New test raises questions on IVF and Down’s syndrome

A test designed to spot chromosome abnormalities in eggs could be a “revolution” in fertility, helping older women determine their chances of having an IVF baby, according to doctors.

But in developing the test, they added, worrying evidence emerged that in-vitro fertilisation may boost the risk of a baby with Down’s syndrome.

The method entails counting the sets of chromosomes in oocytes, as human eggs are called, at stages in a maturation process known as meiosis. The idea was to vet imbalances in chromosome numbers that cause embryo abnormalities and thus miscarriage – or, in the case of an additional chromosome 21, the mental handicap known as Down’s syndrome.