While the devastating effects of parental alcohol use on children’s health are well known, the specific impact of childbirth on parental alcohol consumption has rarely been examined in the general population. We sought to examine patterns of alcohol use associated with childbirth. Data were drawn from the US National Epidemiologic Survey on Alcohol and Related Conditions. We compared successively the characteristics of alcohol use among females living with a child under 1 year with (i) those of females not living with children under 1 year and (ii) those of females living with an older child. Mean daily ethanol intake was lower among females living with a child under 1 than among females either not living with children under 1 year (p < 0.001) or living with an older child (p < 0.01). Moreover, low-to-mild drinking frequencies fell among females living with a child under 1, compared with females either not living with children under 1 year (adjusted odds ratio (AOR) = 0.56; 95% CI [0.40, 0.80] for at least once a month and AOR = 0.40; 95% CI [0.27, 0.58] for less than once a month) or living with an older child (AOR = 0.52; 95% CI [0.36, 0.75] for at least once a month and AOR = 0.66, 95% CI [0.46, 0.94] for less than a month). No significant difference was found for males. Our study suggests that childbirth, as opposed to motherhood per se, reduces several (though not all) dimensions of alcohol consumption in females, but not in males.