Understand the risks

The biological clock is a fact of life, but there's nothing magical about age 35. It's simply an age at which various risks become more discussion worthy. For example:

• It might take longer to get pregnant. You're born with a limited number of eggs. As you reach your mid- to late 30s, your eggs decrease in quantity and quality. Also, older women's eggs aren't fertilized as easily as younger women's eggs. If you are older than age 35 and haven't been able to conceive for six months, consider asking your health care provider for advice.
• You're more likely to have a multiple pregnancy. The chance of having twins increases with age due to hormonal changes that could cause the release of multiple eggs at the same time. The use of assisted reproductive technologies — such as in vitro fertilization — also can play a role.
• You're more likely to develop gestational diabetes. This type of diabetes, which occurs only during pregnancy, is more common as women get older. Tight control of blood sugar through diet and physical activity is essential. Sometimes medication is needed, too. Left untreated, gestational diabetes can cause a baby to grow significantly larger than average — which increases the risk of injuries during delivery. Gestational diabetes can also increase the risk of premature birth, high blood pressure during pregnancy, and complications to your infant after delivery.
• You're more likely to develop high blood pressure during pregnancy. Research suggests high blood pressure that develops during pregnancy is more common in older women. Your health care provider will carefully monitor your blood pressure and your baby's growth and development. You will need more frequent obstetric appointments and you might need to deliver before your due date to avoid complications.
• You're more likely to have a low birth weight baby and a premature birth. Premature babies, especially those born earliest, often have complicated medical problems.
• You might need a C-section. Older mothers have a higher risk of pregnancy-related complications that might lead to a C-section delivery. An example of a complication is a condition in which the placenta blocks the cervix (placenta previa).
• The risk of chromosome abnormalities is higher. Babies born to older mothers have a higher risk of certain chromosome problems, such as Down syndrome.
• The risk of pregnancy loss is higher. The risk of pregnancy loss — by miscarriage and stillbirth — increases as you get older, perhaps due to pre-existing medical conditions or fetal chromosomal abnormalities. Research suggests that the decrease in the quality of your eggs, combined with an increased risk of chronic medical conditions such as high blood pressure and diabetes, could increase your risk of miscarriage. Ask your health care provider about monitoring your baby's well-being during the last weeks of pregnancy.

While further research is needed, studies suggest that men's ages at the time of conception — the paternal age — also might pose health risks for children.