what's the harm fertility
The same things that harm your fertility can do a number on your husband's reproductive health too. Cigarettes, alcohol, a poor diet -- any of these can contribute to lower sperm production or motility (ability to swim). Studies have also traced chromosomal damage in sperm to cigarette smoke and heavy alcohol intake.
A growing body of research has linked alcohol consumption with a decreased ability to get pregnant (it can also harm a developing fetus). Alcohol alters estrogen levels, which may interfere with egg implantation, although pouring an occasional glass of Pinot with your dinner is unlikely to harm fertility.