Eating chocolate can almost halve a woman's risk of developing pre-eclampsia, a condition which increases blood pressure and reduces the transfer of oxygen and nutrients to the baby and often leads to a premature birth. Pregnant women who nibble at a chocolate at least three times a week could halve their risk of the potentially deadly condition, a study has said. The cause of pre-eclampsia remains a mystery, but for some reason the blood vessels in the placenta do not develop properly. This can drive up a woman's blood pressure and reduce the transfer of oxygen and nutrients to the baby. As a result, babies are often born prematurely and smaller than they should be. In such a case, mums-to-be are advised prolonged bed rest and drugs to lower their blood pressure. This is designed to reduce stress on the baby and give it a chance to thrive. However, this does not cure the condition. It simply gives the baby a chance to grow strong enough to survive birth, which often involves a Caesarean section. In the study conducted by Yale University, researchers quizzed 2,500 women on their dietary habits during pregnancy. Each one was asked what type of food they had eaten, including how many times a week they had enjoyed chocolate-based snacks or drinks. When the researchers analysed the results, they found higher rates of chocolate consumption among the women who did not suffer from pre-eclampsia. Nearly half the women who did not develop high blood pressure - the major symptom of the condition - reported regularly eating chocolate throughout much of their pregnancy. But among those who did develop problems, only 36 percent confessed to regular chocolate treats. "Women who reported regular chocolate consumption of more than three servings a week had a 50 per cent or greater reduced risk of pre-eclampsia," dailymail.co.uk quoted a researcher as saying. "Regular chocolate intake during the first or third trimester was equally protective," the researcher added. Last year, Swedish scientists found heart attack survivors who snacked on chocolate at least twice a week could slash their risk of dying from heart disease by up to 70 percent