Fish oil for pregnant women is generally not advised. When the FDA (Food and Drug Administration) sends out a warning that pregnant women should avoid consuming most fish during pregnancy, you know it is a warning not to be ignored.
The reasoning behind the warning is the contamination of mercury in most of the oily fish, which causes mercury poisoning in the growing fetus. There is enough mercury to be told do not eat fish when pregnant; therefore, pregnant women do well to heed this warning to save their babies.
Since eating fish is such a danger the next best way to obtain the vital nutrients derived from fish is by taking high quality health supplements, which guarantee the omega 3 oil to be clean and free of mercury. One of the best fish oil supplements is krill oil, and really, krill is not an actual fish. Krill is a small crustacean that lives in the Antarctic Ocean, where the krill are clean, and mercury free.
In addition to krill oil containing the optimum level of omega 3 fatty acids, it is also high in antioxidants such as astaxanthin, which gives the body a strong immune system. This is helpful because if the optimum levels of omega 3 fatty acids are taken, the need for the optimum levels of antioxidants are also needed. If omega 3 is taken without the increase in antioxidants the omega 3 derived from fish oil can become rancid without antioxidants present to prevent oxidation of the fish oil. Krill oil contains just the right amounts of both omega 3 and antioxidants so this is never an issue.
Krill oil also contains optimum levels of DHA and EPA as well. It is completely safe for pregnant women and perfect for the growing fetus. You cannot say this of "oily fish" like salmon and tuna. Those are more contaminated these days from the presence of mercury in the oceans. This contamination makes it much more risky for pregnant women to consume these fish, which is why most physicians warn against eating it. Krill oil is pure and free of contaminates. Krill oil contains optimum levels of antioxidants and fatty acids, which makes it the most beneficial way for pregnant women to get these vital nutrients.