Morphometric and morphokinetic differences in the sperm- and oocyte-originated pronuclei of male and female human zygotes: A time-lapse study
Document Type
Journal Article
Publication Title
Journal of Assisted Reproduction and Genetics
Publisher
Springer
School
School of Medical and Health Sciences
RAS ID
52124
Abstract
Purpose:
To study the morphometric and morphokinetic profiles of pronuclei (PN) between male and female human zygotes.
Method(s):
This retrospective cohort study included 94 consecutive autologous single day 5 transfer cycles leading to a singleton live birth. All oocytes were placed in the EmbryoScope + incubator post-sperm injection with all annotations performed retrospectively by one embryologist (L-SO). Timing parameters included 2nd polar body extrusion (tPB2), sperm-originated PN (tSPNa) or oocyte-originated PN (tOPNa) appearance, and PN fading (tPNF). Morphometrics were evaluated at 8 (stage 1), 4 (stage 2), and 0 h before PNF (stage 3), measuring PN area (um2), PN juxtaposition, and nucleolar precursor bodies (NPB) arrangement.
Results:
Male zygotes had longer time intervals of tPB2_tSPNa than female zygotes (4.8 ± 0.2 vs 4.2 ± 0.1 h, OR = 1.442, 95% CI 1.009–2.061, p = 0.044). SPN increased in size from stage 1 through 2 to 3 (435.3 ± 7.2, 506.7 ± 8.0, and 556.3 ± 8.9 um2, p = 0.000) and OPN did similarly (399.0 ± 6.1, 464.3 ± 6.7, and 513.8 ± 6.5 um2, p = 0.000), with SPN being significantly larger than OPN at each stage (p < 0.05 respectively). More male than female zygotes reached central PN juxtaposition at stage 1 (76.7% vs 51.0%, p = 0.010), stage 2 (97.7% vs 86.3%, p = 0.048), and stage 3 (97.7% vs 86.3%, p = 0.048). More OPN showed aligned NPBs than in SPN at stage 1 only (44.7% vs 28.7%, p = 0.023).
Conclusion(s):
Embryos with different sexes display different morphokinetic and morphometric features at the zygotic stage. Embryo selection using such parameters may lead to unbalanced sex ratio in resulting offspring.
DOI
10.1007/s10815-021-02366-z
Access Rights
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Comments
Orevich, L. S., Watson, K., Ong, K., Korman, I., Turner, R., Shaker, D., & Liu, Y. (2022). Morphometric and morphokinetic differences in the sperm-and oocyte-originated pronuclei of male and female human zygotes: A time-lapse study. Journal of Assisted Reproduction and Genetics, 39, 97-106.
https://doi.org/10.1007/s10815-021-02366-z