Risk factors for preterm premature rupture of fetal membranes: a multicenter case-control study

The Role of Cerclage in Subsequent Pregnancy following Previable Prelabor Rupture of Membranes

OBJECTIVE

This study aimed to ascertain the outcomes associated with a cervical cerclage among individuals with a history of previable prelabor rupture of membranes (PROM).

STUDY DESIGN

This study was a retrospective cohort study conducted at a single tertiary center between 2011 and 2021. We included individuals with a history of previable (before 24 weeks) PROM and the subsequent viable pregnancy. Women with multifetal gestation, preterm birth (PTB) or cerclage in previous gestation, or abdominal cerclage after trachelectomy were excluded. Primary outcome was PTB rate (delivery <37 weeks). Recurrence of preterm PROM and adverse composite maternal and neonatal outcomes (CMO and CNO) were evaluated as secondary outcomes. CMO included any of the following: suspected chorioamnionitis, endometritis, red blood cell transfusion, uterine rupture, unplanned hysterectomy, or death. CNO included any of the following: previable PTB (<24 weeks of gestation), bronchopulmonary dysplasia, grade 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, mechanical ventilation, seizures, hypoxic ischemic encephalopathy, or death.

RESULTS

During the study period, 118 individuals had a history of previable PROM and a documented subsequent pregnancy, out of which 74 (62.7%) met inclusion criteria. Nineteen (25.7%) of eligible individuals underwent a cerclage for prior previable PROM and were compared with controls (n = 55, 74.3%). Women who underwent a cerclage had higher rates of PTB < 37 weeks (63.2 vs. 10.9%, p < 0.001; odds ratio [OR]: 14.00, 95% confidence interval [CI]: 3.97-49.35) and < 34 weeks (21.1 vs. 3.6%, p = 0.03; OR: 7.07, 95% CI: 1.18-42.39) compared with those without cerclage. Furthermore, recurrent preterm PROM and previable PTB rates were higher among patients who underwent cerclage. The survival curve further indicated that individuals with cerclage delivered earlier. CMO and CNO rates were similar in those with and without cerclage.

CONCLUSION

Cerclage placement in individuals with prior previable PROM was associated with higher rates of recurrent preterm PROM and PTB.

KEY POINTS

· The management of individuals in a subsequent pregnancy following previable PROM is a conundrum.. · Cerclage following previable PROM is associated with higher rates of recurrent preterm PROM and PTB.. · Composite maternal and neonatal outcome rates were similar in those with and without cerclage..

Preterm Prelabor Rupture of Membranes Linked to Vaginal Bacteriome of Pregnant Females in the Early Second Trimester: a Case-Cohort Design

Preterm prelabor rupture of membranes (PPROM) is a major cause of spontaneous preterm birth (sPTB), one of the greatest challenges facing obstetrics with complicated pathogenesis. This case-cohort study investigated the association between vaginal bacteriome of singleton pregnant females in the early second trimester and PPROM. The study included 35,255 and 180 pregnant females with PPROM as cases and term-birth without prelabor rupture of membranes (TWPROM) and term prelabor rupture of membranes (TPROM) pregnant females as controls, respectively. Using 16S rRNA sequencing, the vaginal microbiome traits were analyzed. Females with PPROM had higher alpha and beta diversity (P < 0.05) than TWPROM and TPROM. The presence of L. mulieris was associated with a decreased risk of PPROM (adjusted odds ratio [aOR] = 0.35; 95% confidence interval [CI]: 0.17-0.72) compared with TWPROM. Meanwhile, the presence of Megasphaera genus (aOR = 2.27; 95% CI: 1.09-4.70), Faecalibacterium genus (aOR = 3.29; 95% CI: 1.52-7.13), Bifidobacterium genus (aOR = 3.26; 95% CI: 1.47-7.24), Xanthomonadales genus (aOR = 2.76; 95% CI: 1.27-6.01), Gammaproteobacteria class (aOR = 2.36; 95% CI: 1.09-5.14), and Alphaproteobacteria class (aOR = 2.45; 95% CI: 1.14-5.26) was associated with an increased risk of PPROM compared with TWPROM. Our results indicated that the risk of PPROM can decrease with vaginal L. mulieris but increase with high alpha or beta diversity, and several vaginal bacteria in pregnant females may be involved in the occurrence of PPROM.

The abundances of LTF and SOD2 in amniotic fluid are potential biomarkers of gestational age and preterm birth

Neonates who are born preterm (PT) are usually characterized by immature physiological development, and preterm birth (PTB) is the leading cause of neonatal morbidity and mortality if intensive medical care is not available to PTB neonates. Early prediction of a PTB enables medical personnel to make preparations in advance, protecting the neonate from the subsequent health risks. Therefore, many studies have worked on identifying invasive or noninvasive PT biomarkers. In this study, we collected amniocentesis-derived (at the second trimester of gestation) amniotic fluid (AF) samples. At delivery, AF samples were classified into PTB or full-term birth (FTB). We first applied protein mass spectrometry technology to globally screen AF proteins, followed by specific protein validation with ELISA. We identified four protein biomarkers of PTB, including lactotransferrin (LTF), glutathione-disulfide reductase (GSR), myeloperoxidase (MPO) and superoxide dismutase 2 (SOD2). Further analyses demonstrated that their abundances were negatively correlated with neonatal weight and gestational age. In addition, by mimicking survival rate analysis widely used in tumor biology, we found that LTF and SOD2 were prognostic factors of gestational age, with higher levels denoting shorter gestational age. Finally, using the abundances of the four protein biomarkers, we developed a prediction model of PTB with an auROC value of 0.935 (sensitivity = 0.94, specificity = 0.89, p value = 0.0001). This study demonstrated that the abundances of specific proteins in amniotic fluid were not only the prognostic factors of gestational age but also the predictive biomarkers of PTB. These four AF proteins enable identification of PTB early in the second trimester of gestation, facilitating medical intervention to be applied in advance.

Obstetric complications and outcomes of singleton pregnancy with previous caesarean section according to maternal age

INTRODUCTION

To delineate obstetric complications and neonatal outcomes by maternal age in singleton pregnancies with previous caesarean section (CS).

METHODS

A retrospective study involved 7715 singleton gestations with previous CS was conducted in a single centre. Statistical methods were used to describe and analyse the incidence of various complications and adverse outcomes classified by maternal ages. After selecting the reference group (30-34 years), multivariate logistic-binomial regression model was used to investigate the outcomes using SPSS.

RESULTS

From 2013 to 2017, the proportion of advanced maternal age (AMA, ≥35 years) women with a history of CS increased yearly, especially in the 35-39 years age group. AMA women accounted for 39.4% of all pregnancies and has a high incidence of in vitro fertilization(IVF), progesterone therapy in early pregnancy, pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), placenta previa, premature rupture of membranes (PROM) and postpartum haemorrhage (PPH). Compared to the 30-34 years group, the risks of PIH, GDM, placenta previa, PROM and PPH increased in AMA pregnancies. Very advanced age (≥40 years) may be associated with placenta accreta while young mothers (20-24 years) have a higher prevalence of premature birth. Vaginal bleeding during pregnancy is a risk factor for maternal complications, maternal and neonatal morbidity.

DISCUSSION

AMA is associated with increased risk of PIH, GDM, placenta previa, PROM and PPH. Vaginal bleeding may be a predictor during pregnancy.

The Effect of Von Willebrand Disease on Pregnancy, Delivery, and Postpartum Period: A Retrospective Observational Study

Background and Objectives Several reports indicate that women with von Willebrand disease (VWD) are at an increased risk of bleeding and other complications during pregnancy and childbirth. The aim of this study was to investigate the effect of VWD on the course of pregnancy, childbirth, and the postpartum period. Materials and Methods This was a retrospective study that compared many variables between women with VWD (n = 26) and women without VWD (n = 297,111) who gave birth between 2002 and 2016 in Slovenia. Data were obtained from the Slovenian National Perinatal Information System. Results Women with VWD were not more likely to have a miscarriage, vaginal bleeding during pregnancy, anemia, intrauterine growth restriction, or imminent premature labor. However, women with VWD were more likely to experience childbirth trauma-related bleeding (OR, 10.7; 95% CI: 1.4, 78.9), primary postpartum hemorrhage (OR, 3.7; 95% CI: 0.9, 15.8), and require blood transfusion after childbirth (OR, 16.3; 95% CI: 2.2, 120.3). No cases of stillbirth or early neonatal death were observed in women with VWD. Conclusion Although women with VWD did not demonstrate an increased risk of vaginal bleeding during pregnancy or poor fetal outcomes, they had a higher risk of primary postpartum hemorrhage and requiring blood transfusion.

