Pretreatments before the induction of ovulation in assisted reproduction technologies: Evidence-based medicine in 2007

Many pretreatment modalities used prior to ovulation induction have been proposed to increase the success rate in women undergoing assisted reproductive technologies. However, no clear evidence from well-designed clinical trials has shown a benefit of these treatments. We conducted a systematic review to explore the effect of different pretreatment therapies on outcomes of in vitro fertilization (IVF) cycles. Studies were limited to women treated prior to undergoing controlled ovarian hyperstimulation in IVF cycles with low-dose aspirin, metformin, growth hormone, oral contraceptives, or corticosteroid supplementation versus placebo or no supplementation. Searches were conducted in the Cochrane Library, MEDLINE, EMBASE, and ISI Proceedings, and all randomized controlled trials that evaluated the effectiveness of those therapies compared with placebo or no treatment in women before IVF were included. The main outcome measures considered were clinical pregnancy and live birth rates, miscarriage rate, number of oocytes retrieved, cycle cancellations, and the incidence of ovarian hyperstimulation syndrome. We conclude that, currently, no clear evidence indicates that using any of these pretreatment modalities is superior to no treatment in IVF cycles. Even when the studies are pooled, small sample size and low power preclude a complete assessment of adjuvant treatment modalities before ovulation stimulation in IVF cycles.