The latest research, published in the journal Epidemiology, found that women who ate chocolate at least five times a week were up to 40% less likely to get the condition than women who ate it less than once a week.
Scientists at Yale University in the US tracked 2,291 pregnant women. They took blood samples to measure levels of theobromine, a chemical that occurs naturally in chocolate and has been linked with other health benefits, such as curing persistent coughs.
Those with the highest levels of theobromine from eating chocolate were least likely to suffer pre-eclampsia.
The actual cause of pre-eclampsia is still not known, but when it does occur blood vessels in the placenta do not develop properly, driving up a woman’s blood pressure and reducing the transfer of oxygen and nutrients to the baby.
As a result, babies are often born prematurely and many die.
Currently, the only treatment involves prolonged bed rest and drugs to lower the mother’s blood pressure. This is designed to reduce stress on the baby and give it a chance to thrive.
However, while this gives the baby a chance to grow strong enough to survive birth it is by no means a cure.