Pregnancy Outcomes Associated With Use of Tobacco and Marijuana

Tobacco and marijuana are the most common drugs of abuse among pregnant women. Cigarettes have been extensively studied and increase the risk of miscarriage, preterm birth, premature rupture of membranes, placental dysfunction, low birth rate, stillbirth, and infant mortality. There are sparse data on the specific effects of electronic cigarettes and smokeless tobacco in pregnancy. Literature on marijuana in pregnancy is limited by confounding, bias, and the retrospective nature of studies that do not capture contemporary trends in use. However, several studies suggest an association between marijuana and fetal growth restriction, low birth weight, and neurodevelopmental differences in offspring.

Expression of the Costimulatory Molecule B7-H4 in the Decidua and Placental Tissues in Patients with Placental Abruption

B7 homolog 4 protein (B7-H4), a member of the B7 family, is a immunomodulatory membrane protein. The aim of the study was to evaluate the expression of this protein in the decidua and placental tissues in case of placental abruption (PA) compared to cases of retained placental tissue (RPT) and controls. Tissue samples were obtained from 47 patients with PA, 60 patients with RPT, and 41 healthy controls. The samples were stained for B7-H4 expression, analyzed by an expert pathologist, and a semi-quantitative scale was applied. A statistical analysis revealed that the expression of B7-H4 was significantly higher in the decidua in PA samples compared to samples from patients with RPT (p-value < 0.001) and healthy controls (p-value < 0.001). The expression of B7-H4 in the placental chorionic villus was significantly higher in PA samples in relation to samples from healthy controls (p-value < 0.001) but not in relation to RPT samples (p-value = 0.0853). This finding suggests that B7-H4 might play an important role in mechanisms restoring reproductive tract homeostasis. Further research is necessary in regard to the role of B7-H4 in PA.

Preterm Premature Ruptures of Membrane and Factors Associated among Pregnant Women Admitted in Wolkite Comprehensive Specialized Hospital, Gurage Zone, Southern Ethiopia

Introduction

Preterm premature rupture of membrane is the rupture of membrane before 37 weeks of gestational age. It complicates approximately 3 percent of pregnancies and leads to one-third of preterm births. It increases the risk of prematurity and leads to several other perinatal and neonatal complications, including the risk of fetal death. Although the prevalence and associated factors of preterm premature rupture of the membrane were well studied in high-income countries, there is a scarcity of evidence in Ethiopia, particularly in the study area.

Method

A hospital-based cross-sectional study design was conducted from 1st June to 30th June 2021 in Wolkite comprehensive specialized hospital. One hundred ninety nine (199) pregnant women were included as study subjects using a systematic random sampling technique. Data were collected using a structured interviewer-administered questionnaire. It carried out descriptive statistical analysis and statistical tests like the odds ratio. Both bivariate and multivariate logistic regression analyses were conducted. Statistically, significant tests were declared at a level of p value < 0.05.

Result

The magnitude of preterm premature rupture membrane is 6.6%. Having gestational diabetes mellitus (AOR = 5.99 (95% CI: 1.01, 32.97) and previous history of abortion (AOR = 5.31 (95% CI: 1.06, 26.69) were found to be significantly associated with preterm premature rupture of membrane.

Conclusion

Having gestational diabetes mellitus and having a previous history of abortion were significantly associated with preterm premature rupture of membrane.

Identifying the associated factors with onset of preterm PROM compared with term PROM - A retrospective cross-sectional study

OBJECTIVE

To determine the risk factors associated with the preterm premature rupture of membranes (p-PROM).

MATERIALS AND METHODS

This retrospective cross-sectional study assessed 110 p-PROM cases from among 6642 deliveries at a Japanese perinatal medical center, from June 2016 to September 2018. The control group comprised 220 term PROM (t-PROM) cases. We excluded cases with artificial PROM or rupture of membranes after labor, those with multiple pregnancies, those with p-PROM at 36 weeks and those with t-PROM at 37 weeks. In order to compare p-PROM with t-PROM, univariate and multivariate analysis were performed using several clinical factors at the time of PROM onset.

RESULTS

The p-PROM group included 110 cases with 14-35 weeks PROM, and the t-PROM group included 220 cases with 38-41 weeks PROM. Eleven factors were identified as significant factors on the univariate analysis. A history of cervical conization (OR 37.5, 95% CI: 2.31-607.1), cervical length <25 mm at 28 weeks (OR 9.31, 95% CI: 1.76-49.3), negative Lactobacillus (OR 4.01, 95% CI: 1.18-13.7), and bleeding during the second trimester (OR 3.35, 95% CI: 1.18-9.53) were identified as significant factors by the multivariate analysis. Based on the risk factors identified during the multivariate analysis, we divided the 330 cases in the following three groups: 0 group (n = 244), 1 group (n = 60), and 2-4 group (n = 26). The ratio of p-PROM:t-PROM was calculated and compared for each group. The ratios were 21% (0 group), 57% (1 group), and 100% (2-4 group), indicating statistically significant differences between the groups (p < 0.001).

CONCLUSION

We found that the following four factors were associated with p-PROM: history of cervical conization, cervical length <25 mm at 28 weeks, negative Lactobacillus, and bleeding during the second trimester. Our results suggest that we can identify patients who are at increased risk for p-PROM, based on these factors. Further research is necessary to determine the optimal treatment approach for these patients to prevent p-PROM.

Chlamydia trachomatis, Neisseria gonorrhoea, and Trichomonas vaginalis infections among pregnant women and male partners in Dutch midwifery practices: prevalence, risk factors, and perinatal outcomes

Background

Antenatal screening for HIV, syphilis and HBV has been successfully implemented in The Netherlands, but data on other STI among pregnant women or male partners are limited. Our objectives: (i) to assess the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) among pregnant women and male partners, (ii) to identify risk factors for these STI during pregnancy, and (iii) to identify adverse perinatal outcomes (APO) associated with STI.

Methods

Cross-sectional study. Pregnant women aged ≤ 30 years (n = 548) and male partners (n = 425) were included at 30 midwifery practices during 2012–2016. Participants provided a self-collected vaginal swab (women) or urine sample (men) and completed a questionnaire. Perinatal data were derived from pregnancy cards. APO was defined as premature rupture of membranes, preterm delivery, low birthweight, stillbirth, neonatal conjunctival and respiratory infections. Data were analysed by logistic regression.

Results

STI were present in 2.4% of pregnant women (CT 1.8%, NG 0.4%, TV 0.4%), and in 2.2% of male partners (CT 2.2%, NG 0.2%, TV 0%). Of young women (≤ 20 years), 12.5% had a CT infection. Prevalent STI during pregnancy was associated with female young age (≤ 20 years vs ≥ 21 years) (adjusted OR 6.52, CI 95%: 1.11–38.33), male non-Western vs Western background (aOR 9.34, CI 2.34–37.21), and female with ≥ 2 sex partners < 12 months vs 0–1 (aOR 9.88, CI 2.08–46.91). APO was not associated with STI, but was associated with female low education (aOR 3.36, CI 1.12–10.09), complications with previous newborn (aOR 10.49, CI 3.21–34.25 vs no complications) and short duration (0–4 years) of relationship (aOR 2.75, CI 1.41–5.39 vs ≥ 5 years). Small-for-gestational-age was not associated with STI, but was associated with female low education (aOR 7.81, 2.01–30.27), female non-Western background (aOR 4.41, 1.74–11.17), and both parents smoking during pregnancy (aOR 2.94, 1.01–8.84 vs both non-smoking).

