Maternal genetic liability to autism spectrum disorders and pregnancy outcomes

Few studies have examined the increased risk for pregnancy complications in women with autism spectrum disorder (ASD) diagnosis. The autism genetic propensity in relation to the complications of pregnancy and birth remains unknown, and is an area critical for informing maternal health and reproductive guidance. Here, we assessed whether maternal genetic liability to ASD is associated with pregnancy complications.

The study comprised 28,985 females with at least one pregnancy-related record from the UK Biobank (UKB) cohort. Individual polygenic risk scores (PRS) for ASD were calculated, and pregnancy complications were defined using ICD-10 diagnostic codes. Associations between ASD PRS and pregnancy outcomes were evaluated using logistic regression models adjusted for maternal age at first conception. In the secondary analyses, we used schizophrenia (SCZ) PRS, and analyzed broader, ICD-based clusters of pregnancy outcomes.

Maternal ASD PRS showed no nominally significant associations with pregnancy outcomes. Maternal SCZ PRS was nominally associated with a reduced risk of spontaneous delivery (O80) and forceps/vacuum delivery (O81); however, no associations remained significant after FDR correction.

Higher genetic liability to ASD was not significantly associated with an increased risk of pregnancy complications in the UKB sample. Findings should be interpreted with caution, given the limitations of PRS, potential selection bias in UKB, and the relatively small sample size of females with pregnancy outcomes in the UKB.