Pre-eclampsia is a dangerous condition that occurs in some pregnant women and causes unhealthy rise of blood pressure and represents one of the most common causes of deaths and still born babies. During this condition, toxic molecules called free radicals are released by the placenta and may cause eclampsia, which is very serious for the mother and baby.

Earlier studies pointed out that pregnant women who were taking high doses of vitamin C and E should be well protected from preeclampsia because these vitamins are said to release antioxidants whose function was to protect. However, the latest study suggests just the opposite and warns that large doses of these vitamins could be contributing to preeclampsia to the women who are at risk of the condition.

These statements were proved by studying 2,400 mothers-to-be who suffered from high blood pressure, kidney problems, clotting disorders or diabetes and who were tested by giving extra vitamin supplements or a placebo.
It was showed that women who received the vitamins one week before were at increased risk of giving birth to babies with low birth weight.

The effects of folic acid were not studied and they should be taken as previously recommended before the conception and early in the pregnancy to reduce the risks of spina bifida, a birth defect resulting from the incorrect development of the spinal cord.