Embryo morphology, developmental rates, and maternal age are correlated with chromosome abnormalities

Fertil Steril. 1995 Aug;64(2):382-91.


Objective: To determine some of the unresolved questions related to chromosome anomalies in early human embryos, such are the detection of any advanced maternal age effect; the complete assessment of mosaicism, which requires analysis of all cells; and the relationship with embryonic dysmorphism. Fluorescence in situ hybridization has been used in this study to answer these issues.

Design: Fluorescence in situ hybridization analysis of human embryos using simultaneously probes for three or five chromosomes. Five hundred twenty-four cleavage-stage human embryos obtained by IVF were analyzed by fluorescence in situ hybridization. Embryos were allocated into three groups according to morphological and developmental characteristics (arrested; slow and/or fragmented; morphologically and developmentally normal). The embryos also were analyzed according to maternal age.

Results: Dysmorphic embryos had higher rates of polyploidy and diploid mosaicism. Aneuploidy increased with maternal age in nonarrested embryos. Preimplantation genetic diagnosis successfully detected these abnormalities.

Conclusion: This study demonstrates that, in morphologically and developmentally normal human embryos, cleavage-stage aneuploidy significantly increases with maternal age. The results suggest that implantation failure in older women largely could be due to aneuploidy.

MeSH terms

  • Adult
  • Aneuploidy
  • Chromosome Aberrations*
  • Embryo, Mammalian / ultrastructure*
  • Embryonic and Fetal Development*
  • Female
  • Humans
  • In Situ Hybridization, Fluorescence
  • Maternal Age*
  • Middle Aged
  • Pregnancy
  • Prenatal Diagnosis
  • Trisomy