IVF can improve pregnancy rates amongst couples with unexplained fertility, but there is little evidence to show that IVF results in more live births than other treatments, according to a review of recent studies. “IVF is becoming popular when there is no specific explanation for unexplained fertility as it may be able to overcome a variety of problems,” says Dr Zabeena Pandian, of the University of Aberdeen, Scotland. “However, it is expensive, complicated and can have many adverse effects, including multiple births.”

In reviewing the research Dr Pandian found that most studies are small and vary considerably in their quality, definitions of unexplained fertility and follow-up periods. Because laws governing IVF vary from country to country and IVF treatment is normally privately funded, it is difficult to arrange randomised trials for infertility treatment. “Until more evidence is available, IVF may not be the preferred first line of treatment for these [infertile] couples and it might be appropriate to continue with less invasive options,” she said. Her study was published in the April issue of the Cochrane Library.