Cystic fibrosis in infertility: screening before assisted reproduction

Cystic fibrosis (CF) is the most common autosomal recessive disease in Cauc asians. In 97-98% of men with GF, bilateral congenital absence of the vas d eferens (CBAVD) blocks the transport of spermatozoa resulting in azoospermi a, Abnormalities in sperm parameters have also been identified in males wit h CF. To date, over 800 disease-causing mutations of the CF transmembrane c onductance regulator (CFTR) gene have been identified (also called ABCC7), Current legislation suggests that prior to intracytoplasmic sperm injection (ICSI) treatment, men with CBAVD or unexplained oligozoospermia should be considered for screening. If the male is negative with routine screening th en the female partner is not screened. This is fundamentally wrong because if the female is screened and is found to be CF positive on routine testing , her partner would then need the fullest possible investigation of the CFT R gene. It is ideal to screen both partners in cases of oligozoospermia. Ho wever, if the resources are stretched, then only the female needs to be rou tinely screened because if she is negative, then the couple's residual risk of having a CF or CBAVD child mill be reduced to 1:960. Only when the fema le is found to be a carrier does the male partner need routine screening fo llowed by full testing for known mutations.