Contemporary Management of Endometriosis and Infertility
The relationship between endometriosis and infertility has been recognized for many years. With advanced stages of endometriosis the mechanics of egg pick-up and transport by the fallopian tube is altered by scar tissue. The ovarian surface is often largely covered by adhesions that may inhibit release of the egg from the surface of the ovary. The ovary may be enlarged by the presence of endometriotic cysts that enlarge the ovary and distort the relationship between the tube and ovary impairing the ability of the fallopian tube to access the egg. When endometriosis is minimal, it is more difficult to explain precisely how endometriosis is negatively impacting reproductive function. It has been theorized that endometriotic implants set up a state of chronic inflammation in the pelvis that may alter egg and embryo transport, fertilization, embryonic development, and implantation.
In cases of advanced endometriosis it is clear that surgical correction of the mechanical problems in the pelvis will improve chances for pregnancy, and until the development and refinement of in-vitro fertilization (IVF) techniques, surgery was the best approach. However, surgery has some associated risks and takes time to achieve successful outcomes. Since IVF bypasses the mechanical transport of the egg and embryo and allows the early embryo to be nurtured in the environment of an incubator that simulates the conditions within the fallopian tube, it has proven to be quite effective in resolving infertility associated with advanced endometriosis. This is not to say that IVF success rates in patients with advanced endometriosis are comparable to rates achieved in similar aged non-endometriosis patients. Most studies show a moderately reduced success rate with advanced endometriosis patients compared with aged matched infertile controls. Success is achieved without the need for surgical intervention, recovery from surgery, or the sometimes lengthy wait following surgery before success is achieved. In addition, there is genuine concern that the excision of endometriosis and intra-operative use of energy sources to control bleeding, results in a net loss of ovarian tissue. It is quite possible that operative intervention in cases of advanced endometriosis may reduce the “window of reproductive opportunity” going forward.
Regarding mild or minimal endometriosis, surgical treatment has been utilized for a long time, but the benefits in terms of pregnancy rates following the surgical procedure have been inconsistent and controversial. Alternatively, basic treatments such as the use of clomiphene in conjunction with intra-uterine insemination have shown consistent success rates of approximately 12-14% in patients with “unexplained infertility”. The only way to diagnose early stage endometriosis is through laparoscopy (telescopic evaluation of the pelvis). Because diagnostic evaluation of the pelvis through the use of laparoscopy is usually not part of the basic infertility evaluation, it is quite likely that many cases of mild endometriosis are being successfully treated with interventions such as clomiphene coupled with intra-uterine insemination, injectable medications (gonadotropins) in conjunction with intra-uterine insemination, or IVF. Contemporary infertility management therefore usually leads to successful resolution of unexplained infertility, a percentage of which is most likely associated with endometriosis. This approach leads to earlier achievement of pregnancy while eliminating operative intervention and recovery.