The U.S. Preventive Services Task Force (USPSTF) is nos recommending pregnant women at risk for the high blood pressure disorder preeclampsia should take low-dose aspirin after the first trimester.
The task force first made the recommendation in 2014, but announced its update last week in the Journal of the American Medical Association (JAMA) after new studies found the preventive therapy can guard against the high blood pressure disorder as well as delivery of preterm and low birth weight babies. The studies show no increased risk of placental abruption or other complications such as excessive bleeding.
Preeclampsia causes sudden spikes in blood pressure in pregnant women, which can starve the placenta of oxygen and nutrients. It can lead to other medical problems for both mothers and babies.
It’s important to note the studies and recommendation are for low-dose aspirin – which is defined as 81 milligrams per day – and not regular aspirin.
Dr. Ronald L. Thomas, director of the Division of Maternal-Fetal Medicine and clinical vice chairman of the Department of Obstetrics and Gynecology at West Penn Hospital, said low-dose aspirin has been used in this capacity for more than 50 years.
“Although scientists hedge regarding the ‘exact’ mechanism of the low-dose aspirin intervention,” Thomas said, “there is a reasonable scientific basis for the observed improvements in pregnancy outcome based on minor modifications in the chemistry of prostaglandins”
Thomas said prostaglandins are a common “messenger” in the human body relative to smooth muscle actions and activity. He said essentially the placenta can produce “good guy” and “bad guy” products.
The “bad guys” can constrict blood vessels and starve the placenta of oxygen, but low-dose aspirin can work to counteract them, Thomas said.
Preeclampsia affects 4% to 8% of the population.
Thomas said his department has adopted a policy of recommending universal low-dose aspirin in pregnancy.
“This is based on the value demonstrated by the intervention and the observation that a significant number of patients without risk factors go on to develop complications that may have been decreased or ameliorated with low-dose aspirin intervention,” Thomas said. “Once you already have a preeclampsia, it’s really too late, so this is really preventative.”
Women at risk for preeclampsia include a those with a family history of the disorder, black women, those 35 and older and low-income. Women who had preeclampsia with a previous pregnancy are also at risk along with those having diabetes, kidney disease or an autoimmune disorder.
The recommendation calls for women to begin the preventive therapy after their first trimester.
“Starting this at the end of the first trimester and clearly before 16 weeks, really gives you optimal effects of the low dose aspirin in terms of the three major benefits we talked about,” Thomas said.
Thomas said those with an allergy or sensitivity to aspirin should not take it nor should those with hypersensitivity to NSAIDs or a history of asthma and asthma that’s induced by low-dose aspirin. He added those with a history of active gastrointestinal bleeding or peptic ulcer disease should also avoid taking it.
Thomas said the Society of Maternal Fetal Medicine looked at this issue earlier this year at its national meeting and discussed the idea of putting all pregnant women on low-dose aspirin as a precaution.
“It turns out, it’s cost effective and the reason for that is if you use all of the current criteria to make your recommendations, about a fourth of people won’t have risk factors, and yet they will develop preeclampsia and complications,” he said. “So that’s really the problem with not doing this universally and using risk factors alone.”