Conclusions

Prevalence of STI was low among pregnant women and male partners in midwifery practices, except for CT among young women. The study could not confirm previously observed associations between STI and APO, which is probably due to low prevalence of STI, small study sample, and presumed treatment for STI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-021-01179-8.

Antenatal screening for HIV, syphilis and HBV has been successfully implemented in The Netherlands, but data on other STI among pregnant women or male partners are limited. Our objectives were: (i) to assess the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) among pregnant women and male partners, (ii) to identify risk factors for these STI during pregnancy, and (iii) to identify adverse perinatal outcomes (APO) associated with STI.

Pregnant women aged ≤ 30 years and male partners were included at 30 midwifery practices. Women provided a vaginal swab, partners a urine sample; both completed a questionnaire. Perinatal data were derived from midwives.

STI were present in 2.4% of pregnant women (CT 1.8%, NG 0.4%, TV 0.4%), and in 2.2% of male partners (CT 2.2%, NG 0.2%, TV 0%). Of women ≤ 20 years, 12.5% had a CT infection. Prevalent STI during pregnancy was associated with female young age, male non-Western background, and female with ≥ 2 sex partners < 12 months. APO was not associated with STI, but was associated with female low education, complications with previous newborn, and short duration of the relationship. Small-for-gestational-age was not associated with STI, but was associated with female low education, female non-Western background, and both parents smoking during pregnancy.

Prevalence of STI was low among pregnant women and male partners in midwifery practices, except for CT among young women. The study could not confirm previously observed associations between STI and APO. Probably due to low prevalence of STI, small study sample, and presumed treatment for STI.

Molecular Changes on Maternal-Fetal Interface in Placental Abruption-A Systematic Review

Placental abruption is the separation of the placenta from the lining of the uterus before childbirth. It is an infrequent perinatal complication with serious after-effects and a marked risk of maternal and fetal mortality. Despite the fact that numerous placental abruption risk factors are known, the pathophysiology of this issue is multifactorial and not entirely clear. The aim of this review was to examine the current state of knowledge concerning the molecular changes on the maternal–fetal interface occurring in placental abruption. Only original research articles describing studies published in English until the 15 March 2021 were considered eligible. Reviews, book chapters, case studies, conference papers and opinions were excluded. The systematic literature search of PubMed/MEDLINE and Scopus databases identified 708 articles, 22 of which were analyzed. The available evidence indicates that the disruption of the immunological processes on the maternal–fetal interface plays a crucial role in the pathophysiology of placental abruption. The features of chronic non-infectious inflammation and augmented immunological cytotoxic response were found to be present in placental abruption samples in the reviewed studies. Various molecules participate in this process, with only a few being examined. More advanced research is needed to fully explain this complicated process.

Application of Tissue Engineering and Regenerative Medicine in Prelabor Rupture of Membranes: a Review of the Current Evidence

Preterm prelabor rupture of membranes (PPROM) is the main cause of preterm delivery, resulting in increased perinatal morbidity and mortality. Several techniques have been studied for the healing of ruptured membranes, with some success. Before new techniques using tissue/organ engineering are applied in clinical practice, these techniques must be validated in clinical trials. To address this issue, the objective of this study was to summarize the current literature on interventions to seal or heal the amniotic membranes after PPROM. An electronic search was conducted using the keywords "fetal membranes," "premature rupture," "amnion," "tissue engineering," "fibrin tissue adhesive," "regenerative medicine," "tissue adhesive," "wound healing," and "fetoscopy" through the MEDLINE, Embase, and Cochrane CENTRAL databases, with the limitation of English-language studies. Through a review of the identified studies, it was found that spontaneous healing of the fetal membrane has not been successful. Several efforts have been made to seal membranes before or after rupture using different methods, including amniopatches, collagen, tissue patches, fibrin sealant, mussel-mimetic sealant, engineered cell matrix, and immunological supplements. However, most studies have been conducted in ex vivo or in vivo settings, so the safety and applicability of these techniques to spontaneous rupture of membranes in clinical settings have not been sufficiently tested. Overall, the current evidence is limited regarding the safety and effectiveness of interventions against PPROM.

Prelabor Rupture of Membranes: ACOG Practice Bulletin, Number 217

Preterm birth occurs in approximately 10% of all births in the United States and is a major contributor to perinatal morbidity and mortality (). Prelabor rupture of membranes (PROM) that occurs preterm complicates approximately 2-3% of all pregnancies in the United States, representing a significant proportion of preterm births, whereas term PROM occurs in approximately 8% of pregnancies (). The optimal approach to assessment and treatment of women with term and preterm PROM remains challenging. Management decisions depend on gestational age and evaluation of the relative risks of delivery versus the risks (eg, infection, abruptio placentae, and umbilical cord accident) of expectant management when pregnancy is allowed to progress to a later gestational age. The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented. This Practice Bulletin is updated to include information about diagnosis of PROM, expectant management of PROM at term, and timing of delivery for patients with preterm PROM between 34 0/7 weeks of gestation and 36 6/7 weeks of gestation.

A cut-off value for systemic immune-inflammation index in the prediction of adverse neonatal outcomes in preterm premature rupture of the membranes

AIM

To determine a cut-off value for systemic immune-inflammation index (SII)(neutrophil × platelet /lymphocyte) in the prediction of adverse neonatal outcomes in preterm premature rupture of the membranes (PPROM).

METHODS

This retrospective cohort study was conducted among singleton pregnancies with PPROM. Cases were divided into two main groups: Group 1) PPROM diagnosed at 24th-28th weeks of gestation and Group 2) PPROM diagnosed at >28th-34th weeks of gestation. Thereafter, main study groups were divided into two subgroups: Subgroup A: pregnancies with favorable neonatal outcomes and Subgroup B: pregnancies with composite adverse neonatal outcomes. Subgroups were compared in terms of demographic features, clinical characteristics, laboratory test results and SII values. Furthermore, cut-off values of SII for the prediction of composite adverse neonatal outcomes were determined for two main groups. A Mann-Whitney U test was conducted to compare the median values and the chi-square test was used to compare categorical variables among the groups. Receiver operating characteristic (ROC) curves were used to assess the performance of SII value in predicting composite adverse neonatal outcomes.

RESULTS

Significant differences were observed for median platelet and SII values between the subgroups (P < 0.001 for both in group 1 and P = 0.002 and P = 0.005, respectively, in group 2). Cut-off values of 1695.14 10⁹ /L (83.3% sensitivity, 85.7% specificity) and 1430.90 × 10⁹ /L (71.4% sensitivity, 75.7% specificity) for composite adverse neonatal outcomes were determined, respectively in group 1 and 2 according to the ROC curve analysis.

CONCLUSION

SII may be used as an additional indicator for the prediction of adverse neonatal outcomes in PPROM.

A novel extended prophylactic antibiotic regimen in preterm pre-labor rupture of membranes: A randomized trial

OBJECTIVES

Prophylactic antibiotic use in preterm pre-labor rupture of membranes (PPROM) is associated with a significant reduction in intra-amniotic infection and improved neonatal outcome. However, data is insufficient to determine the optimal antibiotic regimen. Considering the rise in Escherichia coli and Klebsiella pneumonia early-onset sepsis rate and the emergence of ampicillin resistance, our aim is to compare the efficiency of two antibiotic regimens in prolonging pregnancy and reducing infectious morbidity.

DESIGN

This multicenter randomized unblinded controlled prospective trial compared two antibiotic prophylactic protocols in PPROM: ampicillin + roxithromycin vs. cefuroxime + roxithromycin in 84 women with PPROM, from 12/2015-12/2019.

RESULTS

The median latency period was significantly longer (p = 0.039) in the cefuroxime + roxithromycin group (4.63 [0.59-50.18] days) than in the ampicillin + roxithromycin group (2.3 [0.15-58.3] days). Neonatal admission to neonatal intensive care unit rate, hospitalization length, neonatal respiratory distress syndrome, neonatal fever, and need for respiratory support or mechanical ventilation, were similar between the groups. K. pneumonia cultures were significantly more frequent in the ampicillin + roxithromycin group. None of the cultures were group B Streptococcus positive.

