Prior c-section raises stillbirth risk

Previous caesarean section increases the risk of delivering a stillborn infant. Researchers from the University of Oxford analysed information in a database of births and deaths in the Oxfordshire and West Berkshire area of the UK between 1968 and 1989. There were 81,707 pregnancies with complete data for analysis during the 21-year study period. The data showed a previous caesarean section in 5,939 of the pregnancies. Overall, there were 290 stillbirths. The rate of stillbirths was 3.5 per 1,000 deliveries when there was no history of caesarean section, but 4.6 per 1,000 deliveries among women with a history of caesarean section. The calculated risk of stillbirth was 30% higher after a caesarean section delivery. Similar findings have been reported in three other studies suggesting this association may be a causal one. Mothers who had previous caesarean sections tended to be older, to have had fewer children, and have a higher rate of complications during the pregnancy than those with no prior c-sections. The investigators estimate that around 4% of all stillbirths in the population may be attributable to previous delivery by caesarean section. Further research is needed to understand why this is happening. Although there is an increased potential risk of stillbirth in subsequent deliveries after a c-section, the risk to any particular pregnancy is very small.