?When a couple is trying to have a baby, inability to conceive can be due to either partner's infertility. Male infertility--the inability of the man's sperm to fertilize eggs--is mainly responsible for inability to conceive in about 33 percent of cases and is partially responsible for infertility in another 33 percent of cases, according to the Mayo Clinic. If a man is infertile, he fails to produce enough sperm or fails to produce fertile sperm so that his sperm are unable to fertilize the woman's egg. There are several causes for male infertility.
* Genetic problems. Genetic defects can cause a man's sperm to be infertile. Some genetic defects cause the man not to produce enough sperm or to produce sterile sperm. Diseases caused by genetic abnormalities such as cystic fibrosis can also contribute to male infertility.
* Physical problems. In some cases, the man's testicles aren't descended far enough or the portion of the testicle that produces sperm is blocked so that sperm can't easily ejaculate. Infections can also contribute to infertility.
* Exposure to toxins. Pesticides and other poisons can kill sperm or render them sterile. Men who are undergoing cancer treatments may temporarily become infertile because chemotherapy drugs and radiation both kill sperm. Radiation near the testicles is especially problematic, and if the man has had one or both testicles removed due to cancer, he won't be fertile.
* Unhealthy habits. Obesity, malnutrition and overuse of alcohol and drugs can make a man's sperm less fertile or completely infertile. Smoking can also contribute to male infertility.
If a couple can't get pregnant, the man might want to get tested for infertility at an infertility clinic. After doctors determine that the man is infertile, they can develop a treatment plan. If infertility is a result of unhealthy lifestyle choices, the man may be encouraged to stop smoking or drinking or to lose weight. He also may have to take vitamin supplements, particularly vitamin B12 and zinc, to stimulate production of fertile sperm. In some cases, men may need to have surgery to correct physical problems that are causing infertility.
