03/20/2026
When a transfer doesn’t work, the instinct is often to do more testing.
This UCSF study looked closely at one of the most commonly ordered tests: chronic endometritis (CE).
Researchers followed 271 fertility patients undergoing IVF and analyzed endometrial biopsies using standardized methods.
Here’s what they found:
• CE was uncommon, present in just 7.4% of patients
• It was not more common in patients with prior failed transfers
• It did not correlate with other markers used to evaluate the uterine environment (BCL6 or ERA)
Even in patients with multiple failed transfers, CE remained rare.
This challenges a common assumption in fertility care: that inflammation in the uterus is a major driver of implantation failure.
The takeaway is not that testing is bad. It is that testing should be targeted.
At UCSF, research like this helps refine care so patients avoid unnecessary interventions and focus on what actually improves outcomes.
Read this study and more in our published research database available at https://crh.ucsf.edu/research