Congenital bilateral absence of the vas deferens (CBAVD): do genetic disorders modify assisted reproductive technologies outcomes?

OBJECTIVES: To evaluate the impact of common Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene mutations, 5T polymorphism and presence of severe Cystic Fibrosis (CF) on fertility outcomes with Assisted Reproductive Techniques (ART) in patients presenting Congenital Bilateral Absence of Vas Deferens (CBAVD). METHODS: A comparative observational cohort study was performed from 2002 to 2018 with 51 patients with diagnosis of CBAVD. Presence of CFTR mutations and 5T, CF, pregnancy and newborn rates were analyzed. RESULTS: 80.4% percent had some mutation of CFTR gene being Delta F508 the most common (51%). The most frequently described genotype was the 7T/9T (31.4%) with the presence of 5T polymorphism in up to 25.5% of cases. Global newborn rates were 34% in the group using partner spermatozoa. When comparing 5T presence, we observed a decrease in newborn rates when carrying this mutation, without obtaining statistical significance (newborn rate: 5T/non-5T: 7.1/28%, p 0.45). No differences were found when comparing presence of severe CF, common CFTR gene mutations and ICSI-related parameters. CONCLUSION: The analysis of the presence of 5T polymporphism in CBAVD patients may add information when predicting the outcome of assisted reproductive techniques.