There is no evidence to guide use of aspirin for women undergoing in
vitro fertilisation. Aspirin is often prescribed for women undergoing in
vitro fertilisation to help improve their chances of achieving a
successful pregnancy.

The update of this review found no evidence that this treatment is effective. In order to change this conclusion, more research that is adequately powered is needed.

Women undergoing in-vitro fertilization (IVF) are often told that a daily aspirin will help boost the odds of success, but a research review has found no evidence that it works.

The review, reported in the Cochrane Library, combined the results of 13 international studies and discovered that a low daily dose of aspirin had no clear effect on either an IVF pregnancy or birth rates.

Three of the studies looked at birth rates. Of 525 women who used aspirin during their IVF treatment cycle, 108 gave birth. But of 528 women not given aspirin, 119 gave birth.

In theory, aspirin could improve IVF success by boosting blood flow to the ovaries and uterus, and also might help by preventing blood clots in the placental vessels.

But studies have come to mixed conclusions. There is a small majority of women who have repeat miscarriages because of problems with blood clotting, said Roger Lobo, a professor of obstetrics and gynecology at Columbia University in New York, who was not involved in the review.

If a woman undergoing IVF has blood-clotting issues, then aspirin or other anticoagulants may help, he told Reuters Health. But for most women having IVF, "it's really the embryo quality that's the major factor, so I'm not surprised that aspirin shows no benefit overall."

The studies in the review included 2,653 women undergoing IVF. The trials randomized women to take 80 to 100 milligrams of aspirin per day, with the other half assigned to a noaspirin "control" group.

In most studies, women started taking aspirin at the beginning of the IVF process. The duration of the treatment varied from study to study.

One of the larger studies that looked only at pregnancy rates did not suggest a benefit. Of 300 women, the pregnancy rate among aspirin users was 45 per cent, against 28 per cent of the women not on aspirin.

But when researchers combined the results of different studies, they found no overall effect on women's pregnancy or birth rates, or on their risk of miscarriage.

Lobo too noted that many couples undergoing infertility treatment are desperate to try anything that could raise their chances of having a baby, even in theory, but stressed that even low-dose aspirin can have risks, including gastrointestinal bleeding.

"Based on the evidence, there really appears to be no benefit from using aspirin. And if you add to that the fact that there are risks, it probably shouldn't be done," he said

Source: Cochrane Library