Background: The purpose of this study was to evaluate the use of the modified natural cycle (MNC) for IVF in poor responders as a last resort prior to oocyte donation.
Methods: Thirty-two patients with a regular menstrual cycle, FSH levels on day 3 of the cycle >12 IU/l and one or more failed IVF cycles with five or fewer cumulus-oocyte complexes (COCs) retrieved were included in this prospective study. Recombinant FSH 100 IU and GnRH antagonist 0.25 mg/day were started concomitantly when a follicle with a mean diameter of 14 mm was present at ultrasound. HCG 10 000 IU was administered as soon as the mean follicular diameter was > or =16 mm.
Results: Twenty-five out of 78 cycles performed (32.1%) did not result in oocyte retrieval. In nine out of 53 cycles (16.9%) in which oocyte retrieval was performed, no COCs were retrieved. Following fertilization, embryo transfer was performed in 19 out of 44 cycles in which COCs were retrieved (43.2%). No ongoing pregnancy was achieved in 78 MNCs (0.0%; 95% confidence interval 0.0-4.7).
Conclusions: MNC does not offer a realistic chance of parenthood in patients with high levels of FSH on day 3 of the cycle and previous poor response to ovarian stimulation, when offered as a last resort prior to oocyte donation.