Ultrasonongraphy (USG) is a useful and first line investigation used to assess the cause of infertility and to institute treatment accordingly. USG is an effective, safe, inexpensive, radiation free, non-invasive and readily available tool.
Role of ultrasound in female infertility
Ultrasound is used to evaluate the pelvic organs (uterus and ovaries), growing ovarian follicles, and cyclic uterine endometrial changes.
Evaluation of uterus :
A) Structural anatomy - Using both 2D and 3D ultrasound congenital mullerian anomalies can be diagnosed and classified according to ESHRE/ESGE classification of uterine anomalies.
1) Fibroid : seen in 5-10% of infertile women. Distortion of the endometrial cavity, abnormal endometrial receptivity, altered hormonal milieu, and endometrial development are the causative factors for infertility in fibroids.
USG provides the number, exact location and size of fibroids, thus helps in thorough planning of surgical intervention if necessary.
2) Adenomyosis : Adenomyosis results in structural and functional defects of the uterine junctional zone and thus resulting in disturbed uterine peristalsis and sperm transport, increased inflammatory response in the endometrium causing impaired implantation. All these factors contribute to sub fertility and increased risk of miscarriage in Adenomyosis.
The ultrasonographic features of Adenomyosis are globular uterus, asymmetrical myohyperplasia, rain shower appearance and myometrial cyst.
Is a dynamic structure undergoing cyclical changes. The endometrial pattern acts as an indirect measure of hormonal status during the cycle. Pathological features such as thin endometrium, poor endometrial blood flow, presence of polyp or intrauterine adhesions can result in sub fertility. And all these pathologies are accurately assessed using USG (both 2D + 3D).
USG is used for diagnosis and monitoring of treatment cycle in sub fertile women.
1) Follicular monitoring : Is an integral part of investigation in subfertile women. Serial scans during follicular phase evaluates the growth of the follicle, estimates the time of follicular rupture, the ideal time to trigger ovulation and occurrence of ovulation.
2) Antral follicular count: Estimated on day 2 of menstrual cycle, follicles of 2- 8 mm size measured and counted in each ovary. Diminished ovarian reserve diagnosed when AFC < 5. Early diagnosis of diminished ovarian reserve helps planning accurate treatment such as IVF, thus reducing time to pregnancy.
3) Endometriotic cysts : Endometriosis causes profound inflammatory response in the pelvis, affecting oocyte quality, sperm transport and function, luteinized unruptured follicle, defective corpus luteum, altered endometrial receptivity and also presence of adhesions results in sub fertility. Presence of unilocular cyst with ground glass appearance of the contents and peripheral blood flow are the USG features of endometriotic cyst.
4) Functional cysts : Thin walled, unilocular, anechoic cyst with minimal to absent blood flow. Functional cysts are unlikely to cause subfertility.
All these ultrasonographic features helps in early diagnosis and management of female infertility.
Role of ultrasound in male infertility
Ultrasound of scrotum evaluates abnormalities within the testis and the peritesticular structures, such as varicocoeles and epididymal abnormalities. Thus aiding in identifying causative factor for male factor infertility.
Transrectal ultrasound enables high-resolution imaging of the prostate, seminal vesicles and vas deferens and is the modality of choice in diagnosing congenital and acquired abnormalities implicated in the cause of obstructive azoospermia (OA).
Penile ultrasound is used to evaluate physical causes of erectile dysfunction, including structural penile abnormalities, problems with arterial inflow and malfunction of the venous occlusive mechanism.