Do new BP guidelines apply to pregnant women?
In the fall of 2017, two leading heart health organizations lowered the high blood pressure threshold for adults. In September 2018, a study published in Hypertension said if the new guidelines were applied to pregnant women, the number considered to have high blood pressure might double.
Cape Cod Hospital obstetrician-gynecologist Tara Chute, MD, said the new threshold would likely mean more induced births and cesarean deliveries, if adopted by her colleagues.
High blood pressure, or hypertension, can lead to heart failure, heart attack, stroke and chronic kidney disease, according to the Centers for Disease Control and Prevention (CDC), and is on the rise.
The new standard for high blood pressure is 130/80 or above, which was announced in November 2017 by the American Heart Association and the American College of Cardiology The standard was changed to encourage earlier detection and treatment, particularly among younger people, and was expected to increase the number of American adults diagnosed as hypertensive to 46 percent, according to the American College of Cardiology. Currently, 29 percent of Americans have high blood pressure, according to the CDC.
However, medical organizations for pregnant women and fetal health have not adopted the new standard.
Dr. Chute said she and her colleagues stand by the older threshold of 140/90, which is endorsed by both the American College of Obstetricians and Gynecologists and the Society of Maternal-Fetal Medicine.
One reason for adhering to the former threshold is that the American College of Obstetricians and Gynecologists has issued its own reports and guidelines in recent years on hypertension and preeclampsia, a related condition that endangers pregnant women and their unborn babies, she said. Also, doctors use different medications for high blood pressure in pregnancy.
A key difference is that pregnant women should not take certain medicines often prescribed for high blood pressure, such as statins, ACE (angiotensin converting enzyme) inhibitors and ARBs (angiotensin II receptor blockers), Dr. Chute said.
Another difference is that some women develop hypertension during pregnancy.
“After 20 weeks (into a pregnancy), it’s considered gestational hypertension and assumed to be temporary,” she said, adding that this condition does put the patient at higher risk of hypertension after pregnancy.
Teenagers and women over 35 tend to develop hypertension during pregnancy, more often than women in other age groups, “but it can occur at any age,” said Dr. Chute.
About 10 percent of pregnant women are hypertensive, according to Dr. Chute. This can cause babies in the uterus to get fewer nutrients and less oxygen, resulting in smaller size or earlier birth, according to the CDC. Pregnant mothers with hypertension may be at risk for stroke, separation of the placenta from the uterus (placental abruption) and preeclampsia.
During preeclampsia, the pregnant mother’s liver, kidney and other organs don’t function normally, and symptoms may include fluid in the lungs, abdominal pain, vision changes and severe headache. It can progress to seizures, internal bleeding, heart attack and stroke, according to the American College of Obstetricians and Gynecologists. It also can result in lifelong health problems or death for baby and mother.
Most women with preeclampsia recover and give birth to healthy babies, according to the Preeclampsia Foundation. Pre-existing, or chronic, hypertension, raises the risk, as do obesity, diabetes, first pregnancies, multiple fetuses and age, Dr. Chute said.
“Age is risk factor,” she said. “We see it in teenagers and women over 35.”
What You Can Do
At-risk pregnant women are treated with low-dose aspirin and closely monitored, Dr. Chute said.
Her advice to women planning to get pregnant:
- If you are overweight or diabetic, try and get your weight and chronic illnesses under control.
- If you are on medication for high blood pressure, talk to your physician about switching to drugs considered safer for pregnancy, such as beta blockers or calcium channel blockers.