Lowering the risk of developing a life-threatening condition while pregnant is as simple as taking low-dose aspirin every day, according to OB-GYNs at The University of Texas Health Science Center at Houston (UTHealth). They are now recommending their patients take a low-dose aspirin of 81 milligrams daily to prevent preeclampsia as part of routine prenatal care, just like taking a prenatal vitamin.
Preeclampsia, a pregnancy complication characterized by dangerously high blood pressure, is a leading cause of maternal and infant illness and death. It has increased 25% in the last two decades, according to the American College of Obstetricians and Gynecologists (ACOG).
Over the years, research has shown the use of low-dose aspirin in a high-risk population reduces the risk of preeclampsia without causing side effects. Aspirin causes decreased production of the hormone thromboxane A2, which is thought to increase the risk of preeclampsia."
Nana Ama Ankumah, MD, maternal-fetal medicine specialist with McGovern Medical School at UTHealth
New research from the National Institutes of Health shows low-dose aspirin reduces preterm birth among first-time mothers. Currently, ACOG recommends considering low-dose aspirin if a patient presents with one high risk factor or more than one moderate risk factor. The U.S. Preventive Services Task Force published a similar guideline.
Ankumah said the risk factors for preeclampsia are "extremely common," ranging from high risk factors such as diabetes, chronic hypertension, and autoimmune diseases, to moderate risk factors such as being over the age of 35, obesity, and low socioeconomic status.
However, by recommending prophylaxis, or proactive preventive measures, to all women instead of the selective approach, physicians hope to lower the rate of the condition while also saving time.
"Selective screening requires providers to spend time and effort to identify those who might be at risk, leaving room for a significant percentage of those considered at risk to be missed," said Baha Sibai, MD, a maternal-fetal medicine specialist with McGovern Medical School and international expert in preeclampsia. "This is similar to gestational diabetes screening, where initially a list of factors were used to determine risk, but it became obvious that providers were missing patients. As a result, routine screening became the standard."
Sean C. Blackwell, MD, chair of the Department of Obstetrics, Gynecology, and Reproductive Services at McGovern Medical School, consulted with Sibai before implementing the departmental shift in standard clinical care at UT Physicians clinics.
"This change especially makes sense for us because the majority of our patient population is considered at-risk," Blackwell said. "There is a very low cost and risk associated with this therapy, and we hope a universal approach minimizes missed opportunities for treatment at a population level."
The routine use of low-dose aspirin could also reduce rates of other adverse pregnancy outcomes, such as preterm birth and fetal growth restriction, while only costing less than $10 per pregnancy, Sibai said.
"Most patients are amenable once they understand what preeclampsia is and how serious it is. The dose is so small and there's really no side effects, so most patients are fine with adding it to their prenatal vitamin. For perspective, people taking daily aspirin for heart attack are recommended to take 325 mg, about four times the 81 mg we're recommending," Ankumah said.
Under this recommendation, low-dose aspirin is recommended beginning at 12 weeks and continued through delivery. According to ACOG, there is no increased risk of postpartum bleeding or placental abruption. Exclusions include women with allergies to nonsteroidal anti-inflammatory drugs and women with vaginal bleeding.
"This is a major paradigm shift in prenatal care and is just another way we are incorporating several novel aspects to care to provide cutting-edge, evidence-based treatments to our patients," Blackwell said.
Researchers at UTHealth are also investigating how to prevent postpartum hypertension. A recent study led by Conisha Holloman, MD, a maternal-fetal medicine fellow with McGovern Medical School, suggests that all women should be informed about the symptoms of high blood pressure, also known as postpartum hypertension.
The study, published in the American Journal of Obstetrics and Gynecology, looked at 164 women from September 2016 to July 2019 who gave birth at Children's Memorial Hermann Hospital in Houston and were readmitted with high blood pressure. More than 64% of women were readmitted within seven days, and 39% of those women were not diagnosed with high blood pressure prior to being discharged.
"Texas has one of the highest maternal mortality rates in the nation. As clinicians, we're always looking for ways to tailor interventions so we can reduce deaths," Holloman said. "While clearly more research needs to be done on what causes high blood pressure after childbirth, what our study reveals is a strong need to educate all women, not just those who may be at a higher risk, about the signs and symptoms of high blood pressure before they are discharged."