Related Experiment Video
Updated: Oct 2, 2026

Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes
Published on: May 11, 2017
Increase in the rate of diploidy with maternal age in unfertilized in-vitro fertilization oocytes
1Cytogenetics Laboratory, Royal North Shore Hospital of Sydney, St. Leonards, New South Wales, Australia.
Abstract:
Human oocytes which failed to fertilize in vitro were fixed for cytogenetic analysis. Metaphase II chromosomes were identified in 286 oocytes, of which 233 were suitable for cytogenetic analysis. In all, 181 oocytes had a normal haploid karyotype (77.7%), while the remaining 52 were abnormal (28 aneuploid, 14 diploid and 10 tetraploid). The rate of aneuploidy did not increase with maternal age. However, the proportion of diploid oocytes increased significantly with advancing maternal age (P < 0.01), being particularly obvious in women aged > 35 years.
Related Concept Videos
Meiosis II
Oogenesis
Meiosis vs. Mitosis
Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...
Nondisjunction
Oogenesis
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
In Vitro Fertilization
The IVF process begins with ovarian stimulation, during which reproductive endocrinologists prescribe hormonal medications to stimulate the ovaries to produce multiple eggs instead of the single...

