Low-dose aspirin in a short regimen as standard treatment in in vitro fertilization: a randomized, prospective study.

OBJECTIVE

To determine if treatment with low-dose aspirin in a short regimen improves the outcome in a nonselected IVF population as compared with no treatment.

DESIGN

Prospective, randomized study where IVF patients were given aspirin or received no treatment.

SETTING

IVF clinic.

PATIENT(S): The study included 1380 consecutive IVF cycles.

INTERVENTION(S): Women undergoing IVF were randomly assigned to treatment with aspirin 75 mg daily from the day of embryo transfer (ET) until pregnancy test or no treatment in an open study.

MAIN OUTCOME MEASURE(S): Birth rate per ET.

RESULT(S): Background characteristics were similar in the two groups studied except for a minor difference in number of embryos transferred (2.1 vs. 2.0). Birth rate was 27.2% in the aspirin group as compared with 23.2% in the nontreated group, giving an odds ratio, adjusted for number of embryos transferred, of 1.2 (95% confidence interval, 1.0-1.6).

CONCLUSION(S): The increased birth rate with aspirin compared with no treatment was significant. 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.