Reduced Fertility After Cesarean Delivery

OBJECTIVE: To explore the association between mode of delivery and subsequent fertility. METHODS: Deliveries registered in the Medical Birth Registry of Norway were linked to mothers through national identification numbers. The study population was 596,341 women who had their first delivery during 1967-1996, and who were followed up through 2003. We compared rates of continuation to a subsequent birth according to mode of previous delivery (cesarean compared with vaginal). RESULTS: If the first child survived the first year of life, cesarean delivery was associated with a significantly reduced probability of a second birth (relative risk [RR] 0.82, 95% confidence interval [CI] 0.81-0.83 during 1967-1981, and RR 0.88, 95% CI 0.88-0.89 during 1982-1996). Following a stillbirth or an infant loss, the association was less strong during 1967-1981 (RR 0.93, 95% CI 0.89-0.97) and no longer significant during 1982-1996 (RR 1.00, 95% CI 0.97-1.03). A similar pattern was observed from the second to the third birth and in subgroup analyses of women with preeclampsia or breech presentation and in an obstetric low-risk group. CONCLUSION: Cesarean delivery was more strongly associated with reduced fertility if the infant survived than if it was stillborn or died. This suggests that the reduced fertility was to a large degree voluntary and not related to the indication, nor to any physical consequence, of the cesarean delivery. LEVEL OF EVIDENCE: II.