BRITAIN: A series of groundbreaking studies has found that embryos created in fertility clinics contain far more genetic defects than previously thought, even if they are created from eggs donated by young, healthy women.
The discovery suggests that routine screening of embryos for defective DNA before they are implanted could dramatically reduce rates of miscarriage and multiple pregnancy.
Fertility clinics have always known that genetic damage builds up in the eggs of older women and is carried through to their embryos, but eggs from younger women were assumed to be defect-free. The finding suggests that, on average, 42 per cent of eggs from all women have serious genetic defects that could prevent embryos being carried to term.
The researchers now believe that defective eggs are common among the general population, but are rejected early on by the body if they are fertilised.
- (Guardian Service)