Fetal alcohol exposure is a growing public health concern. However, ascertaining its true extent remains challenging as maternal self-reports may lack validity. Increasingly, interest has turned to more objective measures of prenatal alcohol use (PAU) of which one, meconium, is recognized as a valuable tool. This review assesses both the international prevalence of PAU obtained using meconium biomarkers in general maternity populations and, when feasible, the level of agreement between meconium biomarkers and self-reported PAU. A systematic literature search for studies reporting the prevalence of PAU, as determined by meconium biomarker testing, was conducted using multiple electronic databases from 1990 to 2023. Seventeen studies were identified for inclusion and evaluated for methodological quality. Using fatty acid ethyl esters (FAEEs) meconium biomarkers, PAU prevalence varied from 2.4% to 44%. Rates based on EtG (ethyl glucuronide) analysis ranged from 0% to 16.3%, and EtS (ethyl sulfate) analysis from 7.8% to 16.7%. Studies were of moderate quality with high heterogeneity. Prevalence rates based on self-report data ranged from 0% to 46.4%. When reported, none of the reviewed studies identified agreement between meconium-based and self-report-based PAU prevalence rates. Using both self-reports to detect early pregnancy alcohol use, and meconium biomarkers to detect the occurrence of alcohol use later in pregnancy, may provide a more complete picture of PAU prevalence. Furthermore, research is warranted to develop stringent guidance on the ascertainment, storage, analysis, and reporting required in this field.