Gamete intrafallopian transfer: assessment of the optimal number of oocytes to transfer.

The optimum number of oocytes that should be transferred at the time of gamete intrafallopian transfer (GIFT) is important information. Nonessential oocytes can be inseminated and frozen for later use or the extra oocytes can be donated to another women. In this preliminary study, the results of 399 consecutive GIFT procedures were evaluated retrospectively as a function of the number of oocytes transferred. Women who received four or more oocytes were three times more likely to achieve a clinical pregnancy than those who received three or less. There was no statistically significant difference in pregnancy rates between patients who received five, six, seven, or eight oocytes. Oocytes in excess of five may be more effectively used if they are fertilized and frozen as embryos for later transfer rather than replacing them all at the time of GIFT.