CONCLUSIONS

To prolong latency period and reduce gram-negative early-onset sepsis, cefuroxime + roxithromycin is recommended as the first-line protocol in PPROM.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02819570.

Mechanisms of thrombin-Induced myometrial contractions: Potential targets of progesterone

Intrauterine bleeding during pregnancy is a major risk factor for preterm birth. Thrombin, the most abundant coagulation factor in blood, is associated with uterine myometrial contraction. Here, we investigated the molecular mechanism and signaling of thrombin-induced myometrial contraction. First, histologic studies of placental abruption, as a representative intrauterine bleeding, revealed that thrombin was expressed within the infiltrating hemorrhage and that thrombin receptor (protease-activated receptor 1, PAR1) was highly expressed in myometrial cells surrounding the hemorrhage. Treatment of human myometrial cells with thrombin resulted in augmented contraction via PAR1. Thrombin-induced signaling to myosin was then mediated by activation of myosin light chain kinase- and Rho-induced phosphorylation of myosin light chain-2. In addition, thrombin increased prostaglandin-endoperoxidase synthase-2 (PTGS2 or COX2) mRNA and prostaglandin E2 and F2α synthesis in human myometrial cells. Thrombin significantly increased the mRNA level of interleukine-1β, whereas it decreased the expressions of prostaglandin EP3 and F2α receptors. Progesterone partially blocked thrombin-induced myometrial contractions, which was accompanied by suppression of the thrombin-induced increase of PTGS2 and IL1B mRNA expressions as well as suppression of PAR1 expression. Collectively, thrombin induces myometrial contractions by two mechanisms, including direct activation of myosin and indirect increases in prostaglandin synthesis. The results suggest a therapeutic potential of progesterone for preterm labor complicated by intrauterine bleeding.

First-Trimester Prediction of Preterm Prelabour Rupture of Membranes

BACKGROUND

Preterm prelabour rupture of membranes (PPRoM) is commonly associated with preterm delivery and affects up to 3% of all pregnancies. It is associated with high rates of morbidity and mortality for the mother and the newborn.

OBJECTIVES

To identify risk factors for PPRoM and develop a model for first-trimester prediction of risk of PPRoM.

METHODS

A retrospective analysis of a series of women who had first-trimester (11-13+6 weeks) screening for aneuploidy and pre-eclampsia and delivered in the same institution was performed. Univariate and multivariate logistic regression analyses were used to identify maternal and pregnancy factors and then develop a clinical prediction model for PPRoM.

RESULTS

10,280 women were screened between April 2010 and October 2016. 144 (1.4%) had PPRoM. Maternal factors predictive of PPRoM included nulliparity (parous women, OR 0.53; 95% CI 0.4-0.8), pre-existing diabetes mellitus (DM) (Type 1 DM, OR 6.7; 95% CI 2.3-19.4, Type 2 DM, OR 5.3; 95% CI 1.6-18.3), maternal age group (p = 0.004), and BMI category (p = 0.012). Uterine artery pulsatility index (UAPI) and biochemical parameters (PAPP-A, free βHCG) did not reach statistical significance. The predictive model had moderate efficacy with an area under the ROC curve of 0.67.

CONCLUSIONS

Several maternal characteristics collected during first-trimester screening predict PPRoM. Biomarkers currently measured during first-trimester screening (PAPP-A, βHCG, and UAPI) do not predict PPRoM. Whilst a predictive model can be generated with information currently collected at 11-13+6 weeks, this has only modest screening performance. First-trimester screening provides a structured framework where other predictors could improve model performance, and future studies should focus on the addition of other risk factors and biomarkers that may improve screening efficacy.

Prevalence and Sources of Second-Hand Smoking Exposure among Non-Smoking Pregnant Women in an Urban Setting of Vietnam

Exposure to second-hand smoke (SHS) among non-smoking pregnant women can lead to adverse maternal and fetal outcomes. A cross-sectional study was performed from July to August 2016 among 432 pregnant women at Bach Mai Hospital, Hanoi, Vietnam, to assess the prevalence and sources of SHS exposure among non-smoking pregnant women. Socio-economic characteristics and information regarding SHS exposure of participants were collected. Multivariable logistic regression was employed to identify associated factors. Overall, 92.6% and 64.5% of pregnant women were exposed to SHS in their lifetime and in the last 30 days, respectively. Cafeterias and restaurants had the highest proportion of pregnant women exposed to SHS. Those who reported that “smoking is allowed at home” (OR = 3.18; 95%CI = 1.97–5.13); going to working place (OR = 1.86; 95%CI = 1.08–3.19), going to state authority offices (OR = 1.98; 95%CI = 1.15–3.41), and cafeterias (OR = 1.96; 95%CI = 1.22–3.16) had the highest risk of SHS exposure in the last 30 days. We have found a high proportion of SHS exposure among non-smoking pregnant women in Vietnam. This comes from a multitude of sources, including homes, workplaces, cafeterias, and restaurants. The data emphasises the need for further intervention to address this health issue.

Predictors of Caesarean Delivery in Preterm Premature Rupture of Membranes

BACKGROUND:

Preterm premature rupture of membranes (P-PROM) exerts a tremendous influence on pregnancy prognosis. Additionally, it is a major public health concern, as the cause of up to 40% of all preterm births.

AIM:

The objective of this study was to identify predictors of Caesarean Delivery in singleton pregnancies complicated by P-PROM.

MATERIALS AND METHODS:

This is a retrospective observational study of all consecutive singleton P-PROM deliveries (24-37 weeks) over an 18 months at a tertiary referral centre. Pertinent data was collected comprising demographics, obstetric history, pregnancy-associated pathology and delivery from electronic patient records. Univariate statistical analysis comprised Odds Ratio, 95% Confidence interval and Chi-square test with subsequent p-value with statistical significance set at p < 0.05.

RESULTS:

A total of 240 women delivered singletons following P-PROM over an 18-month period. Maternal age ranged between 12-41 years with an average age of 28 ± 6.27 years. Vaginal delivery (VD) was the predominant mode of delivery, accounting for 52.9% (n = 127) of deliveries. The following parameters were identified as predictors of Caesarean Section (CS) in P-PROM: vaginal infection (p = 0.04), previous CS (p < 0.0001), primiparity (p = 0.004), gravidity > 5 (p = 0.009), university education (p = 0.0006) and prenatal care (p < 0.0001).

CONCLUSION:

The advantage of CS over vaginal delivery is expedited delivery of the distressed fetus, while that of vaginal delivery entails avoiding postoperative morbidity. However, large multicentric randomised-controlled studies are needed to elucidate this dilemma definitively.

Epidemiological profile of patients with preterm premature rupture of membranes at a tertiary hospital in São Paulo, Brazil

OBJECTIVE

To perform a descriptive analysis of preterm premature rupture of membranes (PPROM) cases attended in a tertiary hospital.

METHOD

Retrospective analysis of medical records and laboratory tests of patients admitted to a Brazilian tertiary hospital between 2006 and 2011, with a confirmed diagnosis of PPROM and gestational age (GA) at delivery <37 weeks.

RESULTS

A total of 299 pregnant women were included in the study. Nine patients evolved to abortion, and 290 pregnant women remained for the final analysis. There was initial diagnostic doubt in 17.6% of the cases. The oligohydramnios rate [amniotic fluid index (AFI) <5] was 27.9% on admission. Chorioamnionitis was initially diagnosed in 10.8% of the patients and was retrospectively confirmed in 22.9% of the samples. The latency period had a mean of 9.1 days. The main reasons for interruption were premature labor (55.2%), GA ≥36 weeks (27.2%), and fetal distress (6.9%). The delivery method was cesarean section in 55% of cases. The mean birth weight was 2,124 grams, and 67% of the neonates had a low birth weight (<2500 g). The GA at delivery averaged 33.5 weeks. The stillbirth rate was 5.3%, and the early neonatal mortality rate was 5.6%. There were complications at delivery in 18% of mothers.

