Cystic fibrosis mutation screening before assisted reproduction

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians, with a reported incidence of one in 2500. In 97-98% of men with CF, a congenital bilateral absence of the vas deferens (CBAVD) blocks the transport of spermatozoa from testicular or epididymal structures to the outer genital tract, resulting in azoospermia. Abnormalities in semen parameters have also been identified in males with CF. Around 10% of obstructive azoospermia is congenital and is due to mutations the CF gene. It is therefore suggested that men who have CBAVD should be considered for CF screening prior to intracytoplasmic sperm injection (ICSI) treatment. Men with azoospermia of unknown origin should also be considered for screening. Couples requesting surgical sperm retrieval/ICSI should therefore be advised and counselled to bear an elevated risk for CF in their offspring. Counselling of these couples is vitally important in order to help them understand and cope with the diagnosis.