Cesarean delivery or use of antibiotics during the first 2 years of life are not associated with increased risk for attention-deficit/hyperactivity disorder (ADHD), according to study data published in The Journal of Child Psychology and Psychiatry.
Researchers extracted data on mode of delivery and antibiotic use during the first 2 years of life from nationwide data registers for all single live births in Denmark between 1997 and 2010. Outcome measures included clinical ADHD diagnosis or use of an ADHD medication prescription. The study followed 671,592 children between 1999 and 2014 for total 7,300,522 person-years.
Of the total cohort, 17.5% were delivered by cesarean and 72% received antibiotic treatment during the first 2 years of life. Per the adjusted between-within sibling survival model, cesarean delivery was not associated with increased risk for ADHD. This trend was consistent across both intrapartum cesarean and prelabor cesarean, with hazard ratios (95% CI) of 1.09 (0.97-1.24) and 1.03 (0.91-1.16), respectively, compared with vaginal delivery. In the same model, neither penicillin (hazard ratio [HR], 0.98; 95% CI, 0.90-1.07) nor broader spectrum antibiotics (HR, 0.99; 95% CI, 0.92-1.06) were found to affect risk for ADHD compared with no antibiotic use. In a sibling-stratified Cox regression analysis, intrapartum cesarean alone was associated with increased risk for ADHD (HR, 1.21; 95% CI, 1.01-1.45). However, researchers emphasized that the between-within model is significantly more efficient in identifying associations with large effect sizes.
These data reject any association between increased risk for ADHD and changes in children’s microbiota related to cesarean delivery or antibiotic use. Other studies have highlighted other familial or social factors as important to ADHD risk, which authors emphasized as important future research directions.
Axelsson PB, Clausen TD, Petersen AH, et al. Investigating the effects of cesarean delivery and antibiotic use in early childhood on risk of later attention deficit hyperactivity disorder [published online August 23, 2018]. J Child Psychol Psychiatry. doi: 10.1111/jcpp.12961