According to a recent population-based study, which of the following MOST likely describes the associated risk of autism spectrum disorder in offspring when epidural labor analgesia is used?
- □ (A) Increased
- □ (B) Decreased
- □ (C) No association
Autism spectrum disorder is a developmental condition that is present in all socioeconomic and ethnic groups. According to the latest data from the U.S. Centers for Disease Control and Prevention, the prevalence of autism spectrum disorder increased from one in 150 in 2000 to one in 44 in 2018. Autism spectrum disorder has medical and mental health consequences, as well as educational and economic ramifications. Subsequently there is intense interest in identifying causative factors.
Researchers recently conducted a longitudinal cohort study evaluating the association between epidural labor analgesia and increased risk of autism spectrum disorder in offspring. Using population-based data, singleton live births delivered vaginally in a Canadian hospital between 2005 and 2016 were evaluated. The primary outcome was a single autism spectrum disorder diagnosis by age 18 months, using Medical Services and Hospital Abstracts data sets. Multiple covariates were assessed: birth-specific, perinatal, pregnancy-related, prepregnancy, and socioeconomic characteristics.
In the statistical evaluation, if the standardized difference between covariates was less than 0.1, the covariates were considered balanced. The cumulative incidence of an autism spectrum disorder diagnosis before April 1, 2019, was used to compare children whose mothers were and were not exposed to epidural labor analgesia. Modeling was achieved using a Cox proportional hazards regression. A series of regressions was performed. A second analysis, restricted to siblings, was completed to assess unmeasured family variables. To address potential bias, three sensitivity analyses were conducted. These analyses resulted in including only firstborn children, reclassifying autism spectrum disorder as two autism diagnoses on two separate days after age 18 months, and excluding women with missing data. A total of 123,175 births were included in the final analytic cohort, of whom 47,011 had epidural labor analgesia exposure. The authors discovered that before they adjusted their analysis to account for sociodemographic, prepregnancy, and perinatal confounders, there was an association between exposure to epidural labor analgesia and risk of autism spectrum disorder. When confounding elements were taken into consideration, the authors found that the risk of autism spectrum disorder in offspring was not associated with maternal epidural labor analgesia. There was also a lack of association between autism spectrum disorder and epidural labor analgesia on the sensitivity analyses. These results contrast with those of a previous cohort study conducted in California, which found a 37% increased risk of autism spectrum disorder in offspring with intrauterine exposure to maternal epidural analgesia. The authors of the study from Canada conjectured that this difference was due to a lack of evaluating confounders in the other study.
In summary, this cohort study from Manitoba, Canada, found no association between the risk of autism spectrum disorder in offspring and maternal epidural labor analgesia. The authors commented that prior study findings may have negatively influenced women’s and practitioners’ attitudes about epidural labor analgesia – an anesthesia technique currently used by three-quarters of parturients in the U.S. – necessitating future qualitative research on perceptions about this effective and most-popular form of labor analgesia.