CONCLUSION

In one of the few Brazilian reports on the epidemiological profile of PPROM, with GA until 37 weeks and intercurrences generally excluded from assessments (such as twinning and fetal malformations), there is a favorable evolution, with an acceptable rate of complications.

Progestins Inhibit Tumor Necrosis Factor α-Induced Matrix Metalloproteinase 9 Activity via the Glucocorticoid Receptor in Primary Amnion Epithelial Cells

Progestins have been recommended for preterm birth prevention in high-risk women; however, their mechanism of action still remains an area of debate. Medroxyprogesterone acetate (MPA) has previously been shown to significantly inhibit tumor necrosis factor α (TNFα)-induced matrix metalloproteinase 9 (MMP9) messenger RNA (mRNA) expression and activity in primary amnion epithelial cells, a process that may lead to preterm premature rupture of membranes. A mechanism that explains MPA's inhibition of TNFα-induced MMP9 mRNA expression and activity in primary amnion epithelial cells is unclear since these cells lack the classic nuclear progesterone receptor but express a membrane-associated progesterone receptor-progesterone receptor membrane component 1 (PGRMC1) along with the glucocorticoid receptor (GR). Primary amnion epithelial cells harvested from healthy term pregnant women at cesarean section were treated with PGRMC1 (to knockdown PGRMC1 expression), GR (to knockdown GR expression), or control small interfering RNA (siRNA; 10 nm) for 72 hours, pretreated with ethanol or MPA (10^-6 M) for 6 hours, and then stimulated with or without TNFα 10 ng/mL for 24 hours. Real-time quantitative polymerase chain reaction and gelatin zymography were used to quantify MMP9 mRNA expression and activity, respectively. Experimental groups were compared using 1-way analysis of variance. Both TNFα-induced MMP9 mRNA expression and activity were significantly inhibited by pretreatment with MPA; however, only the inhibition of TNFα-induced MMP9 activity was partially reversed with PGRMC1 siRNA. However, GR siRNA reversed both the inhibition of TNFα-induced MMP9 mRNA expression and activity by MPA. This study demonstrates that MPA mediates its anti-inflammatory effects primarily through GR and partially through PGRMC1 in primary amnion epithelial cells.

[Epidemiology, risk factors and child prognosis: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVES

To synthetize the available evidence regarding the incidence and risk factors of preterm premature rupture of membranes (PPROM). To describe the evolution of pregnancy, neonatal outcomes and the prognosis of infants born in a context of PPROM, according to the existence of an associated intrauterine infection and to the latency duration.

METHOD

Consultation of the Medline database, from 1980 to February 2018.

RESULTS

PPROM before 37 and before 34 weeks' gestation occur in 2-3% and <1% of pregnancies, respectively (LE2). Although many risk factors are identified, few are modifiable, and the vast majority of patients have no risk factors (LE2). Consequently, individual prediction of the risk of PPROM and primary prevention measures have not been shown to be effective and are not recommended in clinical practice (Grade B). Most women give birth within the week following PPROM (LE2). The main complications of PPROM are prematurity, intrauterine infection and obstetric and maternal complications (LE2). Latency duration and the frequency of complications decrease with increasing gestational age at PPROM (LE2). Neonatal prognosis is largely conditioned by gestational age at birth, with no apparent over-risk of poor outcomes linked to PPROM compared to other causes of preterm birth (LE2). In contrast, intrauterine infection is associated with an increased risk of in utero fetal death (LE3), necrotizing enterocolitis (LE1) and early-onset sepsis (LE2). The association of intrauterine infection with neurological morbidity remains controversial. Prolongation of latency, from gestational age at PPROM, is beneficial for the child (LE2).

CONCLUSION

PPROM is a major cause of prematurity and short- and long-term mortality and morbidity. Antenatal care is an important issue for obstetric and pediatric teams, aiming to reduce complications and adverse consequences for both mother and child.

Alpha lipoic acid in obstetrics and gynecology

Alpha-Lipoic acid (ALA) is a natural antioxidant synthetized by plants and animals, identified as a catalytic agent for oxidative decarboxylation of pyruvate and α-ketoglutarate. In this review, we analyzed the action of ALA in gynecology and obstetrics focusing in particular on neuropathic pain and antioxidant and anti-inflammatory action. A comprehensive literature search was performed in PubMed and Cochrane Library for retrieving articles in English language on the antioxidant and anti-inflammatory effects of ALA in gynecological and obstetrical conditions. ALA reduces oxidative stress and insulin resistance in women with polycystic ovary syndrome (PCOS). The association of N-acetyl cysteine (NAC), alpha-lipoic acid (ALA), and bromelain (Br) is used for prevention and treatment of endometriosis. In association with omega-3 polyunsaturated fatty acids (n-3 PUFAs) with amitriptyline is used for treatment of vestibulodynia/painful bladder syndrome (VBD/PBS). A promising area of research is ALA supplementation in patients with threatened miscarriage to improve the subchorionic hematoma resorption. Furthermore, ALA could be used in prevention of diabetic embryopathy and premature rupture of fetal membranes induced by inflamation. In conclusion, ALA can be safely used for treatment of neuropatic pain and as a dietary support during pregnancy.

A Novel Approach to Serial Amnioinfusion in a Case of Premature Rupture of Membranes Near the Limit of Viability

Prelabor rupture of the membranes (PROM) near the limit of viability is associated with significant risks for both mother and fetus. Preterm labor, intra-amniotic infection, and placental abruption are the immediate risks to the pregnancy; however, the fetus incurs additional risks related to the sequela of persistent oligohydramnios. Transabdominal intra-amniotic infusions have been studied. Results, suggesting that this intervention may prolong the latency period, and potentially, decrease pulmonary hypoplasia in surviving neonates without evidence of increasing risk of intra-amniotic infection. To our knowledge, the use of antibiotic-infused fluid has not been reported in this clinical scenario. Therefore, we present a case of a patient with PROM before the limit of viability who underwent serial transabdominal amnioinfusions with oxacillin-containing normal saline, which resulted in membrane resealing and neonatal survival with no additional maternal morbidity.

Effect of maternal smoking on stress physiology in healthy neonates

OBJECTIVE

To assess the impact of maternal smoking during pregnancy (MSDP) on the neonatal hypothalamic-pituitary-adrenal axis.

STUDY DESIGN

In a prospective observational study, salivary cortisol and cortisone levels were measured at the fourth day of life during resting conditions and in response to a pain-induced stress event in healthy neonates whose mothers smoked cigarettes during each stage of pregnancy and compared with controls.

RESULTS

Neonates in the control group (n=70) exhibited a physiologic stress response with a significant increase in cortisol (1.3 to 2.1 ng ml^-1; P<0.05) and cortisone (11.8 to 17.8 ng ml^-1; P<0.05) from baseline levels, whereas in neonates from mothers who smoked (n=33), cortisol (0.9 to 0.8 ng ml^-1; P=0.77) and cortisone (11.5 to 13.0; P=0.19) stress response was not significantly different from baseline levels. A two-way analysis of variance confirmed these findings in both groups.

CONCLUSIONS

Healthy neonates whose mothers smoked during pregnancy show a blunted stress response on the fourth day of life. Thus, MSDP leads to a dysregulation of the HPA axis with continued effects in neonatal life. This might explain long-term consequences of MSDP such as overweight, diabetes mellitus and modification of blood pressure control mechanisms in adult life.

ACOG Practice Bulletin No. 188: Prelabor Rupture of Membranes

Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (1, 2). Preterm prelabor rupture of membranes (also referred to as premature rupture of membranes) (PROM) complicates approximately 3% of all pregnancies in the United States (3). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented.

