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Low-dose aspirin may lower risk for preterm preeclampsia
Pregnant woman at high risk for preterm preeclampsia who were treated with low-dose aspirin developed preeclampsia less often than those treated with placebo, according to a study published in The New England Journal of Medicine.
Researchers reviewed data from 1,776 pregnant women at high risk for preterm preeclampsia. Women were assigned 150 mg aspirin per day or placebo from 11 to 14 weeks of gestation through 36 weeks of gestation.
“The dose of 150 mg of aspirin per day was selected on the basis of previous evidence of a dose-dependent benefit to therapy,” Daniel L. Rolnik, MD, of King’s College Hospital in London, and colleagues wrote. “In addition, the commonly used dose of 81 mg of aspirin per day has no appreciable effect on platelet function in up to one third of pregnant women.”
Women were followed up until 36 weeks of gestation through clinical visits and telephone interviews. After some women withdrew (n = 152) or were lost to follow-up (n = 4), 798 women were assigned aspirin (median age, 32 years) and 822 women were given placebo (median age, 31 years).
The primary outcome was defined as delivery before 37 weeks of gestation with preeclampsia. Secondary outcomes included stillbirth or neonatal death, adverse pregnancy outcomes before 34 weeks of gestation, before 37 weeks or after 37 weeks, neonatal therapy, death and neonatal complications and low birth weight.
Thirteen women (1.6%) in aspirin group developed preterm preeclampsia vs. 35 women (4.3%) in the placebo group (OR in the aspirin group = 0.38; 95% CI, 0.2-0.74). Results were unchanged after a sensitivity analysis including women who withdrew or were lost to follow-up.
Rolnik and colleagues reported that medication adherence was good, with 79.9% of participants taking at least 85% of the required tablets.
Neonatal adverse outcomes and other adverse events did not differ between the groups, according to the researchers. – by Darlene Dobkowski
Disclosures: The researchers report no relevant financial disclosures.
Perspective
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Prior studies of aspirin for prevention of preeclampsia have been mixed in regards to aspirin dosing, timing of aspirin administration and indications for therapy. Most importantly, guidelines regarding which women are at high risk for preeclampsia with associated preterm birth have varied and generally take into account a prior history of preeclampsia. Gestational weeks at which aspirin was administered also varied. Guidelines were generally based on meta-analyses of individual trials.
The current study by Rolnik et al published in NEJM specifically aimed to study aspirin at 150-mg dosage, based on prior evidence, from 11 to 14 weeks gestation. The study specifically enrolled women with singleton pregnancy deemed to be at high risk for preterm preeclampsia. The authors found that aspirin in the selected population did lead to a significant reduction in the incidence of preterm preeclampsia. There was no statistically significant difference in adverse events.
The current study provides more rigorous data for the use of aspirin in women at high risk for preterm preeclampsia, specifically in women with a first pregnancy without prior history of preeclampsia with preterm birth. This has implications to extend the support of using aspirin in women with their first pregnancy.
Women with preeclampsia/preterm birth are also at increased risk of long-term CV events such as HF and stroke. Currently, indications for primary prevention use of aspirin in women is not quite as robust as it is for men. Whether chronic use of aspirin in women with a prior history of preeclampsia, remote from their pregnancy history, could be indicated for primary CV prevention is unknown.
