Single Embryo OK for Older Women
<P>Embryo Quality Key to IVF Success</P>
May 31, 2006 – When it comes to assisted reproduction, embryo quality rather than a woman's age should determine whether one or two embryos are transferred, new research suggests.
Researchers in Finland report that infertile women between the ages of 36 and 39 with good quality embryos had just as much success in conceiving when a single embryo was transferred following in vitro fertilization (IVF) as younger women.
In the U.S. and many other countries, the transfer of two embryos is the norm in women over the age of 35 to maximize the chances of achieving a successful pregnancypregnancy. But the practice dramatically increases the risk of twin births, which are far more risky than single-delivery births.
40% Delivered Babies
The Finnish study included only women older than 35 and younger than 40 who received either elective single embryo transfers with good quality or poorer quality embryos or double embryo transfers.
About a third of the women achieved a pregnancy with single embryo transfer using a high-quality embryo and a quarter had a live birth after just one try. These figures are comparable to those seen in earlier studies of younger women.
When more than one attempt with single embryo transfer was made using frozen embryos, 40% of the older women in the study with good quality embryos ended up delivering a baby.
The twin birth rate in women who got elective single embryo transfers was just 2%, compared with nearly 17% in the double embryo transfer group. The study is published in the June issue of the journal Human Reproduction.
"As well as elective selective embryo transfer having the potential to be as successful in women up to 40 as it is in younger women, it also reduces the risk of multiple births compared with double embryo transfer and therefore increases the safety of assisted reproduction in this age group," senior researcher Hannu Martikainen, MD, noted.
It's Different in the U.S.
Assisted reproduction specialist David Adamson, MD, FRCSC, agrees that embryo quality is more important than a woman's age in determining whether she should have a single or double embryo transfer when undergoing assisted reproduction.