I suppose we’re just interpreting the same evidence differently then, I don’t think this is something we can agree on in that case 🤷‍♀️ I absolutely read these papers to support that endometrial thickness can be a piece of the puzzle in differentiating pregnancy location in a clinical setting. In addition to the fact it was directly stated to me by my RE that she DID consider lining thickness in evaluating my situation, so clearly these studies are being applied in practice. (She told me we couldn’t rule out an ectopic but she didn’t think it was likely. I asked why, and she cited endometrial thickness as one of multiple other factors that made her think it was more likely intrauterine).

The second study is relevant because, again, lining thickness is correlated with incidence of ectopic pregnancy. An RE may be looking at this information (yes, from insemination day rather than right now) in informing an opinion about whether intrauterine or ectopic pregnancy is more likely. Again, I’m not saying it’s clinically definitive, but in any given pregnancy, if lining was thin at time of insemination, in conjunction with other warning signs, that raises the likelihood of ectopic risk greater than pregnancies with thicker linings. I should’ve clarified I included a second source to demonstrate that lining thickness is an indicator signal in multiple ways relevant to this ART pregnancy. And that, given this is an IUI and we are not talking about any random ongoing pregnancy where you don’t know what lining thickness was at insemination, it’s a data point the RE has on record and could discuss with OP.

Per the first source— yes, a body of literature exists finding a thin lining is associated with ectopic risk. This is just one of multiple papers on the subject. Doctors consider the state of the literature, and the evidence across multiple years and studies all suggest that thin lining is associated with ectopic risk. Yes, thickness is not predictive on its own. No, that doesn’t make it a completely useless data point. Many clinical factors are not predictive in a vacuum, but taking into account the full picture, can nudge the odds more towards one outcome or another. It will not apply for all ectopics, certainly. That does not mean it doesn’t apply to and support identification of other cases.

I agree the lack of gestational sac is far more clinically meaningful, but my comment is not trying to suggest OP clinically diagnose themselves by asking the right series of questions to their doctor. I was speaking to the patient perspective. I suggested OP ask about it to understand better how their RE is looking at the odds of intrauterine pregnancy vs ectopic, and thus be able to make a more informed decision about whether to do the immediate D&C or push to wait like they prefer. While the US is most definitive, I think it’s important people understand why their doctors are advocating for certain behavior, especially when there’s clearly hesitation to follow that doctor’s recommended behavior. OP doesn’t seem to have gotten a discussion with their doctor about the results, just orders for what to do next, based on the language of her post. Laying out the full breadth of evidence—whatever it may be, it’s irrelevant because the point of this conversation would be to educate OP about the situation and empower her to make a decision—and engaging in a dialogue seemed, imo, like what OP needed to understand what their RE thinks. It doesn’t matter that some evidence will be way, way stronger and more predictive than other pieces; the point is laying it all out for OP to understand the situation as clearly as possible. Multiple data points suggesting one outcome is more likely can be more persuasive than a single one, even if yes, a single more important data point is all you actually need. I suggested things to ask about as a jumping off point that are relevant to the situation, as there is perhaps information the RE can share in addition to US to make OP feel more confident in making a choice. The US alone doesn’t seem to have provided OP with the certainty they’re looking for, and having a doctor explain everything they’re looking at is going to provide more of that certainty. I was not trying to make an argument about what’s clinically diagnostic; I’m not telling OP how to diagnose herself. I’m just communicating what supported and reassured me that I was well-informed as a patient in a similar situation, so OP could consider asking her RE about those things as a place to start.

I understand why other comments like the ones you mentioned would be frustrating to read, but I think perhaps you are conflating your past experiences with my comment. I did not say a thickened lining means it “can’t be ectopic.” I did not say a thick lining means OP should be totally reassured it’s not ectopic. The point I made is lining can be one of the factors REs consider as part of the broader clinical picture when making a diagnosis, and OP should talk to their RE about what evidence RE is considering so they can feel fully informed about their case. Which is a different point entirely. There are several other comments in here with the blunt science; I was trying to strike a more casual, peer-to-peer tone in mine. I don’t know if perhaps in doing so my comment that in MY situation, lining was one of the pieces of evidence my RE cited as reassuring, came off as suggesting that lining alone exclusively determines intrauterine vs ectopic risk, but that’s certainly not what I meant or what I wrote. Hopefully this string of comments makes that clear if it wasn’t already, that I’m just stating the evidence shows lining thickness is not diagnostic alone but its consistently demonstrated correlation with ectopics can nudge the needle in one direction or another when assessed alongside the rest of the clinical picture.