Abstract
We performed a literature review of studies comparing the effectiveness of progestins in preventing premature ovulation during ovarian stimulation for assisted reproductive technology (ART). Five randomized trials and cohort studies involving a total of 2404 women, which compared; i) two different progestins or ii) two different doses of the same progestin were included. The primary outcome was live birth rate (LBR) per woman. Secondary outcomes were live birth or ongoing pregnancy (LB/OP) per woman and per embryo transfer (ET), ongoing pregnancy, clinical pregnancy, positive pregnancy test, numbers of oocytes and metaphase-two oocytes, duration of stimulation and gonadotropin consumption. The primary outcome was not reported in most studies however there were no differences between progestins for secondary outcomes. All progestins seem to effectively prevent premature ovulation in ART cycles. Low-quality evidence suggests that progestins can effectively prevent premature ovulation in ART cycles.