Endometrial thickness..

There should be a standard disclaimer when talking about fertility treatments.  Something like: nothing is absolute.  The grey areas in fertility treatments are huge!  Studies more often contradict each other than agree, it seems!

This is true when talking about endometrial thickness.  Nevertheless we still need we some guidelines.

In general, as endometrial thickness after IVF stimulation increases so does pregnancy rate.  Endometrial thickness between 6mm-14mm is ideal.  Pregnancies do occur when the endometrial thickness is < 6mm or >14mm but it seems not as often.  To this end, we sometimes cancel/postpone/modify treatment if the endometrial thickness is outside this range. 

The largest study published to date :

Richter KS, Bugge KR, Bromer JG, Levy MJ Rellationship between endometrial thickness and embryo implantation, based on 1,294 cycles of in vitro fertilization with transfer of two blastocyst-stage embryos. Fertil Steril. 2007 Jan;87(1):53-9.

I hope this helps!

Dr. Beth Taylor

Often patients become concerned about endometrial thickness during their IVF cycle.  There is strong data to show that there is a trend towards higher pregnancy rates with thicker endometrium, but there is not a definitive lower or upper threshold where pregnancy does not occur.  Endometrial thickness on ultrasound is a surrogate marker for endometrial receptivity.  Another feature that is often overlooked is the endometrial pattern.  Most fertility physicians would like to see a triple-layer, or trilaminar pattern for the endometrium.  However, pregnancies still occur when there is a non trilaminar pattern.

If there is a concern about the endometrial thickness, one has to ask if there are any interventions that can realistically change the endometrial thickness, and will these interventions increase the chance of pregnancy.  In many instances, there are few interventions that will alter the thickness within a patient.  The thickness is primarily dependent on estrogen levels, but estrogen levels are well above physiologic levels during an IVF cycle, so adding estrogen is rarely going to help.  Some novel treatments are often offered (baby aspirin, viagra vaginal suppositories), but the data on these treatments is limited.

Most importantly, prior to embarking on an IVF cycle, ensure that you have had an appropriate and adequate uterine cavity evaluation.  Often couples will have had an HSG three years earlier that was normal, and then embark on an IVF cycle only to find out during the stimulation phase of the IVF cycle that they have an endometrial polyp or small intracavitary fibroid, thereby jeopardizing there chance of conceiving.  Our policy is to have a uterine cavity evaluation within 1 year of the start of an IVF cycle (either an HSG, saline infusion sonogram, or hysteroscopy).

In the case of a 7.5 mm endometrium - it is always nice to have the 10-11 mm thickness (ie the average/typical thickness).  In my opinion, if the pattern was trilaminar without evidence of polyps and there were no other mitigating factors with the treatment, I believe that it would be appropriate to perform the embryo transfer, as opposed to freezing the embryos and doing a frozen embryo transfer.

Always remember, it is our goal to help you achieve a successful pregnancy from your treatment.  However, it is your treatment, so always ask questions of your physician whenever you have questions or concerns about your treatment.  We always want you to feel that the care that we provide you has lived up to your expectations.

Jon Havelock, MD, FRCSC, DABOG

Co-Director, Pacific Centre for Reproductive Medicine

Board Certified, Obstetrics and Gynecology (ABOG)

Board Eligible, Reproductive Endocrinology and Infertility (ABOG)

Thank you Dr. Jon Havelock. and Dr. Beth Taylor, your input on our forum is very appreciated by both Acubalance clients and women reading this forum from all parts of the world.  Very valuable information. I want to comment and add to Dr Havelock’s post.  I have copied the excerpt below:

“If there is a concern about the endometrial thickness, one has to ask if there are any interventions that can realistically change the endometrial thickness, and will these interventions increase the chance of pregnancy.  In many instances, there are few interventions that will alter the thickness within a patient.  The thickness is primarily dependent on estrogen levels, but estrogen levels are well above physiologic levels during an IVF cycle, so adding estrogen is rarely going to help.  Some novel treatments are often offered (baby aspirin, viagra vaginal suppositories), but the data on these treatments is limited.” – Dr. John Havelock

I would like to add that there are other treatments that may be beneficial.  Acupuncture has been shown to increase blood flow to the lining.  One study demonstartes  acupuncture can not only thicken endometrial lining but increase vascularization of the lining as well, it is well known that a lining can be thick yet not full of life giving blood (vascularized) (study: acupuncture can reduce blood flow impedance in the uterine arteries).

We have had a few cases where there were lining issues for a frozen or donor cycle.  We trreated each of  these cases 4-5 consecutive days in a row and all were told they had significant lining improvement (testimonial from client).

For the RE’s reading this or patients with a history of lining isssues you may want to use acupuncture as effective intervention to help improve the chances of pregancy.