Of interest is the finding that higher household income (>$100,000 AUD per year) not only increased the likelihood of drinking throughout pregnancy but also predicted drinking at binge levels before the woman was aware of her pregnancy. Higher income has been noted by other studies as a predictor for ‘light social drinking’ [35], but not for binge drinking. Our finding may reflect the detailed information collected in this study about maternal drinking, which not only captured regular drinking patterns but also occasional binge drinking defined as having five or more standard drinks as a once off episode (≥50 g AA). When women are asked about their regular drinking patterns, they may not consider reporting a one-off occasion of binge drinking without being prompted for this information.
