Question

Why is it that women exceeding 40 years of age have more chances of having a child with Down’s syndrome?​

Answer 1

The women exceeding 40 years of age have more chances of having a child with Down’s syndrome because increased age affects the meiosis of chromosomes adversely. The meiosis remains incomplete until fertilization. It remains arrested at prophase-I and the chromosome is unpaired. If the fertilization occurs after a very long gap, the chromosomes will have to remain unpaired for a longer time. The longer the time of unpairing, the greater are the chances of its non-disjunction, and hence conditions like trisomy arise.

Answer 2

Required Answer :-

• A woman's chances of giving birth to a child with Down syndrome increase with age because older eggs have a greater risk of improper chromosome division.
• A woman's risk of conceiving a child with Down syndrome increases after 35 years of age.