WASHINGTON – with a large National Institutes of Health–funded trial currently recruiting women with a prior history of the disorder with preterm delivery at less than 34 weeks, Maged Costantine, MD, said at the biennial Diabetes in Pregnancy Study Group of North America meeting.
More should be learned about low-dose aspirin, in the meantime, once the outcomes of a global study involving first-trimester initiation are published, said another speaker, Cynthia Gyamfi-Bannerman, MD, MS. Low-dose aspirin currently is recommended for preeclampsia prevention starting between 12 and 28 weeks, optimally before 16 weeks.
The biological plausibility of using pravastatin for preeclampsia prevention stems from the overlapping pathophysiology of preeclampsia with atherosclerotic cardiovascular disease – endothelial dysfunction and inflammation are common key mechanisms – as well as common risk factors, including diabetes and obesity, said Dr. Costantine, director of the division of maternal-fetal medicine at Ohio State University, Columbus, who is chairing the study.
In animal models of preeclampsia, pravastatin has been shown to upregulate placental growth factor, reduce antiangiogenic factors such as soluble fms-like tyrosine kinase 1 (sFlt1), and upregulate endothelial nitric oxide synthase. Mice have shown improved vascular reactivity, decreased proteinuria, decreased oxidative stress, and other positive effects, without any detrimental outcomes.
A pilot randomized controlled trial conducted with the Obstetric-Fetal Pharmacology Research Units Network and published in the American Journal of Obstetrics and Gynecology in 2016 assigned 10 women to 10 mg daily pravastatin and 10 women to placebo. The drug reduced maternal cholesterol concentrations but there were no differences in birth weight or umbilical cord cholesterol concentrations between the two groups.
Women in the pravastatin group were less likely to develop preeclampsia (none, compared with four in the placebo group), less likely to have an indicated preterm delivery (one, compared with five in the placebo group), and less likely to have their neonates admitted to the neonatal ICU.
There were no differences in side effects, congenital anomalies, or other adverse events. Dr. Costantine, principal investigator of the pilot study, and his colleagues wrote in the paper that the “favorable risk-benefit analysis justifies continued research with a dose escalation” ().
The new multicenter randomized controlled trial is randomizing 1,550 women to either 20 mg pravastatin or placebo starting between 12 weeks 0 days and 16 weeks 6 days. The primary outcome is a composite of preeclampsia, maternal death, or fetal loss. Secondary outcomes include a composite of severe maternal morbidity and various measures representing preeclampsia severity and complications, as well as preterm delivery less than 37 weeks and less than 34 weeks and various fetal/neonatal outcomes.
“In addition, we’ll look at development,” Dr. Costantine said, with offspring assessed at 2 and 5 years of age. The trial is sponsored by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Heart, Lung, and Blood Institute.
In the meantime, he said, the use of pravastatin to ameliorate early-onset preeclampsia is being tested in a small European proof-of-concept trial that has randomized women with early-onset preeclampsia (between 24 and 31 6/7 weeks) to 40 mg pravastatin or placebo. The primary outcome is reduction of antiangiogenic markers. Results are expected in another year or 2, he said.
The aspirin trial referred to by Dr. Gyamfi-Bannerman has been looking at the 81-mg dose of aspirin initiated between 6 0/7 and 13 6/7 weeks in nulliparous women who had no more than two previous pregnancy losses. The key question of the Aspirin Supplementation for Pregnancy Indicated Risk Reduction in Nulliparas (ASPIRIN) trial – conducted in the NICHD Global Network for Women’s and Children’s Health – is whether low-dose aspirin can reduce the rate of preterm birth. Preeclampsia is a secondary outcome (.
“It may eventually be that the use of baby aspirin is further expanded to reduce the risk of preterm birth,” she said.
Overall, “we need more data on first-trimester use [of low-dose aspirin] and long-term outcomes,” Dr. Gyamfi-Bannerman said. And with respect to preeclampsia prevention specifically, more research is needed looking at risk reduction levels within specific groups of patients.
Since 2014, the U.S. Preventive Services Task Force (USPSTF) has called for low-dose aspirin at 81 mg/day in women who have one or more high-risk factors for preeclampsia (including type 1 or type 2 diabetes mellitus), and consideration of such treatment in patients with several moderate-risk factors. The American College of Obstetricians and Gynecologists’ recommendation varies slightly in that it advises treatment in patients with more than one (versus several) moderate-level risk factors ().
Moderate-level risk factors include nulliparity, obesity, family history of preeclampsia, a baseline demographic risk (African-American or low socioeconomic status), and prior poor history (intrauterine growth restriction/small-for-gestational-age, previous poor outcome). “This is just about everyone I see,” Dr. Gyamfi-Bannerman said.
Dr. Gyamfi-Bannerman said she’d “love to see more data on higher doses” of low-dose aspirin – data that compares 81 mg/day with 150 mg/day, for instance.
A study published in 2017 in the New England Journal of Medicine randomized 1,776 women at high risk for preeclampsia to 150 mg/day or placebo and found a significant reduction in preterm preeclampsia (4.3% vs. 1.6%) in the aspirin group. Women in this European trial were deemed to be at high risk, however, based on a first-trimester screening algorithm that incorporated serum markers (maternal serum pregnancy-associated plasma protein A and placental growth factor) and uterine artery Doppler measures ().
“So it was a very interesting study, very provocative, but it’s hard to know how it would translate to the U.S. population [given that such screening practices] are not the way most of us are practicing here,” said Dr. Gyamfi-Bannerman, codirector of the Preterm Birth Prevention Center at Columbia University, New York, and professor of obstetrics and gynecology at the university.
The USPSTF based its recommendations on a systematic review that pooled data from 15 high-quality randomized controlled trials, including 13 that reported preeclampsia incidence among women at highest risk of disease. They found a 24% reduction in preeclampsia, but the actual risk reduction depends on the baseline population risk and may be closer to 10%, she said.
In a presentation on gaps in knowledge, Leslie Myatt, PhD, of the department of obstetrics and gynecology at Oregon Health and Science University, Portland, emphasized that preeclampsia is a syndrome with a heterogeneity of presentation and pathophysiology. “We don’t completely understand the pathophysiology,” he said.
Research needs to be “directed at the existence of multiple pathways [and subtypes],” he said, such that future therapies can be targeted and personalized.
Dr. Costantine did not report any disclosures. Dr. Gyamfi-Bannerman reported a Society of Maternal Fetal Medicine/AMAG Pharmaceuticals unrestricted grant and Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Heart, Lung and Blood Institute funding. Dr. Myatt reported that he has no financial or other ties that pose a conflict of interest.