Bed rest following embryo transfers not recommended for women undergoing IVF

Many clinical interventions used during in-vitro fertilisation (IVF), including ultrasound guidance at the time of embryo transfers appear to increase pregnancy rates, however prolonged bed rest should not be recommended, finds a new study led by UCL researchers. The research team from UCL, University College London Hospitals NHS Foundation Trust (UCLH), the University of Birmingham and University Hospitals Coventry and Warwickshire NHS Trust undertook a comprehensive review to investigate the effectiveness of 38 different interventions performed at the time of embryo transfer. IVF involves several integrated stages: stimulating the ovaries to obtain several eggs; fertilising the eggs to form embryos in the lab; and finally, transferring an embryo back to the mother's womb. The process of embryo transfer is particularly delicate as optimal conditions need to be in place to maximise the chances of an embryo implantation and clinical pregnancy. Analysing data from 188 randomised controlled trials involving more than 59,530 participants, the study found that performing an embryo transfer under ultrasound guidance increased the chances of pregnancy by 26%. Other promising interventions included the use of soft embryo transfer catheters, which may cause less trauma to the lining of the womb, compared to hard ones (12% improvement), and using a substance called hyaluronic acid could also help improve embryo implantation in the womb. The peer-reviewed study, published in Human Reproduction Update , importantly found that prolonged bed rest (for more than 20 minutes) immediately after embryo transfer was associated with a 15% reduction in the chances of clinical pregnancy.