Impact of Smoking and Alcohol on Reproductive Health

Smoking and alcohol consumption remain significant modifiable risk factors affecting both male and female reproductive function. Tobacco smoke introduces numerous toxins that can impair gametogenesis, disrupt hormonal regulation and promote oxidative stress within ovarian and testicular tissues. In women, smoking has been linked to diminished ovarian reserve, altered steroidogenesis, irregular menstrual cycles and reduced endometrial receptivity, all of which may culminate in longer time to conception and higher rates of infertility. In men, smoking is associated with poorer semen parameters, DNA damage in spermatozoa and increased risk of pregnancy loss. Alcohol exerts a dose-dependent effect on fecundability, with heavier intake correlated with lower probability of conception per menstrual cycle. Mechanistically, alcohol can perturb the hypothalamic–pituitary–gonadal axis, impair follicular maturation and compromise sperm quality. Combined exposure to tobacco and alcohol appears to exacerbate reproductive dysfunction via synergistic oxidative stress and epigenetic modifications that may carry implications for offspring health. Public health strategies targeting cessation of smoking and moderation of alcohol intake before and during the preconception period are therefore essential to improve fertility outcomes and reduce global burden of infertility.

Research from Nature Portfolio

Recent analyses have synthesised observational data to clarify the relationship between alcohol intake and female fertility. A comprehensive dose-response meta-analysis of nearly 100 000 women demonstrated a linear decrease in fecundability with every increment of 12.5 g ethanol per day, indicating that even light drinking may modestly reduce the probability of conception in a given cycle. The study highlighted that moderate-to-heavy consumption is associated with a more pronounced decline in fecundability, whereas the impact of specific beverage types varied minimally. These findings underscore a quantitative link between alcohol dose and time to pregnancy, providing a robust basis for clinical recommendations on alcohol moderation for women planning conception.

Impact of Smoking and Alcohol on Reproductive Health publication trend

The graph below shows the total number of articles in impact of smoking and alcohol on reproductive health across all publications each year (not limited to Nature Index journals).

Technical terms

Fecundability: The probability of achieving pregnancy in one menstrual cycle.

Dose-response meta-analysis: A statistical technique that quantifies how varying levels of an exposure relate to changes in an outcome.

Mendelian randomisation: A genetic epidemiology method using inherited genetic variants as proxies to infer causal effects of modifiable exposures on health outcomes.

Ovarian reserve: The pool of available oocytes in a woman’s ovaries, reflecting her reproductive potential.

Oxidative stress: An imbalance between pro-oxidant molecules and antioxidant defences, leading to cellular damage.

References

1. Cardiovascular disease risk factors and infertility: multivariable analyses and one-sample Mendelian randomization analyses in the Trøndelag Health Study. Human Reproduction Open (2024).
2. Associations between health behaviours, fertility and reproductive outcomes: triangulation of evidence in the Norwegian Mother, Father and Child Cohort Study (MoBa). BMC Medicine (2023).
3. Female alcohol consumption and fecundability: a systematic review and dose-response meta-analysis. Scientific Reports (2017).