HealthDay News — Induction and/or augmentation during childbirth significantly increased the odds of autism, results of a study that involved more than 600,000 births indicate.
The likelihood of autism increased by 23% among mothers who had induced or augmented labor compared with those who had unassisted labor, Simon G. Gregory, PhD, from the Duke University Medical Center in Durham, N.C., and colleagues reported in JAMA Pediatrics.
They examined data from the North Carolina Detailed Birth Record and Education Research Database, which included information on 625,042 live births, including 5,648 children with a documented designation for autism.
The cohort included children with birth records from 1990 to 1998 that were linked to educational data from the school years 1997 to 1998 and 2007 to 2008. The researchers classified births into four categories: no labor induction or augmentation, labor induction only, augmentation only and both induction and augmentation.
After controlling for potential confounders related to socioeconomic status, maternal health, pregnancy-related events and conditions and birth year, children whose mothers had induced or augmented labor were at consistently increased odds for developing autism compared with children born to mothers with unassisted labor. Odds ratios were as follows:
- Induced/augmented (OR 1.23; 95% CI: 1.02-1.47)
- Induced only (OR 1.10; 95% CI: 1.07-1.24)
- Augmented only (OR 1.15; 95% CI 1.07-1.24
Compared with girls, boys exhibited increased odds of autism diagnosis (OR 3.04, 95% CI 2.86-3.24). Children with autism also had higher rates of fetal distress and meconium, the researchers found.
Other factors associated with a greater likelihood for autism diagnosis included fetal distress (OR 1.25, 95% CI: 1.15-1.36), meconium (OR 1.22, 95% CI: 1.11-1.34), birth ≤34 weeks (OR 1.25, 95% CI: 1.11-1.41) and maternal diabetes (OR 1.23, 95% CI: 1.07-1.41).
First born birth order, older maternal age, higher maternal education and non-Hispanic black race/ethnicity also increased the odds of an autism diagnosis; however, whether child birth was vaginal or cesarean did not.
“While these results are interesting, further investigation is needed to differentiate among potential explanations of the association including underlying pregnancy conditions requiring the eventual need to induce/augment, the events of labor and delivery associated with induction/augmentation, and the specific treatments and dosing used to induce/augment labor,” the researchers concluded.