The Association Between Infertility and Endometriosis and the Treatment

Endometriosis is a gynecological disease affecting women in their reproductive years. The reported incidence of endometriosis among infertile women is 20-50%, and 39-59% among those with pelvic pain. This is in contrast to 15-18% incidental findings of endometriosis among women undergoing tubal sterilization. The question of whether endometriosis causes infertility has been a subject of debate for many years. In this review, the association between infertility and endometriosis and the treatment are discussed.

Diagnosis
Currently, the best classification of endometriosis is the revised American Fertility Society (r-AFS) classification. This classification is based on the amount of endometriosis and adhesions. There are four stages of endometriosis: Minimal (stage 1); Mild (stage 2); Moderate (stage 3); and Severe (stage 4).

Transvaginal ultrasound examination or magnetic resonance imaging can detect ovarian endometrioma in stage 3 or 4 endometriosis. Stage 1 and 2 endometriosis can only be diagnosed by visualization either at laparoscopy, laparotomy, or by histopathology.

Laparoscopy is the most common method for diagnosing stage 1 or 2 endometriosis. However, mini-laparoscopy has also been used for this purpose. Recently, transvaginal hydrolaparoscopy (THL), which can be performed in the office or clinic setting, appears to be a promising procedure in the early diagnosis of endometriosis.1

At laparoscopy, stages 1 and 2 endometriosis are seen as endomet-riotic implants with or without filmy adhesions on the adnexa. The implants vary in appearance and color (Figures 1 and 2). The red-colored lesions are thought to be more active than the white, black, or blue powder-burn lesions. To help explain the findings to the patient it is a good habit to complete the r-AFS form and diagram at the end of the procedure. This will also leave an accurate operative report and avoid unnecessary repeat laparoscopy.

Do Stages 1 & 2 Endometriosis Cause Infertility?
Endometriosis is often encountered during investigation for infertility. It is generally accepted that stages 3 and 4 endometriosis cause infertility, but the association between stages 1 and 2 endometriosis is less clear. Some authors suggest that the pregnancy rate after laparoscopic treatment of minimal and mild endometriosis is higher than no treatment.2,3 Others could not confirm this association. However, a recent randomized Canadian study4 suggests that stages 1 and 2 endometriosis are associated with infertility (see next section).

Figure 1. Classic bluish endometriotic implants.

Figure 2. Nonpigmented endometriotic implants.

Conservative Treatment: Excision vs Vaporization
Several studies have shown that the results of conservative surgical treatment for endometriosis by laparoscopy are similar and more effective than those achieved by laparotomy.5 To date, there is little doubt that the best conservative surgical treatment is by laparoscopy. It is also better than medical treatment. The results of the randomized Canadian trial clearly demonstrate that ablation of endometriotic implants increases the pregnancy rate in infertile women with stages 1 and 2 endometriosis.4 The 30.7% pregnancy rate in the first 36 weeks after laparoscopic treatment of endometriosis was significantly higher than the 17.7% after diagnostic laparoscopy only. In this study, laparoscopic treatment of endometriosis increased the cumulative probability of conception by 73%. The elimination of endometriosis was primarily achieved by electrocoagulation and laser.

Recently, the author and Al-Took6 compared the reproductive performance of infertile women after laparoscopic treatment of stage 2 endometriosis by electrocoagulation and by surgical incision. Electrosurgery was done by coagulating superficial endometriosis with bipolar forceps, and deep implants were coagulated with monopolar electrocautery. Excision was performed by grasping the peritoneum harboring the endometriosis, undermining and separating it from the underlying tissue. The normal peritoneum was excised around the implants with laparoscopic scissors. The results show that there is no difference in the reproductive performance after surgical excision (57.1%), or after electrocoagulation (53%). However, excision of endometriosis has several advantages.7 It provides specimen for histopathological examination, and the use of cold instruments such as laparoscopic scissors decreases the risks of thermal injury. Also, on several occasions, the seemingly superficial endometriosis represented the apex of a larger and deeper endometriotic nodule. This would be difficult to detect if the implants are just vaporized with laser or electrocoagulated. Compared to laser, laparoscopic scissors for surgical excision are much less costly. The difference between these two modalities in women with endometriosis-related pelvic pain remains to be seen.

Conclusions
It has been shown that even in its early stages, endometriosis is one of the causes of infertility. The pregnancy rate can be increased by eliminating the lesions during a diagnostic laparoscopy for infertility investigation. Unless the patients will be treated with in-vitro fertilization, infertile women, particularly those with endometriosis, will benefit from laparoscopic treatment. In our institution, laparoscopy is performed if all basic infertility investigations are normal, and after three cycles of superovulation and intrauterine insemination.

However, we are beginning to evaluate the use of transvaginal hydrolaparoscopy as another tool in the early detection of endometriosis and as a 'second-look' follow-up procedure.

References:

References

1. Gordts S, Campo R, Rombauts L, Brosens I: "Transvaginal hydrolaparoscopy as an outpatient procedure for infertility investigation." Human Reprod 1998,13:99-103.

2. Hughes EG, Fedorkow DM, Collins JA: "A quantitative overview of controlled trials in emdometriosis-associated infertility." Fertil Steril 1993, 59:963-70.

3. Nowroozi K, Chase JS, Check J, Chung W: "The importance of laparoscopic coagulation of mild endometriosis in infertile women." Int J Fertil 1987, 32:442-4.

4. Marcoux S, Maheux R, Berube S, and the Canadian Collaborative Group on Endometriosis: "Laparoscopic surgery in infertile women with minimal or mild endometriosis." N Engl J Med 1997, 337:217-22.

5. Adamson GD, Pasta DJ: "Surgical treatment of endometriosis-associated infertility: meta-analysis compared with survival analysis." Am J Obstet Gynecol 1994, 171:488-504.

6. Tulandi T, Al-Took S: "Reproductive outcome after laparoscopic excision and electrocoagulation of mild endometriosis." Fertil Steril 1998, 69:229-31.

7. Redwine DB: "Conservative laparoscopic excision of endometriosis by sharp dissection: life table analysis of reoperation and persistent or recurrent disease." Fertil Steril 1991, 56:628-34.

Dr. Tulandi is professor of obstetrics and gynecology at McGill University in Montreal, Quebec, Canada. He is an associate director of McGill Reproductive Center at the Royal Victoria Hospital, and program director of the fellowship program in reproductive endocrinology, infertility and reproductive surgery. Dr. Tulandi's current research projects include prevention of post-surgical adhesion formation, ectopic pregnancy, laparoscopic treatment of polycystic ovaries, endometriosis, uterine myoma, and many aspects of gynecologic endoscopic procedures.