Alteration of Maternal Serum Ferritin in Pregnancy and Maternal-fetal Infections: A retrospective cohort study.

Objectives: To investigate the association of altered serum ferritin during pregnancy with chorioamnionitis and neonatal sepsis. Methods: This retrospective cohort study included 78,521 pregnant women who attended antenatal check-ups at maternal and child health centers in Fujian Province, China. Study lasted from January 2014 to January 2019. A total of 59,812 pregnant women were followed up. Patients with suspected infection before the delivery were selected and divided into the chorioamnionitis and non-chorioamnionitis groups according to placental pathology. Differences in late and early pregnancy serum ferritin between the two groups were compared. Multiple logistics regression was used to adjust for confounding factors and to analyze the association between serum ferritin changes and pregnancy outcomes. Importance of altered serum ferritin during pregnancy was assessed by receiver operating characteristic (ROC) curve and net reclassification index (NRI). Results: Clinical records of 8506 pregnant women were included in the study. there were 1010 (11.9%) cases of confirmed chorioamnionitis and 263 (3.1%) cases of neonatal sepsis. There was a significant difference in maternal serum ferritin changes between the groups with and without chorioamnionitis. No significant difference was detected in cases with or without neonatal sepsis. Multiple logistic regressions, corrected for confounding factors yielded similar conclusions. Maternal serum ferritin difference NRI 12.18% (p = 0.00014) was similar to the ROC results in predicting the occurrence of chorioamnionitis. Conclusion: Differential serum ferritin during pregnancy may predict chorioamnionitis but does not correlate well with neonatal sepsis.