Pregnant women tend to avoid fish altogether during their pregnancy because for years it was considered unsafe. In many ways, it still is. Much of the fish that is caught commercially contains mercury. Mercury can have seriously negative side effects on your baby’s development, so avoiding it during your pregnancy makes sense. If you eat a fish that contains mercury, it takes an entire year to flush it out, pregnant or not. For that reason, your baby will be stuck with the dangerous chemical for the duration of his or her development, even if you ate the fish a few months before you conceived.

However, some fish contains less mercury than others. A recent study shows that women who avoid larger fish, such as shark and tilefish, won’t consume enough mercury to harm their baby. While the mercury levels in fish are relatively low right now, these fish are simply so massive that they contain more than most.

On the other hand, eating fish with low levels of mercury is safe, and the benefits actually outweigh the risks. Fish has high levels of Omega 3 fatty acids, which have proven to be extremely beneficial during pregnancy. Farm-grown tilapia is cited as one of the safest fish to consume during pregnancy because the mercury levels are low and the Omega 3 fatty acid levels are high. If possible, you should actually go out of your way to consume tilapia during your pregnancy. Omega 3 fatty acids have been shown to prevent preterm labor and promote brain development in fetuses.

Despite what you may have heard for the years leading up to your pregnancy, you don’t have to completely avoid fish for nine months. The mercury levels are low, so occasional consumption will benefit your baby more than it will harm him or her. Of course, you shouldn’t eat a serving of fish at every meal. Though the mercury level is low in one serving, it is three times as high in three servings. Tilapia in particular is the safest fish to eat, but other small fish such as single servings of salmon or canned tuna are safe as well. Also, farm-grown fish are always a better choice.

If you’re still nervous about eating fish during your pregnancy but would like to reap the benefits of Omega 3 fatty acids, speak with your health care provider about taking supplements that contain them.

Source: Arienne Bloomingdale et al: A Qualitative Study Of Fish Consumption During Pregnancy. American Society for Nutrition Volume 92 Issue 5 pp. 1234-1240 November 2010