(900) Prediction Model for Spontaneous Onset of Active Labor After Pre-Labor Rupture of Membranes at Term

Term pre-labor rupture of membranes (PROM) is a significant event that may pose risks for maternal and fetal complications. We aimed to develop a predictive model for the spontaneous onset of active labor within 24 hours following membrane rupture at term.

Study Design:

1. 1. A retrospective cohort study in a single, university-affiliated tertiary medical center which included women who presented at term (37-41 weeks) with PROM and were managed conservatively upon patient request, without induction of labor, (January 2011 – December 2023).
2. The primary outcome was spontaneous onset of active labor, defined as cervical dilation to 6 centimeters (cm), within 24 hours after membrane rupture.
3. Exclusion criteria included: women who received oxytocin during the 24 hours after PROM and before reaching active labor (6 cm dilatation), women with non-clear amniotic fluid, the necessity for cesarean delivery, suspected infection and non-reassuring fetal monitoring.
4.Potential risk factors including demographic, medical and obstetric characteristics were examined.
5. Repeat amniotomy was defined as the need for additional amniotomy, after admission with PROM.
6. Prediction model was built using a backward variable selection based upon significant risk factors which were found in the multivariable logistic regression (P < .05).

Results:

1. Overall, during the study period 10,633 women met the inclusion criteria and were enrolled.

< 2.Within 24 hours after PROM, 6,961 (65.4%) had spontaneous onset of active labor.

< 3. Spontaneous onset of labor after PROM was associated with parity, cervical dilatation and cervical length at admission, repeat amniotomy, and GBS status.

< !4. The prediction model for onset of labor within 24 hours after PROM had an area under the curve (AUC) of 0.813 with accuracy of 75.94% 

Conclusion:

The predictive model effectively identifies women at higher chance of spontaneous active labor within 24 hours following PROM. This model may improve clinical decision-making and labor management strategies after term PROM.