Study: Autism Linked with Induced-Labor Delivery

Another tantalizing—and surprising—clue in the search for causes

A new study has shown a startling correlation between induced and augmented labor and autism. The researchers—teams at Duke and the University of Michigan—examined birth records of 625,000 North Carolina kids born between 1990 and 1998 and compared them to school records, looking for autism diagnoses. (The current overall rate of autism in the United States is one in 88 children, with four times as many boys diagnosed as girls.)

The study showed that moms whose labor was induced or augmented were more likely to have an autistic child than those who had neither procedure; for moms who were both induced and augmented, the risk was 23 percent greater. A male child born to a mom whose labor was both induced and augmented was 35 percent more likely to have an autism diagnosis than a male child whose mom had neither. A male child whose mother was only augmented was 15 percent more likely to be autistic than male children whose moms had neither procedure; female children of augmented moms were 18 percent more likely to be diagnosed with autism.

The researchers as well as scientists not involved in the study note that as always, correlation isn’t causation. Since induction and augmentation are usually used when a labor isn’t progressing normally, it’s unclear whether the induction and augmentation processes themselves might create the increased risk, or whether underlying factors that create the need for the procedures, such as genetic or environmental factors, do. But statistics show a marked increase in induced births, from 9.5 percent of all births in the early ‘90s to 23.4 percent in 2010, and augmented births, from 10.9 percent in 1989 to 17.3 percent in 2002, the most recent available year.

Autism diagnoses have similarly skyrocketed, by 78 percent nationwide from 2000 to 2012. Most experts peg that increase to wider awareness of the condition and an expansion of the diagnostic criteria several years ago. And the researchers didn’t suggest any changes in current medical procedure in the wake of their study. Still, the numbers are enough for women to want to make sure induction and/or augmentation is medically necessary for their health and that of their babies, and not being done merely for the convenience of the doctor or mom.