By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

Hypertension of pregnancy, or pre-eclampsia, is one of the commonest causes of death during pregnancy, and also results in many premature deliveries. The cause is unknown, but a popular theory is that reduced blood flow to the placenta may be the culprit, which leads to the release of substances such as free radicals that damage the endothelium (the inner lining) of the maternal blood vessels. Free radicals are harmful chemicals whose formation may be prevented by antioxidants such as vitamins C and E.

A study from England identified 283 pregnant women who were thought to be at high risk of pre-eclampsia, either because an ultrasound test indicated reduced placental blood flow, or because they had had pre-eclampsia during a previous pregnancy. At 16 to 22 weeks of pregnancy, they were randomly allocated to receive either 1000 mgs of vitamin C plus 400 IU of vitamin E, or inert placebo tablets. The main result was that pre-eclampsia occurred less frequently (8% versus 17%) in the women who took the vitamins than in the control group. Blood tests that reflected the extent of damage to the endothelium also improved in the group taking vitamins.

Doctor’s comments

Taking extra amounts of vitamins C and E, both of which are thought to be quite safe during pregnancy, cut the chances of getting pre-eclampsia in half. This is a potentially exciting development in the prevention of hypertension during pregnancy, but larger trials will be needed to confirm the finding.

Where it was published