Evaluating the impact of the second-stage and pushing duration on maternal and neonatal outcomes: a systematic review and meta-analysis.

OBJECTIVE

This systematic review and meta-analysis aimed to investigate the association between the duration of the second stage of labor-including both total duration and the active pushing-and adverse maternal and neonatal outcomes, stratified by parity.

DATA SOURCES

We conducted a comprehensive literature search of MEDLINE, Embase, and Cochrane databases from inception through October 2024.

STUDY ELIGIBILITY CRITERIA

Eligible studies reported maternal or neonatal outcomes related to second-stage duration or pushing duration, with data stratified by parity. Studies involving multiple gestations and those with prior cesarean deliveries were excluded.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two independent reviewers performed data extraction and quality assessments; disagreements were resolved by a third reviewer. Cesarean delivery was prespecified as the primary maternal outcome, while other maternal and neonatal outcomes were analyzed as secondary outcomes. To quantify the association between prolonged second-stage or pushing duration (≥60 minutes) and each outcome, we performed post-hoc random-effects meta-analyses (Mantel-Haenszel) restricted to outcomes for which ≥2 eligible studies used <60 minutes as the reference category. Thus, only those studies meeting this criterion were pooled.

RESULTS

In total, 26 studies met the inclusion criteria: 18 retrospective cohort studies, 1 prospective cohort study, 6 secondary analyses of clinical trials, and 1 randomized controlled trial. Among nulliparous individuals, a second stage exceeding 1 hour was associated with increased risks of cesarean delivery, blood transfusion, perineal laceration, and chorioamnionitis; pushing beyond 1 hour was similarly associated with cesarean delivery and postpartum hemorrhage. Comparable trends were observed in multiparous individuals. Across both parity groups, neonatal intensive care unit admission was more frequent when the second stage exceeded 1 hour. In nulliparous individuals, pushing beyond 60 minutes was significantly associated with a low 5-minute Apgar score and neonatal intensive care unit admission. Only one study specifically evaluated pushing duration among multiparous individuals, finding no significant associations with neonatal morbidity.

CONCLUSION

Evidence indicates maternal and neonatal morbidity begins to rise within the first hour of the second stage and climbs with further prolongation, although the exact tipping point varies. Active pushing ≥60 minutes was associated with an increased risk of maternal morbidity, while neonatal effects are less certain; in nulliparas, we found an increased neonatal morbidity with pushing ≥60 minutes. Because the pooled estimates rely on a small, clinically heterogeneous subset of studies, these findings should be viewed with caution. Future studies should examine the individualized approach to determine the optimal timing of intervention, stratified by parity and epidural status, to refine duration guidelines.