Maternal outcomes according to cesarean uterine incision between 23 and 27 weeks' gestation

Cesarean delivery between 23 and 27 weeks' gestation is a risk factor for performing classical and inverted T uterine incisions. When attempting cesarean delivery via a low transverse incision at a very preterm gestational age, having difficulty in delivery of the fetus may require conversion to an inverted T-incision. We sought to examine maternal short-term outcomes according to the type of attempted uterine incisions in preterm deliveries.

This was a multihospital retrospective cohort study of women undergoing cesarean delivery between 23 0/7 and 27 6/7 week' gestation from 2005 through 2014. Cases were classified as attempting low transverse incision if the uterine incision was a low transverse or an inverted T incision. Composite maternal outcome (postpartum hemorrhage, transfusion, endometritis, sepsis, wound infection, deep venous thrombosis/pulmonary embolism, hysterectomy, respiratory complications, and intensive care unit admission) was compared between cases where a low transverse incision was attempted and those with a classical uterine incision. We also examined operative time and Apgar score at 5 minutes. Multivariable logistic regression or linear regression was used to obtain adjusted p-value or adjusted odds ratios (aOR) with 95% confidence interval (95%CI), controlling for maternal age, gestational age, body mass index (kg/m²), and preterm premature rupture of membranes.

Of 311 women undergoing cesarean delivery between 23 0/7 and 27 6/7 week' gestation, attempting low transverse incision occurred in 127 (41%). Of these, conversion to an inverted T or J uterine incision occurred in 14 (11%). There was no difference in the composite outcome between cases with attempting low transverse incision and those with classical incision (17.3 versus 23.4%, respectively; aOR 0.58 [95%CI 0.30-1.11]). Cases in which a low transverse uterine incision was attempted had shorter median operative time (46 versus 55 minutes; adjusted p-value < 0.01). No differences were seen in the Apgar score at 5 minutes (adjusted p-value = .81).

The incidence of conversion from a low transverse to an inverted T uterine incision in very preterm cesarean deliveries was low. Attempting a low transverse compared to a classical uterine incision was associated with similar odds of the primary outcome and shorter operative time.