Factors associated with maternal serum C-reactive protein throughout pregnancy: A longitudinal study in women of Rio de Janeiro, Brazil.

Objectives: The aim of this study was to evaluate the longitudinal changes of C-reactive protein (CRP) concentrations during pregnancy and to assess whether socioeconomic, anthropometric, dietary, behavioral, and biochemical factors are associated with these changes.

Methods: This was a prospective cohort study of 115 adult pregnant women, followed at gestational weeks 5 to 13, 20 to 26, and 30 to 36. Serum concentrations of CRP (mg/L) were measured by the immunoturbidimetric method with ultrasensitive kits (sensitivity 0.05 mg/dL). The statistics included descriptive analysis (mean + SD) and longitudinal linear mixed-effects models, reporting the β coefficient and 95% confidence intervals (CI).

Results: Serum CRP concentrations progressively increased throughout pregnancy (β = 0.121; 95% CI, 0.071-0.171). Parity (β = 1.579; 95% CI, 0.731-2.427) and prepregnancy body mass index (BMI) (β = 0.316; 95% CI, 0.053-0.587) were positively associated and dietary glycemic load was negatively associated (β = -0.203; 95% CI, -0.380 to -0.026) with CRP concentrations in the multiple model. Prepregnancy obese women presented a more pronounced increase of CRP concentrations compared with normal weight women (β = 0.210; 95% CI, 0.059-0.360 versus 0.115, respectively; 95% CI, 0.049-0.181). A statistically significant interaction was observed between parity and gestational age (β = -0.045; 95% CI, -0.084 to -0.005), indicating that the variation of CRP throughout pregnancy differed according to parity categories.

Conclusion: CRP concentrations increased throughout pregnancy. Parity and prepregnancy BMI were positively associated and dietary glycemic load was negatively associated with concentrations of CRP.