Factors associated with cesarean birth in nulliparous women: A multicenter prospective cohort study

There is widespread concern around the rising rates of cesarean births (CBs), especially among first-time mothers, despite evidence suggesting increased morbidities after birth by cesarean. There are uncertainties around factors associated with rising rates of CBs among first-time mothers in Ireland, and insight into these is essential for understanding the rising trend in CBs. Therefore, this study aimed to identify the factors associated with CBs in nulliparous women.

A prospective cohort study was conducted in three maternity hospitals in the Republic of Ireland between 2012 and 2017. Data were collected from 3047 nulliparous women using self-administered surveys antenatally and at 3 months postpartum and from consenting women's hospital records (n = 2755) and analyzed using the Poisson regression to assess associations between demographic and clinical factors and the main outcome measures, planned and unplanned CBs.

Common risk factors for planned and unplanned CBs were being aged ≥40 years, being in private care, multiple pregnancy, and fetus in breech or other malpresentations. An unplanned CB occurred for 22.43% (n = 377/1681) of women who did not have induction of labor (IOL) or who had IOL with no epidural, but the risk was about twice as high for women who had IOL and epidural.

Findings confirm multifactorial reasons for CB and the challenge of reversing the increasing CB rate if maternal age, overweight/obesity, infertility treatment, multiple pregnancy, and preexisting hypertension in Ireland continue to increase. There is a need to address prelabor interventions, especially IOL combined with epidural analgesia with respect to unplanned CB.