Among women pregnant for the first time, antioxidant vitamins supplementation does not appear to curb the risk of developing preeclampsia - that is, pregnancy-related high blood pressure and kidney impairment -and other serious complications, report doctors from Australia.

“We were disappointed by the findings of our study, as antioxidant vitamin therapy appeared to be a promising preventive strategy,” Dr. Alice R. Rumbold from Women’s and Children’s Hospital in North Adelaide told Reuters Health. “However our study, the largest research trial completed to date investigating vitamin C and E supplements for women in their first on-going pregnancy, did not confirm this.”

In the trial, reported in this week’s New England Journal of Medicine, 1,877 women with a first pregnancy were randomly assigned to daily supplementation with 1000 milligrams of vitamin C and 400 IU of vitamin E, or to placebo. Women began taking the tablets from between 14 and 22 weeks of pregnancy until delivery.

According to the team, there were no significant differences between the vitamin group and placebo group in the risk of preeclampsia, death or a serious outcome for the baby, or having a very small infant.

Also, antioxidant vitamins were associated with an increase in the risk of the mother developing high blood pressure and having to take medications to bring it down.

“Our results do not support routine supplementation with vitamins C and E during pregnancy for women in their first pregnancy,” Dr. Rumbold told Reuters Health.

The authors of a related editorial conclude that “until more data are available, given the scant evidence of benefit and the potential harm, supplemental antioxidant therapy ... should not be prescribed as part of routine practice.”

Drs. Arun Jeyabalan and Steve N. Caritis from the University of Pittsburgh note in their commentary that there could be subgroups of women who may benefit from antioxidant therapy in pregnancy and, hopefully, several large international trials of antioxidant therapy in pregnancy now in progress will tell.

SOURCE: New England Journal of Medicine, April 27, 2006.