Nutritionist Caroline says:

When it comes to comfort food, you can't beat boiled eggs and soldiers, but while you're pregnant you should avoid eating raw or partially cooked eggs. This is to cut the risk of a very unpleasant type of food poisoning caused by salmonella bacteria that some eggs are contaminated with.
Salmonella is unlikely to directly harm your unborn baby, but could make you extremely ill. Thorough heating kills the bacteria, so providing eggs are cooked until both the white and yolk are solid, they're safe to eat.
As well as soft-boiled eggs, foods made with raw eggs, such as homemade sorbet, mousse and mayonnaise should also be avoided unless they are made with pasteurised eggs.