How Are Men Affected by Cystic Fibrosis?

Males account for slightly more than 50 percent of all cases of cystic fibrosis (CF) but generally have better outcomes than females until about age 20. After that, men and women experience roughly equal outcomes for long-term survival. Still, males with CF tend to live an average of 2 years longer than females.^1,2

The differences in men’s and women’s life expectancy are not fully understood. Some researchers believe the sex hormones play a role in how the cilia in the respiratory system work and in sodium transport across cell membranes. Doctors do know that males tend to acquire more serious lung infections later in life than females.

How does cystic fibrosis impact males versus females?

Cystic fibrosis does seem to impact men and boys slightly differently than it impacts women and girls.

For instance, males are more likely than females to experience pancreatic insufficiency, a common symptom of CF in which the pancreas does not supply enough enzymes to the intestines to digest food properly. One study found that 87 percent of men with CF showed signs of pancreatic insufficiency compared to 84 percent of women.²

Meanwhile, males become infected with the bacteria Burkholderia cepacia (B. cepacia) at higher rates than females (8.7 percent vs. 7.8 percent). Men tend to have fewer acute exacerbations per year compared to women and develop CF-related diabetes at lower rates.

Infertility in men with cystic fibrosis

Ninety-eight percent of all men with CF are infertile.^3,4 The CFTR genetic mutation that causes CF also results in a blocked or missing vas deferens. This defect prevents sperm from mixing with semen, so most males with CF ejaculate without sperm. This does not impact sexual desire or performance.

Males with CF may also experience other reproductive issues. They are four times more likely to develop fluid accumulation around the testes (hydrocele), which can decrease how well the testes work. There is also a 15-fold increase in having an undescended testicle. Some men produce a lower volume of sperm or no mature sperm.⁵

Assistive reproduction for men with cystic fibrosis

Men with CF who want to father children may be able to have their sperm extracted and used to fertilize an egg. There are different procedures used to take sperm. There are performed under anesthesia and include:

• Microepididymal sperm aspiration (MESA), in which a small cut is made in the scrotum and sperm is gathered
• Percutaneous epididymal sperm aspiration (PESA), an alternative to MESA in which a needle is inserted into the scrotum to collect sperm
• Testicular sperm extraction (TESE), in which a small sliver of the interior of the testicle is removed to collect sperm. This is generally only performed if MESA or PESA did not work.^4,6

After their sperm are collected, it can be used for in vitro fertilization (IVF) if the man wishes to father children.