Congenital bilateral absence of the vas deferens: clinical characteristics, biological parameters, cystic fibrosis transmembrane conductance regulator gene mutations, and implications for genetic counseling.

Conclusion(s): A palpable scrotal vas deferens was found in 13% of CBAVD patients. Semen volume of #1.0 mL and semen pH of ,7.0 in CBAVD patients were associated with a higher risk of severe CFTR gene mutations. Patients with CBAVD and renal agenesis should be screened for CFTR gene mutations before assisted reproductive techniques are used. (Fertil Steril t 2000;74:1164 ‐74. ©2000 by American Society for Reproductive Medicine.)