Fertility and Your Age

More women today find they want to put off pregnancy until their careers are well established, or until they've gotten more life experience. However, research shows that pregnancies in women over the age of 35 suffer from more problems than those in younger women. How great are the risks compared with the benefits, and what do you really need to be concerned about?

How Old Is Too Old to Have a Baby?

According to the Mayo Clinic, a woman's fertility peaks between the ages of 20 and 24. However, fertility rates remain relatively constant through the early 30s, after which they begin to decline.

At age 30 to 35, fertility is 15 to 20 percent below maximum. From age 35 to 39, the decrease is 25 to 50 percent. From 40 to 45, the decrease is 50 to 95 percent.

Technically, any woman who has not gone through menopause, and who does not have other reproductive problems, can become pregnant. Successful pregnancies have been reported in women as old as 59.

Pregnancy Risks After 35

The risk of miscarriage increases after age 35; by the early 40s, more than 50 percent of pregnancies end in miscarriage. Many of these occur at an early stage and may not even be detected, or may be mistaken for a late period. The majority of these miscarriages are due to the chromosomal abnormalities in the fetus.

Other age-related factors affecting fertility include less frequent and/or irregular ovulation, and endometriosis, in which tissue that attaches to the ovaries or fallopian tubes interferes with conception.

When they do get pregnant, women older than 35 may have a higher risk of developing gestational diabetes, preeclampsia, and placenta previa. There is also a potentially higher risk of having a baby with low birth weight, and of chromosomal abnormalities such as Down syndrome.

Aiming for a Positive Pregnancy

Although older women may find it somewhat harder to achieve pregnancy, the overall outcomes are excellent. In fact, birth rates for mothers in their 30s and 40s have increased dramatically over the past 25 years. According to the National Center for Health Statistics, the birth rate for women age 35 to 39 nearly doubled between 1978 and 1998. Between 1981 and 1997, the birth rate for women in their 40s increased 92 percent.

If you're over 35 and thinking of getting pregnant, a few simple tips will help minimize the risks:

• Start taking prenatal vitamins
• See your doctor for pre-pregnancy checkups
• Eat well
• Exercise regularly
• Cut out nicotine, alcohol, and drugs

Finally, if you don't succeed in getting pregnant within six months, see a reproductive endocrinologist (fertility specialist) to discuss next steps.

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