Failure to collect oocytes in assisted reproductive technology: a retrospective

While there is much information and discussion on pregnancy failure after assisted reproductive technologies, less emphasis is placed on the failure to collect oocytes after apparently successful ovarian stimulation. This retrospective survey reviewed 4973 treatment cycles in order to obtain information about the likelihood of this event. Overall 42 women (43 treatment cycles) failed to have oocytes collected [0.86% of treatments started and 0.92% of women given human chorionic gonadotrophin (HCG)]. However, in only six cases was this failure unexpected (0.1%) with no obvious potential clinical reason (i.e. all six cases had: HCG administered; more than two follicles >15 mm in diameter; oestradiol values >2000 pmol/l; <38 years old; normal body mass index). Indifference concerning uncommon events is fraught with peril, as although rare, the particular outcome may be devastating to the individual, both economically and psychologically. Eighteen of the 42 women did not return for on-going treatment suggesting increased contact by clinic staff may be required when oocyte retrieval is not achieved. These data suggest that the failure to collect oocytes after apparently successful ovarian stimulation is rare and random. The information has proved useful in allaying the fears of couples contemplating assisted reproductive technologies.