Received May 03, 1997
Accepted June 17, 1997

lntroduction: The present study evaluates our five years experience with I VF in natural cycles. Material and Methods: Fromjanuary 1992 to december 1 996, 1 67 patients underwent an IVF programme in natural cycle (339 cycles). Our protocol required daily ultrasound monitoring starting from day 8 of the cyc/e. When the follicular mean diameter reached 15mm, the patients were asked to perform at home an urinary LH test to detect the LH surge. Pick-up was carried out 22-24 hours after the first LH positive test or 36 hours after the administration of 5000 IU of hCG. Results: Out of 339 cycles started, we performed 271 pick-up (79. 9% per cycle) and retrieved 183 oocytes (67.5% per pick-up). We transferred 115 pre-embryos (62.8% fertilization rate) and 17 pregnancies were achieved (10.1% per patient, 5,0% per cycle, 6.2% per pick-up, 14.7% per transfer). Conclusions: Our data, despite of obvious advantages (no risk of hyperstimulation syndrome, no spare pre-embryos, high repeatedly, low cost), conflrm the limits of IVF in natural cycles. ln fact, they require very accurate monitoring, difficult timing of pick-up and offer a low pregnancy rate per cycle.