In an in-vitro model using human fetal membranes, 17-α hydroxyprogesterone caproate is not an optimal progestogen for inhibition of fetal membrane weakening

BACKGROUND

The progestogen 17-α hydroxyprogesterone caproate (17-OHPC) is 1 of only 2 agents recommended for clinical use in the prevention of spontaneous preterm delivery, and studies of its efficacy have been conflicting. We have developed an in-vitro model to study the fetal membrane weakening process that leads to rupture in preterm premature rupture of the fetal membranes (pPROM). Inflammation/infection associated with tumor necrosis factor-α (TNF-α) induction and decidual bleeding/abruption associated thrombin release are leading causes of preterm premature rupture of the fetal membranes. Both agents (TNF-α and thrombin) cause fetal membrane weakening in the model system. Furthermore, granulocyte-macrophage colony-stimulating factor (GM-CSF) is a critical intermediate for both TNF-α and thrombin-induced fetal membrane weakening. In a previous report, we demonstrated that 3 progestogens, progesterone, 17-alpha hydroxyprogesterone (17-OHP), and medroxyprogesterone acetate (MPA), each inhibit both TNF-α- and thrombin-induced fetal membrane weakening at 2 distinct points of the fetal membrane weakening pathway. Each block both the production of and the downstream action of the critical intermediate granulocyte-macrophage colony-stimulating factor.

OBJECTIVE

The objective of the study was to characterize the inhibitory effects of 17-OHPC on TNF-α- and thrombin-induced fetal membrane weakening in vitro.

STUDY DESIGN

Full-thickness human fetal membrane fragments from uncomplicated term repeat cesarean deliveries were mounted in 2.5 cm Transwell inserts and cultured with/without 17-alpha hydroxyprogesterone caproate (10^-9 to 10^-7 M). After 24 hours, medium (supernatant) was removed and replaced with/without the addition of tumor necrosis factor-alpha (20 ng/mL) or thrombin (10 U/mL) or granulocyte-macrophage colony-stimulating factor (200 ng/mL). After 48 hours of culture, medium from the maternal side compartment of the model was assayed for granulocyte-macrophage colony-stimulating factor and the fetal membrane fragments were rupture strength tested.

RESULTS

Tumor necrosis factor-alpha and thrombin both weakened fetal membranes (43% and 62%, respectively) and increased granulocyte-macrophage colony-stimulating factor levels (3.7- and 5.9-fold, respectively). Pretreatment with 17-alpha hydroxyprogesterone caproate inhibited both tumor necrosis factor-alpha- and thrombin-induced fetal membrane weakening and concomitantly inhibited the induced increase in granulocyte-macrophage colony-stimulating factor in a concentration-dependent manner. However, contrary to our prior reports regarding progesterone and other progestogens, 17-alpha hydroxyprogesterone caproate did not also inhibit granulocyte-macrophage colony-stimulating factor-induced fetal membrane weakening.

CONCLUSION

17-Alpha hydroxyprogesterone caproate blocks tumor necrosis factor-alpha- and thrombin-induced fetal membrane weakening by inhibiting the production of granulocyte-macrophage colony-stimulating factor. However, 17-alpha hydroxyprogesterone caproate did not also inhibit granulocyte-macrophage colony-stimulating factor-induced weakening. We speculate that progestogens other than 17-alpha hydroxyprogesterone caproate may be more efficacious in preventing preterm premature rupture of the fetal membranes-related spontaneous preterm birth.

Practice Bulletin No. 172: Premature Rupture of Membranes

Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (1, 2). Preterm premature rupture of membranes (PROM) complicates approximately 3% of all pregnancies in the United States (3). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented.

Myometrial cytokines and their role in the onset of labour

Human labour is an inflammatory event, physiologically driven by an interaction between hormonal and mechanical factors and pathologically associated with infection, bleeding and excessive uterine stretch. The initiation and communicators of inflammation is still not completely understood; however, a key role for cytokines has been implicated. We summarise the current understanding of the nature and role of cytokines, chemokines and hormones and their involvement in signalling within the myometrium particularly during labour.

The role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding

BACKGROUND

Human pregnancy requires robust hemostasis to prevent hemorrhage during extravillous trophoblast (EVT) invasion of the decidualized endometrium, modification of spiral arteries and post-partum processes. However, decidual hemorrhage (abruption) can occur throughout pregnancy from poorly transformed spiral arteries, causing fetal death or spontaneous preterm birth (PTB), or it can promote the aberrant placentation observed in intrauterine growth restriction (IUGR) and pre-eclampsia; all leading causes of perinatal or maternal morbidity and mortality. In non-fertile cycles, the decidua undergoes controlled menstrual bleeding. Abnormal uterine bleeding (AUB) accompanying progestin-only, long-acting, reversible contraception (pLARC) accounts for most discontinuations of these safe and highly effective agents, thereby contributing to unwanted pregnancies and abortion. The aim of this study was to investigate the role of decidual cells in uterine hemostasis, menstruation, inflammation, adverse pregnancy outcomes and abnormal uterine bleeding.

METHODS

We conducted a critical review of the literature arising from PubMed searches up to December 2015, regarding in situ and in vitro expression and regulation of several specific proteins involved in uterine hemostasis in decidua and cycling endometrium. In addition, we discussed clinical and molecular mechanisms associated with pLARC-induced AUB and pregnancy complications with abruptions, chorioamnionitis or pre-eclampsia.

RESULTS

Progestin-induced decidualization of estradiol-primed human endometrial stromal cells (HESCs) increases in vivo and in vitro expression of tissue factor (TF) and type-1 plasminogen activator inhibitor (PAI-1) while inhibiting plasminogen activators (PAs), matrix metalloproteinases (MMPs), and the vasoconstrictor, endothelin-1 (ET-1). These changes in decidual cell-derived regulators of hemostasis, fibrinolysis, extracellular matrix (ECM) turnover, and vascular tone prevent hemorrhage during EVT invasion and vascular remodeling. In non-fertile cycles, progesterone withdrawal reduces TF and PAI-1 while increasing PA, MMPs and ET-1, causing menstrual-associated bleeding, fibrinolysis, ECM degradation and ischemia. First trimester decidual hemorrhage elicits later adverse outcomes including pregnancy loss, pre-eclampsia, abruption, IUGR and PTB. Decidual hemorrhage generates excess thrombin that binds to decidual cell-expressed protease-activated receptors (PARs) to induce chemokines promoting shallow placentation; such bleeding later in pregnancy generates thrombin to down-regulate decidual cell progesterone receptors and up-regulate cytokines and MMPs linked to PTB. Endometria of pLARC users display ischemia-induced excess vasculogenesis and progestin inhibition of spiral artery vascular smooth muscle cell proliferation and migration leading to dilated fragile vessels prone to bleeding. Moreover, aberrant TF-derived thrombin signaling also contributes to the pathogenesis of endometriosis via induction of angiogenesis, inflammation and cell survival.

CONCLUSION

Perivascular decidualized HESCs promote endometrial hemostasis during placentation yet facilitate menstruation through progestational regulation of hemostatic, proteolytic, and vasoactive proteins. Pathological endometrial hemorrhage elicits excess local thrombin generation, which contributes to pLARC associated AUB, endometriosis and adverse pregnancy outcomes through several biochemical mechanisms.

Obstetric outcome of second trimester antenatal bleeding

OBJECTIVE

To evaluate the clinical significance of vaginal bleeding in pregnant women between 14th and 22th gestational weeks.

METHODS

This retrospective case-control study was conducted between September 2010 and December 2013. Two-hundred nineteen pregnant women with vaginal bleeding between 14th and 22th gestational weeks were compared with 325 pregnant women without vaginal bleeding for their maternal and early neonatal outcomes.

RESULTS

Mean gestational age and birth weight of study group were significantly different from those of the control group respectively (37.9 ± 2.8 versus 38.9 ± 1.4 and 3071 ± 710 versus 3349 ± 446 for groups p < 0.001). Vaginal bleeding between 14th and 22th gestational weeks had increased risk of having preterm birth (PB) and preterm premature rupture of membranes (PPROM) (OR: 10.8, 95% CI: [4.5-26.1]; OR: 12.0, 95% CI: [3.5-40.6], respectively). Gestational diabetes mellitus (GDM) and polyhydramnios ratio in the study group was significantly higher than the control respectively (4.1% versus 1.2%, p = 0.031; 1.9% versus 0%, p = 0.025).

