KEEP them close. Women having IVF can now incubate embryos in their own bodies before they are implanted in the womb. Results from a clinical trial suggest the incubation device could work as well as conventional IVF and be far cheaper.

Cylindrical in shape, INVOcell is held in the vagina by a flexible diaphragm. The embryos are kept in an inner chamber at body temperature and gases such as carbon dioxide and oxygen diffuse in and out at levels matching natural fertilisation. After five days the embryos will have grown into balls of about 100 cells. The device is then removed and doctors choose the embryo that looks healthiest to implant.

In a US trial of 40 women, the device performed almost as well as conventional incubation, with 65 per cent of the women becoming pregnant regardless of the method used. Fifty-five per cent who used in-body incubation went on to give birth compared with 60 per cent who had the standard method. “We were very pleased with the results,” says Kevin Doody of the Center for Assisted Reproduction in Bedford, Texas, who carried out the trial.


Doody wants to offer the device to women at his clinic, and reckons that it could halve the cost per cycle, typically $16,000 to $20,000 in the US. In conventional IVF, incubators are set up to mimic the body and have to be regularly monitored to ensure early embryos are supplied with the right amounts of gas and that conditions are optimal for five days. Because the woman’s body acts as a natural incubator, such expensive equipment isn’t needed, he argues.

Doody sees the device being used for relatively uncomplicated IVF cases in clinics with simpler equipment, perhaps in countries where many people can’t afford standard IVF. More complex cases, where a sperm has to be injected into an egg, say, would take place in conventional clinics with highly skilled personnel.

A trial of the device in Colombia also produced successful pregnancies. “Organising a lab for INVO is very simple and cheap compared to the sophisticated labs for conventional IVF,” says Elkin Lucena at the Center for Fertility and Sterility in Bogotá, who carried out the trial there. “For developing countries that’s really important.”

Although the manufacturers of INVO were given permission to sell it in the US in November, not everyone is convinced it has proved its worth. “Those that genuinely cannot afford IVF may well leap to this if it’s substantially cheaper,” says Simon Fishel of the CARE Fertility Group in Nottingham, UK. But he warns that there are “serious attendant risks” that fertility clinics need to decide whether to accept. These include problems that arise from abnormal fertilisation that go unnoticed because the embryo can’t be checked during incubation. Doody counters that any abnormal embryos are likely to die naturally before the device is removed from the woman, leaving only the fittest for implantation.

(Image: Phanie Sarl/Corbis)

This article appeared in print under the headline “Women can ‘grow’ own IVF embryos”