What We Know about Smoking and a Woman’s Fertility

It is well accepted that smoking is detrimental to ovarian function and female fertility. Smoking has been shown to be toxic to ovarian follicles and eggs, demonstrating a direct correlation between smoking and decline in fertility.

Excessive smoking is linked to the premature onset of diminished ovarian reserve (loss of eggs from the ovary) which leads to a decline in fertility. In fact, several studies report that pregnancy rates from in vitro fertilization (IVF) are reduced by 45-50% for women who smoke! Also, women exposed to second hand smoke had lower chances of success than their non-smoking peers. In cycles where a couple’s embryos are placed into a gestational carrier, pregnancy rates were lower (19% vs. 44%), if the carrier was a smoker.

In this study, all of the embryos came from couples who did not smoke. The conclusion of this study was that smoking adversely affected the vascular blood flow to the uterus, making it less receptive in regard to implantation. To make matters worse, smoking increases the chance of a miscarriage once a woman does become pregnant. This is a compounding negative effect on fertility.

Male Fertility and Smoking

Many couples have assumed that smoking is not detrimental to the male in regard to fertility as long as the sperm count is normal. However, there is evidence that smoking is harmful to sperm and sperm function.

Pregnancy rates for couples undergoing IVF were evaluated for male non-smokers and to smokers. Women who had non-smoking partners had a higher pregnancy rate (32% vs. 18%). It was thought that reason for the lower pregnancy rate was that the sperm from the male partners who smoke had more difficulty fertilizing an egg. However, this study also evaluated the 2 groups where eggs were directly injected with sperm , a procedure called intracytoplasmic sperm injection (ICSI).

Despite utilizing this technique, there was still a difference in the pregnancy rates (38% vs. 22%). ICSI did not increase the pregnancy rate for the women with male smokers. Therefore, the problem with male smokers was not simply that the sperm was unable to penetrate the egg. Male smokers clearly have a lower chance of fathering a pregnancy.

This should be enough evidence to convince a man to discontinue smoking. Never mind the other risks associated with smoking such as lung cancer, bladder cancer, esophagus cancer, throat cancer, larynx cancer (voice box), mouth cancer, stomach cancer, leukemia, heart disease, stroke, artery disease, chronic lung disease, premature aging of the skin, etc…