Prophylactic low-dose aspirin – 81 mg per day – should be started after 12 weeks’ gestation in women at high risk for developing preeclampsia, according to a draft recommendation issued by the U.S. Preventive Services Task Force in April.
The recommendation applies to asymptomatic pregnant women at increased risk for preeclampsia who have no contraindications to using low-dose aspirin and have not experienced adverse effects associated with aspirin previously.
"The USPSTF found adequate evidence of a reduction in preeclampsia, preterm birth, and IUGR [intrauterine growth restriction] in women at increased risk for preeclampsia who received low-dose aspirin, thus demonstrating substantial benefit," the recommendations state. In a review of clinical trials, low-dose aspirin (at doses of 50-160 mg per day) reduced the risk of preeclampsia by 24%, the risk of preterm birth by 14%, and the risk of IUGR by 20%. There also was "adequate evidence" that the risks of placental abruption, postpartum hemorrhage, and fetal intracranial bleeding were not increased with low-dose aspirin, the USPSTF statement said.
The draft recommendations were based on a review of data on low-dose aspirin and preeclampsia in 23 studies of women at high or average risk of preeclampsia, which was published online April 8 in Annals of Internal Medicine (doi: 10.7326/M13-2844).
The recommendation is considered a "B" recommendation, defined as one that has a "high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial." The statement includes a table to help identify patients who are at an increased risk of preeclampsia.
The last statement about low-dose aspirin and preeclampsia, issued by the USPSTF in 1996, concluded that there was not enough evidence to support a recommendation for or against the use of aspirin for preventing preeclampsia. The American College of Obstetricians and Gynecologists recommends low-dose aspirin, starting late in the first trimester, in women with a history of early-onset preeclampsia and preterm delivery before 34 weeks’ gestation, or a history of preeclampsia in more than one previous pregnancy.
The USPSTF is an independent panel of nonfederal experts in prevention and evidence-based medicine, which includes ob.gyns., pediatricians, family physicians, nurses, and health behavior specialists, according to the USPSTF website.
The draft recommendations are available here. Comments on the recommendations can be submitted via the website until May 5, 2014, at 5 p.m. EST.