What you need to know about pregnancy after age 40 - Mayo Clinic Press (2024)

The number of women having babies later in life has dramatically increased in recent years. About 9% of first births in the United States are now to women over age 35, which is a 23% increase from 20 years ago. More than 100,000 U.S. women a year give birth over the age of 40.

While it becomes harder to get pregnant over 35 — and definitely after 40 — when it does happen, there are upsides. An observational study of mothers over 40 found better health and development in their children up to 5 years of age. In this study, the children of older parents got hurt less and had higher rates of immunization and better social and language development. In addition, older parents tended to have more patience and gave their children more attention. They also had more emotional and financial stability.

Egg quantity and quality diminishes

The main challenge of fertility after 40 is that it’s harder to get pregnant naturally and even through reproductive medicine. When a girl is born, her ovaries hold 6-7 million eggs. In puberty, she has 300,000 to 500,000, and that number goes down to 25,000 by the time she turns 37. By the time a woman enters menopause, she has only 1,000 eggs. And it’s not only an issue of quantity but also quality. Older eggs tend to have more genetic mutations. When an egg is fertilized, these changes can affect whether it develops into a healthy embryo and fetus. Because of this, miscarriage is a much bigger risk.

After about age 37, the ecosystem of your reproductive system changes. Lower egg quality, along with changes in the composition of reproductive hormones such as FSH, anti-mullerian hormone (AMH) and inhibin B, makes it more difficult to get and stay pregnant. Diseases like leiomyomas, tubal disease and endometriosis also become more prevalent as you age. In addition, a history of ovarian surgery, chemotherapy, pelvic infection, or smoking, or a family history of early menopause, may affect the size of the ovarian follicles that hold and release eggs. This could impact fertility too.

And let’s not forget: It’s not just about women. As men age, their sperm decline in numbers, start swimming slower and develop more genetic abnormalities. Research has shown that babies born to older fathers experience increased rates of many diseases, including neurodevelopmental disorders on the autism spectrum.

Reproductive technology can help

Reproductive technology can help a lot, and its use is growing. A recent demographic study predicted that by the year 2100, 400 million people worldwide could be conceived with assisted reproductive technologies. But these methods are not foolproof, and age is still a factor. In women under 35 with fertility obstacles, a little over 40% of in vitro fertilization cycles lead to bringing home a baby. That percentage goes down to 12% in women ages 41 to 42 years, 5% in women ages 43 to 44 years, and 1% for women older than 44 years. Women over 40 may have the option of using donor eggs from younger women, and more than half those cycles result in a child.

If you’re over 40 and hoping to get pregnant, talk to your doctor about your options before you start trying. Working with your healthcare team and understanding your own body, as well as the statistics and risks, is essential to help you make smart decisions and achieve a healthy pregnancy and birth before you reach menopause.