Trial of labour following two previous caesarean sections - A UK cohort study

To assess the (i) predictors of and associated rates of success and; (ii) maternal and perinatal outcomes of women undergoing trial of labour after two previous caesarean sections (TOLA2C).

This retrospective cohort study collected data from two regional obstetric centres with 12,000 deliveries per annum collectively. The population included singleton pregnancies undergoing (i) TOLA2C, (ii) elective repeat caesarean section following two caesarean sections (ERCS) and (iii) trial of labour after one caesarean section (TOLA1C). Data was collected electronically from 2013 to 2021. Statistical analysis included Fisher exact and Kruskal-Wallis test to compare unpaired samples alongside univariate and multivariable logistic regression. The primary outcome measure was maternal and perinatal outcome.

The three groups included; n = 146 TOLA2C, n = 206 ERCS and n = 99 TOLA1C. TOLA2C had a success rate of 65 % compared to 74 % for TOLA1C (p = 0.16). The optimal predictor of successful TOLA2C was previous successful TOLA1C OR 8.65 (95 % CI 2.75-38.41). TOLA2C was associated with greater risk of endometritis and/or sepsis postnatally compared to the other two groups [10.3 % (n = 15) versus 0.5 % (n = 1) and 3 % (n = 3) for ERCS and TOLA1C respectively p < 0.01]. It was also associated with longer maternal hospital stay [2.4 days (+/-1.8) versus 1.8 (+/-0.8) and 1.8 (+/-1.7) p < 0.01], a greater proportion of neonates with Apgar scores less than 7 (p=<0.01) and higher rates of neonatal unit admission [14 % (n = 20) versus 5 % (n = 11) versus 4 % (n = 4) (p=<0.01)].

Women considering trial of labour following two caesarean sections should be counselled regarding the potential increased risk of endometritis, sepsis and adverse neonatal outcome.