Cesarean Delivery Upon Request in Pregnancies Following Vaginal Delivery: A Nationwide Study.

Background: The increasing rate of cesarean delivery (CD) is a significant concern in many societies worldwide. Vaginal delivery (VD) is preferred over CD for subsequent pregnancies after successful VD, for women with no specific obstetrical indications, primarily because of concerns about potential complications arising from the surgical procedure. However, the factors that influence the decision of requesting a CD have not yet been thoroughly investigated. This study aimed to examine the underlying reasons that lead mothers to choose CDs in subsequent pregnancies following a VD.

Methods: This retrospective study included women who underwent VD in their first pregnancy between 2011 and 2020 and had a second pregnancy and childbirth within the study period. The analysis focused on women eligible for a trial of labor (TOL) in their second pregnancy, excluding those with conditions necessitating a CD. The study defined two groups: the TOL in second pregnancy (TOLS) group, consisting of women with one previous VD who attempted a VD in their subsequent pregnancy; and the CD on maternal request in second pregnancy (CDRS) group, comprising women with one past VD who opted for a CD in their second pregnancy without medical indication. The TOLS and CDRS groups were compared regarding obstetric and neonatal outcomes.

Results: During the study period, 372,749 women met the inclusion criteria: 368,311 women in TOLS group and 4,438 women in CDRS group. In the regression analysis for the CDRS, several factors were identified as increasing the risk of choosing CD, including age (adjusted odds ratio [aOR], 1.06; 95% confidence interval [CI], 1.05-1.07), interval between the first and second pregnancies (aOR, 1.32; 95% CI 1.29-1.35), a history of pre-existing hypertension (aOR, 1.76; 95% CI, 1.17-2.65), gestational diabetes mellitus (GDM) during the first pregnancy (aOR, 1.19; 95% CI, 1.05-1.36), hypertensive disease during pregnancy (HDP) (aOR, 1.33; 95% CI, 1.06-1.67), preterm labor during the first pregnancy (aOR, 1.57; 95% CI, 1.32-1.86), postpartum hemorrhage (aOR, 1.33; 95% CI, 1.21-1.47), traumatic event during delivery (aOR, 1.19; 95% CI, 1.12-1.28), surgical VD (aOR, 1.29; 95% CI, 1.19-1.40), and pregnancies with abortive outcomes between the first and second pregnancies (aOR, 1.18; 95% CI, 1.08-1.29). Additionally, women with pre-existing diabetes (aOR, 1.53; 95% CI, 1.24-1.89), pre-existing hypertension (aOR, 1.69; 95% CI, 1.26-2.26), GDM (aOR, 1.23; 95% CI, 1.11-1.37), or HDP (aOR, 2.57; 95% CI, 2.24-2.94) during the second pregnancy continued to exhibit an increased risk of opting for CD even after adjustment.

Conclusion: CD after VD was more prevalent among women with certain demographic characteristics and obstetric histories. Investigating the factors influencing women to request CD can be helpful in making informed decisions about safe delivery methods and may also affect the CD rate.