Background: Ovulation induction plays an important role in the pregnancy outcome of
assisted reproduction. Individualized controlled ovarian hyper-stimulation (COH) based on the
prediction of the ovarian response for each individual is regarded as the treatment of choice.
Objective: This review summarizes the various protocols available at present and then examines the
use of COH protocols for different causes of infertility.
Results: The advantage and efficacy of mild stimulation are proposed as suitable for poor responders
and women of advanced age. For women with endometriosis or adenomyosis, the reproductive
outcomes of assisted reproduction benefit from prolonged downregulation with a gonadotropinreleasing
hormone (GnRH) agonist before the start of ovarian stimulation. For high responders, a
GnRH antagonist protocol facilitates a GnRH agonist trigger and the segmentation of in vitro fertilization
cycle to avoid ovarian hyperstimulation syndrome. The efficacy of various adjuvant therapies,
including growth hormone, estrogen, levothyroxine, vitamin D, melatonin and myo-inositol is