Transrectal ultrasound and partial ejaculatory duct obstruction in male infertility.

Partial ejaculatory duct obstruction, due to either a congenital or an acquired cyst or ejaculatory duct stenosis secondary to calcification, chronic inflammation, can produce a wide spectrum of seminal fluid abnormalities. Sperm density may range from azoospermia to normospermia while ejaculate volume can be low to normal. Sperm motility is consistently diminished (less than 30%). We have treated 2 patients with ejaculatory duct stenosis whose diagnosis was accurately made with transrectal ultrasonography (TRUS). We now suggest that TRUS be used when there is a low semen volume (less than 1.0 cc), or low motility (less than 30%), or oligospermia (less than 20 million sperm/mL), and normal findings on physical examination with normal serum gonadotropin values in the absence of any other explanation.