Morphologic Evaluations of Embryos Produced InVitro (Experiment 1)
At 6 h after IVF, inseminated oocytes were pooled together, and after being washed 3 times in culture medium, the oocytes were randomly assigned to culture in 5 culture drops. Morphologic evaluations of embryos were conducted 12, 24, 30, 36, and 48 h after IVF. The embryos at different stages were separately mounted on slides and fixed in 25% (v:v) acetic alcohol, stained with 1% (w:v) orcein in 45% (v:v) acetic acid, and examined under a phase-contrast microscope. Fertilization rates were calculated by adding the cleaved embryos and one-cell oocytes that had been penetrated by spermatozoa. birth control yasmin
Among the cleaved embryos, four different morphological characteristics were observed in the present study. They were 1) morphological normality: embryos with each blastomere having one nucleus; 2) fragmentation: embryos with one or more than one blastomere having no nucleus; 3) binuclea-tion: embryos with one or some blastomeres having two nuclei; and 4) embryos with both fragmented and binucle-ate blastomeres. The details of these different morphologies at 2- to 4-cell stages are shown in Figure 1A.