The IVF Future – Single Embryo

Is the transferring of a single embryo the way forward for many couples?

All couples having to go through In Vitro Fertilisation (IVF) want the best chance possible of attaining a positive result.  The whole process is incredibly stressful and costly and to ensure the best outcome, over 90 percent of clinics within Britain transfer more than one embryo into the womb as common practice in a hope to maximise the chances of success.

Having more than one embryo implanted can result in multiple births which can mean a greater risk of complications and more general cost to the family.  Doctors who practice the single embryo option feel that selecting the healthiest embryo is their main aim.  There are many complications with multiple pregnancies which can include a greater risk of death, disability or babies being born prematurely.

Other countries around the world recommend the implantation of no more than three embryos at any given time but some scientists and doctors feel that all clinics should follow standard guidelines.

In Vitro Fertilisation (IVF)

IVF is the process of fertilising egg cells outside of the body to produce embryos which are then implanted into the woman’s womb at a later stage. 

It is a long process where the woman uses hormones to stimulate the growing of follicles within the ovaries.  Once the follicles are developed enough the woman will have minor surgery to drain the follicles and the resulting egg cells are placed into a Petri dish where the man’s sperm is then introduced and fertilisation should take place. 

After a few days, the best quality fertilised embryos are then implanted into the uterus which will hopefully result in a successful pregnancy.  Figures show that one in 66 births are as a result of IVF.


This is the culturing of the embryos for five days instead of the usual three days.  After this amount of time, the embryos are now blastocysts so when they are transferred into the womb, the chances of implantation are increased.  Not all fertilized embryos make it to the blastocyst stage so there is a risk involved to the couple who are in danger of losing embryos during the culturing process.

Single Embryo Techniques

A technique being studied in Guy’s Hospital in London is being led by Mr Yacoub Khalaf.  It is intended to show that using this technique of implanting one embryo can be just as effective as implanting two embryos and they hope the results will encourage all fertility clinics to adopt similar guidelines in an effort to reduce complications in multiple births.  The study is being carried out on women under 35 years old who have produced four quality embryos during their IVF cycle and to date, their success rates have increased to 41 percent from 35 percent.

The study is also being offered to some woman between 35 and 39 and some woman who produce three quality embryos.  The success they have achieved was due to the blastocyst procedure.

Researchers in Finland undergoing a long running study have found single embryo implanting resulted in reduced health costs as well as a higher success of live births.  The results of over 1,500 women under 40 were studied over two time periods at the Oulu University Hospital where both single and two embryos were implanted. 

The results for single embryo transfers were 42 percent with only 37 percent success for those with two embryos transferred.

IVF Success

Over one million babies have been born using the IVF process. 

The first 'test tube' baby was Louise Joy Brown who was born on 25th July 1978 in Oldham, Greater Manchester.  Louise and her parents received a huge amount of media attention and varying reaction from around the world, sparking a debate on the number of embryos that should be transferred which is still ongoing to this day.

This debate was enraged further when in January 2009 Nadya Suleman from the USA had six embryos implanted resulting in eight babies born nine weeks premature, the medical costs of which have not been disclosed but are estimated at over one million dollars.  Nadya was a single mother who already had six young children and her treatment caused much controversy worldwide.