Assisted by Naturopathic Medical Graduates Emily Rotella, Maria Wong, Natalia Ytsma, and Sara Mohammed
Butting out the Spark before it has a Chance to Ignite
Cigarette smoke can alter one’s ability to not only conceive but to also carry a fetus to term. Smoking has been shown to have significant detrimental effects on many of the organs in the body including the reproductive system. It has the ability to affect fertility through various modes of exposure; first hand, second hand and in utero. Smoking can delay a couple’s ability to conceive naturally for more than a year.1 A study published by Reproductive Endocrinology looked into the fertility of all couples that were expected to deliver within a 9-month period to determine if first hand and/or second hand smoke delayed their ability to conceive.2 The study showed the largest decline in fertility among women who smoked and were exposed to second hand smoke. It also found that male smoking was independently linked to infertility, even if they did not expose their partners to second hand smoke. They found that women who smoked had a decreased ability to conceive both naturally, by twenty percent, and through IVF, by thirty three percent.2 However, other investigations have noted up to a sixty percent increase in infertility among women who smoke.3 The study also found little evidence to note a difference in fertility between those who smoked 1 cigarette per day and those who smoked up to 14, illustrating that all exposure has negative consequences to fertility.2
Smoking has been shown to affect fertility through a decrease in ovarian reserve and antimullerian hormone (AMH) and an increase in irregular menses and ovarian insufficiency.1 AMH is only produced in small, growing ovarian follicles and thus blood levels can be an indicator of the number of developing follicles. This hormonal decrease may provide insight into the reasons why female smokers have decreased likelihoods of undergoing successful IVF treatment.4 Decreases in AMH are also seen in women approached menopause and studies have found that women who smoke tend to experience menopause 1-1.5 years earlier.3 Smoking not only impacts one’s ability to conceive but also impacts outcomes of pregnancy. It is associated with an increased risk of miscarriage, increases in bacterial vaginosis (which is independently linked with an increased miscarriage risk), preterm labour and delivery of infants with low-birth weights.3
Impact on Males
In males, cigarette smoking can result in several alterations in the functionality of reproductive cells and increase in the number of abnormal cells. It has been shown to decrease seminal sperm counts, increase spermatozoal DNA fragmentation and decrease sperm motility.2 Not only can current smoking in males affect fertility, but it has also been demonstrated that in utero exposure to maternal smoking can have significant long-term implications on male fertility.5 Men who were exposed in utero demonstrated a reduction in sperm concentration, total sperm count, motility, normal morphology, and testis size.5 Moreover, these alterations in semen quantity, quality and testicular size were not noted in those exposed in childhood but not in utero.5 Thus it is of significant importance to advise female smokers that it may not only have a detrimental effect on their personal fertility but also a generational effect on the fertility of their sons.
The Sooner you Quit the Better
There is hope for the fertility of smokers through cessation. It has been demonstrated that the adverse effects of smoking on female fertility is largely reversible. This is notable by comparing the conception rates of ex-smokers with never smokers, which is fundamentally comparable and also through noting that IVF rates are not reduced in ex-smokers.2 However, there is a permanent detrimental effect of cigarette smoking on ovarian follicular depletion as seen via the reduction of AMH.2 Improvements in male fertility are also seen post smoking cessation. Semen analysis of men 3 months after quitting smoking showed an improvement in sperm concentration and sperm vitality. However no changes were observed in sperm morphology and DNA fragmentation.6 Therefore, it would be most beneficial to educate both men and women about the harmful effects of cigarette smoke on their fertility both in the short term and long term.
Chris Habib, BSc, ND, is an evidence-based naturopathic doctor with over a decade of education in healthcare. He is the clinic director of the multi-disciplinary clinic Mahaya Forest Hill and the Sales Director of the herbal company Perfect Herbs. Chris is also involved in teaching, research, and publishing. He is a clinic supervisor at the naturopathic college and teaches the board exam preparation course. He is also Associate Editor for the Journal of Restorative Medicine and Naturopathic Currents Magazine.
References:
- Alvarez, S. Do some Addictions Interfere with Fertility? Fertility and Sterility. 2015;103(1):22-26.
- Hull, M. North, K., Taylor, H. et al. Delayed conception and active and passive smoking. Reproductive Endocrinology. 2000;74(4):725-733.
- Augood, C. Duckitt, K. and Templeton, A. Smoking and Female Infertility. Human Reproduction. 1998: 13(6);1532-1539.
- Freour, T. Masson, D. Mirallie, S. et al. Active smoking compromises IVF outcome and affects ovarian reserve. Reproductive Biomedicine Online. 2008:16;96-102.
- Jensen, T. Jorgensen, N. Punab, M. et al. Association of In Utero Exposure to Maternal Smoking with Reduced Semen Quality and Testis Size in Adulthood: A Cross-Sectional Study of 1,779 Young Men from the General Population in 5 European Countries. American Journal of Epidemiology. 2004:159(1);49-58.
- Santos, E. Lopez-Costa, S. and Chenlo, P. Impact of Spontaneous smoking Cessation on Sperm Quality: Case report. Andrologia. 2001:43;43.