Conception is an unpredictable business, whether natural or assisted. Many fertilised eggs are lost before a woman even realises she is pregnant, and only around a third ever result in a baby. So conceiving a child can take many months, even for couples with no fertility problems.
For those undergoing IVF treatment, the average success rate in the UK is just under 20 per cent for a single treatment cycle. Although this is not much lower than the success rate for natural conceptions, IVF is a costly and invasive procedure. But a new study reported in this week's BioNews could eventually result in IVF treatment that is much more predictable, and therefore successful, than at present.
As the authors of the study point out, the problem with IVF has always been how to choose the 'best' embryos to transfer, that is, those most likely to implant into the womb and develop into a baby. At present, doctors do this by examining the embryos under a microscope, and rejecting any that appear visibly abnormal. In contrast to this low-tech approach, scientists can also test embryos for specific genetic conditions, but this is a lengthy and costly procedure. The new technique is a more general method that aims to identify the 'high quality' embryos that are most likely to grow normally.
The research is still in its infancy, and has not yet been tested in patients. The technique also needs to be adapted so that it is easy to carry out in a clinical setting. But if the trials prove successful, it could change the face of fertility treatment. It would reduce the need to transfer multiple embryos to the womb, and could reduce the need for drugs, as fewer eggs would be needed for each treatment cycle. The researchers say the eventual aim is for fertility clinics to transfer just one embryo to achieve a pregnancy, a success rate higher than that of most natural conceptions.