Role of gonadotropin-releasing hormone agonists, human chorionic gonadotropin (hCG), progesterone, and estrogen in luteal phase support after hCG triggering, and when in pregnancy hormonal support can be stopped.

Luteal phase support is mandatory in ovarian stimulation cycles in assisted reproductive technology owing to a deficit in LH pulsatility after the effects of exogenous hCG-used for triggering ovulation-vanish. This is classically accomplished by means of exogenous P administration, but emerging new options include microdoses of hCG and exogenous GnRH agonist. Although luteal phase support is commonly continued for up to 10 weeks into pregnancy, there is accumulating evidence that it can be stopped after the first ultrasound or even after a positive pregnancy test.