The relationship between poor glycaemic control at different time points of gestational diabetes mellitus and pregnancy outcomes.

We aimed to identify the complications of gestational diabetes mellitus (GDM) associated with poor control of fasting plasma glucose (FPG) and postload plasma glucose (PPG) on the 75-g oral glucose tolerance test (OGTT). This retrospective study included 997 singleton pregnancy GDM patients who were assigned to poor or good glycaemic control groups. Multivariate analysis indicated that poor FPG control and poor PPG control were both independent predictors of hypertensive disorder complicating pregnancy (HDCP) (odd ratio (OR) of 2.551 (95% CI [1.146-5.682],  = .022) and OR of 2.084 (95% [1.115-3.894],  = .021) compared with good glycaemic control groups, respectively). Poor PPG control promoted the rate of caesarean delivery (1.534 (95% CI [1.063-2.214]),  = .022), whereas good PPG control increased the risk of premature rupture of membranes (PROM) (0.373 (95% CI [0.228-0.611]),  < .001). Conclusively, poor control FPG and PPG dissimilarly affect pregnancy complications in GDM; these findings may help clinicians in the effective implementation of measures to prevent pregnancy complications in GDM.IMPACT STATEMENT Previous studies displayed that GDM patients with 2-h PPG elevated at 24-28 week of gestation had a 2.254-fold increased risk of postpartum dysglycaemia. Abnormal plasma glucose in GDM mother increased the probability of childhood obesity in the offspring. With the implementation of China's second-child policy, the incidence of GDM is rising. Our results indicated that the older patients with GDM, the greater the risk of abnormal plasma glucose control. In addition, maternal age and prenatal BMI were notably correlated with poor plasma glucose control of FPG and PPG, respectively. We also found that both poor FPG and PPG control notably increased the incidence of HDCP in pregnant women. The incidence of PROM was higher in the good PPG control group compared with the poor PPG control group. This study displayed that the effects of poor FPG and PPG control on pregnancy complications and newborn outcomes were heterogeneous, which might be related to the specificity of plasma glucose metabolism at different time points. Good glycaemic control, especially PPG control, was of great significance for improving pregnancy complications and perinatal conditions.