Outcome of in-vitro fertilization through natural cycles in poor responders

This prospective study examines the benefits of using natural cycles instead of stimulated cycles in poor responders to in-vitro fertilization (IVF) treatment. Eleven patients in whom puncture was cancelled or who failed to conceive because of a poor response were included in the analysis. The data for natural cycles (n = 16) were compared with data obtained during previous stimulated cycles (n = 25) in the same women. Out of 16 natural cycles, 13 (81.3%) were scheduled for oocyte retrieval compared to 13 out of 25 stimulated cycles (52%). Eighteen metaphase II oocytes were obtained during stimulated cycles, giving a 66% fertilization rate. In natural cycles, 11 metaphase II oocytes were available giving a fertilization rate of 78.6%. A mean number of 51.5 +/- 25 ampoules of gonadotrophins per cycle were used during ovarian stimulation. Three clinical pregnancies were obtained after embryo transfer in natural cycles (18.8%/started cycle) compared to none in stimulated cycles. Our findings demonstrate that an encouraging number of pregnancies can be achieved by IVF during natural cycles in poor responders to ovarian stimulation. This may not be the first approach to consider in IVF but it should be offered as an alternative after two ovarian response failures using classical protocols of stimulation.