Raleigh, N.C. — While medical professional agree that severe chronic hypertension or high blood pressure during pregnancy should be treated with medications, the approach to mild hypertension has caused a divide.
But a new study suggests that treating mild hypertension in pregnancy can be good for mom and baby.
The study, known as the Chronic Hypertension and Pregnancy trial or CHAP, was the largest-ever clinical trial of hypertension during pregnancy.
The trial included more than 60 sites across the country, including in the Triangle, and was led by the University of Alabama at Birmingham.
The trial evaluated the effects of prescribing blood pressure medication to pregnant women with mild chronic hypertension. The results showed that treatment improved pregnancy outcomes without compromising the baby’s growth and overall health.
Dr. Kim Boggess, MD, professor in the UNC Rex Department of Obstetrics and Gynecology and principal investigator at the UNC Medical Center site for this study, said the research “will likely change clinical care for pregnant patients with hypertension.”
Boggess answered some of our questions about the study, which was published in the New England Journal of Medicine.
Dr. Boggess answered our questions about the study below:
Tell me about the study you have been working on involving hypertension. What have been your most interesting findings?
Dr. Boggess: Treatment of hypertension in pregnancy is controversial. The CHAP study examined the effect of treating mild hypertension in pregnant patients on both maternal and infant outcomes. The findings show that treating pregnant patients with mild hypertension (< 160/100 mm Hg) with medical therapy lowers the chance of having an adverse pregnancy outcome.
What is considered hypertension in women? What ranges should people be looking for in their blood pressure?
Dr. Boggess: Definitions of hypertension are the same for women as for men, as well as for pregnant patients. Sustained blood pressure > 140/90 mm Hg is considered hypertension, and in nonpregnant patients would be an indication for medical therapy. Severe hypertension is defined as > 160/110 mm Hg. The challenge for pregnant patients is that prior to the CHAP study it was unclear if treating mild, chronic hypertension (between 140/90 -159/109 mm Hg) provided any benefit or added any risk to the mother and fetus.
What can women do before they get pregnant to make sure their blood pressure is under control?
Dr. Boggess: Regular health care; maintenance of healthy weight; regular exercise
What dangers exist for pregnant women with uncontrolled and undiagnosed high blood pressure?
Dr. Boggess: The dangers are the same for pregnant patients with uncontrolled and/or undiagnosed hypertension as nonpregnant patients (such as heart attack, heart failure, stroke). However, because of the pregnancy there are additional risks: preeclampsia, placental abruption (where the placenta separates early), preterm birth, delivery of a small baby, or fetal or infant death.
What can blood pressure control do to help ensure a healthy pregnancy and birth?
Dr. Boggess: Based on the findings of the CHAP study we found that controlling mild chronic hypertension in pregnancy lowers blood pressure and can improve pregnancy outcomes by reducing the composite risk for severe preeclampsia, medically indicated preterm birth, placental abruption, and fetal or infant death.