Latency Period after Preterm Premature Rupture of Membranes: Singletons versus Twins

Impact of cannula diameter on pregnancy outcomes after minimally invasive fetal laser surgery in the treatment of twin-to-twin transfusion syndrome: A systematic review and meta-analysis

INTRODUCTION

Preterm prelabor rupture of membranes (PPROM) remains a major complication of fetal laser surgery in the treatment of twin-to-twin transfusion syndrome (TTTS). The aim of the study was to determine the impact of cannula size on pregnancy outcomes, with a particular focus on PPROM.

MATERIAL AND METHODS

The protocol was developed and registered in the PROSPERO database under registration number CRD42022333630. The PubMed, Web of Science, and EMBASE databases were searched electronically on May 18, 2022, and updated on March 2, 2023, utilizing a combination of the relevant MeSH terms, keywords, and word variants for "TTTS" and "laser". Randomized controlled trials, prospective and retrospective cohorts, case-control studies, and case reports/series with more than five participants were considered eligible for inclusion. Studies reporting the cannula diameter and PPROM rate after laser surgery in the treatment of monochorionic pregnancies affected by TTTS between 16- and 26 weeks' gestation were included. Data was extracted independently, and when appropriate, a random-effects meta-analysis was undertaken to calculate pooled estimates and their confidence intervals. Heterogeneity in the effect estimates of the individual studies was calculated using the I2 statistic. The primary outcome was PPROM rate. Secondary outcomes were survival rate, preterm birth, and incomplete surgery. The quality of the included studies was assessed using a modified quality in prognosis study tool.

RESULTS

We included a total of 22 studies, consisting of 3426 patients. Only one study was scored as low quality, seven as moderate quality, and the remaining 14 as high quality. The mean PPROM rate after laser surgery treating TTTS was 22.9%, ranging from 11.6% for 9 French (Fr) to 54.0% for 12 Fr. Subsequent meta-regression for the clinically relevant PPROM rate before 34 weeks of gestation, showed increased PPROM rates for increased cannula size (p-value 0.01).

CONCLUSIONS

This systematic review confirmed PPROM as a frequent complication of fetal laser surgery, with a mean PPROM rate of 22.9%. A larger cannula diameter relates to a significant higher PPROM risk for PPROM before 34 weeks gestation. Hence, the ideal balance between optimal visualization requiring larger port diameters and shorter operation time and more complete procedures that benefit from larger diameters is crucial to reduce iatrogenic PPROM rates.

Ambulation for latency during expectant management of preterm prelabor rupture of membranes: a randomized controlled trial (AMBLE)

BACKGROUND

Individuals hospitalized with preterm prelabor rupture of membranes are often advised to limit their activity or adhere to bed rest. Some evidence suggests that greater activity is associated with longer latency and improved outcomes, but no high-quality evidence from a randomized controlled trial exists.

OBJECTIVE

This study aimed to evaluate whether encouragement to ambulate at least 2000 steps daily affects latency among individuals with preterm prelabor rupture of membranes compared with usual care.

STUDY DESIGN

This was a multisite unblinded, 2-arm randomized trial of individuals at 23 0/7 to 35 0/7 weeks of gestation undergoing inpatient expectant management of preterm prelabor rupture of membranes with planned delivery at least 7 days away. Each participant wore a Fitbit Inspire that tracked steps. The intervention arm was encouraged (verbal and Fitbit-based reminders) to reach a goal of 2000 steps per day. The usual-care arm was allowed ad libitum activity with no step goal or reminders. The primary outcome was latency (days) from randomization to delivery. Secondary analyses included composite neonatal and maternal clinical outcomes and maternal mental health survey results. Statistical analyses were conducted with an intent-to-treat approach under a Bayesian framework using neutral priors (a priori assumed 50:50 likelihood of longer latency in either arm). A total of 100 participants were required to have 80% power to demonstrate a 4-day difference in latency with 75% certainty (Bayesian probability).

