(GLASGOW) — A new study suggests women undergoing in-vitro fertilization (IVF) should receive no more than two embryos, regardless of their age or the quality of the embryos. But some fertility doctors say the benefits and risks of transferring extra embryos still depend on the woman.
In IVF, a woman’s eggs are fertilized outside of her body and the resulting embryos are transferred into her uterus. Because not all embryos will successfully implant and result in pregnancy, doctors often transfer more than one — a practice that increases the odds of multiples and, consequently, the risk of complications.
The British study, which was based on a review of more than 120,000 IVF cycles yielding 33,514 live births in the UK, found a higher live birth rate and lower complication rate among women who received two embryos compared with women who received three, regardless of their age. Transferring two embryos was associated with a higher live birth rate than transferring one, and the live birth rate was lower among women over 40, irrespective of the number of embryos transferred.
“In older and younger women, the transfer of two embryos was associated with greatest live birth rates,” the study authors wrote in their report, published Wednesday in The Lancet. “A clear implication of our study is that transfer of three embryos should no longer be supported in women of any age.”
The American Society of Reproductive Medicine and the Society for Assisted Reproductive Technology currently recommend transferring no more than two embryos in women younger than 38, no more than four embryos in women aged 38 to 40, and no more than five embryos in women 41 to 42.
Copyright 2012 ABC News Radio