RESUMEN
To determine the effect of low-dose aspirin on ovarian response, implantation and pregnancy rates in patients undergoing in-vitro fertilization [IVF] cycles. We performed a randomized analysis of 145 infertile women with a mean +/- SD age of 29.6 +/- 4.47 years who underwent cyles of IVF. Patients received 100 mg of aspirin [n=72] or placebo [n=73] daily. This study was conducted in Royan Institute, Tehran, Iran from April 2002 to January 2004. Aspirin was started on the 21st of their preceding menstrual cycle and it was continued until menstruation or a negative pregnancy test. Pregnant women received the medication until 12 weeks of pregnancy. The main outcome measures were number of follicles >/= 15mm, number of oocytes retrieved, serum E2 levels, cancellation rate, Ovarian Hyperstimulation Syndrome [OHSS] occurrence, number of embryos transferred, and implantation and pregnancy rates. There were statistically significant differences between the treatment group and the control group in the number of follicles [7.4 +/- 4.1 versus 9.0 +/- 4.8] and OHSS occurrence [5.6% versus 23.3%] but not in the other measures. The addition of aspirin low dose [100 mg/daily] to the standard long protocol for oocyte retrieval did not improve implantation and pregnancy rates in unselected patients undergoing IVF cycles