Diagnostic Approach in Women with Suspected Endometriosis or Tubal Damage as a Cause of Infertility

Initial Evaluation with Transvaginal Ultrasound

The American College of Radiology recommends transvaginal ultrasound as the initial imaging modality to detect endometriomas and evaluate ovarian reserve in women with suspected endometriosis, with a sensitivity of 96% and specificity of 99% for deep infiltrating endometriosis 1, 2, 3
Transvaginal ultrasound allows for the identification of endometriomas, antral follicle count, and ovarian volume measurement to assess ovarian reserve, with a high diagnostic precision for endometriosis 4
A common pitfall is assuming a normal transvaginal ultrasound rules out endometriosis, as up to 21% of women with surgically confirmed endometriosis have a normal hysterosalpingogram 1, 2

The American College of Radiology indicates hysterosalpingography (HSG) to evaluate tubal patency and the uterine cavity in the study of infertility, especially when tubal damage is suspected, with a sensitivity of 82-90% and specificity of 91-98% for diagnosing endometriomas 1, 2, 5
Tubal damage accounts for 14% of known cases of female infertility, with chlamydial salpingitis being a major cause 6
HSG is particularly useful when there is a history of pelvic inflammatory disease, which causes tubal scarring, occlusion, and peritubal adhesions 6

The American College of Radiology recommends pelvic magnetic resonance imaging (MRI) when transvaginal ultrasound findings are indeterminate or when deep infiltrating endometriosis needs to be evaluated before fertility-preserving surgery, with a sensitivity of 92.4% and specificity of 94.6% for detecting intestinal endometriosis 1, 2, 7
MRI has a sensitivity of 82-90% and specificity of 91-98% for diagnosing endometriomas, and is useful for evaluating deep infiltrating endometriosis, especially in the rectovaginal septum and uterosacral ligaments 1, 2, 7
No routine intravenous contrast is required for endometriosis evaluation, although it is useful for evaluating pelvic inflammatory disease or ovarian masses with enhancing components 1, 2, 7

Transrectal ultrasound can be useful for detecting deep infiltrating endometriosis, with a sensitivity of 97% and specificity of 96% for rectovaginal endometriosis 1, 7
This study showed 80% sensitivity and 97% specificity for diagnosing implants in uterosacral ligaments 1, 7

The American College of Radiology states that laparoscopy with biopsy remains the definitive diagnostic method, although it is reserved for cases where empirical therapy fails or when immediate diagnosis is needed 3, 4
Laparoscopy is the standard for diagnosing and staging endometriosis, especially for detecting small endometrial implants not well visualized on imaging 4
A critical warning is that only an experienced surgeon familiar with the protean appearances of endometriosis should rely on visual inspection to make the diagnosis; peritoneal biopsy should be performed to confirm questionable lesions 8

Women with endometriosis may present with reduced markers of ovarian reserve, including decreased antral follicle count 4
An ovarian volume of <3 cm³ and <5 antral follicles present are indicators of decreased ovarian reserve in women with endometriosis 4
Up to 44% of women experience recurrence of symptoms within the first year after surgery, potentially leading to progressive ovarian damage 4, 8

Step 1: Initiate with transvaginal ultrasound in all patients with suspected endometriosis or tubal damage 3, 4
Step 2: Perform hysterosalpingography to evaluate tubal patency when tubal factor is suspected 1, 2, 6
Step 3: Request pelvic MRI if transvaginal ultrasound is indeterminate or if fertility-preserving surgery is planned and deep infiltrating endometriosis needs to be mapped 1, 2, 7
Step 4: Consider diagnostic laparoscopy when empirical therapy fails or when definitive histological confirmation is required 3, 4