3. Results
3.1. Detailed findings from the Colorado experiment
3.1.1. Embryo production
Cleavage rates were not different for oocytes fertilized
with X-sorted (67 3%; N ¼ 3985) or nonsorted sperm
(69 2%; N ¼ 1785), but the proportion of oocytes that
became a blastocyst was lower (P < 0.05) for oocytes
fertilized with X-sorted sperm (13 1%) than for oocytes
fertilized with nonsorted sperm (23 2%).