CONCLUSION

Pregnant women with vaginal bleeding was a significantly risk factor for PB, PPROM, GDM, and polyhydramnios. Consequently, these pregnancies should be closely followed up for maternal and fetus complications.

Progesterone inhibits in vitro fetal membrane weakening

OBJECTIVE

Inflammation/infection and abruption are leading causes of preterm premature rupture of the membranes. Recently, we identified granulocyte-macrophage colony-stimulating factor (GM-CSF) as a critical mediator of both tumor necrosis factor-α- (TNF; modeling inflammation) and thrombin-induced (modeling abruption) weakening of the fetal membranes. We found that (1) TNF and thrombin both induced GM-CSF in the choriodecidua, (2) blockade of GM-CSF action with neutralizing antibodies inhibited both TNF- and thrombin-induced fetal membrane weakening, and (3) GM-CSF alone induced fetal membrane weakening. GM-CSF is thus part of an overlap of the inflammation and abruption-induced fetal membrane weakening pathways. The effects of progesterone analogs on the pathways by which fetal membranes are weakened have not been investigated. We examined the effects of progesterone, medroxyprogesterone acetate (MPA) and 17α-hydroxyprogesterone (HP) on TNF- and thrombin-induced fetal membrane weakening.

STUDY DESIGN

Full-thickness fetal membranes from uncomplicated term repeat cesarean deliveries were mounted in Transwell inserts in Minimum Essential Medium alpha and incubated at 37°C in 5% CO2. The choriodecidua side of the fetal membrane fragments were preincubated with progesterone, MPA, HP, or vehicle for 24 hours. Fetal membranes were then exposed to TNF, thrombin, or GM-CSF on the choriodecidua side for an additional 48 hours. The fetal membrane tissues were then strength tested, and medium from the choriodecidua and amnion compartments was assayed for GM-CSF content.

RESULTS

TNF and thrombin both weakened fetal membranes and elevated media GM-CSF levels on the choriodecidua side of the fetal membrane. Pretreatment with progesterone, MPA, or HP inhibited both TNF- and thrombin-induced fetal membrane weakening and also inhibited the induced increase in GM-CSF. GM-CSF decreased fetal membrane rupture strength by 68%, which was inhibited by progestogen pretreatment with a potency order: progesterone <MPA <HP.

CONCLUSION

Progestogen pretreatment blocks TNF- and thrombin-induced fetal membrane weakening by inhibiting both the production and action of GM-CSF. These findings are consistent with the administration of progestogens in the prevention of preterm premature rupture of the membranes.

A retrospective comparison of antibiotic regimens for preterm premature rupture of membranes

OBJECTIVE

To evaluate whether the use of ampicillin and azithromycin leads to a similar latency period in preterm premature rupture of membranes as ampicillin and erythromycin and whether the substitution of azithromycin for erythromycin effects rates of other outcomes.

METHODS

We performed a retrospective cohort study of women with preterm premature rupture of membranes between 24 and 34 completed weeks of gestation and compared two groups: those who received ampicillin and erythromycin and those who received ampicillin and azithromycin. Primary outcome was length of latency (defined as time from first antibiotic dose to delivery) and secondary outcomes were rates of chorioamnionitis, cesarean delivery, Apgar scores, birth weight, neonatal death, neonatal sepsis, and neonatal respiratory distress syndrome.

RESULTS

Of 168 women who met inclusion criteria, 75 received ampicillin and erythromycin and 93 received ampicillin and azithromycin. There was no difference in latency between groups: 9.6±13.2 days (erythromycin) compared with 9.4±10.0 (azithromycin) days (P=.40). Secondary outcomes did not differ between groups. We had 80% power to detect a difference of 5 days.

CONCLUSION

Among women with preterm premature rupture of membranes between 24 and 34 completed weeks of gestation, substitution of azithromycin for erythromycin in the recommended antibiotic regimen did not affect latency or any other measured maternal or fetal outcomes.

LEVEL OF EVIDENCE

III.

Individualized assessment of preterm birth risk using two modified prediction models

OBJECTIVES

To construct two prediction models for individualized assessment of preterm delivery risk within 48h and before completed 32 weeks of gestation and to test the validity of modified and previously published models.

STUDY DESIGN

Data on 617 consecutive women with preterm labor transferred to a tertiary care center for threatened preterm delivery between 22 and 32 weeks of gestation were analysed. Variables predicting the risk of delivery within 48h and before completed 32 weeks of gestation were assessed and applied to previously published prediction models. Multivariate analyses identified variables that were incorporated into two modified models that were subsequently validated.

RESULTS

Two modified prediction models were developed and internally validated, incorporating four and six of the following variables to predict the risk of delivery within 48h and before completed 32 weeks of gestation, respectively: presence of preterm premature rupture of membranes and/or vaginal bleeding, sonographic cervical length, week of gestation, fetal fibronectin, and serum C-reactive protein. The correspondence between the actual and the predicted preterm birth rates suggests excellent calibration of the models. Internal validation analyses for the modified 48h and 32 week prediction models revealed considerably high concordance-indices of 0.8 (95%CI: [0.70-0.81]) and 0.85 (95%CI: [0.82-0.90]), respectively.

CONCLUSIONS

Two modified prediction models to assess the risk of preterm birth were constructed and validated. The models can be used for individualized prediction of preterm birth and allow more accurate risk assessment than based upon a single risk factor. An online-based risk-calculator was constructed and can be assessed through: http://cemsiis.meduniwien.ac.at/en/kb/science-research/software/clinical-software/prematurebirth/.

Decidual GM-CSF is a critical common intermediate necessary for thrombin and TNF induced in-vitro fetal membrane weakening

INTRODUCTION

Inflammation/infection and decidual bleeding/abruption are highly associated with pPROM. As no animal model for pPROM exists, we have developed an in-vitro model system for the study of human fetal membrane (FM) weakening/rupture. Using it we have demonstrated that both TNF/IL-1 (modeling inflammation) and thrombin (modeling bleeding) weaken full thickness FM in a dose dependent manner concomitant with inducing biochemical changes similar to those seen in the FM physiological weak zone.

METHODS

As the physiological site of infection and bleeding is the choriodecidua (CD), we modified our model system with full thickness FM tissue mounted on modified Transwell culture inserts to permit directional TNF/thrombin exposure on the decidua only (rather than both sides of the FM). After incubation, medium was sampled separately from the CD facing (maternal side) or from the amnion facing (fetal side) compartments and probed for cytokine release and confirmed with western blots. The FM was strength tested within the insert.

RESULTS

Full-thickness FM fragments exposed to TNF or thrombin on CD side only showed dose dependent weakening and biochemical changes consistent with previous reports. Concomitantly, GM-CSF increased markedly on the CD but not the amnion side. Numerous proteases including MMP1 and MMP3 also increased on the CD side. Pre-incubation with GM-CSF antibody blocked both thrombin and TNF induced weakening. Finally, GM-CSF weakened FM in a dose dependent manner.

DISCUSSION

GM-CSF is a critical common intermediate in the thrombin and TNF FM weakening pathways.

Changes in maternal blood inflammatory markers as a predictor of chorioamnionitis: a prospective multicenter study

PROBLEM

To evaluate the inflammatory pattern in maternal circulation from women with preterm premature rupture of membranes (PPROM) considering the occurrence of histologically confirmed chorioamnionitis (HCA).

METHOD OF STUDY

A prospective study was conducted in 121 women with PPROM between 24 and 34 + 0 weeks of gestation. Association between white blood cells (WBC) count, plasma CRP, IL-6, MCP-1 and IP-10 levels, and HCA was assessed.

RESULTS

The rate of HCA was 44.7% (54/121). During the 5 days preceding delivery, median CRP, WBC, and IL-6 levels were significantly higher in the HCA than in no-HCA group (P < 0.001). Variations in IL-6, IP-10 levels, during the 24-72 hr before delivery, were predictors of the occurrence of HCA, but the diagnostic accuracy was low [Receiver Operating Characterictic (ROC) curve, area under the curve (AUC) = 0.56].

