Most women going through IVF are faced with sadness and disappointment as only one in four treatments are successful – but now the University of Manchester might have the solution.
The predominant reason 75% of IVF treatments are unsuccessful is the embryo fails to attach to the endometrium – the mucus membrane of the uterine wall – and the pregnancy is lost at a very early stage.
Prospective mothers who repeatedly suffer this failure often have altered levels of microRNA, tiny protein molecules that impact gene expression, in the endometrium.
Researchers at the university’s Institute of Human Development decided to experiment with varied levels of microRNA-145 and its target, the receptor for insulin-like growth factors (IGF1R).
The study revealed IGF1R has a previously unknown role to play in the attachment process and when it is reduced there is a higher probability that the embryo won’t implant.
Professor John Aplin, who led the study, said: “When an embryo is ready for implantation, its replacement is carefully timed to coincide with the window of maximal receptivity in the uterus.
“This window is open for no more than four days. Our study suggests that the presence of IGF1R during this period is required for the embryo to stick to the uterus.”
MicroRNA-145 plays a role in this process as over-expression inhibits the growth of IGF1R.
The lab work conducted by the team showed that varying this level had a direct effect on IGF1R.
More research is needed to confirm the findings, particularly as the uterus is difficuly to observe at the time of implantation.
But the university believe developing treatments to suppress microRNA-145 could lead to improved rates of attachment.
Professor John Aplin said: “This is one of the hardest groups of women to treat in fertility science and rates are still very low across the board. Repeated IVF cycles are stressful and can be expensive too.
“Greater understanding of the mechanisms which control success or failure can lead directly to treatments to make IVF cycles more efficient so that infertile couples can start their families.”
Image courtesy of Teza Harinaivo Ramiandrisoa, with thanks.
