Evaluation of the value of fasting plasma glucose in the first trimester for the prediction of adverse pregnancy outcomes.

Aims: To evaluate the importance and usefulness of fasting plasma glucose (FPG) in the first trimester in predicting adverse pregnancy outcomes.

Methods: A retrospective study of 22,398 singleton pregnancies was conducted. Participants were divided into subgroups according to first-trimester FPG (low FPG, FPG < 5.1 mmol/L; medium FPG, 5.1 mmol/L ≤ FPG < 5.6 mmol/L; high FPG, 5.6 ≤ FPG < 7.0 mmol/L) and oral glucose tolerance test(OGTT) results (normal and abnormal) during pregnancy. Patient characteristics and risk of adverse pregnancy outcomes were compared. Then, the whole population of women with abnormal OGTT served as a reference, and the relative risks of maternal and neonatal complications in normal OGTT women were analyzed by categorical analyses and logistic regression. Subgroup analyses were performed according to pre-pregnancy body mass index (BMI).

Results: The frequency of adverse pregnancy outcomes increased with increasing FPG levels during the first trimester, regardless of OGTT results. High FPG + Abnormal OGTT had the worst outcome. Compared to the whole population of women with abnormal OGTT, Normal OGTT + Medium FPG showed the same risk of PIH and macrosomia. Normal OGTT + High FPG showed the same risk of PIH, macrosomia as well as LGA and preterm birth. Additionally, Normal OGTT + Medium FPG + BMI ≥ 24 kg/m showed significantly higher risk of PIH (OR = 1.867, 1.245-2.800), macrosomia (OR = 1.748, 1.304-2.344) and LGA (OR = 1.274, 1.019-1.593). Furthermore, the OR value for PIH was 3.759 (1.680-8.412) in Normal OGTT + High FPG + BMI ≥ 24 kg/m compared to women with abnormal OGTT.

Conclusions: First-trimester FPG values can help identify women at increased risk for adverse pregnancy outcomes. Increased attention and management should be given to women with early pregnancy FPG ≥ 5.10 mmol/L despite a normal OGTT, especially if their BMI ≥ 24 kg/m.