Definition

Thousands of women are living successfully with diseases like asthma, epilepsy, and ulcerative colitis. When these women become pregnant, though, they are often considered to have high-risk pregnancies.

Description

A pregnancy can be considered a high-risk pregnancy for a variety of reasons. Twins, triplets, and other multiple pregnancies are always considered high-risk because of the increased chance of premature labor. A pregnancy is also considered high-risk when prenatal tests indicate that the baby has a serious health problem (for example, a heart defect). In such cases, the mother will need special tests, and possibly medication, to carry the baby safely through to delivery. Complications caused by pregnancy itself, such as preeclampsia or gestational diabetes, can also turn a normal pregnancy into a high-risk pregnancy. Finally, many women who have chronic illnesses require special attention when they become pregnant. This entry will discuss the special needs of pregnant women who have chronic illnesses.

When women with chronic illnesses become pregnant, they are often considered to have high-risk pregnancies. It is difficult to predict what will happen to various medical conditions during pregnancy. Of the women who have asthma, for example, 25% will get worse during pregnancy, 50% will have no change due to pregnancy, and 25% will actually get better during pregnancy. No one understands why this is so, and no one can predict the experience a woman might have.

Most women will see one healthcare provider during pregnancy, either an obstetrician, a midwife, or a nurse practitioner. Women who have a medical problem may need to see a medical specialist as well. These women may also need the expert advice and care of a perinatologist. A perinatologist is a medical doctor (obstetrician) who specializes in the care of women who are at high risk for having problems during pregnancy. Perinatologists care for women who have pre-existing medical problems as well as women who develop complications during pregnancy.

Diagnosis

A woman who has a medical problem will have even more tests than the average pregnant woman. These might include tests to monitor the medical problem or blood tests to check the levels of medication. In most medical conditions, pregnancy changes the amount of medication that is necessary to control the problem. Frequent blood tests let the doctor adjust medication as often as needed.

Some medical conditions can increase the risk of birth defects. The doctor may suggest an ultrasound to check the baby early in the second trimester (16-18 weeks of pregnancy). At that point, the baby is large enough that the doctor can see the organs and structures clearly.

Other medical conditions may affect the baby's growth. The provider may request ultrasound exams every few weeks to make sure the medical condition is not interfering with the baby's growth and health.

Treatment

Treatment varies widely with the type of disease, the effect that pregnancy has on the disease, and the effect that the disease has on pregnancy. Additional tests may help determine the need for changes in medication or additional treatment.

Prognosis

The prognosis depends in large part on the specific medical condition. Some medical conditions make it difficult to get pregnant and lead to a higher risk of problems in the baby. An example of this type of condition is thyroid disease. In thyroid disease, the thyroid gland (located in the neck) may produce too much or too little thyroid hormone. Abnormal levels of thyroid hormone can cause problems in pregnancy and affect the health of the baby. Fortunately, thyroid disease can be treated with medication. As long as the level of thyroid hormone is controlled throughout pregnancy, there should be no problems for mother or baby.

There is a large group of medical conditions that usually does not interfere with pregnancy, but is affected by pregnancy. This group includes asthma, epilepsy, and ulcerative colitis. For example, some women with ulcerative colitis experience a worsening of their symptoms during pregnancy, while others will have no change or may get better during pregnancy. No one understands why this is so, but each of these women should be monitored very carefully throughout pregnancy.

There is also a group of medical conditions that can have a major impact on pregnancy. Women with lupus (disease caused by alterations in the immune system that result in inflammation of connective tissue and organs) or kidney disease face real risks during pregnancy. Pregnancy can cause their symptoms to worsen significantly and can lead to serious illness. Because these diseases can affect the mother's ability to supply oxygen and nutrients to the baby through the placenta, they can cause problems for the baby as well. These babies may not be able to grow and gain weight properly (intrauterine growth retardation). There is also an increased risk of stillbirth.

Diabetes is a medical condition that is both affected by pregnancy and affects pregnancy. Diabetes can lead to miscarriages, birth defects, and stillbirths. When a woman monitors her blood sugar carefully and treats high levels with insulin, the risk of these negative outcomes drops a great deal. Unfortunately, pregnancy makes diabetes much harder to control. In general, blood sugar and the need for insulin to control it rise throughout pregnancy.

Most medical conditions do not lead to complications in pregnancy. With frequent visits to healthcare providers, and careful attention to medication, women with medical problems usually enjoy healthy, successful pregnancies. There are a few medical conditions that can cause health risks to both mother and baby during pregnancy. Women with these medical problems should consider these risks before deciding to become pregnant. Many of these women will benefit from the care of a perinatologist during pregnancy. Only rarely (in the case of severe heart disease, for example) are the risks to the mother so high that she should not consider pregnancy at all.

Prevention

A pre-pregnancy visit with a healthcare provider is especially important for a woman who has a medical problem. The doctor will discuss how women with this condition usually fare during pregnancy. For some diseases (such as lupus), pregnancy can mean increased risk of health problems for mother and baby.

Sometimes, the medication a woman needs to control a medical condition can cause problems for the baby. There may be another medication available that is safer for use in pregnancy. In some cases there is no other medication, and a woman must weigh the risks to the baby when deciding whether or not to become pregnant.

A woman who has not had a pre-pregnancy visit should contact a healthcare provider as soon as she learns she is pregnant. Often, the provider will schedule the first prenatal visit within a day or two, instead of waiting until 8-10 weeks of pregnancy. This is because certain medical conditions can increase the risk of miscarriage. The provider will want to be sure that any medication is adjusted properly to increase the chance of having a successful pregnancy.

Key Terms

Gestational diabetes

Diabetes of pregnancy leading to increased levels of blood sugar. Unlike diabetes mellitus, gestational diabetes is caused by pregnancy and goes away when pregnancy ends. Like diabetes mellitus, gestational diabetes is treated with a special diet and insulin, if necessary.

Preeclampsia

A disease that only affects pregnant women. The most common signs and symptoms are increased blood pressure, swelling in the hands and feet, and abnormal results on special blood and urine tests.

Premature labor

Labor beginning before 36 weeks of pregnancy.

Further Reading

For Your Information

Books

• Carlson, Karen J., and Stephanie A. Eisenstat, eds. "Medical Problems in Pregnancy." In Primary Care of Women. St. Louis, MO: Mosby-Year Book, Inc. 1995, 346-383.
• Cunningham, Gary, et al. "Medical and Surgical Complications in Pregnancy." In Williams Obstetrics, 20th ed. Stamford, CT: Appleton & Lange, 1997, 1045-1316.

Gale Encyclopedia of Medicine. Gale Research, 1999.