Closely Spaced Pregnancies are Associated with Increased Odds of Autism in California Sibling Births
Understanding the fetal environment, and thus the role it may play in risk for autism, depends to a large extent on understanding maternal physiology. While previous studies have addressed associations of autism with pre- and perinatal factors, pre-conceptional factors have received less attention. For women who have a previous child, the interval between pregnancies may affect the physiological state at which they enter the next pregnancy. In this study, we looked at pairs of first- and second-born siblings born in California between 1992-2002 and found that children born following shorter intervals were at increased risk of autism, relative to both the general population and their first-born siblings. Possible explanations include depletion of maternal nutritional reserves or improved ascertainment associated with observing the development of children who are close in age.
Read our paper: Cheslack-Postava,K., Liu,K. & Bearman,P.S. (2011) Closely Spaced Pregnancies are Associated with Increased Odds of Autism in California Sibling Births. Pediatrics, Volume 127: 246-253.