Studies suggest that a father's age at the time of conception (paternal age) might pose health risks for a baby. However, this field of research is still relatively small and results have been mixed. More research is needed.

Studies have shown that when paternal age is over 40, there might be a small increase in the risks of adverse pregnancy outcomes or risks to children's health, including:

• Pregnancy loss. Advanced paternal age might be associated with a slightly higher risk of pregnancy loss before week 20 of pregnancy (miscarriage) or stillbirth.
• Rare birth defects. Older paternal age might slightly increase the risk of certain rare birth defects, including defects in the development of the skull, limbs and heart.
• Autism. Research shows a link between older paternal age and an increased frequency of autism spectrum disorder.
• Schizophrenia. Studies suggest an older paternal age might increase the risk of the severe mental disorder schizophrenia and might be associated with earlier onset of schizophrenia symptoms.
• Childhood acute lymphoblastic leukemia. Older paternal age might be associated with a slightly increased risk of childhood acute lymphoblastic leukemia, a cancer that results in abnormal white blood cell production.

Researchers believe the increased risk of health conditions might be due to random genetic mutations in sperm that occur more commonly in older men than in younger men. Despite the increase in these risks, however, the overall risks remain small and less certain than those associated with maternal age over 40.

If you're older than 40 and you're considering having a baby or you're concerned about your reproductive health, consult your doctor.