1. Drug protocols for ovulation induction. A
Drug protocols for ovulation induction. A. Downregulation of gonadotropin-releasing hormone (GnRH) agonist protocol. This is also known as the long protocol. In this diagram, the long protocol is combined with combination oral contraceptive (COC) pill pretreatment. With the long protocol, GnRH agonists are begun typically 7 days prior to gonadotropins. GnRH agonists suppress endogenous pituitary release of gonadotropins. This minimizes the risk of a premature luteinizing hormone (LH) surge and thus premature ovulation. During all protocols, serial serum estrogen levels and sonographic surveillance of follicular development accompany gonadotropin administration. Human chorionic gonadotropin (hCG) is administered to trigger ovulation when sonography shows three or more follicles measuring at least 17 mm. Eggs are retrieved 36 hours later. Embryos are transfer back to the uterus 3–5 days following retrieval. Progesterone supplementation, with either vaginal preparations or intramuscular injection, follows during the luteal phase to support the endometrium. The goal of COC pretreatment is to prevent ovarian cyst formation. One of the major drawbacks of GnRH agonist therapy is the induction of initial transient gonadotropin release or flare, which may lead to ovarian cyst formation. Functional ovarian cysts can prolong the duration of pituitary suppression required prior to gonadotropin initiation and may also exert a detrimental effect on follicular development because of their steroid production. Moreover, COC pretreatment may improve induction results by providing an entire cohort of follicles synchronized at the same developmental stage that will reach maturity at the same time once stimulated by gonadotropins. B. GnRH flare protocol. This is also known as the short protocol. GnRH agonists initially bind gonadotropes and stimulate follicle-stimulating hormone (FSH) and LH release. This initial flare of gonadotropes stimulates follicular development. Following this initial surge of gonadotropins, the GnRH agonist causes receptor downregulation and an ultimately hypogonadotropic state. Gonadotropin injections begin 2 days later to continue follicular growth. As with the long protocol, continued GnRH agonist therapy prevents premature ovulation. C. GnRH antagonist protocol. As with GnRH agonists, these agents are combined with gonadotropins to prevent premature LH surge and ovulation. This protocol attempts to minimize risk of ovarian hyperstimulation syndrome (OHSS) and GnRH side effects, such as hot flashes, headaches, bleeding, and mood changes.
Source: Treatment of the Infertile Couple, Williams Gynecology, 3e
Citation: Hoffman BL, Schorge JO, Bradshaw KD, Halvorson LM, Schaffer JI, Corton MM. Williams Gynecology, 3e; 2016 Available at: Accessed: October 09, 2017
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