Intake of wine, beer and spirits and waiting time to pregnancy

Background: A high intake of alcohol may prolong waiting time to pregnancy, whereas a moderate intake may have no or perhaps even a positive effect on fecundity. In previous studies on fecundity, different types of beverages have not been taken into consideration, although moderate wine drinkers appear to have fewer strokes, lung and digestive tract cancers, and overall mortality than both abstainers and moderate drinkers of beer or spirits. We examined the association between different types of alcoholic beverages and waiting time to pregnancy. Methods: Self-reported data were used for 29 844 pregnant women, recruited to the Danish National Birth Cohort in 1997-2000. Main outcome measures were odds ratios for a prolonged waiting time to pregnancy according to consumption of wine, beer and spirits. Results: All levels of wine intake compared with non-wine drinking or with consumption of beer or spirits had subfecundity odds ratios between 0.7 and 0.9. No association was seen regarding beer drinking, while the association with spirits was J-shaped. Conclusion: Our findings suggest that wine drinkers have slightly shorter waiting times to pregnancy than both non-wine drinkers and consumers of other alcoholic beverages. Whether this is an effect of wine itself or the characteristics of the wine drinker is not known.