No correlation seen for elective, emergency cesarean section in sibling control analysis
FRIDAY, June 26, 2015 (HealthDay News) — While initial study results suggested children born by cesarean section are more likely to be diagnosed with autism spectrum disorder, the association did not remain in additional analysis of sibling pairs, implying the increased risk was more likely due to unknown genetic or environmental factors. The findings were published online June 24 in JAMA Psychiatry.
Eileen A. Curran, M.P.H., from the Cork University Maternity Hospital in Ireland, and colleagues examined the correlation between mode of delivery and ASD. The cohort included all singleton live births in Sweden from 1982 through 2010. Data were included for 2,697,315 children and 28,290 ASD cases. A total of 13,411 sibling pairs were included in sibling control analysis.
The researchers found that, compared with unassisted vaginal delivery, elective CS and emergency CS correlated with ASD in adjusted analysis (hazard ratios, 1.21 [95 percent confidence interval (CI), 1.15 to 1.27] and 1.15 [95 percent CI, 1.10 to 1.20], respectively). Elective CS was not associated with ASD in partially or fully adjusted models in the sibling control analysis (odds ratios, 0.97 [95 percent CI, 0.85 to 1.11] and 0.89 [95 percent CI, 0.76 to 1.04], respectively). In partially adjusted analysis, emergency CS correlated with ASD (odds ratio, 1.20; 95 percent CI, 1.06 to 1.36); the effect was no longer significant in the fully adjusted model (odds ratio, 0.97; 95 percent CI, 0.85 to 1.11).
“The association did not persist when using sibling controls, implying that this association is due to familial confounding by genetic and/or environmental factors,” the authors write.
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