DES Grandchildren (Third Generation): There are ongoing questions about whether the effects of DES exposure can be passed to subsequent generations through epigenetic changes. Animal studies in mice have shown third-generation effects, like elevated tumours. Preliminary data suggests DES granddaughters may have higher risks of infertility or menstrual irregularities, and DES grandsons may have increased rates of hypospadias.  

For example, a 2011 French cohort study found a modest increase in hypospadias among boys whose grandmothers took DES. These findings, based on small sample sizes, are not conclusive. Researchers are monitoring DES-exposed families for transgenerational effects. Currently, no specific screening is recommended for DES grandchildren, but research continues.