Prenatal Ultrasound and the Risk of Autism: An Unanswered Question

Investigators from Boston University conducted a case-control study to assess the association between prenatal ultrasound exposure and autism spectrum disorder (ASD) in children. For the study, the investigators reviewed clinical records and ultrasonographic data in children born at >37 weeks’ gestation at Boston Medical Center between 2006 and 2014. Cases were children diagnosed with ASD by a behavioral pediatrician and identified based on specific ICD-9 codes. There were 2 sets of controls matched to cases on gender, maternal age (±3 years), and birth date (±90 days). First, approximately 1 child with developmental delay (but not ASD) in at least 2 domains was matched to each case. The second group of controls included 2 children with typical development matched to each case. The exposure variables included number of prenatal scans, total time of …