess its usefulness.

Early-term birth and its association with universal two-child policy: a national cross-sectional study in China

OBJECTIVE

To describe the epidemiology of early-term birth (ETB) at the national level in China, and explore the association and mediating factors between ETB and policy between universal two-child policy and ETB, so as to explain the potential reason for such a relationship and provide evidence for future ETB interventions in the era of the new birth control policy.

DESIGN

Cross-sectional study.

PARTICIPANTS

The cross-sectional study used data from China Labour and Delivery Survey between 2015 and 2016. A total of 75 132 survey data collected from 89 hospitals in 25 provinces were included in the analysis. We further explored the association between the universal two-child policy and ETB.

RESULTS

The weighted incidence of ETB was 30.1 per 100 all births (95% CI 30.06% to 30.14%) or 29.88 per 100 live births (95% CI 29.97% to 30.05%) between 2015 and 2016 in China. There was an association between the universal two-child policy and ETB (relative risk, RR 1.19, 95% CI 1.15 to 1.23), which was not mediated by maternal age (RR 1.17, 95% CI 1.13 to 1.22), previous uterine scars (RR 1.18, 95% CI 1.14 to 1.22), parity (RR 1.19, 95% CI 1.15 to 1.24) and other measured conditions (each p<0.05). Stratified analysis showed that the association between universal two-child policy and ETB were the strongest in multiparous young women or women without previous uterine scars (each p<0.05), and disappeared in all women of advanced maternal age (each p>0.05).

CONCLUSION

The incidence of ETB was high in China when compared with most of reported countries, and there might be a link between two-child policy and ETB. Obstetric practice such as selective induced labour and caesarean section should be revised with ETB risks in mind, when ETB is more likely to happen under the universal two-child policy. Preventing ETB should not be neglected in multiparous young women or those without previous uterine scars under the new policy.

Dynamic measurement of amnion thickness during loading by speckle pattern interferometry

INTRODUCTION

In previous studies on the mechanical parameters of amnions (AM), there is a limitation due to the lack of an accurate thickness measurement, which is an important parameter for determining AM-specific mechanical properties. As a bottleneck, the characterization of the basic mechanical properties of AM are greatly restricted, even with the proposal of fracture criteria.

METHOD

First, the initial thickness of the AM is estimated by the interpolated-volume-area method. Second, through combinations of our self-developed mini-biaxial tensile device with speckle pattern interferometry, this is the first time that researchers can accurately obtain the AM thickness at each transient moment in the process of loading.

RESULTS

Based on the experimental results, an accurate stress-strain curve could be obtained. Two important mechanical parameters-the fracture energy density and amnion rupture modulus-could be extracted as 0.184±0.036MPa and 108.57±17.32MPa, respectively. The fracture energy density and amnion rupture modulus provide objective criteria and a scientific basis for the evaluation of AM rupture.

DISCUSSION

The tensile stress-strain curve of a normal human amnion shows a distinct J-shape. This proves that the experimental results are basically reliable. Both important parameters --the fracture energy density and amnion rupture modulus, can be calculated from the stress-strain curve. Extracting these two parameters is critical for the evaluation and prediction of ROM, PROM and PPROM.

Trial of labor after cesarean (TOLAC) in women with premature rupture of membranes. J Matern Fetal Neonatal Med 2019;33:2976-2982. [PMID: 30652525 DOI: 10.1080/14767058.2019.1566312]

Introduction: The aim of this study was to assess the success rate of a trial of labor after a previous cesarean section (TOLAC) in the settings of premature rupture of membranes (PROM) and to compare conservative management with spontaneous labor and induction of labor.Methods: This was a retrospective cohort study conducted in a single tertiary care center between January 2011 and March 2017. Women with singleton pregnancy and a previous cesarean section (CS) who presented with PROM and underwent TOLAC were included. Outcomes and rate of successful vaginal delivery after induction of labor were compared to conservative treatment and spontaneous labor.Results: Among 830 women who met the inclusion criteria, 723 (87.1%) had a spontaneous onset of labor following PROM and 107 (12.9%) had an induction of labor. The rate of successful TOLAC was similar between the groups (75.7 vs. 81.6%, respectively, p = .22). However, induction of labor was associated with an increased risk for uterine rupture (1.87 vs. 0.96%, p < .001), operative complications (6.7 vs. 2.3%, p < .001), and composite maternal postpartum complications (21.4 vs. 10.7%, respectively, p = .014) compared to conservative management with spontaneous initiation of labor. There was no difference in neonatal outcome between the groups.Conclusion: Induction of labor following PROM in women with a previous CS is associated with high successful vaginal delivery rate. However, the risk for uterine rupture and operative and maternal complications is significantly increased compared to spontaneous initiation of labor.