Red Blood Cells in The First Trimester and The Risk of Gestational Diabetes: A Prospective Cohort Study

Background: This research aimed to assess the potential association of gestational diabetes (GDM) with early trimester hematological parameters including hemoglobin (Hb), red blood cell (RBC), white blood cell (WBC), and platelet count (PLT) through a prospective cohort study. Methods: : The prospective cohort included pregnant women subjected to prenatal examination at Shantou and Beijing hospitals in China from March 2014 to December 2015. Data were collected since the first perinatal visit in obstetrics clinics, and then participants were followed up at 24, 32, 36 gestational weeks and the time of delivery, respectively. Multivariable adjusted logistic regression models were conducted to estimate odds ratio (OR) and its corresponding 95% confidence interval (95% CI). Results: : A total of 1004 pregnant women with singletons, less than 12 gestational weeks, and without history of chronic disease were eligible for analysis. The incidence of GDM was 18.82%, and the mean age was 29.50 ± 3.84 years. Total of 187 (18.63%) women who had abnormal RBC level and 222 (22.11%) had abnormal Hb in the first trimester of pregnancy. After multivariable adjustment, each unit increment in numeric RBC or Hb was associated with 177% and 4% increased risk for GDM. The risk for GDM was significantly increased with higher RBC (OR: 2.00 for RBC>4.55×1012 /L) and Hb (OR: 2.14 for Hb>139 g/L) levels in the first trimester. Conclusions: : Elevated RBC and Hb in the first trimester are associated with increasing risk of GDM. Further evidence are warranted to confirm these possible causal relationships.