A great many cravings seem to come out of the blue, and may come with an overwhelming fierceness.
The extreme hormonal changes that you go through during pregnancy have a powerful impact on your sense of smell and taste buds. Some sceptical experts aren't convinced that food cravings can be put down to just hormones, but they do believe that certain cravings may be significant. Take for example the craving for ice and off-the-wall substances such as laundry starch and cigarette butts have been linked to iron deficiency, even though not one of these items contain any significant quantities of iron.
Alternative medicine practitioners believe that a chocolate craving may be triggered by a vitamin B deficiency. Some mums-to-be may require more essential fatty acids. When flax seed oil is added to their diet, their food cravings disappear. A craving for red meat indicates the body's cry for protein. And the mum-to-be who has an insatiable appetite for fresh peaches may have a need for beta-carotene.
Still, the link between what your body needs and what you crave seems weak. If it were strong we would all be craving broccoli and fresh fruit, rather than the chocolate and crisps most of us long for now and then.