A new study of children who were born with congenital heart disease (CHD) has found that they have increased odds of developing autism spectrum disorder.
“To our knowledge, this is the only study in which there has been a comparison between [autism spectrum disorder] and multiple CHD subtypes,” wrote Eric R. Sigmon, MD, of Emory University, Atlanta, and coauthors. “Our findings are consistent with previous studies of CHD developmental outcomes, which have shown an increased risk of developmental and academic delay after CHD diagnosis and treatment.” The study was published in Pediatrics.
To further investigate the association between CHD and autism, the researchers performed a case-control study using the Military Health System administrative database. They uncovered 8,760 cases of children with autism spectrum disorder and matched each one with three controls (n = 26,280). From that sample size, they identified 1,063 children with CHD: 401 in the autism spectrum disorder group and 662 in the control group.
Before analysis, children with autism spectrum disorder had an odds ratio of 1.85 of having any form of CHD, compared with controls (95% confidence interval, 1.63-2.10). After adjustment for covariates – including genetic syndromes, maternal age and morbidity, perinatal morbidity, and neonatal complications – the OR was 1.33 (95% CI, 1.16-1.52).
In the sensitivity analysis – which included only 593 children with CHD – the OR was a similar 1.32 (95% CI, 1.10-1.59).
Left heart obstructive lesion was significantly associated with autism spectrum disorder after covariate adjustment (OR, 1.42; 95% CI, 1.04-1.93), but the finding was no longer significant in the sensitivity analysis.
The authors noted the potential limitations of their study, including the general weaknesses of administrative data, which they attempted to counter with the sensitive analysis. In addition, they recognized that children with either autism spectrum disorder or CHD “tend to present for care more frequently,” which could have created an ascertainment bias.
In an accompanying editorial, Johanna Calderon, PhD, David C. Bellinger, PhD, and Jane W. Newburger, MD, MPH, stated that more work needs to be done to further quantify the relationship between CHD and autism spectrum disorder (Pediatrics. 2019 Oct 10. doi: 10.1542/peds.2019-2752). The three authors – all affiliated with Boston Children’s Hospital and Harvard Medical School, also in Boston – reiterated the acknowledgment from Dr. Sigmon and coauthors that the “etiologic pathways that might explain” the link between the two remains unknown. They also noted their surprise that autism spectrum disorder risk appears to be increased in children with modestly severe forms of CHD, stating that this finding required additional investigation.
“Despite the strengths of this study,” they wrote, “it raises more questions than answers.”
The study was funded by the Congressional Directed Medical Research Programs Autism Research Award. The authors reported no conflicts of interest.
SOURCE: Sigmon ER at al. Pediatrics. 2019 Oct 10. doi: 10.1542/peds.2018-4114.