Alcohol consumption and fecundability: prospective Danish cohort study.
Level 3 - non-randomized controlled study
Prospective cohort study
PubMed 27581754 · doi:10.1136/bmj.i4262
What was done
A prospective cohort study tracked 6,120 Danish women aged 21–45 years in stable relationships trying to conceive naturally without fertility treatments (2007–2016). Alcohol consumption was self-reported (beer, wine, dessert wine, spirits) and categorized into weekly servings (0, 1–3, 4–7, 8–13, and ≥14). Participants contributed menstrual cycles for up to 12 cycles until pregnancy, initiation of fertility treatment, loss to follow-up, or study completion. Proportional probability regression estimated adjusted fecundability ratios (FRs).
What was found
Overall, 4,210 of 6,120 participants (69%) achieved pregnancy. Median alcohol intake was 2.0 servings per week (IQR 0–3.5). Compared to no alcohol intake, adjusted FRs across weekly intake categories were: - 1–3 servings: 0.97 (95% CI 0.91 to 1.03) - 4–7 servings: 1.01 (95% CI 0.93 to 1.10) - 8–13 servings: 1.01 (95% CI 0.87 to 1.16) - ≥14 servings: 0.82 (95% CI 0.60 to 1.12) Adjusted FRs for exclusive beverage types compared to no intake were 1.05 (95% CI 0.91 to 1.21) for wine (≥3 servings), 0.92 (95% CI 0.65 to 1.29) for beer (≥3 servings), and 0.85 (95% CI 0.61 to 1.17) for spirits (≥2 servings).
Why it matters
These findings suggest that low-to-moderate alcohol intake (fewer than 14 servings per week) does not meaningfully impair natural female fertility.
Limits
Alcohol intake was self-reported and subject to recall or reporting bias. The study did not differentiate regular moderate intake from binge drinking episodes, nor did it track intake specifically during the fertile window. Statistical precision was lower for the highest intake category (≥14 servings/week), resulting in wide confidence intervals.
Cited by
- supports In a study of Danish women, consuming up to 14 alcoholic drinks per week did not affect fertility, with negative effects appearing only above 14 drinks per week, and beer and wine showed equal odds of fertility.