By Lisa Rapaport (Reuters Health) – Obsessive-compulsive disorder that surfaces during adolescence or early adulthood may actually have origins in the circumstances surrounding pregnancy and infancy, a Swedish study suggests. Smoking during pregnancy, cesarean section delivery, preterm birth, unusually low or high weight at birth and breech presentation at labor were all associated with an increased risk of obsessive-compulsive disorder (OCD) later in life, the study found. “Children who were born prematurely and to mothers who experienced serious problems with labor and delivery were at increased risk to develop OCD many, many years later,” Dr. James Leckman, author of an accompanying editorial, said by email.