CFTR and Azoospermia: On the contrary, obstructive azoospermia is suggested from a combination of normal testicular volumes, reduced semen volume and alterations in pH, normal reproductive hormone levels, normal testicular patter with dilated epididymes or absence/obstruction of vas deferens at scrotal colour Doppler ultrasound, abnormal results at TRUS (for example, ejaculatory duct obstruction, absence of seminal vesicles), and known CFTR gene mutation.