Micromorphometry and spermatozoa binding patterns of fertilized and unfertilized human oocytes after in-vitro fertilization

Human oocytes (n = 380) from 71 in-vitro fertilization patients were measured 18 h after insemination to find out if certain parameters of oocyte morphology could be related to fertilization. In addition, the number and distribution patterns of spermatozoa bound to or within the zona pellucida of 534 oocytes were analysed. The mean diameter of the human oocyte was 167.7 +/- 9.5 microns and its mean volume was 2.5 x 10(6) micron 3. There were no significant differences in diameter between 112 fertilized and 168 unfertilized oocytes, although they displayed differences in the size of the perivitelline space and the zona pellucida. The age of the patients had no significant effect on the morphometry of the oocytes. Sperm binding patterns did not correlate with fertilization. The number and distribution of the spermatozoa on the surface of the zona pellucida was extremely heterogeneous and was not related to the occurrence of fertilization. All possible binding and distribution patterns were in the same range in both fertilized and unfertilized oocytes. In conclusion, the micromorphometry of human oocytes and their sperm binding patterns were not related to the occurrence of fertilization.