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In long protocol IVF, GnRH agonist is staed on
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The correct answer is  Gonadotropin-Releasing Hormone Agonist ProtocolsIn the long protocol, a GnRH agonist is staed in the luteal phase (day 21) of the previous cycle. This diminishes the GnRH agonists flare effect and suppresses endogenous FSH and dominant follicle selection to promote synchronous follicular growth. After 10 to 14 days of GnRH agonist administration, a pelvic ultrasound and estradiol level are used to confirm suppression and gonadotropin stimulation begins. The GnRH agonist is continued (the dose may be halved or unchanged) throughout the cycle until the hCG trigger.The long protocol provides for better oocyte yields and pregnancy rates in normal responders when compared with shoer protocols that use later administration or early cessation of agonists. GnRH microdose flare protocols have been developed that may improve oocyte yield in poor responders. Microdose flare regimens involve pretreatment with 14 to 21 days of combination oral contraceptives.Four days following the cessation of the oral contraceptive pills, a microdose (leuprolide 25 mg) of agonist is added in the early follicular phase to take advantage of the agonist flare effect. Gonadotropin stimulation is initiated 1 to 2 days later while continuing the agonist.Reference: Novak's Gynecology; 14th edition; Chapter 32; Infeility and Assisted Reproductive Technology