By Sarah Phillips
Cardiff University scientists have developed a novel technique which may be used in humans to improve fertility treatments. It is hoped that the technique, which is currently used in mice, may be adopted to increase IVF success rates and reduce the number of multiple births.
The researchers made use of an advanced imaging technique to observe the discrete movements that occur in an egg at fertilization. These findings, which were funded by the Wellcome Trust, were published in the international journal, Fertility and Sterility.
The research was led by Professor Karl Swann from Cardiff University’s School of Medicine. He said, “We already know from previous research in mice that sperm entry into the mouse egg triggers ‘rhythmic cytoplasmic motions’, which may help to predict successful embryo development.”
Current IVF treatment involves the fertilization of eggs in the laboratory, then makes use of specific selection criteria to choose those embryos which are the healthiest for implantation into the mother’s womb.
However, Professor Swann added, “the implantation of selected eggs using current methods requires days in culture and does not always succeed.” It is believed that the new technique may be used to predict the best embryo for IVF, and reduce the chance of multiple pregnancies which is the biggest risk of fertility treatment.
The Cardiff scientists worked with a team at Oxford University to observe distinct rhythmic patterns in the human egg. From the key method used in mice, it is possible to show that the same ‘rhythmic cytoplasmic motions’ occur in human eggs.
Patients attending the IVF Wales clinic at the University Hospital of Wales donated eggs that had failed to fertilise following treatment. The eggs were injected with the protein ‘PLC-zeta’ during the Human Fertilisation Embryology Authority (HFEA)-approved procedure and then imaged for several hours.
The procedure revealed significant results as scientist observed distinct internal movements, the first time they have been detected in human eggs. These movements importantly correlate with the exact timing of biochemical changes during fertilisation.
Professor Swann added, “Previous analyses of mouse fertilisation have suggested that using this technique may provide an early and effective indication of a successful pregnancy after IVF. We have now discovered that this method has the potential to be applied to human eggs.’’
A considerable amount of further research is needed to confirm whether the movements observed directly correspond to positive pregnancy. However the new technique shows a lot of promise in helping scientists to make significant improvements to fertility treatment.