Delayed pushing in the second stage of labor may facilitate delivery and avoid potential adverse outcomes. This retrospective cohort study was designed to assess the effectiveness of delayed pushing, estimate its effect on delivery mode, assess its relationship with maternal and neonatal well-being, and estimate its effect on the duration of second stage of labor.
The study included consecutive women admitted at term who reached the second stage of labor; those who delayed pushing were compared with those who pushed immediately. Data on maternal demographics and outcomes and neonatal outcomes were obtained from medical records. Delayed pushing, used at the practitioner’s discretion, was defined as initiation of pushing 60 minutes or greater after complete dilatation. Baseline characteristics were compared between the 2 groups using χ2 analysis and the Student t and Mann-Whitney U tests. Mode of delivery and rates of maternal and neonatal outcomes were compared using χ2 and Fisher exact tests. P < 0.05 was considered statistically significant.
Of 5388 women who met inclusion criteria, 5290 were included in the analysis; 471 (8.9%) delayed pushing, and 4819 (91.1%) pushed immediately. The 2 groups did not differ in rates of diabetes and severe preeclampsia. Those who pushed immediately were more likely to use regional anesthesia, receive oxytocin, and have a high fetal station (zero station or above) when complete. The median length of the first stage of labor was 523 minutes in the delayed pushing group and 473 minutes in the immediate pushing group (P < 0.01). Delayed pushing was associated with lower rates of spontaneous vaginal delivery (77.5% vs 86.6%) and significantly increased risks of cesarean birth (3.2% vs 1.4%) and operative vaginal deliveries (19.3% vs 12.0%). Among multiparous women, similar results were seen. In nulliparous women, no differences in rates of mode of delivery were seen. Among women with high fetal station at the start of the second stage, delayed pushing did not affect mode of delivery. Maternal fever during the second stage or postpartum was increased in the delayed pushing group (10.9% vs 6.0%). Rates of postpartum hemorrhage (PPH) were 0.6% and 2.0% in the delayed pushing and immediate pushing groups, respectively. The rates of medication or blood transfusion used to treat PPH were not different between the 2 groups. Rates of retained placenta and shoulder dystocia did not differ significantly between the groups. Infants born to women who delayed pushing were more likely to have an umbilical artery pH <7.2 (10.8% vs 7.7%), but their rates of neonatal intensive care unit and high-acuity nursery admissions were not increased. Apgar scores less than 7 did not correlate with delayed or immediate pushing. Compared with women who pushed immediately, women who delayed pushing had a longer median second stage (129 vs 22 minutes; P < 0.01) and spent more time pushing (median, 26 vs 10 minutes; P < 0.01). When a 30-minute delay was used to define delayed pushing, it was still associated with increased risks of cesarean births (2.4% vs 1.4%, operative vaginal deliveries (16.2% vs 11.8%), maternal second-stage postpartum fever (9.6% vs 5.6%, and umbilical cord pH less than 7.2 (9.6% vs 7.5%). Rates of spontaneous vaginal delivery were also decreased in women who delayed pushing (81.4% vs 86.8%). Rates of PPH did not differ significantly between the groups. Delayed pushing was again associated with increased length of the second stage (85 vs 18 minutes; P < 0.01) and longer duration of pushing (20 vs 10 minutes; P < 0.01). The association of delayed pushing with longer durations of second-stage labor and pushing times persisted in analysis by parity and regional anesthesia use.
These findings do not support the routine use of delayed pushing to decrease duration of pushing and minimize adverse perinatal outcomes. However, the practice of delayed pushing in the second stage deserves further study. Large, prospective, randomized controlled trials are necessary to clarify the optimal management of second stage labor.