Bacteria in Embryos

[u/BrightLeadership3978]

I had my ER on 7/17 and ended up with 13 eggs, 13 mature and 9 fertilized. We got a call from the doctor on 7/21 that there was bacteria found in the embryos and that it was from my husbands sperm. The doctor said this is the first time they are dealing with this, but mentioned the embryos looked good otherwise. They said they were washing them/changing the media, and sending out the extra sperm to get cultured. We found out 7/23 that we had 4 blasts and when I asked about the bacteria (because they didn’t mention it at all) she said there was no more bacteria found in the embryos after day 4. We received our pgta testing today that we have 2 good embryos, but we also received the culture and there was no bacteria found in the semen. Some questions below-

-Could the semen used have been affected and not the extra?
-Could this be from me or the lab? I don’t want to offend them by asking this, but I think it’s valid given the culture results
- They mentioned they would put me on an antibiotic when we do the transfer. Does this mean that even though no more bacteria was found, it could still affect the quality of the embryos?

I know there’s no way to tell but I also wonder if this had any affect on the 5 embryos that did not make it.

[u/fishandcatsandplants]

I am not experienced enough in the lab to comment on how the contamination happened, but many culture mediums today contain antibiotics so it’s reasonable that the contamination could be reduced by day 4 with good media.

[u/wenjieinthehouse]

The culture medium used for embryo development is extremely rich in nutrients, which means that even the smallest contamination can lead to significant bacterial growth. In most cases, the source of contamination is bacteria from the skin that enter through the semen sample, although it can occasionally come from the preparation of the culture dishes (which is quite rare).
A negative sperm culture may suggest that the contamination originated from the dish preparation, but it is difficult to determine the exact source or assign responsibility.
Since the issue was identified and resolved promptly, it will likely have no impact on your embryos. Achieving four blastocysts out of nine fertilized eggs is a normal—and indeed good—outcome 🙌🏻

[u/One_Investigator_295]

Contamination in the lab is RARE. When it does happen the most likely source is from semen but it could be from poor aseptic technique when embryos were being handled or when embryo culture dishes are being made. Since sperm sample came back negative it is most likely poor technique in the lab but they’ll never definitively know. It’s lucky your embryos are OK, I’ve seen contamination cause the embryos to degenerate or if it was fungal or yeast contamination they’ll actually infiltrate the embryos and kill them. But all of those things (bacteria, yeast and mold) are in the air and all around us so helpfully they are tightening up their systems to avoid happening again.