Plasma vitamin C levels and preterm prelabor rupture of membrane among Egyptian pregnant women

Abstract

Aim of the work To study the relationship between plasma vitamin C level and the risk of occurrence of preterm prelabor rupture of membranes (PPROM) among Egyptian pregnant women. Methods This was a cross-sectional study at the Obstetrics and Gynecology Department of Suez Canal University Hospital from February 2011 to February 2012. The study was carried out in two phases. First, a pilot study was carried out on 36 pregnant women, 12 women in each trimester of pregnancy, to determine baseline plasma vitamin C concentration among Egyptian pregnant women. The main study group included 60 women (study group); 30 women had PPROM between 24 and less than 37 weeks’ gestation with a singleton pregnancy. The control group included 30 pregnant women without PPROM matched for gestational age; patients with multiple pregnancies, greater than 37 weeks’ gestation, fetal distress, vaginal bleeding, preterm labor, or chorioamnionitis were excluded from the study. All the participating women were subjected to the following: assessment of full history, general and local examination, ultrasound examination, sterile speculum examination for the detection of escape of amniotic fluid from the cervical canal, nitrazine test, fern test, laboratory investigation to rule out chorioamniotis, and a vitamin C assay by an enzyme-linked immunosorbent assay. Results The pilot study showed that there was a decreasing trend in the mean plasma vitamin C levels as gestational age increased; the mean±SD in the first, second, and third trimesters, respectively, was 0.64±0.03 versus 0.61±0.06 versus 0.60±0.02 mg/dl. Although the decrease from the first to the third trimester was highly significant (P=0.0009), the decreasing trend was not significantly different after the second trimester The mean plasma vitamin C concentration in the study group was significantly lower than that in the control group (0.40±0.3 vs. 0.60±0.4 mg/dl, respectively, P=0.033). Plasma vitamin C concentration was significantly correlated with the mean packed cell volume (r=0.35, P=0.05) and social class (r=0.375, P=0.041) in patients with PPROM. Other studied variables such as age, parity, gestational age, and previous PPROM showed insignificant correlations with plasma vitamin C levels (P>0.05). Conclusion We concluded that low levels of plasma vitamin C concentration had a significant association with PPROM. Also, the mean packed cell volume and social class was associated significantly with low plasma vitamin C concentrations in patients with PPROM.