Prolonged second-stage labor may carry risks

According to a new retrospective study in Obstetrics & Gynecology, second-stage labor that lasts more than 2 hours may increase the risk of complications.

Researchers from The Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development looked at electronic medical record data from 19 hospitals from 2002 to 2008. They analyzed 43,810 nulliparous and 59,605 multiparous singleton deliveries at 36 weeks or greater gestational age with vertex presentation and that reached 10-cm cervical dilation. For nulliparous women, prolonged second stage was defined as greater than 3 hours with an epidural and greater than 2 hours without an epidural; in multiparous women, it was defined as greater than 2 hours with an epidural and greater than 1 hour without an epidural. Outcomes for mothers and infants were compared and adjusted odds ratios (aORs) were calculated while controlling for maternal race, body mass index, insurance, and region.

[Related: When's the right time for operative delivery?]

Prolonged second-stage labor occurred in 9.9% of nulliparous and 3.1% of multiparous women who had an epidural; it occurred in 13.9% of nulliparous and 5.9% of multiparous women who did not have an epidural. Vaginal delivery rates with prolonged second stage when compared with within guidelines were 79.9% compared with 97.9% and 87.0% compared with 99.4% for nulliparous women, with and without epidural, respectively, and 88.7% compared with 99.7% and 96.2% compared with 99.9% for multiparous women, with and without epidural, respectively (P<.001 for all comparisons).

Patience: The answer to the cesarean epidemic?

Neonatal morbidity associated with prolonged second-stage labor included sepsis in nulliparous women (with epidural: 2.6% compared with 1.2% [aOR 2.08, 95% confidence interval {CI} 1.60-2.70]; without epidural: 1.8% compared with 1.1% [aOR 2.34, 95% CI 1.28-4.27]); asphyxia in nulliparous women with epidural (0.3% compared with 0.1% [aOR 2.39, 95% CI 1.22-4.66]); and perinatal mortality without epidural (0.18% compared with 0.04% for nulliparous women [adjusted OR 5.92, 95% CI 1.43-24.51]); and 0.21% compared with 0.03% for multiparous women (adjusted OR 6.34, 95% CI 1.32-30.34). No cases of hypoxic-ischemic encephalopathy or perinatal death were found among the women with epidurals who had a prolonged second stage (3533 nulliparous and 1348 multiparous women).

The investigators concluded that a prolonged second stage of labor may carry risks and that the benefits of increased vaginal delivery should be weighed against these risks.

To get weekly advice for today's Ob/Gyn, subscribe to the Contemporary Ob/Gyn Special Delivery.