If you’re a male and you and your partner are having trouble conceiving a child naturally, the blame may lay with one of your habits — smoking.
As a recent WebMD article notes:
What appears to be happening is that smoking-damaged sperm lose much of their ability to fight off destructive oxygen molecules — free radicals — in the seminal fluid. Interestingly, in addition to making spermcells more sensitive to oxidative stress, smoking itself increases the concentration of free radicals in the seminal fluid.
The upshot of this finding is that the damage to sperm appears to be temporary. This means if a male quits smoking, within several months he can, for all intents and purposes, reverse the fertility issues caused by smoking.