How quickly you get symptoms after eating an infected food depends on the bacteria involved. Some forms of food poisoning can happen within a couple of hours others may take a couple of days. Prawns, and other seafood, can be particularly potent sources of bacteria, which may not be destroyed unless the food is very well cooked. Any bad taste or smell may be masked by strong spices or other flavouring. Many women worry about the effect of food poisoning on their baby. After all, you feel so awful yourself, how can the baby not be affected?! However, although it is true that pregnancy may increase your risk of getting food poisoning, these illnesses rarely cause direct harm to unborn babies. This is because the placenta is an effective barrier against most bacteria – these bugs being generally too big to pass through the placental ‘filter’. (The most important exception to this is the small listeria bacterium – the causative organism of ‘listeriosis’. This particular bacterium lurks in the soil, on vegetation, and in some foods – in particular, soft and blue-veined cheese and some convenience foods. Listeriosis may cause flu-like symptoms including fever and headache and, sometimes, diarrhoea and vomiting. If are worried that you may have caught listeriosis, see your GP urgently.) Although your baby may be temporarily disturbed should you become dry and feverish as a result of food poisoning, he or she is very, very unlikely to be really harmed. The amniotic fluid in which he floats will reduce the direct effect of a high temperature. Your body’s stores of energy and nutrients will feed him whilst you are not eating (that’s why pregnant women get plumper!), and your increased plasma volume (the watery part of blood) will help keep you and your baby hydrated.