CONCLUSION

An increase in IL-6, CRP, IP-10 maternal plasma levels was confirmed in PPROM women with HCA. Longitudinal follow-up of these markers did not add valuable information regarding HCA.

Synergy and interactions among biological pathways leading to preterm premature rupture of membranes

Preterm premature rupture of membranes (PPROM) occurs in 1% to 2% of births. Impact of PPROM is greatest in low- and middle-income countries where prematurity-related deaths are most common. Recent investigations identify cytokine and matrix metalloproteinase activation, oxidative stress, and apoptosis as primary pathways to PPROM. These biological processes are initiated by heterogeneous etiologies including infection/inflammation, placental bleeding, uterine overdistention, and genetic polymorphisms. We hypothesize that pathways to PPROM overlap and act synergistically to weaken membranes. We focus our discussion on membrane composition and strength, pathways linking risk factors to membrane weakening, and future research directions to reduce the global burden of PPROM.

A case-control study on risk factors for preterm deliveries in a secondary care hospital, southern India

Introduction. Preterm birth is the leading cause of newborn deaths and the second leading cause of death in children under five years old. Three-quarters of them could be saved with current, cost-effective interventions. The aim of this study was to identify the risk factors of preterm birth in a secondary care hospital in Southern India. Methods. In the case-control study, records of 153 antenatal women with preterm birth were included as cases. Age matched controls were women who had a live birth after 37 weeks of gestational age. Gestational age at delivery and associated risk factors were analyzed. Results. The preterm birth rate was 5.8%. Common risk factors associated with preterm birth were hypertensive disorders of pregnancy (21.4%), height <1.50 m (16.8%), premature rupture of membranes (17.5%), and fetal distress (14.9%). Mean birth weight for preterm babies was 2452 grams while the birth weight for term babies was 2978 grams. Conclusion. The commonest obstetrical risk factor for preterm birth was hypertensive disorders of pregnancy and nonobstetrical risk factor was height <1.50 m. The percentage of preterm birth was low, comparable to developing countries.

Preterm premature rupture of the fetal membranes: association with sociodemographic factors and maternal genitourinary infections

OBJECTIVE

this study aimed to investigate the incidence of premature rupture of fetal membranes in preterm singleton pregnancies and its association with sociodemographic factors and maternal self-reported genitourinary infections.

METHODS

this was a population-based cross-sectional study, which included all mothers of newborns of singleton deliveries that occurred in 2010, with birth weight ≥ 500 grams, who resided in the city of Rio Grande. Women were interviewed in the two maternity hospitals. Cases were women who had lost amniotic fluid before hospitalization and whose gestational age was less than 37 weeks. Statistical analysis was performed by levels to control for confounding factors using Poisson regression.

RESULTS

of the 2,244 women eligible for the study, 3.1% had preterm premature rupture of fetal membranes, which was more frequent, after adjustment, in women of lower socioeconomic status, (prevalence ratio [PR]=1.94), with lower level of schooling (PR=2.43), age > 29 years (PR=2.49), and smokers (PR=2.04). It was also associated with threatened miscarriage (PR=1.68) and preterm labor, (PR=3.40). There was no association with maternal urinary tract infection or presence of genital discharge.

CONCLUSIONS

the outcome was more common in puerperal women with lower level of schooling, lower socioeconomic status, older, and smokers, as well as those with a history of threatened miscarriage and premature labor. These factors should be considered in the prevention, diagnosis, and therapy approach.

Practice bulletins No. 139: premature rupture of membranes

Preterm delivery occurs in approximately 12% of all births in the United States and is a major factor that contributes to perinatal morbidity and mortality (). Preterm premature rupture of membranes (PROM) complicates approximately 3% of all pregnancies in the United States (). The optimal approach to clinical assessment and treatment of women with term and preterm PROM remains controversial. Management hinges on knowledge of gestational age and evaluation of the relative risks of delivery versus the risks of expectant management (eg, infection, abruptio placentae, and umbilical cord accident). The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented.

Thrombin weakens the amnion extracellular matrix (ECM) directly rather than through protease activated receptors

INTRODUCTION

Preterm premature rupture of fetal membranes (pPROM) is a major cause of preterm birth. Abruption associated thrombin production, and infection-inflammation associated cytokine production reportedly play major roles in pPROM. Utilizing an in vitro model-system we have confirmed that both thrombin and inflammatory cytokines remodel and biomechanically weaken amnion, the load-bearing component of FM. Also, we have shown thrombin directly weakens isolated amnion but cytokines weaken amnion only indirectly by initially interacting with choriodecidua and releasing unidentified soluble activator(s). This study's purpose was to determine whether thrombin weakens the isolated amnion through thrombin receptor-protease activated receptors (PARs 1,2,3,4), activation of previously secreted extracellular matrix (ECM) enzymes, or by direct action on the ECM.

METHODS

Primary amnion cells and isolated amnion were tested for PARs by immunohistochemistry, Western Blot and rtPCR. Cell-free amnion ECM was produced by devitalizing isolated amnion by exposure to UV light and subsequent freeze-thaw cycles. Devitalized amnion membrane explants were incubated with thrombin and biomechanically tested.

RESULTS

PARs were not found in amnion or amnion cells. Thrombin induced dose-dependent weakening of devitalized amnion explants. Preincubation with the thrombin inhibitor hirudin prevented thrombin-induced weakening. Thrombin converted pro-MMP2 embedded in the devitalized amnion ECM to multiple active forms. Thrombin also directly digested gelatin gels in zymograms suggesting the possibility of direct degradation of amnion ECM components.

DISCUSSION

Thrombin appears to directly weaken the amnion ECM and additionally activates stored pro-MMP2 to active forms that may further enhance amnion ECM degradation.

CONCLUSION

Thrombin weakens amnion directly rather than through PARs.

Histological chorioamnionitis: effects on premature delivery and neonatal prognosis

BACKGROUND

Chorioamnionitis is closely related to premature birth and has negative effects on neonatal morbidity and mortality.

METHODS

In this prospective study, 43 mothers who delivered earlier than 35 gestational weeks and their 57 infants were evaluated clinically and with laboratory findings. Placentas and umbilical cords were investigated histopathologically for chorioamnionitis and funisitis.

RESULTS

The overall frequency of clinical and histological chorioamnionitis (HCA) was 8.3% and 23.2%, respectively. The frequency of HCA was 47.3% and 83.3% in mothers delivered <32 weeks and <30 weeks, respectively. Maternal demographic and clinical findings and also leukocyte and C-reactive protein values were not indicative of HCA. Infants of mothers with HCA had significantly lower Apgar scores together with higher SNAP-PE-II and CRIB scores. These infants had increased mechanical ventilator and surfactant requirements, higher incidences of patent ductus arteriosus, early sepsis, and bronchopulmonary dysplasia, and higher mortality rates. The effect of HCA on neonatal morbidity and mortality was more prominent than the effect of low birthweight and lower gestational age.

CONCLUSION

Chorioamnionitis not only causes premature deliveries, but is also associated with neonatal complications and increased mortality. Clinical findings and infectious markers in mother or infant do not predict the diagnosis of histological chorioamnionitis. Therefore, placental histopathology may have a role in predicting neonatal outcome in premature deliveries, especially those below 30 weeks.

The impact of tobacco use on preterm premature rupture of the membranes

OBJECTIVE

To determine if tobacco use increases the incidence of preterm premature rupture of the membranes (pPROM) or alters perinatal outcomes after pPROM.

STUDY DESIGN

This is a secondary analysis of the databases of three completed Eunice Kennedy Shriver National Institute of Child Health and Human Development-supported Maternal Fetal Medicine Units Network studies. Self-reported tobacco exposure data was obtained. Its relationship with the incidence of pPROM and associated neonatal outcome measures were assessed.

RESULTS

There was no difference in the incidence of pPROM when comparing nonsmokers to those using tobacco. Although a trend was seen between the incidence of pPROM and the amount smoked, this did not reach statistical significance. Among the patients with pPROM, the use of tobacco was not associated with an increase in perinatal morbidity.

CONCLUSION

Our data do not support a significant relationship between tobacco use and pPROM.