Daily vitamin C supplements can reduce the risk of rupture of the membranes that enclose the fetus and amniotic fluid, according to the results of a study from the National Institute of Perinatology in Mexico City. Investigators pursued the results of previous studies, which had been unable to determine whether the addition of vitamin C during pregnancy would help reduce the risk of premature rupture of membranes (PROM). PROM is considered to be responsible for at least 40% of all cases of preterm labor.
The researchers randomly assigned 120 pregnant women to take 100 mg of vitamin C or an inactive placebo daily, starting at the 20th week of gestation. Among the 109 women who completed the study, vitamin C levels increased in the supplement group and decreased in the placebo group. PROM occurred in only 4 of 52 pregnancies (8%) in the vitamin C group, compared with 14 of 57 pregnancies (25%) among the placebo group. The investigators concluded, however, that vitamin C supplements may be important to maintaining a pregnancy to term.