Thin Endometrium and FET Outcome - Is there a correlation?

It is boring in hotel room and it is drizzling outside. So I am sitting in the room doing nothing. As usual, I have no mood to watch television programme. I did a short search in pubmed regarding thin endometrium and pregnancy outcome in  FET or IVF cycle. I feel so happy when I learn something new and also to update my blog with some decent information. Am I obsessed? I think I am not. When I watch TV or sit without doing anything a kind of depression sets in. My thoughts waver too much in the negative direction. I feel happy and relaxed when my mind is working, especially regarding my FET stuff and my blog. My DH is not happy about it. His accusation is that I am stressing myself too much. How will I make him understand how I feel? :(

So here we go: As always, there are two different views on whether thin endometrium affects the outcome of FET or IVF cycle. A paper in Clin Exp Obstet Gynecol.states that a 47 year old woman with an endometrial thickness of 4 mm conceived twins using donor embryos (PMID: 22268266). I do understand exceptions cannot become the norm.  But this information does give me lots of hope. My belief that embryo competency is important than endometrium thickness might be true. But my RE who has extensive experience in the field of IVF does not agree with me :) Might be my view is flawed, who knows? There is one more publication which makes me happy. You can view it here (PMID: 1513611). I could just get the abstract which states that, the largest study to date on the association of endometrial thickness and subsequent pregnancy rates following frozen embryo transfer, with the endometrium prepared by estrogen and progesterone found no improved or adverse outcome if the endometrium is too thick or thin :) I am now on progynova for a longer time. I started progynova on May 31^st and I added progesterone only on June 23^rd. So I am on estrogen supplement (increased from 6mgs to 64mgs as of now) for 24 days. I am bit uncomfortable with this long-time stimulation to grow my endometrium to decent thickness. 'Will this have an adverse effect on my endometrial receptivity? Will my endometrium quality be compromised?' These are the questions which haunt me sometimes. But my fear seems to be unnecessary. This (PMID: 16983519) paper states that long-term estrogen administration to bring the lining to a decent thickness is beneficial and does have a positive effect on pregnancy rate (infact the pregnancy rate was higher when compared to the control group!).

Now, I will also cite papers which say endometrial thickness is important and thin endometrium compromises pregnancy outcome. This paper (PMID: 22346080) states that mean endometrial thickness is significantly higher in pregnant women compared to non-pregnant.  But they concluded that ‘the mean difference between two groups was <1 mm which may not be clinically meaningful. Although there may be a relationship between endometrial thickness and pregnancy, implantation potential is probably more complex than a single ultrasound measurement can determine.’ So, they did not find a sure correlation between endometrial thickness and pregnancy rate. Another study states that in donor embryo cycles thin endometrium is one among several factors which  can compromises the cycle outcome (PMID: 15482759). This study (PMID: 17681313) says that in medicated FET an endometrial thickness of 9-14mm on the day of progesterone administration is positively associated with pregnancy outcome than an endometrial thickness of 7-8 mm :( One more interesting publication states that, in ICSI cycles (that is ART cycles performed due to male factor infertility) the endometrial thickness has no effect on pregnancy outcome while in IVF cycle endometrial thickness (where female fertility problems are involved) is a factor which determines pregnancy outcome (PMID: 8671501).

In short, studies fail to show a strong negative correlation between Pregnancy Rate (PR) in IVF/FET cycles and thin endometrium. There are several other factors which play a role in embryo implantation. The most important of it all is the age of the woman or the embryo quality.

Now after reading all this I just wish that my two little blasties have a competent genome. No matter how much I obsess nothing is going to change. Whatever happens will happen and let me face the reality with a strong heart and calm mind :)