Association Between Red Blood Cell Distribution Width in Late Pregnancy and the Incidence of Adverse Perinatal Outcomes: A Retrospective Cohort Study

Background and Aims

This study aimed to quantify adverse perinatal outcomes (APO), including small/large for gestational age (SGA/LGA) and preterm birth (PTB), in pregnant women with abnormal red cell distribution width (RDW) and explore the related mechanisms.

Methods

This study included 11,659 pregnant women who delivered in a specialized hospital. At the time of admission, the lipid profiles and whole blood cell counts were assessed, and APO was analyzed.

Results

Women with high RDW (>18.5% [the 97.5^th percentile]) in late pregnancy had a higher risk of LGA compared with those with low RDW (<12.3% [the 2.5^th percentile]), whereas women with low RDW had a higher risk of SGA and PTB, compared with those with high RDW. A 1% increase in RDW was associated with an increased risk of LGA and a decreased risk of SGA and PTB. Consistent associations were observed in sensitivity analysis among pregnant women of non-advanced age, non-obesity, non-pregnancy complications, and non-PTB (for SGA/LGA only). Increased RDW was significantly associated with increased triglycerides and decreased high-density lipoprotein cholesterol (HDL-C). Triglycerides and HDL-C significantly mediated 10.63 and 15.8% of RDW-associated LGA, 9.51% and 9.40 of RDW-associated SGA, and 8.44 and –8.25% of RDW-associated PTB, respectively.

Conclusion

Abnormal RDW was associated with an increased risk of APO, and the RDW-associated APO risk could be partially mediated by triglycerides and HDL-C, suggesting that RDW may be a promising APO predictor.