Male infertility affects about 98% of men with cystic fibrosis (CF). However, that does not mean they cannot father biological children. Infertility caused by cystic fibrosis is the result of a missing piece of the male reproductive system.
The sperm canal, or vas deferens, is missing in most men with CF. This is also known as congenital bilateral absence of the vas deferens, or CBAVD. The sperm develop in the testicles, but since they have no transport to the semen, they cannot be ejaculated out to reach and fertilize an egg during intercourse. Lack of sperm in the ejaculate also contributes to a thinner ejaculate and lower semen volume for men with CF.
It is also important to note that even though most men with CF are infertile, this is not the case for all of them. Some male CF patients do have sperm present in their ejaculate.
