In an effort to improve success rates with ovulation induction and intrauterine insemination (IUI), some doctors and providers routinely prescribe progesterone supplementation to patients that undergo such treatments.  A recent study by Green et al, a systematic review and meta-analysis comprised of 11 randomized controlled trials (with a total of 2.842 patients that underwent a total of 4,065 cycles), was published in the journal Fertility & Sterility and investigated whether or not routine progesterone supplementation in the luteal phase improves pregnancy after ovulation.  The authors of the study found that progesterone luteal phase support/supplementation was beneficial to those who underwent ovulation induction with injectable gonadotropins in conjunction with IUI and that there was one additional live birth for every 11 patients with such a treatment.  Progesterone luteal phase support was not beneficial in those who underwent ovulation induction with clomid or combination clomid/gonadotropin cycles.