Both fish and shellfish are considered excellent sources of iodine, high quality proteins and omega 3 fatty acids. Fish also contains many different nutrients which are extremely vital for the body. However, almost all quantities of fish contain traces of mercury. When in normal health, ingesting traces of mercury doesn't cause any major health issues but when a woman is pregnant, mercury may cause harm to the development of the unborn baby. Since the baby is still developing, a damage to the nervous system may cause many developmental impediments and may finally cause birth defects or congenital diseases.
According to the FDA, pregnant and nursing mothers may consume fish but should ideally avoid consuming fish such as tile fish, shark, king mackerel and swordfish, all of which contain high levels of mercury. Crab, scallops, cod, shrimps, clams, canned salmon, catfish and pollock contain very low amountsof mercury, hence, they are considered relatively safer to consume.
