Women experiencing the following conditions should not exercise during pregnancy, according to The American College of Obstetricians and Gynecologists:
- pregnancy-induced hypertension (preeclampsia, toxemia);
- preterm ruptured membranes;
- preterm labor in a previous or current pregnancy;
- insufficient cervix/cervical cerclage;
- persistent second- or third-trimester bleeding; or
- intrauterine growth restriction.
Symptoms of pregnancy-induced hypertension include elevated blood pressure, protein in the urine, increased weight gain, and increased swelling. This condition decreases blood flow to the uterus so that the placenta, which nourishes the fetus, lacks any reserves. The typical treatment for this condition is bedrest if the fetus is not mature, and delivery if the baby is mature. Any exercise, with its combined impact of stress on the mother's body and dehydration, can be very dangerous to the fetus, risking fetal injury or death.
Premature Rupture of the Membranes
Rupture of the membranes prior to full-term gestation causes amniotic fluid, which surrounds and protects the fetus, to leak from the uterus, and is more critical if it occurs early in pregnancy. The loss of amniotic fluid subjects the fetus to umbilical cord compressions and resulting injuries. There also is an increased risk of infection of the uterus and/or the placenta and fetus. The typical treatment is primarily bedrest and other efforts to ensure prolonged pregnancy. Exercise could increase the leakage of amniotic fluid and make the condition worse.
Premature delivery (which occurs after preterm labor) increases the risk of disease, long-term injury, developmental delay, mental retardation, and death for the baby. Women who experience-or have experienced-preterm labor must limit their activity and often take medications to stop uterine contractions so that they avoid premature delivery. The stress of exercise can increase the likelihood of preterm labor in these women.
Insufficient Cervix/Cervical Cerclage
In the condition known as insufficient, incompetent, or weak cervix, the cervix painlessly opens (dilates) long before it should (in the second trimester or early third trimester), usually resulting in a preterm delivery. This increases the risk of disease, long-term injury, developmental delay, mental retardation, and death for the baby. Any form of exercise will place unnecessary force on the cervix if it is insufficient. Bedrest and decreased activity are recommended. Cerclage is a suturing procedure done to reinforce an insufficient cervix.
Persistent Second- or Third-trimester Bleeding
Normally, the placenta attaches to the side or top of the uterine cavity, but in placenta previa, an abnormal attachment, the placenta attaches to the lowest part of the uterus, thus possibly blocking the baby's exit. In placental abruption, also abnormal, the attachment is loose or separating. Both conditions can cause bleeding. Treatment is pelvic rest and usually bedrest. Increasing activity during exercise may lead to further bleeding.
Intrauterine Growth Restriction
This condition is diagnosed by ultrasound examination or through measurements of abdomen growth during pregnancy. It is often due to abnormal changes that lead to an inability of the placenta to adequately provide oxygen and nutrients to the fetus. As a result, the fetus doesn't grow adequately. Exercise is not recommended because it limits blood flow to the uterus, further compromising the fetus.
Other Situations Where Exercise is Not Recommended
Women with a number of other relatively rare conditions should coordinate any exercise program with their physicians and obtain an exercise prescription for the pregnancy. Included among these conditions are chronic hypertension (high blood pressure), active thyroid disease, and a number of cardiac conditions, such as acute myocardial diseases, congestive heart failure, rheumatic heart disease, and certain forms of congenital heart disease. Women with thrombophlebitis, an inflammation of the vein due to clot formation, or a recent pulmonary embolus, the closure of an artery in the lung due to a clot or foreign body, should also discuss their situation with their physicians before beginning an exercise program.
Pregnant women suffering from acute infectious diseases that are viral or bacterial, signaled by a fever, should postpone exercise until they are well.
Another rare condition is isoimmunization, in which antibodies made by the mother cross the placenta and destroy red blood cells of the fetus. If this condition is present, exercise should be stopped because the fetus is anemic and needs all the oxygen it can get for normal development of tissues. Exercise could potentially limit the amount of oxygen delivered to it.
It is important to raise any concerns about exercise with your physician. Not every medical complication prohibits a woman from exercising during pregnancy. For instance, pregnant women with diabetes may greatly benefit from an exercise program because it will allow better and easier glucose control.