SYDNEY – Frozen embryos and their subsequent transfer for In Vitro Fertilization offer infertile couples the same success rate of conceiving a child as those using fresh embryos, researchers said Thursday.
The research, published in the New England Journal of Medicine and led by Lan N. Vuong from the Medical University of Ho Chi Minh in Vietnam and Ben Mol from the University of Adelaide in Australia, shows that pregnancy and live birth rates project similar results in both cases.
According to a statement from the University of Adelaide, the study divided about 800 women with fertility problems unrelated to polycystic ovarian syndrome into two groups.
All women were given one cycle of IVF, with fresh embryos transferred into the first group and frozen embryos that had already been thawed without the use of IVF drugs into the other group.
After the first cycle of IVF, ongoing pregnancy occurred in 36 percent of women in the frozen embryo group and in 35 percent of the fresh embryo group.
The live birth rates after the first embryo transfer were 34 percent in the frozen embryo group and 32 percent in the fresh embryo group.
“Previous research has shown that women who experience infertility because of PCOS benefit from significantly higher live birth rates from frozen embryos in IVF procedures, but evidence was lacking for this approach in non-PCOS patients,” said Mol.
The study also shows that infertile women not suffering from PCOS have the equivalent chance of conceiving a baby from frozen embryos.
“After the first fresh embryo transfer, it will be possible to freeze the remaining embryos and transfer them one by one, which is safe and effective,” said Mol.
“Frozen embryo techniques are growing in popularity in fertility clinics worldwide,” Vuong said, referring to the increasing importance of his research.
The study further noted that the results were based specifically on an embryo-freezing method called Cryotech vitrification, so they may not be applicable to other techniques.