By Joseph A. Hill, III, M.D., Board-Certified in Reproductive Endocrinology and Infertility
Potentially modifiable lifestyle factors can affect your ability to have a baby. These factors include age, smoking, caffeine consumption, alcohol consumption, weight, diet and exposure to environmental pollutants. We have previously reviewed the impact of aging on fertility and in this installment we review the adverse effects of smoking and infertility.
SMOKING
Smoking either by men or women can adversely affect the ability to conceive and deliver a healthy baby. In men, smoking can negatively affect sperm production, motility and the way they look (morphology). Smoking can also cause DNA damage leading to chromosome abnormal sperm. Men in couples having In Vitro Fertilization (IVF) and Intra-Cytoplasmic Sperm Injection (ICSI) have decreased success rates if they smoke compared to couples having these fertility procedures in which the man does not smoke.
In women, cigarette smoking can alter hormone levels critical for successful pregnancy. Both active and passive (second-hand) smoking can hinder egg production, fertilization, and implantation. Smoking is also associated with an increased chance of miscarriage. Smoking can reduce your chances for pregnancy even with IVF. Women having IVF who smoke do not respond to ovulation induction medications as well as non-smokers. In smokers where eggs are obtained, their ability to fertilize is decreased and if they are able to fertilize, embryo quality and implantation potential are decreased compared to that in non-smokers. Twice as many IVF cycles are needed to achieve pregnancy for smokers compared with non-smokers. In one large study of 8457 women having their first IVF cycle there was a 28% decrease in having a child in smokers compared with those who did not smoke. Studies from fertility centers across the country have reported that if a woman ever smoked in her lifetime her risk of not becoming pregnant from IVF more than doubled and the risk increased with each year of smoking. Smokers who are pregnant following IVF also have twice the risk of early pregnancy loss compared to non-smokers.