Trial of labour versus elective caesarean delivery for estimated large for gestational age foetuses after prior caesarean delivery: a multicenter retrospective study

BACKGROUND: Lower rates of successful trial of labor after cesarean (TOLAC) in association with fetal macrosomia were previously reported. This study aimed to compare TOLAC to elective caesarean delivery (CD) in women with estimated fetal weight large for gestational age (eLGA) and a prior CD. Primary outcome was to analyse the mode of delivery in case of TOLAC. Secondary outcome was to compare maternal and foetal morbidity. METHODS: We conducted a retrospective, descriptive, multicentric, cohort study in five maternity units between January and December 2020. Inclusion criteria were: women with a single prior CD and eLGA or neonatal weight > 90th percentile with singleton pregnancy and gestational age ≥ 37 weeks. Main outcome measures: rate of vaginal delivery, maternal and fetal morbidity including: shoulder dystocia, neonatal hospitalization, fetal trauma, neonatal acidosis, uterine rupture, 3(rd) and 4(th) perineal tears, post-partum hemorrhage, and a need for blood transfusion. RESULTS: Four hundred forty women met inclusion criteria, including 235 (53.4%) eLGA. 170 (72.3%) had a TOLAC (study group) and 65 (27.7%) an elective CD (control). 117 (68.82%) TOLAC had a vaginal delivery. No significant differences were found between the two groups in the rates of: postpartum haemorrhage, transfusion, Apgar score, neonatal hospitalization, and foetal trauma. Cord lactate was higher in the case of TOLAC (3.2 vs 2.2, p < 0.001). Median fetal weight was 3815 g (3597–4085) vs. 3865 g (3659–4168): p = 0.068 in the study vs. controls group respectively. CONCLUSION: TOLAC for eLGA fetuses is legitimate because there is no difference in maternal–fetal morbidity, and the CD rate is acceptable.