Robyn's Nest - The Parenting Network - Reproductive Health and Pregnancy over Age 35

Reproductive Health and
Pregnancy after 35

Most women over age 35 have healthy pregnancies and healthy babies. Recent studies suggest, however, that older moms do face some special risks. Since the late 1970s, birth rates for women in their late 30s and 40s have increased dramatically. According to the National Center for Health Statistics, between 1978 and 1998, the birth rate for women age 35 to 39 nearly doubled. Between 1981 and 1997, the rate increased 92 percent for women in their 40s. Advances in medical care now help women in their late 30s and 40s have safer pregnancies than in the past. However, women should be aware of the risks associated with later childbearing so that they can make informed decisions about their pregnancies.

How much does age affect fertility?

Women generally have some decrease in fertility starting in their early 30s. It is not unusual for a woman in her mid-30s or older to take longer to conceive than a younger woman. Age-related declines in fertility may be due, in part, to less frequent ovulation, or to problems such as endometriosis, in which tissue similar to that lining the uterus attaches to the ovaries or fallopian tubes and interferes with conception. If conception has not taken place after six months of trying, a woman over age 35 should consult her physician. Many cases of infertility can be treated successfully.

While women over age 35 may have more difficulty conceiving, they also have a greater chance of bearing twins. The likelihood of naturally conceived (without fertility treatment) twins peaks between ages 35 and 39, then declines.

How do preexisting health problems affect pregnancy?

At any age, a woman should consult her health care provider before trying to conceive. A preconception visit helps ensure that she is in the best possible physical condition before conception. This visit is a good time to discuss any concerns a woman and her partner may have about a pregnancy. A preconception visit is especially important if a woman has a chronic health problem, such as diabetes or high blood pressure. These conditions, which are much more common in women in their late 30s and 40s than in younger women, can endanger the pregnant woman and her developing baby. But careful medical monitoring and appropriate choice of medications, started before conception and continued throughout pregnancy, can reduce the risks associated with these conditions and, in most cases, result in a healthy pregnancy.

Women over 35 are at increased risk of developing high blood pressure and diabetes for the first time during pregnancy.

This makes it especially important that older mothers get early and regular prenatal care. With early diagnosis and proper treatment, these disorders usually do not pose a major risk to mother or baby.

What is the risk of birth defects in babies of women over 35?

The risk of bearing a child with certain chromosomal disorders increases as a woman ages. The most common of these disorders is Down syndrome, a combination of mental retardation and physical abnormalities caused by the presence of an extra chromosome 21 (humans have 23 pairs of chromosomes). At age 25, a woman has about a 1-in-1250 chance of having a baby with Down syndrome; at age 30, a 1-in-1,000 chance; at age 35, a 1-in-400 chance; at age 40, a 1-in-100 chance; and at 45, a 1-in-30 chance.Most doctors offer pregnant women who are 35 or older the option of prenatal testing (with amniocentesis or chorionic villus sampling) to diagnose or, more likely, rule out Down syndrome and other chromosomal abnormalities. About 95 percent of women who undergo prenatal testing receive the reassuring news that their baby does not have one of these disorders. If prenatal testing rules out chromosomal defects and the mother is healthy, the baby probably is at no greater risk of birth defects than if the mother were in her 20s.

What is the risk of miscarriage as a woman gets older?

Most miscarriages occur in the first trimester for women of all ages. The rate of miscarriage in older women is significantly greater than that in younger women. A recent Danish study found that about 9 percent of recognized pregnancies for women aged 20 to 24 ended in miscarriage. The risk rose to about 25 percent at age 35 to 39, and more than 50 percent by age 42. The increased incidence of chromosomal abnormalities contributes to the age-related risk of miscarriage.

Does the risk of pregnancy complications and adverse pregnancy outcomes increase after age 35?

While women in their late 30s and 40s are very likely to have a healthy baby, they do face more complications along the way. Besides the increased risk of diabetes and high blood pressure, women over 35 have an increased risk of placental problems. The most common placental problem is placenta previa, in which the placenta covers part or all of the opening of the cervix. The University of California at Davis study found that first-time mothers over age 40 were up to 8 times as likely as women in their 20s to have this complication. Placenta previa can cause severe bleeding during delivery, which can endanger mother and baby, but complications often can be prevented with a cesarean delivery. Some studies suggest that women having their first baby at age 35 or older are at increased risk of having a baby who is low birthweight (less than 5 ½ pounds) or premature (born at less than 37 full weeks of pregnancy). And these risks rise modestly but progressively with a woman's age, even if she does not have age-related chronic health problems such as diabetes and high blood pressure. The Danish study also found that women over age 35 had an increased risk of ectopic pregnancy (in which the fertilized egg implants outside of the uterus, usually in the fallopian tube). The Danish study and a 1997 Canadian study found a slightly increased risk of stillbirth. However, neither of the Mount Sinai studies found an increased risk of stillbirth, even in women over 40. The newborns of mothers in their 40s may suffer more complications (such as asphyxia and brain bleeds) than those of younger mothers, according to the University of California at Davis study. However, in spite of the increased risk of complications, there were no more deaths among babies of older mothers, and the vast majority of babies recovered and did fine.

Pregnant women who are 35 or older face some special risks, but many of these risks can be managed effectively with good prenatal care. And it's important to keep in mind that the increased risk, even for the oldest women, is modest.

Do women over 35 have more problems in labor and delivery?

First-time mothers over 35 are more likely than women in their 20s to have difficulties in labor. Studies suggest that fetal distress and a prolonged second stage of labor are more common in older mothers. This may account, in part, for the increased rate of cesarean sections among women over 35. First-time mothers over age 40 have the highest risk of c-section, 47 percent, according to the University of California study. Similarly, other studies have reported that first-time mothers over age 35 have about a 40 percent chance of a c-section, compared to about a 14 percent risk for first-time mothers in their 20s.

How can a pregnant woman reduce her risks?

Today, women in their late 30s and 40s who are planning pregnancy generally are in excellent health, and can look forward to healthy pregnancies. However, along with the special concerns about pregnancy past age 35, it's important to take into account childbearing risks that apply to all women. It is especially important for women over age 35 to follow the basic rules for a healthy pregnancy.

Plan for pregnancy by seeing a health care provider before you conceive.

Take a multivitamin containing 400 micrograms of folic acid daily before you become pregnant and through the first month of pregnancy to help prevent neural tube defects.

Get early and regular prenatal care.

Eat a variety of nutritious foods, including foods containing folic acid, like orange juice, peanuts, beans, lentils, fortified breakfast cereals and leafy green vegetables.

Begin pregnancy at a healthy weight (not too heavy or too thin).

Stop drinking alcohol before you try to conceive, and continue to avoid alcohol during pregnancy.

Don't smoke during pregnancy and avoid secondhand smoke. It's best to quit before you become pregnant.

Don't use any drug, even over-the-counter medications or herbal preparations, unless recommended by a health care provider who knows you are pregnant.

reprinted in part with permission from www.modimes.org

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Pregnancy over Age 35

Reproductive Health and Pregnancy after 35