Plasma vitamin C levels and risk of preterm prelabour rupture of membranes

Abstract

Preterm prelabour rupture of membranes (PPROM) is a leading cause of preterm births. Its attendant contribution to maternal and perinatal morbidity and mortality makes it imperative to identify factors that may help prevent this condition. This study examined the association between plasma vitamin C concentration and the risk of (PPROM) amongst pregnant women in a tertiary hospital setting. This was a prospective cross sectional study conducted at the Obstetric and Gynaecology Department of University of Benin Teaching Hospital (UBTH), Benin City. The study was in two phases, first a pilot study to determine baseline plasma vitamin C concentration amongst pregnant women in UBTH was conducted. In the main study 80 pregnant women were recruited into two groups of those with PPROM (40 cases) and those without PPROM (40 controls) matched for gestational age. Plasma vitamin C concentration was determined for all study participants and their sociodemographic characters were used to generate a database for analysis. In the pilot study, plasma vitamin C concentration decreased with increasing gestational age of pregnancy. In the main study plasma vitamin C concentration was significantly lower in women with PPROM than controls without PPROM, 0.53 ± 0.05 vs. 0.58 ± 0.05 mg/dl; P = 0.0001. Both groups (case and control) were comparably matched in age, parity and social class. There was a significant association between low vitamin C levels and the occurrence of PPROM (95% CI 1.53-11.88; P = 0.008). Plasma vitamin C was found to be lower in women with PPROM. Low plasma vitamin C concentration may thus be an associated risk factor for PPROM. Hence improved dietary or drug supplements may be a useful adjunctive strategy to reducing the incidence of PPROM and its attendant adverse sequelae. While this intervention is advocated, further multicentre investigation of the effects of vitamin C on risk of preterm PROM is suggested.