(HealthDay News) – In vitro fertilization (IVF) treatment is associated with a small but significant increase in the risk of mental retardation, but not with autistic disorder, according to a study published in the July 3 issue of the Journal of the American Medical Association.
Sven Sandin, from King’s College London, and colleagues conducted a prospective cohort study using Swedish national health registers to examine the correlation between IVF and autism or mental retardation. More than 2.5 million infants born between 1982 and 2007, 1.2% conceived by IVF, were followed for a mean of 10 years, through December 2009.
The researchers found that 1.5% of children with autistic disorder and 1.1% with mental retardation were conceived by IVF. Compared with spontaneous conception, the relative risk for autistic disorder after any procedure was 1.14 (95% confidence interval, 0.94–1.39). For mental retardation, the corresponding relative risk was significantly increased, at 1.18. On restriction of the analysis to singletons, the associations were not statistically significant. A significantly increased risk of autistic disorder was seen following intracytoplasmic sperm injection (ICSI) using surgically extracted sperm and fresh embryos (relative risk, 4.6), while the risks of mental retardation were increased for ICSI using surgically extracted sperm and fresh embryos and using ejaculated sperm and fresh embryos (relative risk, 2.35 and 1.47, respectively), compared with IVF without ICSI with fresh embryo transfer.
“Compared with spontaneous conception, IVF treatment overall was not associated with autistic disorder but was associated with a small but statistically significantly increased risk of mental retardation,” the authors write.