Neonatal and maternal outcomes with prolonged second stage of labor

Abstract

Objective: To assess neonatal and maternal outcomes when the second stage of labor was prolonged according to American College of Obstetricians and Gynecologists guidelines.

Methods: Electronic medical record data from a retrospective cohort (2002-2008) from 12 U.S. clinical centers (19 hospitals), including 43,810 nulliparous and 59,605 multiparous singleton deliveries at 36 weeks of gestation or greater, vertex presentation, who reached 10-cm cervical dilation were analyzed. Prolonged second stage was defined as: nulliparous women with epidural greater than 3 hours and without greater than 2 hours and multiparous women with epidural greater than 2 hours and without greater than 1 hour. Maternal and neonatal outcomes were compared and adjusted odds ratios calculated controlling for maternal race, body mass index, insurance, and region.

Results: Prolonged second stage occurred in 9.9% and 13.9% of nulliparous and 3.1% and 5.9% of multiparous women with and without an epidural, respectively. Vaginal delivery rates with prolonged second stage 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). Prolonged second stage was associated with increased chorioamnionitis and third-degree or fourth-degree perineal lacerations. Neonatal morbidity with prolonged second stage included sepsis in nulliparous women (with epidural: 2.6% compared with 1.2% [adjusted odds ratio (OR) 2.08, 95% confidence interval (CI) 1.60-2.70]; without epidural: 1.8% compared with 1.1% [adjusted OR 2.34, 95% CI 1.28-4.27]); asphyxia in nulliparous women with epidural (0.3% compared with 0.1% [adjusted OR 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). However, among the offspring of women with epidurals whose second stage was prolonged (3,533 nulliparous and 1,348 multiparous women), there were no cases of hypoxic-ischemic encephalopathy or perinatal death.

Conclusions: Benefits of increased vaginal delivery should be weighed against potential small increases in maternal and neonatal risks with prolonged second stage.

Level of evidence: : II.

Figure 1

Mode of Delivery and Neonatal Outcomes According to Duration of Second Stage in Women by Parity and Epidural Status. A. Vaginal delivery; B. Nonoperative vaginal delivery; C. Composite maternal morbidity; D. Composite neonatal morbidity. Prolonged second stage as per American College of Obstetricians and Gynecologists guidelines was defined as: for nulliparous women > 3 hours with epidural or > 2 hours without; multiparous women > 2 hours with epidural or > 1 hour without. (15) Maternal composite morbidity included postpartum hemorrhage, blood transfusion, cesarean hysterectomy, endometritis, or intensive care unit admission (ICU). Neonatal composite morbidity included shoulder dystocia, 5 minute Apgar < 4, need for continuous positive airway pressure resuscitation or higher, neonatal ICU admission, sepsis, pneumonia, hypoxic-ischemic encephalopathy/ periventricular leukomalacia, seizure, intracranial hemorrhage/periventricular hemorrhage, asphyxia, or perinatal death. Error bars indicate 95% confidence intervals and asterisks are for significance in the unadjusted models. All associations remained significant after controlling for maternal race, BMI, insurance and region. (Note that unadjusted composite maternal morbidity rates were not higher for multiparous women with prolonged second stage, but there was a significantly increased odds for multiparous women with an epidural after adjustment.)

Figure 1

Mode of Delivery and Neonatal Outcomes According to Duration of Second Stage in Women by Parity and Epidural Status. A. Vaginal delivery; B. Nonoperative vaginal delivery; C. Composite maternal morbidity; D. Composite neonatal morbidity. Prolonged second stage as per American College of Obstetricians and Gynecologists guidelines was defined as: for nulliparous women > 3 hours with epidural or > 2 hours without; multiparous women > 2 hours with epidural or > 1 hour without. (15) Maternal composite morbidity included postpartum hemorrhage, blood transfusion, cesarean hysterectomy, endometritis, or intensive care unit admission (ICU). Neonatal composite morbidity included shoulder dystocia, 5 minute Apgar < 4, need for continuous positive airway pressure resuscitation or higher, neonatal ICU admission, sepsis, pneumonia, hypoxic-ischemic encephalopathy/ periventricular leukomalacia, seizure, intracranial hemorrhage/periventricular hemorrhage, asphyxia, or perinatal death. Error bars indicate 95% confidence intervals and asterisks are for significance in the unadjusted models. All associations remained significant after controlling for maternal race, BMI, insurance and region. (Note that unadjusted composite maternal morbidity rates were not higher for multiparous women with prolonged second stage, but there was a significantly increased odds for multiparous women with an epidural after adjustment.)