By James N. Martin, Jr, MD
President, The American Congress of Obstetricians and Gynecologists
Up to seven percent of pregnant women will develop preeclampsia, a serious pregnancy-related condition that can affect the placenta, liver, kidneys, blood, brain, and other organs. It is a leading cause of maternal and infant sickness and death in the US.
While the cause of preeclampsia is unknown, high blood pressure is a main contributing factor. Normally, blood pressure changes throughout the course of the day—for example, it increases when you exercise and slows when you’re at rest. But when it stays elevated, it can strain the heart and blood vessels, increasing the risk of heart attack and stroke and damage to the kidneys, brain, and eyes. During pregnancy, high blood pressure can also restrict the flow of blood, oxygen, and nutrients to the fetus.
Some women have ongoing (chronic) high blood pressure before they get pregnant. Others may develop high blood pressure during pregnancy, usually after the 20th week of gestation. Women who have chronic or gestational high blood pressure, are pregnant for the first time, have had preeclampsia in a previous pregnancy, are 35 years or older, are carrying more than one fetus, have certain medical conditions such as diabetes or kidney disease, are obese, are African American, or have certain immune disorders such as lupus or blood diseases are at increased risk of developing preeclampsia.
Other symptoms of preeclampsia include increased amounts of protein in the urine, headaches, visual problems, and swelling of the hands and face. Severe preeclampsia may be accompanied by lung, liver, kidney, or clotting complications and seizures (eclampsia).
If you have chronic high blood pressure, it’s important to make efforts to lower blood pressure before pregnancy by losing weight and taking medication as prescribed. Regular prenatal care during pregnancy can help detect preeclampsia early in all pregnant women. At each prenatal visit, a woman’s weight and blood pressure are taken along with a urine sample to monitor any changes. You may be checked more often if your blood pressure is high.
The gestational age of the fetus, the severity of the mother’s preeclampsia, and risks to mother and fetus will be assessed to guide the decision on when to deliver. Some women will be monitored to see if the situation improves, or—if the risk to the fetus is greater in the womb than in a special nursery—delivery may be necessary. Women with slightly increased blood pressure who are not near the end of pregnancy may be prescribed bed rest at home or in the hospital.
For more information, the ACOG Patient Education Pamphlet “High Blood Pressure During Pregnancy” is available at www.acog.org/publications/patient_education.♀