Maternal serum C‐reactive protein in early pregnancy and occurrence of preterm premature rupture of membranes and preterm birth

Abstract

The aim of this study was to determine the relationship between maternal serum C-reactive protein (CRP) levels in the first 20 weeks of pregnancy and later occurrence of preterm premature rupture of membranes and preterm birth. A prospective cohort study that measured maternal serum CRP levels in 778 pregnant women in the first half of pregnancy was performed in the city of Noor (north Iran), and included follow-up of patients up to time of delivery. Preterm premature rupture of membranes and preterm birth were defined as the occurrence of membranes rupture and birth, respectively before 37 weeks of gestation. Of the 778 pregnancies studied, 19 (2.41%) preterm premature rupture of membranes and 58 (7.3%) preterm births were seen. Median CRP levels in preterm premature rupture of membranes and preterm birth cases were much higher than in term deliveries (7 and 6.8 respectively vs 2.4 mg/L; 66.67 and 64.76, respectively vs 24.38 nmol/L). CRP levels >4 mg/L had statistically significant relationships with preterm premature rupture of membranes (OR 5.91, 95% CI 2.07-16.89) and preterm birth (OR 8.95, 95% CI 4.60-17.43). With a cut-off level of 4 mg/L of CRP, sensitivity, specificity, and likelihood ratios (LR(+) and LR(-) ) for preterm birth were 81, 70, 2.70, 0.28%, respectively, and for preterm premature rupture of membranes they were 79, 67, 2.41 and 0.31%, respectively. It seems that the inflammatory marker, CRP, can be used in the early stages of pregnancy to identify women at risk of experiencing preterm premature rupture of membranes and preterm birth.