Adherence to low-dose aspirin improves pregnancy outcomes

Women who adhere to a low-dose aspirin regimen while trying to conceive, and throughout pregnancy, are more likely to have a live birth, research has suggested (26 January 2021)​[1]​.

A team of researchers used data from an earlier trial that looked at the effects of aspirin on reproduction in 1,227 women with previous pregnancy losses who were trying to conceive.

The earlier trial found that women assigned to taking low-dose aspirin daily before pregnancy did not have better pregnancy outcomes compared with women given placebo. However, many of the patients in the trial did not adhere closely to the aspirin protocol.

In the analysis, the researchers compared outcomes for women who took low-dose aspirin for at least four days each week with the outcomes for women given placebo.

They found that close adherence to the aspirin regimen led to 8 more pregnancies (95% confidence interval [CI] 4.64 to 10.96], 15 more live births [95% CI 7.65 to 21.15] and 6 fewer pregnancy losses [95% CI -12.00 to -0.20] for every 100 women in the trial.

The beneficial effect of aspirin was stronger if women began taking it before pregnancy and weaker if they started taking it after the sixth week of gestation.

“Efforts geared toward improving daily adherence to [low-dose aspirin] may yield improvements in aspirin’s effectiveness on reproductive outcomes for women trying to conceive,” the researchers concluded in Annals of Internal Medicine.