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Well... I'm not suprised that your are confused. The publications you have been looking at a quite complex for the layperson. Heck, they're complex for for me too. Its difficult to sort through all the information to find what you're looking for, and even then, to be sure that you can trust it.
The first link is a lengthy review of the literature surrounding the effect of E2 on everything imaginable. Although informative, the authors are a little biased in their interpretation. They have selected a multitude of references that support their argument, but came up a little short on studies that refute their position.
The general consesus is that very high levels of estrogen can have a negative impact on endometrial receptivity. This is most common in PCOS patients (hyper-responders) that get up in 5-6000 pg/ml range. The question is how high is too high. I think it is generally accepted that levels in excess of 5000 pg/ml are too high, but many patients run E2s in the 3-4000 range become pregnant and carried to term. So its less clear what effect the intermediate values will have. Also, one must consider that circulating levels of any hormone are only half the story. These hormones must also bind to receptor molecules on the outside and inside of the cell to be effective in facilitating a response from the cell. Once all the receptor molecules for a given cell are occupied by the hormone, having more hormone around won't have any additional effect. The cell is "maxed out" so to speak. One hormone will induce the cell to make additional receptors or make receptors for another hormone. This is what makes it so complex to interpret.
The second linked article basically says the same thing. There are pros and cons to any manipulation of nature. Ovarian stimulation is no exception. An increased number of follicles means that the E2 will go up to supraphysiological levels. As with most things, its a trade off. The trick is to balance the stimulation so that the E2 does not get too high, but still allow the follicles to reach a size that will allow the eggs inside to mature and be of good developmental potential. You need to keep in mind that endometrial thickness is not directly tied to E2 levels (i.e. the higher the E2, the thicker the endometrium). Once all the endometrial E2 receptors have homone bound (i.e. saturated), more E2 doesn't have any additional stimulatory effect.
From what I know and read in the linked articles, the E2s in the 1700-2600 range that you had wouldn't have a detrimental effect on the endometrium. It is more troubling that your E2 dropped so precipitously when they lowered your medication on the first cycle. Not a good sign. The following cycle, they kept the E2 down, your endometrium was of adequate thickness, but (da) the follicles weren't mature.
The paper concluding that endmetrial biospy in the same cycle improves implantation has been discussed at length in the IVF community, but so far, has not been confirmed. The dogma is that an endometrial biopsy in the same IVF cycle is one of the worst things you can do since it may cause a blood clot in the uterine cavity that would prevent implantation. The authors of this study are out on a limb, but I try to keep an open mind.
Dopper US is another one of these "flash in the pan" things that everybody thinks is interesting, but doesn't really pan out. As expected, blood flow is correlated with implantation and ongoing pregnancy. The problem is that medications that increase blood flow to the endometrium do not improve implantation rates significantly. Clearly, there's more to the story than just blood flow to the endometrium.
When the Fallopian tubes are patent (open) and the psrm is fine, natural cycle IVF has the same pregnancy rates as timed intercourse. Save your money.
The progesterone suppositories are standard progesterone replacement following an IVF retrieval. It was not done to "rescue" the endometrium from a high E2. Progesterone is necessary to "turn on" endometrial recitivity that will allow implantation to occur.
I think (if I may be so bold) you are driving yourself crazy with all this stuff. I relaize that you want as much information as posible (and that's a good thing), but biology has a lot of variation and it is a very difficult beast to tame. Sometimes we are at the mercy of the beast and there's nothing we can do.
I hope you get some clear answers from your RE on Thursday. I think you should ask what she plans to do about the endometrial thickness on any subsequent cycle. 7mm is not that great and she knows it.
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