Prenatal ultrasound pinpoints early signs of autism spectrum disorder

Prenatal ultrasound in the second trimester appears to detect anomalies in the heart, kidneys, and head common in foetuses who are likely to develop autism spectrum disorder (ASD), according to a study.

The retrospective case-sibling-control study included children diagnosed with ASD (cases; n=229); their own typically developing, closest-in-age siblings (TDS; n=201); and typically developing children from the general population (TDP; n=229). The children were matched by year of birth, sex, and ethnicity.

Researchers examined data from hundreds of prenatal ultrasound scans from the foetal anatomy survey conducted during mid-gestation. Results showed ultrasonography foetal anomalies in 29.3 percent of ASD cases as opposed to only 15.9 percent in the TDS group (adjusted odds ratio [aOR], 2.23, 95 percent confidence interval [CI], 1.32–3.78) and 9.6 percent in the TDP group, (aOR, 3.50, 95 percent CI, 2.07–5.91).

Of note, ASD cases had a higher prevalence of multiple co-occurring anomalies. ASD diagnosis was strongly associated with ultrasonography foetal anomalies in the urinary system (aOR, 2.08, 95 percent CI, 0.96–4.50), heart (aOR, 8.67, 95 percent CI, 2.62–28.63), and head and brain (aOR, 1.96, 95 percent CI, 0.72–5.30). These anomalies were also linked to more severe ASD symptoms.

Female children with ASD had significantly more ultrasonography foetal anomalies (43.1 percent vs 25.3 percent; p=0.013) and a higher prevalence of multiple co-occurring anomalies (15.7 percent vs 4.5 percent; p=0.011) than males. There were no sex-related differences observed among TDS and TDP controls.

Compared with TDP foetuses, ASD foetuses were more likely to have a narrower head (aOR, 0.81, 95 percent CI, 0.70–0.94) and a relatively wider ocular-distance (aOR, 1.29, 95 percent CI, 1.06–1.57).

The findings shed light on the abnormal multiorgan embryonic development of ASD and foetal ultrasonography biomarkers for ASD.