Researchers at RMIT University have found a way to better identify the “golden window” when a uterus is ready for pregnancy – a finding that may help increase IVF success rates.
The team identified a Teflon-like molecule that makes the surface of the uterus slippery and prevents embryos from implanting, finding that levels of this molecule on the surface of the uterus decrease at some point in the menstrual cycle. . This shrinkage allows the uterus to become more sticky, opening the “golden window” for successful pregnancy.
The correct timing of an embryo transfer is essential for the chances of achieving pregnancy, but identifying the right time in a woman’s cycle with absolute precision has remained a challenge, with IVF success rates remaining. , on average, less than 50%.
Before the discovery of RMIT, scientists believed that implantation of embryos relied on molecules that actively promote the adhesion of an embryo to the wall of the uterus, but lead researcher Professor Guiying Nie said that the team’s discovery had changed long-held scientific thinking about embryo implantation.
âWe were looking for something that helps embryos stick together when the vital part of the puzzle turned out to be a slippery molecule that has the opposite effect – it keeps them from sticking,â she said.
Research has found a significant difference in IVF success rates when embryos are transferred while this molecule is present or absent on the surface of the uterus.
Professor Nie, who heads the Implantation and Pregnancy Research Lab at RMIT’s School of Health and Biomedical Sciences, said: âEvery embryo is precious to families struggling with infertility. , it is therefore essential to choose the right time.
âWe hope that with further developments, our discovery can help clinicians identify precisely when each patient is most likely to achieve pregnancy, by offering fully personalized IVF treatment. “
The results, published in journals Fertility and sterility and Human reproduction, could have significant implications for IVF treatment and success rates.
Pregnancy success rate
The retrospective clinical study, co-designed by Professor Nie and Professor Luk Rombauts of Monash IVF, examined the levels of the anti-implantation molecule, known as podocalyxin (PCX), in the endometrium of 81 women undergoing IVF treatment.
A uterine biopsy was taken in the middle of the luteal phase (about seven days after ovulation) of a woman’s menstrual cycle, a complete cycle before a frozen embryo is transferred.
While women with low levels of PCX had a pregnancy success rate of 53%, women for whom the molecule was not reduced had a success rate of only 18%.
Prof Rombauts said measuring PCX levels in the mid-luteal phase can be used as a screening test, but it could also indicate a reason for infertility, making the molecule a potential target for treatment.
“These results offer us a promising avenue for both improving IVF success rates and potentially treating an underlying cause of infertility,” he said.
The research team has already started working to better understand the role of PCX and its regulation in the body, with the aim of developing treatments for infertility.
Professor Nie said analysis for this molecule could be done in a standard pathology lab, making it relatively cost-effective to implement a future screening test.
“The only way we can currently test the PCX is to do tissue biopsies, which cannot be taken at the time of embryo transfer,” she said.
âWe need more research to develop non-invasive, real-time approaches to measure PCX on the day of embryo transfer. Our hope is to provide a simple test that can help patients and increase the accuracy and personalization of IVF treatment. “