In this study Darios Getahun, from Kaiser Permanente in Pasadena led a team of researchers looking into the links between perinatal complications and autism. The team looked at the medical records of 594,638 children, born between 1991 and 2009. They found that children who had been exposed to antepartum complications were 22% more likely to develop autism while those exposed to intrapartum complications were 10% more likely. For children exposed to antepartum and intrapartum complications the risk was 44% greater.
You can read the abstract of this article here.