Repeated implantation failure despite donor eggs—should we try a second donor or attempt a new cycle with an HLA-C-compatible donor?

Selmar26 · July 19, 2026 at 11:44 AM

Hello everyone,

My husband and I are really hoping to hear about your experiences or opinions. We’re currently facing a difficult decision and would appreciate any advice.

I’m 49 years old, and my husband is also 49. Due to my age, we need to rely on egg donation. PGT-A was performed during both treatment cycles.

First donor (IVI Madrid)

13 mature eggs
10 normally fertilized
9 blastocysts (7 on Day 5, 2 on Day 6)
All 9 blastocysts were tested using PGT-A and reported as “normal/not affected.”
We had a total of 6 frozen embryo transfers.

Result: Not a single implantation.

The embryologists were very satisfied with the embryos’ development, yet implantation never occurred.

Second donor (IVI Madrid)

After the many unsuccessful transfers, IVI recommended changing donors.

Result:

6 mature eggs
4 normally fertilized
2 blastocysts
After PGT-A, 1 euploid embryo remained.

This embryo was transferred and implanted immediately. Unfortunately, the pregnancy ended in a miscarriage in the 6th week.

Our current situation

We are now considering continuing treatment at Reproclinic Barcelona.

The treating physician has suggested

performing the next transfer during a natural cycle and
specifically select an HLA-C-compatible donor.

She noted that the significant difference between the two donors might indicate that better immunological or genetic compatibility could play a role.

We are aware that the scientific evidence for HLA-C/KIR matching is limited so far. Nevertheless, we are wondering whether this approach might be worthwhile in our situation.

Our Questions

If you were in our shoes, would you:

proceed with the second donor, since the first embryo did implant immediately,

or

start over at Reproclinic with a carefully selected HLA-C-compatible donor, in the hope of obtaining several good embryos?

Has anyone had a similar experience where changing donors made all the difference?

And does anyone have experience with KIR/HLA-C matching in egg donation?

We’d really appreciate hearing about your experiences or thoughts.

Thank you in advance!

Vida Fertility Institute · July 20, 2026 at 11:12 AM

Dear Selmar26,

Thank you very much for sharing your experience with us.

Yes, we have noticed a difference in the results of the immunological donor selection. That’s for sure. So many failed embryo transfers from PGTA-tested donor eggs are not normal.

You don’t have to be tied to a specific clinic to have a KIR-HLA test performed. If I were in your shoes, I would therefore have this test done first before making a decision about switching clinics. If your results come back “normal”—that is, showing no incompatibility with the donor—I would want to know what both clinics’ plans are for ensuring success this time: Perhaps a comprehensive examination of the endometrium to rule out other issues before creating more embryos.

I hope this helps,

Dr. Katharina Spies.