We evaluated ova recovered from 13 fertile women undergoing uterine lavage for purposes of embryo donation, and assessed differences in blastocyst production and ovum yield among subjects. Six women produced 10 blastocysts during 31 insemination cycles (32%). Yet, despite undergoing at least four insemination cycles apiece, seven women produced no blastocysts in 52 lavage attempts. Comparing the ovum recovery rates between the blastocyst-producing and non-blastocyst-producing groups, we found the former more likely to yield ova (P less than or equal to 0.05), and more importantly 10 to 20 recovered ova were blastocysts. We conclude that donor fecundity is highly variable among fertile women, and that reproductive history alone does not predict ovum donor efficiency.