4. Discussion
scar rupture
IOL, SCAR, DEHISCENCE, COMPLICATION, GESTATIONAL HYPERTENSION, SECONDARY, COMPLICATED PREGNANCIES
In our pilot randomized controlled trial, we found that in the uncomplicated pregnancies with a previous caesarean delivery, IOL at 40 completed weeks achieved significantly higher successful vaginal deliveries than planned expectant management till 41 weeks. Our study was not powered to analyze maternal or perinatal outcomes. We had strict inclusion criteria to reduce the possible rates of scar dehiscence. So, we excluded many women from the trial who could have undergone TOLAC if they were in spontaneous labour. However, 13 (43%) of the women in the expectant group in our study went into spontaneous labour. Seven of these thirteen (54%) delivered vaginally. Another seven women (23%) in the expectant group developed a maternal or foetal complication needing induction before 41 weeks (one woman (3.3%) developed gestational hypertension de novo). The VBAC rates among those induced after 40 weeks in the expectant arm were much lower (19%) than those who had spontaneous labour (54%). The VBAC rate of spontaneous labour after 40 weeks compares well with those induced before 40 weeks.The landmark ARRIVE trial [To our knowledge, there are no randomized controlled trials on this subject in women with previous caesarean delivery. Only a few cohort studies are comparing IOL with expectant management in women with a previous caesarean section at term. The first study was a large retrospective cohort of 16 years [In another secondary analysis study of an obstetric cohort from the consortium of safe labour, among women with previous caesarean section who attempted TOLAC, the authors [A 3-year retrospective cohort was recently published [In our study, we had strict inclusion criteria. We took 3 mm as the cut-off for eligibility for TOLAC though RCOG recommends scar thickness above 2 mm. We took a higher cut-off for the total thickness of the scar on sonography because IOL has a 2 to 3 times higher risk of scar rupture, and the meta-analysis done in 2013 [