Is there an increased risk for drug treated attention deficit/hyperactivity disorder in children born after in vitro fertilization?

BACKGROUND: There is mounting evidence that children born after in vitro fertilization (IVF) run an increased risk of neurological complications and notably cerebral palsy. Whether developmental disturbances occur more often than expected is debated. AIM: To investigate the risk for ADHD in children conceived after IVF. METHODS: Children conceived after IVF and born between 1982 and 2005 were identified from all IVF clinics in Sweden. Children who developed attention deficit/hyperactivity disorder (ADHD) were identified with the use of a register over all prescribed drugs in Sweden, using prescriptions for methylphenidate or atomixetine as indicators of ADHD. Maternal and neonatal characteristics were obtained by linkage with the Medical Birth Register and relevant confounders were adjusted for using Mantel-Haenszel procedures. We studied 28 158 children born after IVF and compared them with 2 417 886 children in the population. RESULTS: After adjustment for year of birth, maternal age, parity, smoking, BMI, and maternal education and after exclusion of women who did not cohabit, a weak but statistically significant association was found with an odds ratio=1.18, 95% confidence interval 1.03-1.36. The effect was stronger in girls (OR=1.40) than boys (OR=1.11) but this difference could be random. After adjustment for length of involuntary childlessness, the OR decreased slightly and lost statistical significance. CONCLUSIONS: The study suggests a weak association between IVF and drug treated ADHD.