Uterine Fluid Offers Important Clues to Success of IVF Embryo Transfer
Article Summary
- Clinical obstetrics/gynecology and immunology researchers found the makeup of uterine fluid at the time of in vitro fertilization may influence the success of embryo transfer.
- Dr. Natasa Strbo and colleagues studied fluid samples taken from 24 women during IVF embryo transfers.
- The researchers found differences in the presence and level of immune cells and distinctions in fluid samples taken from the upper uterine cavity compared to the lower uterine cavity.
A collaboration between experts in clinical obstetrics/gynecology and immunology suggests the makeup of uterine fluid at the time of in vitro fertilization (IVF) could be associated with the success of embryo transfer.
“The primary reason we looked at uterine fluid is there are no diagnostic tools to assess uterine receptivity at the time of the embryo transfer,” said Natasa Strbo, M.D., D.Sc., assistant professor of microbiology and immunology at the University of Miami Miller School of Medicine.
Techniques that test how likely an embryo is to implant, such as taking a biopsy of the endometrium, are done up to a month in advance and invasive. The precise and complex requirements for successful embryo implantation preclude use of any invasive technique at the time of IVF, Dr. Strbo added.
Targeting the Window of Opportunity
Dr. Strbo worked with George Attia, M.D., an associate professor of obstetrics, gynecology and reproductive sciences and director of the UHealth Center for Reproductive Medicine, and colleagues including Suset Rodriguez, M.D., Laura Padula, Eva Fisher, Annabel Lyons, Carolina Rodriguez, Katelyn Rivas, Mohammed Ibrahim, M.D. and Michael Paidas, M.D.
The team evaluated fluid samples taken from 24 women during IVF embryo transfers. This proof-of-concept study looked at the presence and proportion of immune cells in the uterine fluid.
One aim was to identify immune cells released by the endometrium into the uterine fluid within the “window of opportunity” during which optimal conditions exist for embryo transfer.
“If you are outside of that window of opportunity, then the implantation will never happen,” Dr. Strbo said.
The full results of the study were published in the American Journal of Reproductive Immunology.
Dr. Strbo and colleagues found significant differences in the presence and level of immune cells that could be explored in future studies. They also discovered distinctions in fluid samples taken from the upper uterine cavity compared to the lower uterine cavity.
“The location of interest is the upper uterus because that’s where the embryo gets transferred,” Dr. Strbo said. “This was a pilot study and we wanted to explore if there were differences in the immune cells in different parts of the uterus.”
The Bigger Picture
If future studies demonstrate a role for uterine fluid analysis, it may influence the best time for embryo receptivity. The implications go beyond infertility.
“We think the same procedure can be used to diagnose other OB/GYN complications,” Dr. Strbo said, mentioning detecting uterine cancer, ovarian cancer, endometriosis or “anything that changes the normal environment in the uterus.”
Moving forward, Dr. Strbo and colleagues plan to correlate their immunologic findings at the time of IVF with pregnancy outcomes. They also want to expand beyond the presence of immune cells to explore gene activation and the role of cell signaling — the release of cytokines — in the receptivity of the uterus for implantation.
Tags: Dr. George Attia, Dr. Natasa Strbo, IVF