Empty follicle syndrome—Still an enigma

Empty follicle syndrome (EFS), although rare with an incidence of 0.2–7%, is a frustrating condition where no oocytes are retrieved in in vitro fertilization (IVF), even though ultrasound and estradiol measurements show the presence of many potential follicles. It is a complex phenomenon that cannot be explained by low bioavailability of human chorionic gonadotrophin alone; neither can it be reliably diagnosed by the measurement of serum beta-human chorionic gonadotrophin (bhCG) on the day of oocyte retrieval (OR), except possibly when the bhCG concentration is very low. Here we report a case who underwent intracytoplasmic sperm injection (ICSI) for her partner's severe oligoasthenozoospermia. Controlled ovarian hyperstimulation (COH) was done in her first cycle of ICSI, using a gonadotrophin-releasing hormone (GnRH) agonist long protocol with follicle-stimulating hormone (FSH) and human menopausal gonadotrophin (HMG). However, as we were unable to retrieve any oocytes, her COH protocol was changed in the subsequent cycle with a successful outcome.