Timing of operative vaginal delivery and associated perinatal outcomes in nulliparous women

Abstract

Objective. To compare perinatal outcomes in nulliparous women who had operative vaginal delivery early during second stage (1–3 h) to those who delivered vaginally with a prolonged second stage (>3 h).

Methods. This is a retrospective cohort study of nulliparas with term, singleton, vaginal deliveries beyond the first hour of second stage. Women who underwent operative vaginal deliveries (OVD) during 1–3 h of the second stage were compared to women who delivered vaginally but with a second stage duration of >3 h. Perinatal outcomes were examined using chi-square test, and potential confounders were controlled for using multivariable logistic regression analysis.

Results. Nulliparas delivered vaginally beyond 3 h of second stage had lower odds of third or fourth degree perineal lacerations (aOR = 0.63, 95% CI 0.51–0.77), neonatal cephalohematoma (aOR = 0.48, 95% CI 0.28–0.83) and admissions to intensive care nursery (aOR = 0.70, 95% CI 0.49–0.99) compared to operative vaginal deliveries during 1–3 h of second stage.

Conclusion. Compared to nulliparas who had operative vaginal deliveries performed early (1–3 h) in the second stage, women who delivered later (>3 h duration of second stage), either by spontaneous or operative vaginal delivery, had lower risk of third or fourth degree perineal lacerations without incurring risk of increased adverse neonatal outcomes.

Keywords:

• Operative vaginal delivery
• perineal laceration
• prolonged second stage

Acknowledgments

Dr. Yvonne W. Cheng is supported by the UCSF Women's Reproductive Health Research Career Development Award, NIH, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (K12 HD001262). Dr. Aaron B. Caughey is supported by the Robert Wood Johnson Foundation as a Physician Faculty Scholar. Dr. Katherine Bianco is supported by March of Dimes Reproductive Sciences Development Program Scholar/NIH/NICHD