Factors associated with a latency < 7 days after preterm premature rupture of membranes between 22 and 32 weeks of gestation in singleton pregnancies

Objective: To identify factors at admission associated with a latency < 7 days after Preterm premature rupture of membranes (PPROM) between 22 and 32 weeks of gestation in singleton pregnancies.

Material and methods: A retrospective comparative study of all women with singleton pregnancies admitted for PPROM to an academic tertiary center during the 5-year period of 2015-2019. Women who gave birth < 7 days and ≥ 7 day after PPROM were compared. We determined risk at admission associated with a latency < 7 days after PPROM by logistic regression and identified high-risk subgroups by classification and regression tree (CART) analysis.

Results: Among 174 eligible births, 76 (44%) women gave birth < 7 days after PPROM and 98 (56%) later. The two groups had similar maternal baseline and obstetric characteristics. In multivariate analysis, the following variables reported at admission were independently associated with a latency < 7 days: painful uterine contractions (aOR 3.9, 95%CI 1.1-7.4), cervical length < 20 mm (aOR 2.4, 95%CI 1.2-4.8), and C reactive protein ≥ 10 mg/L (aOR 2.4, 95% CI 1.3-4.8). Women with painful uterine contractions and cervical length at admission < 20 mm were at highest risk of latency < 7 days (rate: 91%). Conversely, the women at lowest risk were those without uterine contractions, with a cervical length ≥ 20 mm, and C-reactive protein < 10 mg/L at admission (rate: 22%).

Conclusion: Our results may be helpful in determining criteria at admission for selecting women eligible for outpatient care after an initial hospitalization.