Introduction: In case of term prelabor rupture of membranes (PROM), expectant management is a reasonable option. We aimed at assessing the frequency of spontaneous onset of labor after two days of term PROM and its associated factors.
Material and methods: Women delivering at a tertiary center of a singleton in cephalic presentation, after a term PROM with an unfavorable cervix and with an expectant management period of at least two days were included during a 2-year period. Women were excluded in case of induction of labor before or at day 2(D2) or of spontaneous labor before D2. The frequency of spontaneous labor was assessed, then maternal characteristics at admission and at D2 were compared between women with a spontaneous onset of labor before D3, and women with an induced labor at D3. The maternal and neonatal outcomes were compared between the two groups. The factors associated with spontaneous labor in univariate analysis were tested in multivariable analysis.
Results: Among the 11 608 women delivering at term, 933(8.4%) had a term PROM. Among them, 191 had an unfavorable cervix after D2 including 86(45%) women with a spontaneous labor onset between D2 and D3 and 105(55%) induced at D3. Maternal age below 35 years (reference ≥35years) and Bishop score of 3-4 and 5-6 at D2 (reference score 0-2) were significantly associated with spontaneous onset of labor, respectively aOR 2.62; 95%CI[1.26-5.45], aOR 2.38; 95%CI[1.18-4.78] and aOR 10.16; 95%CI[3.67-28.15].
Discussion: In women with a term PROM and an unfavorable cervix, spontaneous labor still occurs in nearly half of women undelivered after two days of expectant management.