Once the follicles reach maturity, an injection of hCG, or LH, is given to finalize follicular development and initiate ovulation 34-36 hours later. IUI inseminations and IVF egg retrievals are scheduled to coincide with this timing. During an IVF cycle, the eggs must be retrieved prior to ovulation or the cycle will be “lost”.
During a normal ovulatory cycle, the hypothalamus releases GnRH which travels to the pituitary and stimulates the release of LH causing ovulation 34-36 hours later. The body responds to a spike in hCG in the same manner as LH, thus hCG initiates ovulation. hCG is known as the “pregnancy hormone” because it is produced by the placenta after pregnancy is established.
Natural drugs in this category include Pregnyl which is derived from omens’ urine and as such contains impurities. Ovidrel is a “pure product”, manufactured using genetic recombinant technologies. It is not known if “product purity” affects the “quality” of ovulation and Ovidrel is significantly more expensive than the natural products.
hCG must be administered cautiously by a reproductive endocrinologist fertility specialist thoroughly trained in its use. Sometimes a woman will experience ovarian hyperstimulation syndrome as a side effect of ovarian stimulation. hCG can make this condition much worse and must be used with caution.
Luveris is a genetically engineered pure product consisting of LH identical to that found in the human body. The indication for LH is in patients with severely depressed levels of LH, a condition known as hypogonadotropic hypogonadism. Some physicians administer Luveris “off label” to improve the quality of the stimulation cycle and it has been used to induce ovulation. Theoretically, LH and FSH can be individually titrated to provide the best stimulation cycle for each patient. However, Luveris is expensive and its clinical usefulness in augmenting ovulation induction cycles has not been established.