Should I Be Eating Fish Leading Up To or During Pregnancy
Pregnancy and Eating Fish
Methylmercury is particularly toxic to the nervous system and the developing brain. Exposure during pregnancy and early infancy is therefore of particular concern. Methylmercury is removed from the body naturally but it takes about several months for the levels to fall. Canned tuna seems to have lower levels of methylmercury than fresh tuna due to different species and/or size of fish used.
Pregnant women eating up to two portions/week fish are unlikely to exceed the PTWI for methylmercury provided that one of these portions is not bluefin or albacore tuna. Such species are not likely to be found in canned tuna marketed in the EU. Other top predatory fish such as marlin, pike, swordfish and shark frequently contain high levels of methylmercury. More specific dietary recommendations regarding fish consumption are given by national food safety authorities in Member States.
Dioxins and dioxin-like compounds affect in particular the developing male reproductive system; therefore exposure of the unborn child through the mother during pregnancy is the most critical period. Dioxins and dioxin-like compounds accumulate in the body's fatty tissue and have very long half-lives which means that it takes many years for the body to clear these chemicals. Consequently the level found in the body or "body burden" during pregnancy is not determined by the dioxin intake at that time but by the accumulation of all previous intakes over many years.
Fatty fish such as salmon and herring contain higher levels of contaminants such as dioxins and dioxin-like compounds than lean fish.
Pregnant women eating up to two portions per week of fatty fish such as non-Baltic herring or salmon will not exceed tolerable intake values (i.e. the PTWI) for dioxin and dioxin-like compounds, although other sources of dietary exposure need to be taken into account.
In previous advice issued in March 2004, EFSA recommended that women of childbearing age (in particular, those intending to become pregnant), pregnant and breastfeeding women as well as young children select fish from a wide range of species without giving undue preference to top predatory fish such as swordfish and tuna. This advice is still valid and should be taken into account in selecting the one or two portions of fish a week which are considered to contribute to a healthy diet. Further and more specific dietary advice regarding fish consumption is provided by national food safety authorities in Member States.