Timing of human chorionic gonadotropin (hCG) hormone administration in IVF/ICSI protocols using GnRH agonist or antagonists: a systematic review and meta-analysis.

To evaluate the effect of altering the timing of human chorionic gonadotropin (hCG) administration on the clinical outcome of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) using gonadotropic hormone releasing hormone (GnRH) agonist or antagonist.