6 doctors weighed in:

Why does your chance of having a downs child increase as you grow old?

6 doctors weighed in
Dr. Robert Kwok
Pediatrics
2 doctors agree

In brief: Old egg less perfect

Down syndrome begins with making eggs (or sperm), in which a "pre-egg" (or pre-sperm) cell with 46 chromosomes splits into 2 eggs (or 2 sperm).
Each egg (or sperm) must get 23 chromosomes, but instead one egg gets both the #21 chromosomes and the other egg gets none. An egg with two #21's mated to a sperm with one #21 creates down syndrome: three #21's. Egg problem occurs more often in older moms.

In brief: Old egg less perfect

Down syndrome begins with making eggs (or sperm), in which a "pre-egg" (or pre-sperm) cell with 46 chromosomes splits into 2 eggs (or 2 sperm).
Each egg (or sperm) must get 23 chromosomes, but instead one egg gets both the #21 chromosomes and the other egg gets none. An egg with two #21's mated to a sperm with one #21 creates down syndrome: three #21's. Egg problem occurs more often in older moms.
Dr. Robert Kwok
Dr. Robert Kwok
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Dr. James Ferguson
Pediatrics
1 doctor agrees

In brief: Negatives accumulate

Girls are born with all the eggs they will ever have and these gradually mature and begin to release after puberty.
The influence of environmental radiation, x-rays. drugs, and many unknown factors age and injure eggs. DS frequency increases with such accumulated influences.Why the same effect is not present for males is unknown.

In brief: Negatives accumulate

Girls are born with all the eggs they will ever have and these gradually mature and begin to release after puberty.
The influence of environmental radiation, x-rays. drugs, and many unknown factors age and injure eggs. DS frequency increases with such accumulated influences.Why the same effect is not present for males is unknown.
Dr. James Ferguson
Dr. James Ferguson
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Dr. Cindy Williams
Pediatrics
1 doctor agrees

In brief: Downs Syndrome

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.
By age 35, a woman's risk of conceiving a child with Down is 1 in 350. By age 40, it's about 1 in 100, by age 45, about 1 in 30. However, most children with Down syndrome are born to women under age 35 because younger women have far more babies.

In brief: Downs Syndrome

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.
By age 35, a woman's risk of conceiving a child with Down is 1 in 350. By age 40, it's about 1 in 100, by age 45, about 1 in 30. However, most children with Down syndrome are born to women under age 35 because younger women have far more babies.
Dr. Cindy Williams
Dr. Cindy Williams
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