Women undergoing IVF using frozen embryos have just as much of a chance of having a baby as those using embryos that haven’t been frozen, a study has suggested.
More than 2,000 women who were undergoing their first IVF cycle were randomly assigned to undergo either a frozen-embryo transfer or an un-frozen embryo transfer, by researchers at the Yale School of Public Health (YSPH) and scientists from China.
The study, published in the New England Journal of Medicine, found the percentage of women who had a live birth using frozen embryos was only slightly lower than those who had embryos that hadn’t been frozen. Researchers called this an “insignificant difference”.
“Frozen embryo techniques are growing in popularity in fertility clinics worldwide,” said lead author Dr Lan N. Vuong from the University of Medicine and Pharmacy at Ho Chi Minh City.
“This is one of the reasons why our research is important for fertility clinicians and researchers, and of course couples who are hoping to have a child.”
The researchers found that women using frozen embryos had a live birth rate of 48.7%, versus a live birth rate of 50.2% for women in the group where the embryos weren’t frozen.
The authors noted: “There were also no significant differences between the groups in rates of implantation, clinical pregnancy, overall pregnancy loss, and ongoing pregnancy.”
There was one difference between the two groups that the researchers noted. The frozen-embryo transfers resulted in a lower risk of ovarian hyperstimulation syndrome (OHSS) than women using fresh-embryo transfers.
OHSS is a medical condition affecting the ovaries of some women who take fertility medication to stimulate egg growth.
Most cases are mild, but in rare cases the condition is severe and can lead to serious illness or death.
Women using frozen embryos had a 0.6% chance of developing OHSS, versus a 2% chance for women receiving embryos that had not been frozen.
“This is an emerging issue of immediate and important concern for couples who are seeking in-vitro fertilization treatment,” said Zhang, the Susan Dwight Bliss Professor of Biostatistics at YSPH, according to Yale News.