A correlative study of oocytes morphology with fertilization, cleavage, embryo quality and implantation rates after intra cytoplasmic sperm injection

Abstract

Introduction: Non-invasive selection of developmentally human oocytes may increase the overall efficiency of human assisted reproduction. Morphologic abnormalities in the oocyte are relevant for determining its developmental fate. The objective is to evaluate the influence of MII oocyte morphology on intra cytoplasmic sperm injection (ICSI) outcomes. Material and Methods: 132 patients undergoing ICSI cycles and having female factors of infertility and unexplained infertility. Couples having male factors of infertility were excluded. A total of 1200 oocytes were retrieved from 132 ICSI cycles, of which 1056 MII oocytes were evaluated. The criteria for morphological evaluations were: (i) Normal MII oocytes showing clear cytoplasm with uniform texture and homogenous fine granularity, a round or ovoid first polar body with a smooth surface, and perivitelline space of normal size. (ii) MII oocytes with extra cytoplasmic abnormalities (first polar body and perivitelline space abnormalities). (iii) MII oocytes with cytoplasmic abnormalities (dark cytoplasm, granular cytoplasm, inclusion body and presents of vacuoles). (iv) MII oocytes with combined abnormalities. Result: From 1056 MII oocytes, 180 (17.04%) had normal morphology while 876 (82.95%) had at least one demonstrable morphological abnormality. Cytoplasmic abnormalities were observed in 516 (58.9%) of the oocytes. Extra cytoplasmic abnormalities were observed in 104 (11.87%) while combined abnormalities were responsible for the remaining 256 (29.22%). There were no significant differences in fertilization, cleavage, and embryo quality between the groups but there was a highly significant difference in implantation rate which was higher in the group of normal oocytes morphology than abnormal oocytes morphology, oocytes with cytoplasmic, extracytoplasmic and combined abnormality 11.11%, 7.33%, 9.03%, 2.3%, and 4.34% respectively. Conclusion: MII oocyte morphology did not affect fertilization, cleavage, and embryo quality, but affecting implantation rate.