The association of birth by caesarean section and cognitive outcomes in offspring: a systematic review.

Purpose Studies have reported children born by caesarean section are more likely to have lower cognitive outcomes compared to those born by vaginal delivery. This paper reviews the literature examining caesarean birth and offspring cognitive outcomes. Methods A systematic search for observational studies or case-control studies that compared cognitive outcomes of people born by caesarean section with those born by vaginal delivery was conducted in six databases (Medline, PubMed, EMBASE, PsychInfo, CINAHL, Web of Science) from inception until December 2019 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were assessed for quality and a narrative synthesis was undertaken considering the evidence for a causal relationship according to the Bradford Hill Criteria. Results A total of seven studies were identified. Of these, four found a significant association between elective and emergency caesarean birth and reduction in offspring cognitive performance as measured by school performance or validated cognitive testing. Three studies found no association. There was variability in the quality of the studies, assessment of the reason for caesarean section (emergency vs elective), measurement of outcomes and adjustment for confounding factors. Conclusion The evidence of an association between CS birth and lower offspring cognitive functioning is inconsistent. Based on currently available data, there is no evidence that a causal association exists. To better examine this association, future studies should (a) distinguish elective and emergency caesareans, (b) adequately adjust for confounding variables and (c) have valid outcome measures of cognition.