Impact of the new guidelines on the management of premature rupture of membranes for the prevention of late preterm birth: an 11-year retrospective study

Neonatal outcomes and risk of neonatal sepsis in an expectantly managed cohort of late preterm prelabor rupture of membranes

OBJECTIVE

Expectant management in patients with prelabor preterm rupture of membranes between between 34^0/7 and 36 ^6/7 weeks (late preterm pPROM or LpPROM) has been shown to decrease the burden of prematurity, when compared to immediate delivery. As the severity of prematurity depends on gestational age (GA) at PROM, and PROM to delivery interval, we first investigated how such variables affect neonatal outcomes (NO). Second, we assessed the risk of neonatal sepsis.

STUDY DESIGN

retrospective cohort study on neonatal morbidity among singleton infants born to expectantly managed mothers with LpPROM in five hospitals affiliated with three Italian academic institutions. The primary NO was a composite of neonatal death, non-invasive (cPAP) or invasive (mechanical ventilation) respiratory support, hypoglycemia (< 44 mg/dl needing therapy), newborn sepsis, confirmed seizures, stroke, intraventricular hemorrhage (IVH), basal nuclei anomalies, cardiopulmonary resuscitation, umbilical-cord-blood arterial pH < 7.0 or base excess < -12.5, and prolonged hospitalization (≥ 5 days). Univariate analysis described differences in the population according to GA at delivery. Multivariate logistic regression was then used to investigate the effects of GA at PROM, and PROM to delivery interval on the NO.

RESULTS

258/606 (42.6 %) women with LpPROM were expectantly managed, as they did not deliver within the first 24 h. The median latency duration was 2 (95 %CI 1-3) days, having no effect on neonatal morbidity on multivariate analysis. Multivariate analysis also showed increased risks of adverse NO among PROM at 34 (OR 2.3 95 %CI 1.03-5.1) but not at 35 weeks when compared to 36 weeks, and among women receiving antenatal corticosteroids (OR 3.6 95 %CI 1.3-9.7), while antibiotic treatment showed a non-significant protective effect (OR 0.2 95 %CI 0.04-1.02). Prevalence of neonatal sepsis was 0.8 % (2/258) CONCLUSION: Expectant management of LpPROM should be encouraged especially between 34⁺⁰ and 34⁺⁶ weeks', when the burden of prematurity is the greatest. Antibiotics may have beneficial effects, while careful consideration should be given to antenatal corticosteroids until future studies specifically address LpPROM.

Transcriptomic profiling of fetal membranes of mice deficient in biglycan and decorin as a model of preterm birth†

Approximately, 25% of all preterm births are due to preterm premature rupture of membranes. Mice deficient in proteoglycans biglycan (Bgn) and decorin (Dcn) display abnormal fetal membranes and increased incidence of preterm birth. We conducted RNA-Seq to profile fetal membranes and identify molecular pathways that may lead to preterm birth in double knockout (DKO) mice (Bgn-/-; Dcn-/-) compared to wild-type (WT) at two different gestational stages, E12 and E18 (n = 3 in each group). 3264 transcripts were differentially regulated in E18 DKO vs. WT fetal membranes, and 96 transcripts differentially regulated in E12 DKO vs. WT fetal membranes (FDR < 0.05, log 2 FC ≥ 1). Differentially regulated transcripts in E18 DKO fetal membranes were significantly enriched for genes involved in cell cycle regulation, extracellular matrix-receptor interaction, and the complement cascade. Fifty transcripts involved in the cell cycle were altered in E18 DKO fetal membranes (40↓, 10↑, FDR < 0.05), including p21 and p57 (↑), and Tgfb2, Smad3, CycA, Cdk1, and Cdk2(↓). Thirty-one transcripts involved in the complement cascade were altered (11↓, 20↑, FDR < 0.05) in E18 DKO fetal membranes, including C1q, C2, and C3 (↑). Differentially expressed genes in the top three molecular pathways (1) showed evidence of negative or purifying selection, and (2) were significantly enriched (Z-score > 10) for transcription factor binding sites for Nr2f1 at E18. We propose that in DKO mice, cell cycle arrest results in lack of cell proliferation in fetal membranes, inability to contain the growing fetus, and preterm birth.

Cellular immune responses in amniotic fluid of women with preterm prelabor rupture of membranes

Background Preterm birth is the leading cause of perinatal morbidity and mortality. Preterm prelabor rupture of membranes (pPROM) occurs in 30% of preterm births; thus, this complication is a major contributor to maternal and neonatal morbidity. However, the cellular immune responses in amniotic fluid of women with pPROM have not been investigated. Methods Amniotic fluid samples were obtained from women with pPROM and a positive (n = 7) or negative (n = 10) microbiological culture. Flow cytometry was performed to evaluate the phenotype and number of amniotic fluid leukocytes. The correlation between amniotic fluid immune cells and an interleukin-6 (IL-6) concentration or a white blood cell (WBC) count in amniotic fluid was calculated. Results Women with pPROM and a positive amniotic fluid culture had (1) a greater number of total leukocytes in amniotic fluid, including neutrophils and monocytes/macrophages and (2) an increased number of total T cells in amniotic fluid, namely CD4+ T cells and CD8+ T cells, but not B cells. The numbers of neutrophils and monocytes/macrophages were positively correlated with IL-6 concentrations and WBC counts in amniotic fluid of women with pPROM. Conclusion Women with pPROM and a positive amniotic fluid culture exhibit a more severe cellular immune response than those with a negative culture, which is associated with well-known markers of intra-amniotic inflammation.