The UK’s fertility watchdog, the Human Fertilisation and Embryology Authority (HFEA), is to consider reducing the number of embryos that can be implanted in women having IVF treatment in order to bring down the rate of multiple births.
The news is welcomed by many doctors and fertility experts because multiple births present more health risks for mothers and their babies.
However, infertile couples will be concerned about the possible increase in cost, time and stress because they would probably have to go through more IVF cycles to achieve a viable pregnancy if fewer embryos are implanted in one procedure.
Multiple pregnancies carry a significantly higher risk that babies will be premature and have more health and developmental problems. Premature babies also have a higher risk of dying. Also mothers with multiple pregnancies tend to suffer higher blood pressure and more frequent miscarriages compared with single baby pregnancies.
Approximately one in every four full term pregnancies after fertility treatment results in a multiple birth. This compares to one in 80 natural full term pregnancies.
The HFEA is expected to revisit the balance between safety and helping infertile couple achieve their desire to have a baby. It says it will release the results of its consultation exercise later in the year, in the autumn.
At the moment the UK rules allow women under 40 to have two embryos implanted in one IVF cycle and women over 40 to have three.
The problem at the moment is that while the IVF specialist knows that the chances of a viable embryo developing for the woman under 40 is one in two, he or she will not be able to tell which of the two is most likely to survive, so they have to implant both of them.
In the longer run, the more cycles that a couple are prepared to undergo, the greater the chance that single-embryo implantation will eventually lead to a viable single embryo pregnancy.
However, the question is, how long will it take, how many cycles, and how much will it cost? Many couples spend thousands of pounds and suffer huge stress and anxiety every time they go through an IVF cycle.
Research is increasingly showing that implanting one embryo is just as likely to result in a viable pregnancy as multiple embryos.
One example is a study published in the Lancet last month that compared two groups of women who were under 38 years of age.
The reserachers, led by Bart Fauser of Utrecht University, investigated one group of women that had single-embryo transfer and mild ovarian stimulation, and the another group of women that had multiple embryo transfers and standard ovarian stimulation.
They found that after one year the rate of pregnancy of the single embryo group was the same as the multiple embryo group, although in the short term, after one or two IVF cycles, the multiple embryo group had a higher pregnancy rate.
More doctors are advising single-embryo transfer, but many also say that patients are not interested because it takes too many IVF cycles and they would rather have twins.
In the US the authorities are moving toward lower numbers of embryos. Last year, the American Society of Reproductive Medicine (ASRM) and the Society for Assisted Reproductive Technology revised their guidelines for assisted reproductive therapies embryo transfer recommending that women under 35 should be given no more than two embryos in one transfer procedure.
They also said that women from 35 to 37 should receive no more than two to three embryos and women from 38 to 40 no more than 4. And women over 40 should be limited to a maximum of 5 embryos per implant.
“The evidence clearly indicates that we can reduce the number of high order multiple gestations and still maintain high pregnancy rates,” said a spokesman for the ASRM.
Written by: Catharine Paddock
Writer: Medical News Today