Most women have lower blood pressures during pregnancy. If a woman's blood pressure increases above 140/90, she is diagnosed with hypertension, or high blood pressure. There are two types of hypertension in pregnancy:

  • Hypertension that was present before pregnancy and that may get worse during pregnancy; and
  • Hypertension that begins during pregnancy and disappears after the delivery of the baby. This is called pregnancy-induced, or gestational, hypertension.

Hypertension in pregnancy can be a serious problem. It increases the mother's risk of kidney and liver problems, stroke, heart failure or heart attack, and placental abruption (premature separation of the placenta from the uterine wall). It is a leading cause of death among expectant mothers. The baby is also at increased risk. In mothers with high blood pressure, the placenta may not work well, so the baby may not get enough oxygen and may be born too early or too small.

If you have high blood pressure, meet with your doctor before you get pregnant. Losing weight may help control your blood pressure and reduce your risk of pregnancy-related problems. In addition, before you conceive, discuss whether any medicines you are taking are safe in pregnancy.