TBO.com - TBO is Tampa Bay Online

Pregnancy After 40 Carries More Risks

ADVERTISEMENT

By SHELLY HOLMSTROM, M.D.

Published: September 20, 2007

More U.S. women are giving birth later in life than in previous generations — even postponing their first pregnancies into their 40s. The number of mothers giving birth at age 40 or older nearly quadrupled between 1980 and 2004, the National Center for Health Statistics reports.

Women delay childbearing for a variety of reasons, including marrying later and choosing to establish their careers before rearing children.

Although most pregnant women 40 and older give birth to healthy children, older moms face more risks associated with childbearing than younger moms. These risks include increased infertility and greater chances for miscarriages, birth defects and pregnancy complications.

Beginning in their early 30s, women experience a natural decline in fertility. Women 40 and older typically take longer to conceive, primarily because they have fewer eggs available.

They also are at a higher risk for miscarriages. Approximately half of pregnant women in their 40s will miscarry, compared with about 10 percent of women in their 20s.

For these reasons, women older than 40 are more apt to require assisted reproductive technologies, such as in vitro fertilization, and may require the use of anonymously donated eggs to conceive.

Advances in technology have improved a woman's ability to become pregnant but cannot fully compensate for this natural decline in fertility.

Older childbearing increases the risk of having an infant with a chromosomal abnormality. Chorionic villi sampling and amniocentesis are diagnostic tests that sample the chromosomes of the unborn child to detect genetic problems, such as Down syndrome.

Women 40 or older are at a higher risk for having a child with a birth defect, such as a heart problem or a clubfoot.

These birth defects may be detected by a detailed ultrasound of the baby. However, because they are not caused by chromosomal abnormalities, such defects would not be picked up by amniocentesis.

Medical conditions that may complicate pregnancy, such as high blood pressure and diabetes, are more common in older pregnant women. They are more likely than their younger counterparts to develop preeclampsia, a high blood pressure disease of pregnancy.

Pre-existing diabetes, especially when poorly controlled, can cause major birth defects, and gestational diabetes increases the chances of delivering a very large infant.

Older women more often have their babies delivered by cesarean section because of their increased likelihood for medical problems, induction of labor, abnormal labor, premature births and multiple births.

C-sections account for 29 percent of births, but women ages 40 and older have C-section rates of nearly 50 percent, according to the Centers for Disease Control and Prevention.

Many older women tend to be well-educated professionals who want to make informed decisions about their pregnancy and childbirth options. Planning is the best way to prevent pregnancy complications at any age.

If you decide to get pregnant after age 40, schedule a preconception counseling visit with your doctor to review your risks and ensure any medical conditions are well controlled.

Despite potentially greater complications of a later pregnancy, doctors can often handle the risks and typically deliver healthy babies.

Dr. Holmstrom is an assistant professor in the Department of Obstetrics and Gynecology at USF Health.

Share this:

Loading Comments...

Email Print

ADVERTISEMENT