Physical disorders that can arise as a consequence of pregnancy, ranging from mild to life-threatening. Extreme conditions can result in termination of the pregnancy or death of the mother.
The most common disorder of early pregnancy, persistent vomiting, is without known cause and usually subsides spontaneously within a few weeks. A more serious threat to pregnancy, vaginal bleeding (within the first 20 weeks), may be a sign of miscarriage (spontaneous abortion) or much less often, ectopic pregnancy (embryonic development outside the uterus, usually within the Fallopian tube). Over 50% of miscarriages are due to a spontaneous chromosomal abnormality in the sperm, egg, or developing embryo. Ectopics are nearly always removed surgically; the involved Fallopian tube usually can be preserved.
Some abnormal conditions in pregnancy are identified as a result of routine blood tests. Examples include rubella (German measles) and syphilis, both of which occur relatively infrequently and can cause birth defects. Rh disease is also uncommon because of prevention by prenatal blood tests and treatment with immunoglobulins in Rh-negative mothers. Routine screening is also recommended for hepatitis B. See also Hepatitis; Prenatal diagnosis; Rh incompatibility; Rubella; Syphilis.
Maternal conditions that may worsen during pregnancy include some forms of heart disease, seizure disorders, hypertensive disease, and acquired immune deficiency syndrome (AIDS). See also Acquired immune deficiency syndrome (AIDS).
Among the most important disorders during the second half of pregnancy are those associated with low birth weight due to either premature labor or fetal growth problems. Low birth weight is associated with twins, hypertensive disorders, smoking, and inadequate nutrition. The hypertensive disorders include pregnancy-induced hypertension (formerly known as toxemia) as well as chronic hypertension that exists before the pregnancy. Signs and symptoms of pregnancy-induced hypertension can include swelling of the hands and face, headaches, and a sudden weight gain of 5 lb (2 kg) or more in 1 week. Vaginal bleeding in late pregnancy, which is a potential emergency condition, often results from a placental problem; either the placenta is abnormally located near or over the cervix (placenta previa), or the placenta separates prematurely from the uterus (abruptio placenta). See also Hypertension.
Far less dramatic than these conditions, but equally important as a cause of fetal distress, is the “post dates” pregnancy, which occurs once pregnancy has extended 2 weeks beyond the date of expected delivery. When a pregnancy reaches 42 weeks, delivery is attempted as soon as possible as the aging placenta may lose its ability to provide adequate oxygen and nutrition.
Increased rest and proper nutrition are especially important in pregnancies complicated by high blood pressure, fetal growth problems, and twins. More immediate management often centers on the timing of delivery. See also Pregnancy.
