Younger and older fathers could be more likely to have a baby with Down syndrome, according to an international analysis of over 2 million pregnancies in China. The researchers collected data on prenatal and postnatal diagnoses of Down syndrome in Shenzhen, China—where prenatal testing is free—since 2012. They identified 2,480 cases of Down syndrome from 2,193,801 pregnancies, and analyzed the data, adjusting for other known factors that can influence Down syndrome risk.
They say the age of both parents, along with the sex of the child, and the mother's education level and miscarriage history were all linked with the risk of Down syndrome. Fathers aged over 40 or under 20 had an especially high likelihood of conceiving a child with Down syndrome, the researchers say. They say more research should be done to confirm this finding because there are likely other influencing factors at play that they were unable to account for.
The study is published in the journal JAMA Pediatrics . More information: Qiongjie Zhou et al, Paternal Age and the Risk of Trisomy 21, JAMA Pediatrics (2024). DOI: 10.
1001/jamapediatrics.2024.3337.