Computer‐controlled, multilevel, morphometric analysis of blastomere size as biomarker of fragmentation and multinuclearity in human embryos
Authors: Hnida, Christina; Engenheiro, Elisabete; Ziebe, Søren
Source: Human Reproduction, Volume 19, Number 2, February 2004 , pp. 288-293(6)
Publisher: Oxford University Press
Abstract:BACKGROUND: Little is known about blastomere size at different cleavage stages and its correlation with embryo quality in human embryos. Using a computer system for multilevel embryo morphology analysis we have analysed blastomeres of human embryos and correlated mean blastomere size with embryonic fragmentation and multinuclearity. METHODS: A consecutive cohort of 232 human 2‐, 3‐ and 4‐cell embryos from patients referred for ICSI treatment were included. Sequences of digital images were taken by focusing at 5‐µm intervals through the embryo. Blastomere sizes and number of nuclear structures were evaluated based on these sequences. The degree of embryonic fragmentation was evaluated by normal morphological assessment prior to transfer and correlated to the blastomere sizes. RESULTS: As a result of normal cell cleavage, mean blastomere size decreased significantly from a volume of 0.28 × 106 µm3 at the 2‐cell stage to 0.15 × 106 µm3 at the 4‐cell stage (P < 0.001). Mean blastomere size decreased significantly (P < 0.001) with increasing degree of embryonic fragmentation, where highly fragmented embryos showed a 43–67% reduction in blastomere volume compared with embryos with no fragmentation. Multinucleated blastomeres were significantly larger than non‐multinucleated blastomeres (P < 0.001). On average, multinucleated blastomeres were 51.5, 67.8 and 73.1% larger than their non‐multinucleated sibling blastomeres at the 2‐, 3‐ and 4‐cell stage, respectively. Furthermore, the average volume of non‐multinucleated blastomeres originating from multinucleated embryos was significantly smaller than the average volume of the blastomeres from mononucleated embryos (P < 0.001). CONCLUSIONS: The results of this study show that the average blastomere size is significantly affected by degree of fragmentation and multinuclearity, and that computer‐assisted, multilevel analysis of blastomere size may function as a biomarker for embryo quality.
Document Type: Research Article
Affiliations: To whom correspondence should be addressed. e‐mail: email@example.com
Publication date: 2004-02-01
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.