In a new study published in the journal The Lancet, researchers say that low doses of aspirin boosts fertility in woman and improve their chances of conceiving a baby and having a live birth — perhaps because aspirin increases the blood flow to the womb.
To conduct the study, researchers at the National Institute of Health randomly assigned more than 1,000 women with a history of pregnancy loss either a daily low dose of aspirin or a placebo, then followed their progress over the next six months as they tried to conceive. There was no difference in pregnancy loss between the two groups, but for the women who had experienced a recent single pregnancy loss the researchers found an increased rate of pregnancy and live birth in the group on the aspirin regime.
Among those women, 78 percent became pregnant during the study, compared to 66 percent of those taking the placebo.
As many as one-third of pregnancies end up being lost, most of them early in the pregnancy, according to Dr. Robert M. Silver, chief of maternal-fetal medicine at the University of Utah. Of those, many are likely the result of decreased blood flow. In those cases, low doses of aspirin, which has blood-thinning properties, may make the difference.
Low-dose aspirin can improve pregnancy outcomes by helping more blood reach reproductive organs and the placenta, as well as thickening the uterine wall. Aspirin may impact several aspects of reproduction, including getting pregnant, forestalling early loss, stillborn, preeclampsia, and placental insufficiency.
Often it is not known what caused a pregnancy loss, so it's hard to identify the women who might be helped with aspirin therapy. Some women with very specific conditions that caused miscarriage are unlikely to benefit.