Videocinematography of fresh and cryopreserved embryos: a retrospective analysis of embryonic morphology and implantation

Abstract

Eleven morphologic criteria were studied from videotapes of 323 fresh and 103 thawed embryos. The proportion of thawed embryos (30/39; 77%) with more than one abnormality was (P = 0.03) higher than that of fresh embryos (5/13; 38%), despite similar implantation rates (18% and 15%, respectively). The best predictor of thawed embryo implantation was cell-cell adherence: when scored "positive," 11 of 17 women (65%) became pregnant, whereas none became pregnant (0/15; P = 0.0002) when blastomeres did not adhere. The total number of abnormalities for thawed embryos was an important prognostic. An increased percentage variation of zona pellucida thickness was the most important prognostic for fresh embryos. When the "best" embryo had a zona pellucida that varied more than 25%, 24 of 60 (40%) resulted in pregnancy; pregnancies were not induced (0/21) when the "best" embryo had less than 10% variation (P = 0.0003).