Association Between Serum Ferritin Concentration and Risk of Adverse Maternal and Fetal Pregnancy Outcomes: A Retrospective Cohort Study

OBJECTIVE: This study evaluated the associations of serum ferritin (SF) concentration during pregnancy with the risk of adverse maternal and fetal pregnancy outcomes. METHODS: We conducted a retrospective study of 2327 pregnant women from 2015 to 2020 in Guangdong, China. SF concentrations were measured at 16–18th and 28–32th week of gestation. Logistic regression models were applied to estimate the association between SF concentration and the risk of adverse pregnancy outcomes. RESULTS: After multivariable adjustment, the odds ratio (OR) of the highest quartile of SF concentration at 16–18th week of gestation was 1.43 (95% confidence interval [CI]: 1.09, 1.89) for gestational diabetes mellitus (GDM) and 1.79 (95% CI: 1.15, 2.79) for small for gestational age (SGA) when compared with the lowest quartile. At 28–32th week of gestation compared with the lowest quartile, women with SF in the highest quartile had an increased risk of SGA (OR: 1.62; 95% CI: 1.01, 2.62). Moreover, the lowest quartile of SF concentration decreased risk of SGA by 90% (95% CI: 0.01, 0.80) when compared with the highest quartile among pregnancy women with GDM. CONCLUSION: Elevated SF concentrations increased the risk of GDM and SGA during pregnancy. Maintaining an appropriately low level of maternal SF at 28–32th week of gestation in women with GDM could reduce the risk of SGA.