Oxidative stress has been proposed as a key factor involved in the development of
pre-eclampsia. Supplementing women with
antioxidants during pregnancy may help to counteract oxidative stress and thereby prevent or delay the onset of
pre-eclampsia.
OBJECTIVES: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2007), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 3), MEDLINE (1950 to October 2007) and Current Contents (1998 to August 2004).
SELECTION CRITERIA: DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and trial quality and extracted data.
MAIN RESULTS: Ten trials, involving 6533 women, were included in this review, five trials were rated high quality. For the majority of trials, the
antioxidant assessed was combined
vitamin C and E therapy. There was no significant difference between
antioxidant and control groups for the relative risk (RR) of
pre-eclampsia (RR 0.73, 95% confidence intervals (CI) 0.51 to 1.06; nine trials, 5446 women) or any other primary outcome: severe
pre-eclampsia (RR 1.25, 95% CI 0.89 to 1.76; two trials, 2495 women),
preterm birth (before 37 weeks) (RR 1.10, 95% CI 0.99 to 1.22; five trials, 5198 women), small-for-gestational-age infants (RR 0.83, 95% CI 0.62 to 1.11; five trials, 5271 babies) or any baby death (RR 1.12, 95% CI 0.81 to 1.53; four trials, 5144 babies). Women allocated
antioxidants were more likely to self-report
abdominal pain late in pregnancy (RR 1.61, 95% CI 1.11 to 2.34; one trial, 1745 women), require
antihypertensive therapy (RR 1.77, 95% CI 1.22 to 2.57; two trials, 4272 women) and require an antenatal hospital admission for
hypertension (RR 1.54, 95% CI 1.00 to 2.39; one trial, 1877 women). However, for the latter two outcomes, this was not clearly reflected in an increase in any other hypertensive complications.
AUTHORS' CONCLUSIONS: