The effect of dydrogesterone supplementation in an IVF programme

Various treatments are given during the luteal phase by most IVF programmes, without any proof of their efficacy. We have performed a double-blind, randomized study with dydrogesterone (125 transfers) against placebo (133 transfers). The pregnancy rate was 21.6 versus 15.0% per transfer cycle with dydrogesterone or placebo, respectively. There was no significant difference between these figures, but taking into account the usual success rate in IVF programmes (15-20%) a difference of 5% would be significant only with two groups of 1500 subjects. This paper discusses the question of how we can come to a definite conclusion on the efficacy of hormonal supplementation during the luteal phase.