Association between fasting plasma glucose variability and maternal and infant outcomes in patients with hyperglycemia during pregnancy: a retrospective cohort study

BACKGROUND: Blood glucose variability (GV) is believed to be closely related to the occurrence of adverse obstetric outcomes. However, few studies have investigated how the change in fasting plasma glucose (FPG) influenced on the adverse obstetric outcomes. This study mainly evaluated the relationship between FPG coefficient of variation (FPG-CV) and adverse outcomes in patients with gestational hyperglycemia and determine the ideal FPG-CV threshold for predicting maternal and infant outcomes. METHODS: We retrospective analyzed the data of 608 pregnant hyperglycemic patients in the Obstetrics Department of Shengjing Hospital Affiliated to China Medical University between June 2019 and December 2021 and followed up inpatients through the Hospital Information System (HIS). We collected the venous FPG from 24–28 weeks of pregnancy to delivery. Maternal and infant outcomes were based on the latest definitions. The chi-square test and logistic regression analysis were performed to evaluate the correlation between FPG-CV and adverse outcomes. Two multivariate binary logistic regression models were used to adjust for confounding factors. Stratified analysis was performed according to hemoglobin A1c (HbA1c) levels (<5.9% and ≥5.9%) and insulin injection (not used and used) in the third trimester of pregnancy. The receiver operating characteristic (ROC) curve was used to evaluate the prediction of FPG-CV on adverse outcomes. RESULTS: All patients were divided into four groups based on the quartile of FPG-CV. The proportion of FPG-SD and insulin injections differed among the groups (P<0.05). Among the outcomes, the highest incidence rate was 26.3% for large for gestational age (LGA), 8.7% for premature delivery. FPG-CV remains independently associated with low birth weight [odds ratio (OR) =1.086, P=0.007], preterm birth (OR =1.069, P=0.012), and preeclampsia (OR =1.180, P<0.001). FPG-CV can predict preeclampsia, with an area under the curve (AUC) of 0.725. CONCLUSIONS: Our results suggest that patients with gestational hyperglycemia should undergo routine FPG monitoring from diagnosis to delivery. Also, the impact of blood glucose fluctuations on adverse outcomes should be considered in the clinical treatment. The rational application of hypoglycemic treatment can stabilize blood glucose levels, however, the effects of different regimens on GV and outcomes should be studied further.