Rescue hCG to treat empty follicle syndrome after the use of a GnRH agonist as oocyte maturation trigger: First report on fresh embryo transfer and clinical pregnancy.

We present a case series and literature review on the use of rescue human chorionic gonadotropin (hCG) in cases of empty follicle syndrome (EFS) after a gonadotropin-releasing hormone agonist (GnRHa) trigger. EFS was diagnosed after failure to collect any oocytes from one ovary. In such cases, a single dose of hCG was administered and the oocyte retrieval was repeated 36 h later. The main outcome measures were the number of mature oocytes (M2) and embryos (2PN), incidence of hospitalisation for severe ovarian hyperstimulation syndrome (OHSS) and clinical pregnancy when fresh embryo transfers occurred. Our population consisted of 322 patients, who had a GnRH agonist as oocyte maturation trigger (2-mg subcutaneous buserelin). Six patients (1.8%) developed EFS after the use of a GnRHa trigger. Mature oocytes were retrieved in 5 patients after the use of rescue hCG. One patient developed severe OHSS. Two patients had a fresh embryo transfer and one clinical pregnancy was reported. This is the first case series to report fresh embryo transfers and a clinical pregnancy with the use of rescue hCG after failure of the GnRHa trigger.