Many of today's women are delaying childbearing until later in life for a variety of reasons, including career choices, financial status, late marriage, and remarriage. In addition, successful treatment of previously infertile women over 40 is occurring. In fact, reports indicate successful pregnancies in women over age 60.
While such extreme cases raise complex social, ethical issues, and medical issues, the fact of the matter is that more women over age 40 are choosing to start a new family or add to their present one. But what risks do these women incur? Let's examine the facts regarding pregnancy in this age group and strategies to reduce the risks.
Although women often have a healthy pregnancy later in life, there is a higher risk for pregnancy complications. These complications can be categorized as follows:
- Medical illnesses affecting the mother and fetus
- Genetic abnormalities and birth defects
- Pregnancy loss
- Complications of labor and delivery
A higher risk of pregnancy complications can start as early as age 35. Nevertheless, proper preparation before pregnancy and early prenatal care can help assure the best chances of healthy outcomes.
Age 35 is not a clear line in the sand. Risks of genetic abnormalities and miscarriage rise progressively throughout a woman's reproductive years. This is because the woman's eggs age as she does. Also, as a woman ages, it is more likely that she will have acquired a medical illness. However, this is a general trend among the entire population.
Maternal and Child Illnesses
Certain medical conditions occur more frequently in pregnant women over 40, including diabetes, high blood pressure, and thyroid disorders. Some of these conditions may not appear until pregnancy. If this is the case, they can be managed. In many cases, the condition will go away after the baby's birth.
Medical illnesses not related to pregnancy can be screened for, diagnosed, and treated in advance. In cases like these, treatment course can improve the chances of a healthy pregnancy and baby. Many of the medications used to treat these disorders can be safely used during pregnancy. If you currently take medication and you are planning a pregnancy, talk to your doctor. A change in medication or an adjustment of dosage may be necessary.
If not properly treated, maternal illnesses can adversely affect the fetus. Uncontrolled high blood pressure can restrict fetal growth and, in severe cases, can result in stillbirth. Undiagnosed diabetes can carry with it a higher risk of birth defects and stillbirth; and, poor blood sugar control during pregnancy can result in abnormally large fetus. Early prenatal care and judicious use of medication can lower these risks significantly.
It is an unfortunate fact that as a woman ages, a higher proportion of her aging eggs contain chromosomal abnormalities. Therefore women who become pregnant after the age of 35, are at risk of having a child with a genetic defect. This risk increases with age. For instance, the likelihood of having a baby with Down's syndrome increases from nearly 1 in 700 in the general population to 1 in 400 at the age of 35. This number increases to 1 in 100 by the age of 40 and up to 1 in 40 at the age of 45.
Pregnancy loss is often seen in the first trimester and in many cases is due to genetic abnormalities of the fetus. Pregnancy loss also increases with advancing age. Below is the risk of miscarriage based on age:
Note: Rate of miscarriage is for women without previous births. Risk of miscarriage increases with previous births and/or miscarriage.
Complications of Labor and Delivery
Complications of labor and delivery that are seen more frequently in women over age 40 include:
- Premature labor
- Premature birth
- Placenta previa—abnormal placement of the placenta over the opening of the cervix
- Preeclampsia—increase in blood pressure during pregnancy
- Fetal distress—signs during childbirth that indicate the fetus may be having problems
The rate of Cesarean section is also considerably higher in this age group.
Lowering the Risks
Although the risks associated with pregnancy after 40 are numerous and sometimes unavoidable, there are several strategies that women over 40 can use to reduce these risks.
See Your Doctor
First and foremost, make an appointment to see your doctor before you get pregnant. This preconception visit will give your doctor the opportunity to diagnose and treat any disorders that might otherwise go undetected prior to the initial prenatal visit.
A thorough evaluation prior to pregnancy will allow your doctor to give you an idea of your individual risk. There may be cases in which pregnancy will be ill-advised. However, for the majority of women over age 40, early prenatal care and good health habits will result in a healthy baby and a happy mother.
The idea is to be as healthy as you can before you get pregnant. Here are some tips:
- If you smoke, talk to your doctor about how you can quit . Also, stay away from secondhand smoke .
- Avoid alcohol . Alcohol can increase the risk of certain birth defects and interfere with proper fetal growth.
- Eat a well-balanced diet . This means one that is rich in fruits, vegetables, whole grains, and low-fat dairy and other protein sources. If you need help, ask your doctor for a referral to a registered dietitian.
- Make sure that meat is cooked well, and is not undercooked. And do not change a cat’s litter box. Both can lead to toxoplasmosis , an infection that can cause birth defects.
- Do not eat fish that is high in mercury. This includes shark, swordfish, king mackerel, and tilefish. If you eat white tuna, limit it to six ounces or less a week.
- Talk to your doctor first before taking any drugs. This includes over-the-counter medicines or herbs.
- Start a prenatal vitamin prior to pregnancy and stick with it. The folic acid in prenatal vitamins is known to reduce certain birth defects. Aim to get 400 micrograms per day of folic acid.
- Exercise regularly , but moderately. Exercise is good for toning muscles and limbering joints, thereby decreasing the normal aches and pains associated with pregnancy. If you do not exercise already, check with your doctor before starting an exercise program. Obesity is a major risk factor in pregnancy at any age.
- Consider getting a vaccine for rubella and chickenpox before becoming pregnant. After getting the shots, wait one month before trying to get pregnant.
If you are concerned about the risk of genetic defects, especially if you have a family history, ask your doctor about tests that can help identify these types of problems. Blood tests are available to screen for some genetic disorders either before or during pregnancy. A triple screen or quad screen blood test may be obtained to evaluate the risk of neural tube defects and Down syndrome.
Genetic amniocentesis (or chorionic villus sampling) is offered to women after the age of 35. Amniocentesis is usually done in the third or fourth month of pregnancy and involves removal of amniotic fluid from the womb for genetic testing. There is a small risk of miscarriage associated with this test.
Chorionic villus sampling can be done earlier in pregnancy and involves the removal of a small amount of placental tissue, which can then be tested for genetic abnormalities. There is also the risk of miscarriage with this test. Discuss the risks and benefits of these tests with your doctor early on so that you will have ample time to make an informed decision.
- Reviewer: Michael Woods, MD
- Update Date: 10/00/2013 -