The Science Bit: Part 6 – A Nobel way for infertile couples to conceive

30 11 2010

British physiologist Professor Robert Edwards has recently been awarded the Nobel Prize for Medicine for his pioneering development of the In Vitro Fertilisation (IVF) technique. IVF has given hope – and children – to thousands of childless couples over the last 30 years, and the procedure is being improved all the time.

There are many reasons why some couples can’t conceive the baby that they so long for, and until fairly recently, childless couples had adoption as their only hope of bringing up children. However, in the mid 1960s, Cambridge Professor Robert Edwards began to study human fertilisation and was successful in creating the first embryo outside of the uterus in 1968. Ten years later, and the technique had been developed and improved so much that on 25th July 1978, Louise Brown, the world’s first “test-tube baby” was born. Since then, it is estimated that more than 4 million children worldwide have been born as a result of this life-changing procedure.

Normally, a female’s eggs are released into the uterus one at a time over the course of the normal menstrual cycle. In order to obtain the highest possible chance of pregnancy however, a woman who wants to undergo IVF will first need to start a course of hormone treatment in order to “ripen” a number of eggs all at once. These are then extracted from the ovaries and mixed with sperm collected from the father where, hopefully, fertilisation occurs.

The embryos are grown in an incubator for a few days and a maximum of 3 are then selected to be implanted into the mother’s uterus – the rest are frozen in case of future need. Only 1 in 5 embryos will successfully implant into the uterus and result in a pregnancy and while this doesn’t sound like very good odds, it’s actually very close the number of pregnancies achieved without IVF.

One of the problems with IVF is that it carries an increased risk of multiple pregnancy. Because of the high cost of IVF – around £4000 to £8000 per cycle, it is something that many couples can only afford to do once, and if using more than embryo gives the greatest chance of success, then this is the option most parents choose. While 8 babies in one go – like “Octomom” Nadya Suleman – is very rare, twins or even triplets are fairly common, but though it may be a blessing for some, a multiple pregnancy carries a much greater risk of gestational complications for the mother, a low birth weight and premature birth for the babies, along with an increased risk of congenital abnormalities. Is it worth risking the health of the mother and the babies to get it right first time?

The general medical consensus is no, the best choice is to opt for single embryo transfer, yet around two thirds of parents still choose to implant the maximum number of embryos that they are allowed (in the UK, two for mothers under 40, three for mothers over 40). Researchers from the Radboud University Nijmegen Medical Centre in the Netherlands predicted that this tendency for parents to go against expert opinion was a result of poor pre-natal care and support provision, as well as the cost factor.

In a simple randomised controlled trial, they looked at the effects of providing better means for parents to make an informed choice, as well as the option to undergo a second cycle of single embryo transfer IVF at no extra cost if the first cycle failed.  Indeed, in their findings recently published in the British Medical Journal, they found that uptake of single embryo transfer IVF was increased when this safety net was offered. Though the results were not statistically significant, the researchers are confident that by improving the amount and quality of information available to those considering IVF, ”a multifaceted patient empowerment strategy… could be an important tool to reduce the twin rate after in vitro fertilisation”.




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