E2 luteal phase priming in a stop GnRH agonist combined with GnRH antagonist using a delta follitropin protocol in a poor responder: clinical case

Melissa María Morales Berrocal^1*Mariana Peña Miranda¹Armando Miguel Roque Sánchez²

• ¹Costa Rican Department of Social Security, San José, Costa Rica
• ²Latin American network of assisted reproduction, CDMX, Mexico

A 30-year-old woman with a body mass index of 20.6 kg/m² consulted due to two years of primary infertility. The patient had a history of two unsuccessful previous rounds of ovarian stimulation for IVF due to poor ovarian response. A novel ovarian stimulation approach incorporating luteal phase estradiol priming in a stop GnRH agonist plus delta follitropin-GnRH antagonist protocol was followed. In vitro fertilization was performed resulting in eight mature oocytes, which were fertilized and developed into two usable blasts. The patient did not achieve pregnancy from either the fresh or subsequent frozen embryo transfer. Our case demonstrates that this combined strategy (estradiol and GnRH agonist) offers dual suppression of FSH and LH, with E2 playing a critical role in preventing premature FSH surges and enhancing granulosa cell receptivity. To our knowledge, this is the first study to provide initial evidence supporting the clinical utility of combining luteal E2 priming, stop GnRH agonist and follitropin delta in this context. This case report constitutes a proof of principle that requires further studies with a large number of patients to replicate and validate the stimulation protocol.