Abstract
Background The duration of first and second stages of labor was increased in the consensus that American College of Obstetricians and Gynecologists (ACOG) published 2014. Studies showed increased adverse maternal and neonatal outcomes in nulliparous women with prolonged second stage of labor. It is not very clear that the impact of labor stage duration on multiparous women.Methods A retrospective cohort study was performed. Cephalic, term, singleton multiparous women were included, who planned for vaginal delivery. Adverse maternal outcomes were defined as referral cesarean delivery, instrumental delivery, postpartum hemorrhage, perineal laceration (3rd and 4th degree), hospitalization stay ≥ 90%th, and adverse neonatal outcomes as NICU, shoulder dystocia, Apgar score ≤ 7(5 min), neonatal resuscitation, assisted ventilation required immediately after delivery. We defined the total stage included the first and second stage of labor.Results There were 7109 parturients included, The duration of first stage was 6.2(3.6–10.0) hours in multiparous women, the second stage was 0.3(0.2–0.7) hours, the total stage was 6.9(4.1–10.7) hours. In the first stage, the rate of overall adverse outcomes was 21%, 23.4%, 28.8%, 35.5%, 38.4% in < 6 h, 6-11.9 h, 12-17.9 h, 18-23.9 h, ≥ 24 h, increased significantly (X2 = 57.64, P0.001). Compared with < 6 h, ARR(95%CI) were 1.10(0.92,1.31), 1.33(1.04,1.70), 1.80(1.21,2.68), 2.57(1.60,4.15);In the second stage, the rate of overall adverse outcomes increased from 20.0%, 30.7%, 38.5%, to 61.2%, 69.6% in < 1 h, 1-1.9 h, 2-2.9 h, 3-3.9 h, ≥ 4 h (X2 = 349.70, P0.001). Compared with < 1 h, ARR (95% CI) were 1.89 (1.50, 2.39), 2.22 (1.55, 3.18), 10.64 (6.09, 18.59), 11.75 (6.55, 21.08); In the total stage, the rate of overall adverse outcomes were 21.5%, 30.8%, 42.4% in < 12 h, 12-23.9 h, ≥ 24 h (X2 = 84.90, P0.001). Compared with < 12 h, ARR (95% CI) were 1.41(1.16,1.72), 3.17 (2.10,4.80).Conclusions The prolonged labor stage may lead to increased adverse outcomes in multiparous women, even in the first stage. The duration of labor stage was an independent risk factor for adverse maternal and neonatal outcomes.
The impact of extending the second stage of labor to prevent primary cesarean delivery on maternal and neonatal outcomes
