Assessment of cervical antibody concentrations fails to enhance the value of cervical length as a predictor of preterm delivery

Objective The purpose of this study was to determine if cervical fluid antibody concentrations can enhance the value of cervical length in predicting risk of preterm delivery. Study design We obtained cervical fluid samples with preweighed cellulose wicks from a prospective cohort of women 23 to 32 weeksʹ gestation with signs and symptoms of preterm labor and intact membranes. Total immunoglobulin A and G (IgA and IgG) concentrations were determined by enzyme-linked immunosorbent assay. Bacterial vaginosis was diagnosed by Gram stain, and cervical length was measured with endovaginal ultrasound. Results For subjects with term (n = 77) and preterm (n = 24) deliveries, median IgA and IgG concentrations were 736 vs 643 μg/mL (P = .33) and 1528 vs 1769 μg/mL (P = .85). For subjects with normal flora (n = 71), intermediate flora (n = 14), and bacterial vaginosis (n = 16), median IgA and IgG concentrations were 717, 624, and 774 μg/mL (P = .90) and 1383, 1553, and 2731 μg/mL (P = .02). In a forward stepwise logistic regression model, cervical length was the only factor associated with preterm delivery (P< .001). Conclusion Measuring the concentrations of IgA and IgG in cervical fluid does not enhance the value of cervical length in predicting risk of preterm delivery.