Previous caesarean delivery linked to low live birth rates following in vitro fertilization

Women with a history of caesarean delivery appear to have lower live birth rates after the first subsequent embryo transfer, according to a retrospective study.

Researchers looked at a registry-based cohort of 7,460 patients with a previous delivery who subsequently underwent an embryo transfer.

The primary outcome was the live birth (≥20 weeks of gestational age or 500 g) rate following the embryo transfer. Secondary outcomes included positive serum human chorionic gonadotropin (hCG), implantation, clinical pregnancy, and ongoing clinical pregnancy. 

Of the patients, 4,587 patients had a previous vaginal delivery and 2,873 had a previous caesarean delivery. Live birth rate was significantly lower among patients with a previous caesarean delivery than those with a previous vaginal delivery (adjusted risk ratio [aRR], 0.84, 95 percent confidence interval [CI], 0.80–0.90).

Previous caesarean delivery was also associated with lower rates of positive hCG (aRR, 0.92, 95 percent CI, 0.88–0.96), implantation (aRR, 0.91, 95 percent CI, 0.86–0.96), clinical pregnancy (aRR, 0.90, 95 percent CI, 0.85–0.95), ongoing pregnancy (aRR, 0.87, 95 percent CI, 0.82–0.92), and live birth with good perinatal outcome (aRR, 0.82, 95 percent CI, 0.76–0.88) when compared with a previous vaginal delivery.

Additional studies are warranted to investigate possible aetiologies that underlie the association between a previous caesarean delivery and low birth rates after in vitro fertilization.