Sun Sentinel Palm Beach Edition
Fewer birth defects for older moms who have IVF
Older women who get pregnant through assisted reproduction may be less likely to have babies with birth defects than those who conceive naturally, a recent Australian study suggests.
The findings challenge the widely held belief that assisted reproduction increases the risk of birth defects in all women, according to the researchers at the University of Adelaide.
“There’s something quite remarkable occurring with women over the age of 40 who use assisted reproduction,” study lead author Michael Davies said in a university news release.
The study included more than 301,000 naturally conceived births, 2,200 in vitro fertilization (IVF) births and nearly 1,400 births from intracytoplasmic sperm injection (ICSI).
Among women of all ages, the average rates of birth defects were 6 percent for naturally conceived births, 7 percent for IVF births and 10 percent for ICSI births. When researchers looked at the births by maternal age, a different picture emerged. The rates of birth defects ranged from a high of 11 percent for women younger than 30 using ICSI to a low of 3.6 percent for women 40 and older using IVF to conceive.
In naturally conceived births, birth defect rates ranged from about 5.6 percent among young women to 8 percent among those 40 and older, according to the findings, published in BJOG: An International Journal of Obstetrics & Gynaecology.
Previous studies have shown that women who undergo assisted reproduction have an increased rate of birth defects overall compared with women who conceive naturally.
It’s also been known that the rate of birth defects increases exponentially from age 35 and on for naturally conceived pregnancies.
“It was widely assumed, but untested, that maternal age would be a key factor in birth defects from assisted reproduction,” Davies said. “However, our findings challenge that assertion.”