Recent research suggests that high doses of vitamin supplements may raise the risk of preeclampsia for pregnant women, rather then protecting them from the disease. Preeclampsia, which causes blood pressure to rise so that it becomes dangerous for the mother and child, affects around 25,000 British women every year. The disease was also associated to the production of toxic molecules called free radicals by the placenta. A previous study, at a smaller scale, suggested that the vitamins could block the damage caused by free radicals. The present study found that women should not take large doses of the vitamins because it does not reduce the risk of preeclampsia and even increases the chances of giving birth to babies weighing less than usual. The research funded by the Wellcome Trust looked at 2,400 expectant mothers, who suffered from high blood pressure, clotting disorders, kidney problems or diabetes which were given either the vitamin supplements or a placebo. Preeclampsia was discovered a week earlier at the women who received the vitamins and also, the risk of delivering low birth-weight babies increased by 15%. "Our findings of an increase in low birth weight and an increased need for treatment for preeclampsia suggest that these high doses of vitamins C and E do not work in preventing preeclampsia in this high-risk group," said researcher Lucilla Poston. The conclusion of the study, according to its authors, is that the findings do not support the prophylactic use of vitamin C and vitamin E in women at high risk for preeclampsia.