Most chromosomal abnormalities are single chromosome abnormalities (45 or 47 chromosomes).

 

45 chromosomal abnormalities More than 47 chromosomal abnormalities

 

More chromosomal anomalies originating from maternal chromosomes

 

Most single chromosome abnormalities are due to meiosis prior to conception.

 

3 chromosomal aneuploidy from abnormal mitosis after conception

 

Abnormalities in maternal chromosomes are often due to meiosis.

 

Paternal chromosome abnormalities are mostly mitotic in origin.

 

 

 

Single aneuploidy was the most common type in both D3 and D5/6 embryos

 

a prevalence of single monosomy over single trisomy (n = 408, P < 0.0001, binomial test) in cleavage embryos

 

The parental origin of aneuploidy was mainly maternal, demonstrating at least a 2-fold increase in the number of affected maternal chromosomes in both monosomies and trisomies