C-reactive protein and the mode of onset of labor in term pregnancies

To evaluate whether C-reactive protein (CRP) levels in maternal serum at post-date follow-up can predict the mode of onset of spontaneous delivery in term pregnancies and the interval to delivery.

Women at 40 completed weeks of gestation were recruited. The interval from CRP sampling to delivery and mode of onset of delivery were noted.

Sixty women were divided into 3 groups according to the mode of onset of labor. Group A presented with spontaneous onset of contractions, Group B presented with pre-labor ruptured membranes (PROM), and Group C completed 42 weeks without spontaneous initiation of labor. There was no association between CRP values and latency from time of sampling to delivery. Mean serum CRP in Group B (12.7 mg/l) was significantly higher than in either Group A(7.2 mg/l) or Group C (10.2 mg/l) (p=0.01). In addition, CRP values in the upper quartile (>12.2 mg/l) had a 37.5%positive predictive value for PROM, with a negative predictive value of 93%.

Women whose labor will start with PROM have higher CRP values at post-date follow-up than women whose labor starts otherwise.