If it gets any worse, there is an obvious risk for an adverse effect to be perceived from the person. A previous study showed no harm to pregnant people who drank more heavily from alcohol in their twenties or thirties. One study has shown that drinking from three bottles of wine after pregnancy caused a decrease in risk compared to alcohol alone when the pregnancy was prolonged, and in many studies that have looked at women in their twenties and thirties (e. , Janssen et al. , 2006; Shanks-Chun and van Oostman, 2008; Shanks et al. , 2009; Chokri and Janssen, 2010; Schulte et al. , 2002; Boudreaux et al. , 2007), but they're not conclusive, and they might be just the type of study that's more stringent with its results. But it's worth noting that, because of the large number of studies that included pregnant women, there's no guarantee that drinking alcohol would only be harmful, that the effect is temporary, and that this is just a generalization. The main question from researchers is when—and whether—they'll need to adjust their methods, especially to women in their thirties, 20s and beyond. After all, the risk of an adverse effect from drinking of any kind is usually small.