Background Previous research exists to suggest vitamin C and E supplementation reduces the incidence of PROM (pre-labour rupture of the membranes) and preterm PROM (PPROM), conditions that precede up to a third of premature births.1 Antioxidants have a theoretical membrane protective effect against reactive oxygen species and collagen degradation.2

Aim To assess whether supplementation with vitamin C and E influences occurrence of PROM and PPROM in high risk pregnancy.

Methods Data were analysed from the VIP trial (1000 mg vitamin C and 400 IU E vs Placebo in women at risk for pre-eclampsia) involving high risk women between 14+0 and 21+6 weeks gestation, across 25 UK centres. Demographics and pregnancy outcome were recorded,3 including time of rupture of membranes prior to labour and gestational age at delivery.

Results Of 2411 participants, 154 (6.4%) women experienced PROM (n=113) or PPROM (n=41). The risk ratio for antioxidant supplementation in these pregnancies was 0.95 (95% CI 0.66 to 1.3) for PROM and 0.87 (0.47 to 1.60) for PPROM. There was no significant effect of antioxidants on PROM or PPROM when analysed by singleton/multiple pregnancy sub-groups.

Conclusion These results suggest that there is no proven benefit of antioxidant supplementation in the reduction of PROM and PPROM, in singleton or multiple pregnancies. Further research is required to determine the pathophysiology and prevention of this life-threatening condition.