The association between maternal cervicovaginal proinflammatory cytokines concentrations during pregnancy and subsequent early-onset neonatal infection.

OBJECTIVE

The aim of this study was to investigate the relationship between the concentration of selected proinflammatory cytokines (IL-1alpha, IL-1beta, IL-6 and IL-8) in cervicovaginal fluid, as measured in midgestation, and the risk of early-onset neonatal infection (EONI).

METHOD: Cervicovaginal fluids were obtained from a cohort of 114 pregnant women at 22 to 34 weeks' gestation. The samples were analyzed for the concentrations of selected proinflammatory cytokines using standard enzyme-linked immunosorbent assay technique (ELISA). Lower genital tract microbiology was diagnosed using Gram stain method according to Spiegel's criteria and by culture.

RESULTS

Mean gestational age at the time of sampling was 29.0 weeks. Mean time between sampling and delivery was 9.3 (SD 4.7) weeks. Bacterial vaginosis (BV) was diagnosed in 27.2% of subjects and M. hominis and U. urealyticum in 22.8% and 26.3%, respectively. Out of 114 women examined, 20 (17.5%) delivered newborns with EONI. Median cervicovaginal concentrations of IL-1alpha, IL-1beta, IL-6 and IL-8 did not differ between women who delivered newborns with EONI as compared to women who delivered newborns without EONI. Women with pathological lower genital tract microflora and low IL-8 concentration (below 25(th) percentile) during pregnancy presented a significant risk of delivering newborns with EONI (OR=4.9; 95% CI, 1.1-22.8). Subjects with pathological lower genital tract microflora and a low concentration of more than one cytokine had the highest risk of delivering a newborn with EONI, OR=16.2, 95% CI, 1.1-234.0.

CONCLUSIONS

Cytokine measurement in cervicovaginal fluid in early gestation could be useful for predicting subsequent EONI only among pregnant women with lower genital tract infection. Maternal genital tract immune hyporesponsiveness as represented by low concentrations of proinflammatory cytokines may create a permissive environment for ascending infection and may lead to subsequent EONI.