Prolonged Uterine Incision-to-Delivery Time tied to Adverse Neonatal Outcomes: Study

A new study published in the American Journal of Obstetrics and Gynecology showed that longer uterine incision-to-delivery intervals were independently linked to higher newborn morbidity and acidemia in non-urgent term cesarean births.

The time that uteroplacental blood flow is disrupted during cesarean birth is known as the uterine incision-to-delivery interval. Due to small sample numbers, a variety of delivery justifications, and the use of surrogate indicators such cord gases or Apgar scores rather than clinical morbidity, previous research assessing its relationship with infant outcomes has produced contradictory results. Thus, this study assessed the relationship between unfavorable newborn outcomes in non-urgent singleton term cesarean births and the uterine incision-to-delivery delay.

All singleton pregnancies delivered by non-urgent cesarean birth at term (≥37 weeks) at a single tertiary medical center between 2017 and 2021 were included in this retrospective cohort analysis. Major fetal abnormalities, fetal mortality, non-reassuring fetal tracing, unsuccessful surgical delivery, cord prolapse, suspected abruption, uterine rupture, or placenta accreta were eliminated, as were deliveries made out of concern for fetal or maternal compromise.

The time between the uterine incision and birth was divided into usual (less than 120 seconds), protracted (between 121 and 239 seconds), and extreme delay (more than 240 seconds). A composite of newborn poor outcomes, like respiratory support, therapeutic hypothermia, birth damage, or neonatal mortality, was the main outcome. Maternal outcomes and umbilical artery cord gases were examples of secondary outcomes.

5,850 (15.4%) of the 38,057 deliveries satisfied the inclusion requirements. In 67.1% of cases, the incision-to-delivery period was less than 120 seconds, in 28.9% it was between 121 and 239 seconds, and in 4.0% it was more than 240 seconds. Prolonged and severely delayed extraction were linked to a greater risk of composite neonatal bad outcomes (adjusted relative risk [aRR] 2.18 and 3.39, respectively), with the risk rising by 0.6 percentage points every minute when compared to intervals <120 seconds.

Neonatal acidemia, involving umbilical artery pH <7.1 and base deficit ≥12 mmol/L, was substantially correlated with intervals ≥240 seconds; the probability of acidemia increased by 1.5 percentage points for every extra minute. These correlations were true for all sensitivity studies. With the exception of greater rates of spontaneous hysterotomy extension in the ≥240-second group, maternal morbidity was generally comparable across groups. Overall, in non-urgent term cesarean births, longer uterine incision-to-delivery intervals were independently linked to a higher risk of both acidemia and newborn morbidity.

Source:

Bart, Y., Sibai, B. M., Bartal, M. F., Mazaki-Tovi, S., & Yoeli, R. (2025). Uterine incision-to-delivery interval and neonatal outcomes among non-urgent, term, cesarean deliveries. American Journal of Obstetrics and Gynecology. https://doi.org/10.1016/j.ajog.2025.12.059