Previous caesarean section is associated with lower subsequent in vitro fertilization live birth rates

This retrospective cohort study examines the association between previous mode of delivery and subsequent live birth rate in women who become pregnant after in vitro fertilization (IVF) or intra cytoplasmic sperm injection (ICSI) after their first delivery. The study included 112 women with a previous caesarean section and 418 women with a previous vaginal delivery, and a total of 1588 embryo transfers between January 2005 and June 2016 (Leiden University Medical Centre, the Netherlands). The mean age was 35 years and mean number of embryos transferred per attempt, 1.18. The study population included a total of 429 pregnancies resulting in 296 live births. The crude odds ratio for a subsequent live birth per embryo transfer was 0.60 (CI; 0.44 to 0.83, p = 0.002) in women with a previous caesarean section compared to women with a previous vaginal delivery. After adjustment for age, fresh/frozen-thawed embryo transfer and quality of the embryo, the odds ratio was 0.64 (CI; 0.46 to 0.89, p = 0.01). It was concluded that in subfertile women trying to achieve a subsequent pregnancy with IVF or ICSI, a history of caesarean section was associated with a reduced live birth rate per embryo transfer compared to women with a history of one previous vaginal delivery.