IVF may cut birth risks for older mums
BABIES conceived naturally and born to mothers over the age of 40 are exposed to higher risks of birth defects than those born to younger mothers.
Women who undergo assisted reproduction also have an increased rate of birth defects compared to women who conceive naturally.
However, against all expectations, researchers at the University of Adelaide in Australia observed a surprising inverse phenomenon in women over 40 who conceived by assisted reproduction.
“There’s something quite remarkable occurring with women over the age of 40 who use assisted reproduction,” says study lead author Professor Michael Davies from the University of Adelaide’s Robinson Research Institute, “[our findings] show that infertile women aged 40 and over who used assisted reproduction had less than half the rate of birth defects of fertile women of the same age, while younger women appear to be at an elevated risk.”
The scientists studied more than 301,000 naturally conceived births, 2,200 IVF births and almost 1,400 births from intracytoplasmic sperm injection (ICSI), recorded between 1986 and 2002.
The average prevalence of birth defects was 5.7% among babies conceived naturally, 7.1% for babies conceived by IVF and 9.9% for babies conceived by ICSI.
Among babies conceived naturally, the corresponding prevalence of birth defects was 5.6% for young women, rising to 8.2% for women aged 40 and over.
The researchers suggest that hormonal stimulation, a preliminary treatment phase for assisted reproduction, could help reverse the age-related decline in ovulation. – AFP-Relaxnews