There is plenty of evidence to show that eating fish is a healthy way to get your omega-3s during pregnancy. However, for some of you there is no amount of data that is going to change your mind when it comes to your comfort level about the risks of eating fish. And also, you just might not have a taste for it. In that case, it is strongly recommended that you take an omega-3 supplement like fish oil and make sure that it has at least 200 mg of DHA. Whether or not this will increase your blood level is hard to know without testing, so we recommend, if possible, that women who are pregnant or looking to become pregnant take a prenatal DHA test before they get pregnant and then again during the first, second and third trimesters.
Here is a helpful blog post.
Here is a helpful video.