One-embryo transfers have better outcome in IVF

WASHINGTON — Infertile women undergoing IVF are much more likely to end up with a healthy baby if they only have one embryo transferred during the procedure, according to new research.

One of the most controversial issues surrounding IVF has been the number of embryos that are transferred into a woman's womb. In the hopes of increasing the chances of having a baby, doctors often place more than one. But that also increases the chances that women will end up having twins, triplets or higher numbers of multiple births. And babies born in multiple births are much more likely to have complications, putting both the mother and the babies at risk.

In the new analysis, researchers at the University of Aberdeen in Britain and elsewhere analyzed data collected about 1,367 women undergoing IVF, including 683 who only had one embryo transferred and 684 who had two.

In a paper published in the British medical journal BMJ, the researchers reported that 27 percent of those who had only one embryo transferred gave birth to a healthy baby, compared with 42 percent who gave birth to a healthy baby after getting two embryos transferred.

But when the women getting one embryo transferred followed that up with a second embryo that had been frozen and then thawed, that boosted the chances of successfully giving birth to a healthy baby to about the same level — 38 percent. And those women were also less likely than those who had gotten two embryos transferred to give birth prematurely or to give birth to babies who were underweight, the researchers found. In fact, women who opted for the one-embryo option were almost five times as likely to carry their babies to full term.

Based on the findings, the researchers recommended that that approach be adopted by more doctors.