LISBON — Prenatal treatment with aspirin cut the incidence of preeclampsia by 10% in a metaanalysis of results from 26 controlled studies that involved more than 30,000 women.
Prophylaxis with aspirin also led to a similar reduction in the rates of preterm delivery (less than 34 weeks), small-for-gestational-age births, and all serious adverse outcomes, Lisa M. Askie, Ph.D., said at the 15th World Congress of the International Society for the Study of Hypertension in Pregnancy.
The metaanalysis “confirms that aspirin works, producing a moderate but consistent 10% reduction in important outcomes,” said Dr. Askie, an epidemiologist at the University of Sydney (Australia).
Many physicians in the United States do not now prescribe aspirin to women at risk for preeclampsia. The new finding may help persuade them to start, commented Dr. Baha M. Sibai, professor and chairman of obstetrics and gynecology at the University of Cincinnati. “Aspirin is safe and inexpensive, so why not offer it” to at-risk women? he asked. “The analysis showed that the number needed to treat [to prevent one serious adverse outcome] was 36. I think this number-needed-to-treat will be persuasive,” he said in an interview.
The metaanalysis by Dr. Askie and her associates was an individual patient-data review, which means that all the data for each patient from every trial were collected and reanalyzed. The researchers initially identified 65 relevant studies of antiplatelet therapy for either the treatment or prevention of pre-eclampsia invloving nearly 40,000 women.
For several reasons, the analysis data were trimmed down to about 31,000 women in 26 trials of preeclampsia prophylaxis. Although various antiplatelet agents were used, about 98% of the women were treated with aspirin.
The reductions in the rates of preeclampsia and other serious adverse outcomes that were associated with aspirin use were statistically significant, compared with those in controls who received placebo. The analysis was unable to find any subset of women for whom aspirin was ineffective for preventing preeclampsia, including women with preexisting diabetes, renal disease, or chronic hypertension, and women who previously delivered a small-for-gestational-age infant.
In addition, the dosage of aspirin used did not have any significant effect on the outcomes.
The analysis did not reveal any adverse effects of treatment and therefore provided “reasonable reassurance of safety,” Dr. Askie said.
The new finding may persuade physicians in the United States to prescribe aspirin to women at risk for preeclampsia. DR. SIBAI