Predictors for prolonged interval from premature rupture of membranes to spontaneous onset of labor at term.

OBJECTIVE

To identify predictors for prolonged interval from premature rupture of membranes (PROM) to spontaneous onset of labor in women presenting with PROM and low Bishop score at term.

METHODS

A retrospective study of women presenting with PROM and Bishop score < 7 at term (≥37weeks) in a tertiary hospital (2013-14). Spontaneous onset of labor was defined as presence of regular uterine contractions and Bishop score ≥ 7. Women with interval from PROM to spontaneous onset of labor of <24hours (short interval group) were compared to those with interval ≥ 24 hours (prolonged interval group). Women who underwent induction of labor at < 24 hours from PROM were excluded.

RESULTS

Among 625 women who met inclusion criteria, 155 (24.8%) had a prolonged interval to onset of labor. In multivariate analysis, prolonged PROM was associated with (OR, 95%CI) cervical dilatation (0.35, 0.24-0.52, p < 0.001), effacement (0.97, 0.96-0.99, p < 0.001) and uterine contraction (0.51, 0.32-0.80, p = 0.004). A multivariable prediction model including maternal age, parity, cervical dilatation and effacement, gestational age and neonatal birthweight was associated with an AUC of receiver-operator characteristic curve of 0.739 (0.631-0.847, p < 0.001) for predicting prolonged PROM.

CONCLUSION

Uterine contractions and cervical examination parameters can be used for prediction of prolonged interval to spontaneous onset of labor in women with term PROM.