Exposures that may affect sperm DNA integrity: Two decades of follow-up in a pregnancy cohort

► Sons of overweight mothers had 22% (95% CI: −3; 52) higher DFI than sons of normal weight mothers. ► Sons of parents with a TTP of >12 months had 14% (95% CI: −4; 34) higher DFI than sons of parents with a TTP of 0–6 months. ► Abstinence time was associated with DFI (p for trend6 days had 87% (95% CI: 47; 138) higher DFI than the group of men with 1–2 days of abstinence. ► The son's own cigarette smoking was not associated with DFI. ► Maternal cigarette smoking during pregnancy was not associated with DFI. Prenatal lifestyle exposures are linked to alterations in conventional semen characteristics. Sperm DNA integrity is another marker of semen quality shown to be altered in mice prenatally exposed to chemicals. From a Danish pregnancy cohort established in 1984–1987, sons were selected for a follow-up study in 2005–2006. We examined associations between prenatal and current lifestyle exposures and DNA fragmentation index (DFI) among 337 men. Sons of overweight mothers had 22% (95% CI: −3; 52) higher DFI than sons of normal weight mothers and sons of parents with a TTP >12 months had 14% (95% CI: −4; 34) higher DFI than sons of parents with a TTP of 0–6 months. Abstinence time was positively associated with DFI (p