PurposeEpidemiological studies assessing the effects of previous cesarean section (CS) on subsequent delivery mode using large nationwide study populations. This study aims to calculate the incidence rates of trial of labors after cesarean section (TOLACs) and evaluate the annual rates of vaginal births after cesarean section (VBAC) during the last decades in Finland.MethodsData from the National Medical Birth Register (MBR) were used to evaluate incidence rates of VABC in the Finnish population (1998–2018). All nulliparous women having their first and second pregnancy during our study period, and with the mode of delivery identified in both of these pregnancies were included in this study. Absolute annual numbers and incidence rates for TOLACs, elective CS, and VBAC were calculated.ResultsThe absolute number of TOLACs had an increasing trend during our study period, increasing up to 2118 TOLACs in 2016. The incidence rates for elective CS after the first CS had a decreasing trend, decreasing from 45% in 1999, to 28% in 2018. The absolute number of VBACs had an increasing trend during our study period, peaking in 2016 (1466 VBACs). The rates for VBAC remained relatively constant, ranging between 38 and 52%, but a slightly increasing trend at the end of the study period was seen.ConclusionDespite the increasing annual total number of deliveries with CS in the first pregnancy, the absolute numbers and rates for VBACs have increased towards the end of the study period in Finland. The epidemiology of TOLACs and VBACs should be better studied around the world, as with the rapidly increasing rate of CSs, these events are becoming more common challenges in health care.