Empty follicle syndrome due to human errors: its occurrence in an in-vitro fertilization programme.

We report five cases in which no oocytes were retrieved after standard ovarian stimulation for in-vitro fertilization (IVF), and in which it was found that mistakes had been made at the time of human chorionic gonadotrophin (HCG) administration. In all five cases, oocyte retrieval was achieved after injecting HCG, when necessary, and reprogramming aspiration 24-36 h later. A mean of 7+/-3.2 MII oocytes were recovered per patient and 3.2+/-0.8 embryos were transferred. Three clinical pregnancies were obtained, and four healthy infants were born. In our programme, these were the only cases of empty follicle syndrome (EFS) that appeared over a total of 1118 cycles, and were all explained by human error in the administration of HCG. Our experience shows that human error could be considered a significant factor in the aetiology of empty follicle syndrome, and that EFS may be in part avoided by taking simple preventive measures.