'More natural' alternative to IVF to be trialled in UK

A device that allows IVF embryos to develop in the womb rather than a laboratory dish, developed by Swiss company Anecova, is to be trialled at CARE Fertility in Nottingham. 

The treatment, named in vivo development, or IVD, has been termed a more natural alternative to IVF and there are hopes that it will lead to fewer embryos with genetic abnormalities being produced.

In normal IVF eggs are fertilised with sperm and allowed to grow for a few days in a laboratory dish containing chemicals and nutrients, before being implanted into the woman's womb. This new technique sees the fertilised embryos being inserted into a perforated silicone capsule, less than 5 millimetres long and 1 millimetre wide, which is then placed into the womb. The capsule is connected to a flexible wire that holds the device inside the uterus, attached to a thread that trails through the cervix to allow the capsule to be removed. The perforations in the capsule allow the woman's natural chemicals and hormones to surround the embryo, without it being able to attach to the lining of the womb. The capsule is removed a few days after insertion, and the embryo is then implanted into the womb in the usual way.

Simon Fishel, who will lead the UK trial at CARE Fertility, said of the new process, 'what's beautiful about it is that the environment exactly matches what the embryo in the natural situation will be used to, and it doesn't have that in the lab'. So far anecdotal evidence suggests that embryos produced in vivo rather than in vitro are of higher quality and so have an increased chance of survival.

The eggs of the 40 women taking part in the trial will be fertilised in the normal way, before being separated into two groups. One group will cultured in the lab dish, as per classic IVF procedure, and the second will be grown inside the womb using IVD. The two sets of embryos will then be compared to ascertain which procedure produces the healthiest embryos. Mr Fishel explained that 'the pilot study suggested the embryos grown by this technique have more cells, are higher quality, and have fewer chromosomal abnormalities, but we need to conduct this trial to see if there's a true benefit'.

Some fertility experts have pointed out that the womb is not the natural place for new embryos to develop. Professor Adam Balen, of the British Fertility Society, explained that in the first few days of natural conception eggs are located in the Fallopian tubes, rather than the womb, and commented, I'd like to see a bit more science before I got too excited about this'. Similarly, Dr Gillian Lockwood, director of Midlands Fertility Services, said that, 'the intrauterine environment may be more natural, but it's still not entirely natural for a newly fertilised egg to be in the uterus.' Richard Kennedy, from the Centre for Reproductive Medicine, added, 'of course the more you circumvent artificial systems the better, but one of my concerns about this would be that you have to put it in, remove it, before then putting it in again'.