YORK (Reuters Health) Jul 18 - Intrauterine and neonatal factors
related to restricted intrauterine growth or fetal distress may be
associated with the development of autism, according to a report in
the July issue of Epidemiology.
In a case-control study nested within a population-based cohort,
Dr. Christina M. Hultman, of the Karolinska Institute, Stockholm,
Sweden, and colleagues examined various maternal characteristics and
pregnancy outcomes among 408 children diagnosed with infantile autism
before 10 years of age and 2040 matched controls.
Conditional logistic regression models showed an association
between daily smoking in early pregnancy (odds ratio [OR] =1.4),
maternal birth outside Europe and North America (OR=3.0), and cesarean
delivery (OR=1.6) and the risk of autism.
The risk of autism was also associated with being small for
gestational age (OR=2.1), a 5-minute Apgar score less than 7 (OR=3.2),
and congenital malformations (OR=1.8).
The researchers observed no association between head circumference,
maternal diabetes, being a twin, or season of birth and the risk of
autism.
"Our observations support the possibility that a subgroup of
children developing infantile autism suffer from intrauterine growth
restriction and are exposed to adverse prenatal and neonatal
asphyxia," Dr. Hultman and colleagues note. "Although several of the
reported associations could be a function of genetic risk in the
fetus, several of the findings are consistent with nongenetic
environmental mediation of risks."
Epidemiology 2002;13:417-423.
