Smoking
Cigarette smoke contains several thousand components including nicotine, polycyclic aromatic hydrocarbons and cadmium, with diverse toxic effects. Cigarette smoking is associated with lower fertility rates, adverse reproductive outcomes and a higher risk of IVF failure. Exposure to cigarette smoke, active or passive, impairs every stage of the reproductive process in women, such as hormone production, embryonic development and implantation and placental formation. This appears to be mainly due to the reduction in blood flow in the uterus. In men, deterioration of semen quality appeared in direct proportion to the quantity of cigarettes smoked. This is due to the increased susceptibility of sperm to oxidative damage, possibly due to cadmium and the myriad of other harmful substances present in cigarette smoke.
There is also a higher incidence of erectile dysfunction in men who smoke.
Further, smoking is a major cause of preterm births and low birth weight babies. It is also associated with an increase in spontaneous abortions.
Prospective parents should stop smoking pre-conceptually.
Women who smoke are ineligible for publicly funded treatment (women need to have been non-smokers for at least 3 months)