Advertisement

764: Second stage tachysystole is associated with adverse neonatal outcomes

      Objective

      Continuous electronic monitoring and tocometry is utilized in over 85% of deliveries in the United States. Although certain contraction patterns have been associated with poor neonatal outcomes, the relationship between contraction patterns in the second stage of labor and adverse outcomes are less understood. The aim of this study is to test the association between contraction characteristics in the second stage of labor and adverse neonatal outcomes.

      Study Design

      This is a prospective cohort study of all women with a term pregnancy (>37 0/7 weeks gestation) in the second stage of labor with an intrauterine pressure catheter (IUPC). Contraction characteristics including frequency, tachysystole (defined as greater than 5 contractions in 10 minutes), Montevideo units, and baseline uterine tone in the second stage of labor were assessed. If the second stage lasted longer than 120 minutes, only the final 120 minutes prior to delivery were included. The primary outcome was composite neonatal morbidity including death, need for hypothermic treatment, need for ventilatory support, meconium aspiration, seizures, or suspected sepsis. Regression models controlling for maternal age, nulliparity, gestational age, body mass index, diabetes, cesarean section, and birthweight >4000 grams were used to test the association between contraction characteristics in the second stage of labor and adverse neonatal outcomes.

      Results

      Of 7319 patients composite neonatal morbidity occurred in 513 (7.0%) neonates. Neonatal morbidity was significantly more common in nulliparous patients, diabetic patients, and those patients who underwent a cesarean section. Tachysystole occurred in 32.1% of all second stage labors and significantly increased the risk of adverse neonatal outcomes (17.9% versus 14.4%, aOR 1.41, CI 1.10, 1.81, p<0.01). Average MVUs, average resting uterine tone, and frequency of contractions in the second stage of labor were not associated with adverse neonatal outcomes.

      Conclusion

      Second stage tachysystole is associated with adverse neonatal outcomes. Providers should avoid tachysystole during the second stage of labor. If tachysystole cannot be avoided in the second stage, pediatric teams should be notified and neonatal resuscitation should be anticipated after deliveries.
      Figure thumbnail fx1