Endometriosis and Infertility: Common Misconceptions
Endometriosis is one of the most common conditions associated with infertility. I say “associated with” rather than “causing” infertility because in many cases, it can be an (added) contributing factor to another underlying issue that is the root cause of a woman’s infertility.
Many times, women are given an oversimplified picture of the correlation between endometriosis and infertility – in essence, that:
- The primary effect of endometriosis is that it impedes the eggs from reaching the fallopian tubes.
- That the severity of infertility is directly proportionate to the anatomical severity of the endometriosis itself.
This gross over-simplification and erroneous view is often used to justify the performance of many unnecessary surgeries for the removal of small innocuous endometriotic lesions, on the basis that such “treatment” can evoke a cure of the infertility.
It is indeed indisputable that even the mildest form of endometriosis can compromise fertility. It is equally true that mild to moderate endometriosis is by no means a cause of absolute “sterility”.
When compared with normally ovulating women of a similar age who do not have endometriosis, women with mild to moderate endometriosis are about three to four times less likely to have a successful pregnancy. Two important reasons for such reduction in fertility potential are:
- Endometriosis is associated with the release of local pelvic “toxins” that significantly reduce the fertilization potential of eggs as they pass via the pelvic cavity from the ovary to the awaiting sperm in the outer fallopian tube.
- Given that the origins of endometriosis almost certainly also involve an abnormal immune response of the uterine lining, many such women tend to reject the embryo (fertilized egg) as it attempts to gain attachment to the uterine wall (endometrium).
The reason that women with mild to moderate endometriosis have a much poorer reproductive performance has less to do with ovulation dysfunction or anatomical disease than the two factors mentioned above. Therefore, it should come as no surprise that the use of fertility drugs, surgery (to ablate small endometriotic deposits and free pelvic adhesions), as well as treatment by intrauterine insemination (IUI) which do not address the primary causes, are unlikely to provide any improvement in pregnancy rate over no treatment at all.
Of course, there are women with mild to moderate endometriosis who are under 35 years and who, in spite of such barriers to fertility, do conceive following fertility hormone therapy, intrauterine insemination (IUI) or surgery. But these women should realize that they probably became pregnant in spite of – rather than due to – such treatment. Then, there is the danger that women who conceive in spite of mild to moderate endometriosis might be lulled into a false sense of complacency, thinking that because they were able to achieve a pregnancy once, they will have no problem doing so again. In reality, the achievement of a viable pregnancy by a woman with mild/moderate endometriosis (by whatever means), does not improve her chances or provide assurance that she will be able to do so again.
Younger women (under 30 years) with mild/moderate pelvic endometriosis (who have patent fallopian tubes, are ovulating normally, and have fertile male partners), have about a 30-40% chance of having a baby within 3 years. Accordingly, they would be fully justified in taking a “wait and see” approach, avoiding surgery, fertility drugs and intrauterine insemination (none of which, in my opinion, is likely to improve their chance of a successful pregnancy over no treatment at all). However, if they prefer to take a more active approach to conception, their best bet is In Vitro Fertilization. The nature of the IVF procedure allows eggs to be removed without their being exposed to the “toxic” pelvic environment. The eggs are then fertilized outside the body and transferred as embryos to the uterus. This nullifies one of the major factors in endometriosis-related infertility.
In addition to this toxic “peritoneal factor” present in all women with endometriosis, our research has shown that up to 1/3 of women with endometriosis (regardless of severity) have an immunologic barrier to implantation. That is, the body’s natural immune response rejects the embryo as a foreign body before it can implant in the uterus. This population of women is not generally able to conceive until the immunologic problem has been diagnosed and suppressed through selective immunotherapy.
It therefore behooves all women with endometriosis who are planning to have a family to be thoroughly tested for immunologic factors including Antiphospholipid Antibodies (APA) and Natural Killer cell activation (NKa). These tests should only be performed by a reproductive immunology reference lab. To my knowledge, no more than a half dozen exist in the United States that are capable of performing these tests with the required sensitivity.
Given the effect of the biological clock, women over 35 years of age who have endometriosis-related infertility need to be very proactive, as they do not have time to waste. Such women should, in my opinion, do IVF as a first line approach.
In the absence of clear evidence of immunologic implantation dysfunction (increased NK cell activity), I often recommend a conservative approach in women under 35 years (who potentially can afford the time to wait). However, it is my opinion that regardless of age, women who have increased NK cell activity should undergo IVF accompanied by immunotherapy with Intralipid (and sometimes with heparin, Clexane or Lovenox added ). Without such treatment, they are not likely to conceive regardless of the treatment approach.