Uterine Incision-to-Delivery Interval and Neonatal Outcomes among Non-urgent, Term, Cesarean Deliveries
By: Yossi Bart, et al published in the American Journal of Obstetrics and Gynecology in December 2025.
Uterine Incision-to-Delivery Interval and Neonatal Outcomes among Non-urgent, Term, Cesarean Deliveries, by: Yossi Bart, published in the American Journal of Obstetrics and Gynecology in December 2025.
This retrospective cohort study examined the uterine incision-to-delivery interval, defined as the time from hysterotomy to complete fetal delivery. Among 5,850 non-urgent, term singleton cesarean deliveries, longer intervals were independently associated with higher rates of a composite adverse neonatal outcome and neonatal acidemia. Compared with intervals under 120 seconds, intervals of 121–239 seconds and ≥240 seconds showed a graded increase in neonatal risk. Maternal outcomes were largely similar, aside from more hysterotomy extensions with prolonged extraction.
Dr. Amos commentary:
The physiologic premise deserves clarification. Direct human data measuring uteroplacental blood flow at hysterotomy are limited, but several mechanisms are biologically plausible.
Uterine incision disrupts myometrial integrity, can provoke localized uterine contraction, transient hypotension, or partial placental separation, and often coincides with exteriorization or manipulation that may further reduce perfusion.
Experimental and indirect clinical data suggest that once the uterus is opened, the placental circulation becomes more vulnerable to even brief delays. That said, the evidence is inferential rather than directly measured, and this study demonstrates association, not mechanism. Importantly, skin-to-uterus time likely conditions what follows, as difficult entry often predicts compromised extraction.
Why this matters:
Neonatal risk appears to rise once the uterus is opened, even without direct perfusion measurements, reinforcing the need to optimize the entire skin-to-uterus-to-delivery sequence rather than focusing on a single interval.