Serum Oestradiol Pattern during Coasting is Different in Antagonist Cycles Compared with Long Agonist Cycles in In Vitro Fertilisation.

Background: GnRH agonists and antagonists have different mechanism of action, and therefore serum estradiol levels might differ during coasting in IVF.

Aims: To compare the change in serum oestradiol levels after withholding the gonadotropins for coasting between long agonist and antagonist cycles.

Study Design: Retrospective study.