The role of transvaginal sonography in diagnosis of female infertility: a study protocol

Introduction

Infertility is the inability to conceive after one year of unprotected intercourse. Approximately 15.5% of women globally are afflicted with infertility.¹ In India, the prevalence ranges from 3.9 to 16.8% (according to the Government website). The standard workup for female infertility includes assessing ovarian reserve, tubal and uterine examination, hormonal issues such as thyroid disorders and prolactin abnormalities, and confirmation of polycystic ovarian syndrome/disorder (PCOS).²

Female infertility causes are difficult to pinpoint. Although there are numerous therapies available, the treatment will be determined based on the cause of infertility. The most significant gains in assisted reproductive technology (ART) have resulted from advancements in pelvic structure evaluation tools.³ Infertility evaluation necessitates histopathological testing as well as visualization using several imaging modalities. There are many causes of infertility, including ovarian (such as ovarian dysgenesis or agenesis, premature ovarian failure, oophoritis, chocolate cyst, and polycystic ovarian syndrome), uterine (such as fibroid, adenomyosis, mullerian duct anomalies, endometrial polyp, endometriosis, endometritis, and intra-uterine adhesions caused by infectious causes such as tuberculosis), cervical aetiology (such as cervical stenosis), tubal aetiology (such as tubal occlusion, hydrosalpinx, pelvic inflammatory illness, and endometriosis).⁴

Because it is inexpensive, convenient, and gives basic information about the morphology of the uterus, cervix, endometrium, adnexa, and ovaries, ultrasound is the chosen initial modality of study for evaluating possible causes of female infertility.⁵

Transvaginal sonography (TVUS) is a well-established and widely adopted diagnostic tool in gynecological imaging. It offers high-resolution visualization of pelvic organs and is considered the first-line modality for assessing uterine morphology, endometrial pattern, ovarian structure, and adnexal pathology. The clinical value of TVUS has been demonstrated across numerous studies dating back over three decades (e.g., Gratton et al., 1990; Ubaldi et al., 1998). A high-frequency transducer is implanted endovaginally to evaluate pelvic organs in detail. But other investigations are needed to confirm TVS’s role and to know how accurate it is in diagnosing various causes of primary and secondary infertility.⁵

However, the heterogeneity of infertility causes in diverse populations and the evolving application of sonographic parameters (such as ovarian stromal assessment, AFC, and Doppler indices) suggest that re-evaluation of TVUS’s diagnostic performance in specific regional contexts remains relevant, particularly when compared against gold-standard methods like hysterosalpingography (HSG) or diagnostic laparoscopy.

Methods

All participants will undergo baseline clinical evaluation followed by TVUS on days 2–5 of the menstrual cycle. Parameters such as endometrial thickness, follicular count, ovarian volume, and uterine morphology will be documented.

Subsequently, patients will undergo confirmatory testing as clinically indicated (HSG for tubal evaluation, laparoscopy for suspected endometriosis, and hormone profile for ovulatory status). TVUS findings will be compared to these reference standards to compute diagnostic accuracy.

Discussion

A study, ‘Role of transvaginal ultrasonography and diagnostic hysteroscopy in assessing endometrial cavity of women presenting with infertility’ was conducted by K. Sarala et al. in 2018. This study concluded that hysteroscopy can be regarded as the gold standard in the diagnosis of infertility. The study compared the transvaginal findings with hysteroscopic findings. The transvaginal findings and hysteroscopic findings were similar. The various causes of infertility were endometrial hyperplasia, submucous fibroids, endometrial polyps, adhesions, and congenital malformations in decreasing order of frequency, respectively. Thus, it was concluded that although hysteroscopy is considered the gold standard, transvaginal sonography can be used as an initial investigation in infertility work.¹⁰

In the study conducted by Maysa S. Elkerdawy et al. on the role of ultra-sonography (USG) in the management of primary infertility, it was found that 60% of patients had uterine abnormalities (mainly subseptate and bicornuate uterus) while approximately 23% of patients had ovarian pathology (mainly polycystic ovaries). Only a small percentage of patients had tubal and cervical pathologies (like hydrosalpinx, cervical mass, etc.). It was further found that USG can be used as a primary tool for investigation.⁴

In the study carried out by Salaam AJ et al. on the topic of evaluation of infertile women using transvaginal USG, primary fertility constituted about 42% of total subjects while secondary infertility constituted about 58%, and about 54% had normal TVS findings and rest (46%) had abnormal findings like uterine fibroid, free fluid in Pouch of Douglas (POD), endometritis, and hydrosalpinx in the decreasing order of frequency. It was also found that there was a significant difference in volume between the right and left ovaries in infertile women with Polycystic Ovaries (PCO). This study found that a high yield of sonographic anomalies was observed on transvaginal sonography in infertile subjects, bolstering TVS's essential function as a useful diagnostic tool for evaluating infertility.¹¹

In the study conducted on transvaginal sonographical findings by Nafeesa Binti Hussain et al. on women presenting with inability to conceive, they inferred the following: 75%of cases were of primary infertility while 25% of cases were of secondary infertility, and the most common pathological findings were polycystic ovarian syndrome (69%), followed by chronic pelvic inflammatory disorder, fibroid, anatomical disorders, endometrial or cervical polyps, and endometritis in decreasing order of frequency. The study concluded that PCO was the most frequent finding in women with infertility, which was easily diagnosed by transvaginal sonography.⁵