Pregnancy at 35 to 39

Ages 35 to 39
YOUR BODY

Fertility continues to decline after age 35, and it takes a nosedive at age 38, says Benjamin Younger, M.D., executive director of the American Society for Reproductive Medicine, in Birmingham, AL. "The decline is due mostly to the fact that the woman's eggs are aging, and they become more difficult to fertilize," he adds.

Up until age 35, most doctors suggest that couples have unprotected intercourse for a full year before seeking infertility treatment; that time period is reduced to six months for women over 35. "The greatest problem for infertile couples is delayed treatment, because there's a big difference in success rates between a woman in her late 30s and one in her early 40s," says Ruth Fretts, M.D., clinical instructor of obstetrics and gynecology at Harvard Medical School. "In fact, many infertility clinics won't accept patients if they're older than 39 or 40."

The risk of high blood pressure during pregnancy is about double for women over 35 compared with younger ones; hypertension affects about 10 to 20 percent of pregnant women in this age group. Gestational diabetes is two to three times more common in women over age 35 than in younger women, and recent studies show the risk is even higher if the woman has gained weight over the years.

The chance of having a cesarean section is about twice as high for women ages 35 to 39 as for those in their 20s, possibly because labor tends to take longer in older women. "When the second stage of labor surpasses two hours, obstetricians often intervene and do a C-section to reduce stress on the fetus," says Gertrud Svala Berkowitz, Ph.D., professor of obstetrics and gynecology and reproductive science at the Mount Sinai School of Medicine in New York City.

YOUR EMOTIONAL SELF

This is the age when your doctor might recommend amniocentesis or some other prenatal screening -- which for many women is anxiety-provoking while they await results -- because the risks of having a baby with Down syndrome or another type of chromosomal disorder begin to rise significantly.

RISKS TO YOUR BABY

The chance of having multiple births, especially twins and even triplets, increases significantly in your late 30s (and early 40s). "This is probably due to the fact that the hormonal stimulation of the ovaries changes slightly as a woman ages, increasing the chances that they'll release more than one egg," says Dr. Younger. "It could be Mother Nature's way of compensating for the fact that more eggs are likely to be defective." Women who take fertility drugs are also at higher risk of multiple births because the drugs stimulate the ovaries to produce more eggs. Even so, the chance of twin, triplet, or other multiple births is still relatively slim.

The miscarriage rate rises after age 35 to close to 18 percent. Rates of stillbirths are about twice as high among older pregnant women than younger ones, according to recent studies, although the reasons are unknown.

Pregnancy at 30 to 34

Ages 30 to 34
YOUR BODY

Fertility begins to decline at age 30, but this change happens gradually, over the next five years or so. If you need infertility treatment, your chances of success are higher than they are for an older woman. For women under age 35 the success rate of in vitro fertilization (IVF), for example, is 25 to 28 percent; for those over age 40, that rate drops to 6 to 8 percent. One study found that the rate of cesarean sections was close to two times higher among women ages 30 to 34 than among those in their 20s, although doctors don't know why.

YOUR EMOTIONAL SELF

"Women who have been fully involved in their job in their 20s often feel emotionally ready to start a family as they enter their next decade," says Glazer. "And they have the energy and the resources to do it. But they may also feel pulled in different directions. They worry about whether they'll be able to return to their work life -- or whether they'll even want to."

RISKS TO YOUR BABY

The miscarriage rate is 11.7 percent. By age 30 your risk of having a baby with Down syndrome is 1 in 952, and a baby with any chromosomal abnormality, 1 in 385.

Pregnancy at 25 to 29

Ages 25 to 29
YOUR BODY

If you exercise and eat sensibly, and continue to do so throughout your pregnancy, you should have an easier delivery and be able to get your body back in shape more quickly than a less fit woman might. Although this is true at any age, in your 20s you are more likely to be at optimal fitness, making delivery and postpartum weight loss easier. In terms of long-term health, if you begin conceiving in your 20s, you may be at decreased risk for breast cancer and ovarian cancer, according to some studies. Doctors think that hormonal changes that occur during ovulation (increased estrogen and progesterone), which stimulate the ovaries and breasts every month, may raise the risk of these cancers; the more often you're pregnant, the less often you ovulate.

YOUR EMOTIONAL SELF

In your late 20s you're more likely to be established in your work life and, depending on when you married, your relationship with your husband may also be in better shape to handle the changes that parenthood brings.

RISKS TO YOUR BABY

The miscarriage rate is 10 percent, only slightly higher than for women five years younger. At age 25, your chances of delivering a baby with Down syndrome are 1 in 1,250, and there's a 1 in 476 chance of having a baby with any chromosomal abnormality.