Smoking, alcohol and coffee consumption and pregnancy loss: a Mendelian randomization investigation

Abstract

Objective: To determine the associations of smoking and alcohol and coffee consumption with pregnancy loss.

Design: Mendelian randomization study.

Setting: The UK Biobank study and FinnGen consortium.

Patients: A total of 60,565 cases with pregnancy loss and 130,687 noncases from UK Biobank and 3,312 cases with pregnancy loss and 64,578 noncases from FinnGen.

Intervention(s): None.

Mains outcome measure: Pregnancy loss.

Result(s): Genetic predisposition to smoking initiation was associated with an increased risk of pregnancy loss in both UK Biobank and FinnGen. The combined odds ratio (OR) was 1.31 (95% confidence interval [CI], 1.25-1.37) for one standard deviation increase in the prevalence of smoking initiation. There were no significant associations of genetically predicted consumption of alcohol (OR, 1.09; 95% CI, 0.93-1.27) or coffee (OR, 0.96; 95% CI, 0.87-1.06) with pregnancy loss.

Conclusion(s): This study on the basis of genetic data suggests the causal potential of the association of smoking but not moderate alcohol and coffee consumption with pregnancy loss.

Keywords: Alcohol; Mendelian randomization; causal inference; coffee; pregnancy loss; smoking.