Features of labor course upon with preterm rupture of membranes and "mature" cervix at gestation of 37 weeks or higher

Abstract

Introduction. Management and the prevalence of labor complications in patients with premature rupture of the membranes (PROM) is a pressing issue. Aim: to assess the features of childbirth course in patients with PROM during a full-term pregnancy and a favourable cervix. Materials and methods. А prospective analysis of labor course and the postpartum period was performed in 189 patients with a singleton pregnancy with occipital presentation, at least 37-week gestation, of low and moderate risk groups, without contraindications for vaginal delivery. PROM as complicated pregnancy was found in 89 subjects (main group), whereas 100 having labor onset with intact fetal membranes were enrolled into comparison group. The features of labor course were analyzed. Results. Primiparous patients dominated in the main group (66.7 %). The latent period between amniotic fluid discharge to labor onset comprised 4.15 ± 3.48 hours and 3.40 ± 2.13 hours in primiparous and multiparous women, respectively, whereas labor activity in 19 % of women did not develop after 6 hour-latent period. The average duration of labor did not depend on the patient parity and was longer in the group with PROM: 8.06 ± 3.51 hours – in primiparous females, 7.21 ± 2.56 hours – in comparison group (T = –1.99; p = 0.04) due to prolonged first stage of labor. In patients with and without PROM, rate of poor uterine contraction strength was 24.7 % and 18.3 % (p = 0.29), cervical dystocia – 2.25 % and 0 % (p = 0.13), use of oxytocin in childbirth – 35.9 % and 18.3 % (p = 0.007), respectively. Caesarean sections in the main group were recorded in 15 cases (16.85 %), fetal vacuum extraction – 6 cases (6.74 %), whereas in the comparison group – per 2 (2,0 %) cases, respectively (χ2 = 16.13; p < 0.001). Conclusion. Patients with PROM and favourable cervix were shown to have duration of labor, occurrence of operative delivery, rupture of the cervix, and use of oxytocin lasting substantially longer compared to those with the rupture of membranes after onset of the labor. PROM with a favourable cervix occurs more often in primiparous females, which is also coupled to peak rate complications. A 6-hour expectant management is considered as insufficient, because an onset of labor activity in 15.7 % of patients developed after latent period lasting more than 6 hours.