Drinking, Smoking, and Pregnancy Preparation

Smoking reduces ovarian reserve and makes ovulation cycles irregular. In men, it lowers sperm motility and causes DNA damage. Smoking during pregnancy markedly increases the risk of premature birth, low birth weight, and miscarriage.

Alcohol can affect fetal neural development even in early pregnancy (just after conception), so completely quitting from the planning stage is safest. The current official position of the medical community is that no "safe amount of alcohol" exists.

Korean medicine likewise holds that alcohol creates damp-heat (seup-yeol) that clouds the uterine environment, while tobacco blocks the circulation of qi and blood, hindering implantation.