Low-Dose Aspirin May Increase Birth Rate From IVF

Laurie Barclay, MD

June 24, 2004

June 24, 2004 -- Low-dose aspirin may increase the birth rate from in vitro fertilization (IVF), according to the results of a randomized, prospective trial published in the June issue of Fertility & Sterility.

"Because of its vasodilatation and anticoagulation properties, aspirin (acetylsalicylic acid) has been used for a variety of reasons during pregnancy, in general in combination with heparin," write Urban Waldenstrom, MD, from Falun Hospital in Sweden, and colleagues. "Although most studies on the treatment of antiphospholipid syndrome during IVF have shown beneficial results, the subject is still controversial."

During 1,380 consecutive IVF cycles at an IVF clinic, women undergoing IVF were randomized to treatment with aspirin, 75 mg daily from the day of embryo transfer (ET) until pregnancy test, or to no treatment in an open study. The main outcome measure was birth rate per ET.

Both groups were similar in clinical characteristics, except that the mean number of embryos transferred was 2.1 vs. 2.0 in the aspirin vs. the nonaspirin group, respectively. The birth rate was 27.2% in the aspirin group and 23.2% in the control group. The odds ratio, adjusted for number of embryos transferred, was 1.2 (95% confidence interval, 1.0 - 1.6).

Study limitations include lack of physician blinding, introducing possible bias, and inability to compare these data with those from studies in which aspirin was combined with other treatment.

The authors recommend additional research to confirm these findings and to determine the optimal timing of aspirin treatment.

"The increased birth rate with aspirin compared with no treatment was significant," the authors write. "Given the importance of every birth in IVF, especially when taking into account the limited number of IVF cycles that are normally performed in an individual woman, any treatment to improve birth rate is important."

Fertil Steril. 2004;81:1560-1564

Reviewed by Gary D. Vogin, MD


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: