When women don't get pregnant after several embryo transfers, the question is often raised whether the problem lies with the embryos or with the womb. Our knowledge today suggests that in the vast majority of cases the embryos are just not perfect enough to make the grade. On the other side of the equation is the mother's womb.
The womb is lined by a cell layer, the endometrium, which becomes receptive for a short time. Research aimed at finding out about endometrial disorders is difficult because it usually requires a procedure to take a small biopsy from within the uterus. Ideally this biopsy should be taken when the lining is receptive but for ethical reasons this can't be done at the time of an embryo transfer. So progress with the research I have been involved in has been slow.
Now, the U.S. research group of Richard Scott Jr. has published a well-designed randomised controlled study that looked at the potential benefit of a small intra-uterine infusion of the pregnancy hormone, hCG. The idea behind this study was that the embryo secretes hCG to tell the endometrium to become more receptive. The researchers hoped that by infusing extra hCG in the uterine cavity they could make the endometrial lining even more receptive. A logical and promising idea!
A total of 300 women were included in this trial. Women were randomly allocated to a group receiving 500 units of hCG dissolved in a small drop of embryo culture media or a group just receiving the culture media. The study results are unfortunately disappointing: there was absolutely no difference in the pregnancy rate between the two groups.
This is just one example but the world of IVF is full of good ideas that remain just that. Good research is always needed to show whether new treatments translate into a real benefit for the patient. There are too many examples of experimental treatments that are both costly and harmful to the patient or the embryo.
The take home lesson is simple: don't be fooled by the good intentions of your doctor, make sure you know the facts.