How to eat well: foods that fail the pregnancy test

By Ian Marber, February 13, 2013

Pregnancy is often a time when more attention is paid to the nutritional content of a diet as opposed to its calories.

There are a few foods that are off limits for pregnant women, including soft and blue cheese, pate and raw eggs. The cheeses, together with pate, carry the risk of listeria as they are made using an edible mold. It doesn’t usually present any problems but even in smaller amounts listeria has been linked to a raised risk of miscarriage and still-birth.

Perhaps the most surprising food to be aware of is oily fish, which may seem strange as fish is usually an excellent choice, containing as it does protein together with the beneficial fats.

Some fish contain a compound called polychlorinated biphenyls (PCBs). Babies born to women who have been exposed to PCBs in food had lower birth weight, reduced immune response and learning difficulties.
PCBs can find their way into sea water hence their presence in some fish and it is the fatty ones that are most easily affected, as the PCBs are held in the fat.

Fish — not all of them oily — to steer clear of include salmon, mackerel, trout, sea bream, sea bass, and halibut.

'The most surprising food to avoid is oily fish'

Fresh tuna can also contain mercury, although levels in tinned tuna are generally lower, but the guidelines suggest fresh tuna no more than twice a week and a medium-size can of tuna no more than four times a week.

These suggestions are made on an either/or basis, so it’s not tinned tuna as well as, say, fresh tuna and salmon. By the way, these recommendations apply to smoked salmon too.

Of course, the omega 3 fats that these fish offer play an important role in the development of the baby, so you might consider taking a supplement of high-quality fish oil, perhaps 1,000mg (sounds a lot but its often only one capsule, but see the pack for precise details).

If you have any doubts or for a complete list of foods to avoid in pregnancy then do check with your health professional as well as a nutrition expert.

Ian Marber is one of the UK’s most highly regarded nutrition experts and the author of 11 books.

Last updated: 9:46pm, March 8 2013