2011 Articles

Closely Spaced Pregnancies are Associated with Increased Odds of Autism in Sibling Births

Cheslack-Postava, Keely; Liu, Kayuet; Bearman, Peter Shawn

The probability that environmental factors,1 in concert with genetics, are involved in the etiology of autism holds promise for the identification of modifiable risk factors for the disorder. Maternal physiology comprises, to a large extent, the fetal environment, and previous studies have found associations between autism and obstetric and perinatal complications implicating that environment, including low birth weight, prematurity, and indicators of hypoxic conditions (reviewed in refs 2 and 3). Although the numerous studies cited in these reviews have focused on prenatal and perinatal factors, the preconceptional factors shaping the fetal environment have received less attention. For women who have undergone a previous birth, the interpregnancy interval (IPI) may affect physiologic parameters at the beginning of subsequent pregnancies.