Fish Consumption in Pregnancy – The Question of Tinned Tuna
As we all know fish is the main source of omega-3 fatty acids which are important for brain development and function in human beings. We know for example, that omega-3 fatty acids are taken up into the developing brain especially during the first trimester of pregnancy and there have been a number of studies which have shown maternal fish consumption in pregnancy has been associated with improved neurodevelopment in infants. There is therefore no doubt that consumption of fish has a positive benefit in the development of the fetal brain.
The down-side however, is the presence of mercury in all fish to a varying degree. It has been shown that mercury is associated with fetal brain damage in high quantities. It has also been shown the developing fetal brain is particularly sensitive to the toxic effects of mercury. It therefore makes sense to try and confine fish consumption to those fish that have relatively high levels of omega-3 fatty acids and low levels of mercury.
The US Food and Drug Administration suggest that pregnant women have two to three serves of fish a week. They recommend that you avoid eating flake, sword fish, orange roughie or tuna – both tinned tuna and fresh tuna have about the same level of mercury. Try and eat those species of fish which are known to have low levels of mercury. This includes anchovies, herring, mackerel, salmon both fresh and tinned, sardines, trout and whiting. In general, these fish have about one tenth the level of mercury of the high risk fish such as flake. It is also recommended that if you are unable to eat fish for any reason that you take omega-3 fatty acids via the appropriate vitamin supplement that will give you 200 – 300mg a day.
Dr Len Kliman is one of Melbourne’s most experienced and respected Obstetricians and Gynaecologists. With over thirty years of experience, he has delivered more than 20,000 babies and still counting!
In 2017, Dr Kliman was awarded an Order of Australia for his services to obstetrics and gynaecology.