RESULTS

Among 163 eligible individuals, 100 (61%) were randomized, and after loss to follow-up, 95 were analyzed. Gestational age at randomization was 29 3/7 weeks (interquartile range, 26 2/7 to 31 5/7) in the intervention arm and 27 4/7 weeks (interquartile range, 25 4/7 to 29 6/7) in the usual-care arm. Median step counts were 1690 per day in the intervention arm (interquartile range, 1031-2641) and 1338 per day in the usual-care arm (interquartile range, 784-1913). Median days of latency were 9 days in the intervention arm (interquartile range, 4-17) and 6 days in the usual-care arm (interquartile range, 2-14). The primary analysis indicated a 65% posterior probability that the intervention increased latency relative to usual care (posterior relative risk, 1.09; 95% credible interval, 0.70-1.71). The relative risk was 0.55 (95% credible interval, 0.32-0.82) for the composite neonatal adverse outcome, with 99% posterior probability of intervention benefit, and was 0.94 (95% credible interval, 0.72-1.20) for the composite maternal adverse outcome, with 70% posterior probability of intervention benefit. There was a 94% posterior probability of the intervention arm having a greater decrease in maternal stress score from baseline to before delivery compared with the usual-care arm (mean arm difference, 3.24 points [95% credible interval, -7.23 to 0.79]). Adjustment for gestational age at randomization had minimal impact on secondary outcome results.

CONCLUSION

Individuals with preterm prelabor rupture of membranes randomized to encouragement to ambulate had a longer latency to delivery and improved neonatal and mental health outcomes, with similar maternal clinical outcomes compared with usual care.

Clinical Factors and Perinatal Outcomes Associated With Short Latency Period in Twin Pregnancies With Preterm Premature Rupture of Membranes Before 34 Weeks: A Retrospective Study

Background

There is a lack of literature on short latency period (SLP) in twin pregnancies with preterm premature rupture of membranes (PPROM). Thus, the aim of this study was to identify the clinical factors and perinatal outcomes associated with SLP in twin pregnancies with PPROM and to establish a predictive model to identify SLP.

Methods

Twin pregnancies with PPROM between 24 0/7 and 33 6/7 weeks were included and a retrospective analysis was performed. Patients were divided into two groups based on the latency period after PPROM: Group 1 ≤24 h (defined as SLP) and Group 2 >24 h (defined as long latency period, LLP), the clinical factors and perinatal outcomes were compared between the two groups. Binary logistic regression and receiver operating characteristic curve analyses were used to identify the independent clinical factors associated with latency period after PPROM and assess the predictive accuracy for SLP.

Results

98 and 92 pregnant women had short and long latency period, respectively. Prolonged latency significantly increased the occurrence of chorioamnionitis. Neonatal outcomes were not affected by latency duration after PPROM. Binary regression analysis revealed that higher gestational age (GA) at PPROM (P = 0.038), presence of uterine contractions (P < 0.001), Bishop score > 4 (P = 0.030), serum procalcitonin levels ≥0.05 ng/mL upon admission, and absence of use of tocolytic agents (P < 0.001) were significant independent predictors of a SLP. A predictive model developed using these predictors had an area under the curve (AUC) of 0.838, and the presence of uterine contractions alone had an AUC of = 0.711.

Conclusion

Uterine contraction was the most important prognosticator for a SLP. A latency period of >24 h was associated with chorioamnionitis, but adverse neonatal outcomes were not observed.

Perinatal outcomes of twin pregnancies with preterm premature rupture of the membranes at 24-34 weeks' gestation

To describe the perinatal outcomes of twin pregnancies with preterm premature rupture of membranes (PPROM) before 34 weeks’ gestation and identify factors associated with discharge without severe or moderate-severe neonatal morbidity. This study was conducted as a retrospective analysis of twin pregnancies with PPROM occurring at 24 0/7 to 33 6/7 weeks’ gestation. Perinatal outcomes were assessed by gestational age (GA) at PPROM and compared between PPROM and non PPROM twins. Factors associated with discharge without severe or moderate-severe neonatal morbidity were identified using logistic regression analysis. Of the 180 pregnancies (360 foetuses), only 17 (9.4%) women remained pregnant 7 days after PPROM. There were 10 (2.8%) cases of prenatal or neonatal death; 303 (84.2%) and 177 (49.2%) neonates were discharged without severe or moderate-severe morbidity, respectively. As GA at PPROM increased, the adverse obstetric and neonatal outcomes decreased, especially after 32 weeks. There was no significant difference in general neonatal outcomes between PPROM and non PPROM twins. The GA at PPROM and latency period were both significantly associated with discharge without severe or moderate-severe neonatal morbidity. Pregnancy complications and 5-min Apgar score < 7 increased severe neonatal morbidity. As GA at PPROM increased, the risk of adverse perinatal outcomes decreased. GA at PPROM and latency period were significantly associated with discharge without severe or moderate-severe neonatal morbidity.