Why does cystic fibrosis make people infertile?

Cystic fibrosis (CF) is a genetic condition that affects multiple organs, including the lungs, pancreas, and reproductive system. While CF can cause infertility in both men and women, the mechanisms behind this infertility are different.

In men:

- Congenital bilateral absence of the vas deferens (CBAVD): CBAVD is a condition in which the vas deferens, the tubes that transport sperm from the testicles to the penis, are absent or abnormally developed. CBAVD occurs in approximately 95% of men with CF. Without the vas deferens, sperm cannot be ejaculated during sexual intercourse, resulting in male infertility.

- Reduced sperm production: CF can also lead to decreased sperm production in the testicles. This can be caused by several factors, including malnutrition, hormonal imbalances, and inflammation associated with CF. Reduced sperm production can contribute to infertility.

In women:

- Thick cervical mucus: CF can cause the cervical mucus to become thicker and less conducive to sperm penetration. This can make it difficult for sperm to reach the egg for fertilization.

- Altered pH levels in the vagina: CF can also affect the pH balance in the vagina, making it less hospitable for sperm survival.

- Tubal scarring and adhesions: Chronic inflammation associated with CF can lead to scarring and adhesions in the fallopian tubes, which can obstruct the path of the egg or sperm, making it difficult for fertilization to occur.

However, it's important to note that not all individuals with CF will experience infertility. With advances in reproductive medicine, such as assisted reproductive techniques (ART), many people with CF are able to have biological children. It is recommended that individuals with CF discuss their fertility options with healthcare professionals to determine the best course of action for their specific situation.