Infertility in men
A serious sign of cystic fibrosis observed in patients is infertility. Infertility occurs due to the absence of a sperm canal in men, also known as the congenital bilateral absence of vas deferens (CBAVD). The sperms in the patients never make it into semen, which makes it impossible for sperms to reach the egg and fertilize it. When sperms are not present in semen, it causes thin ejaculation and lowers semen volume.