Effects of management in gestational diabetes mellitus with normal prepregnancy body mass index on pregnancy outcomes and placental ultrastructures: a prospective cohort study.

A great quantity of gestational diabetes mellitus with normal prepregnancy body mass index have emerged with the new criteria of gestational diabetes mellitus in China based on the International Diabetes in Pregnancy Consensus group criteria, and understanding placental changes and how they affect outcomes are necessary in order to develop effective management approach. The aim of this study was to prospectively explore the effect of active management starting from the late second trimester in gestational diabetes mellitus women with normal prepregnancy body mass index on pregnancy outcomes and placental ultrastructures, and to provide scientific evidences for optimizing the management of gestational diabetes mellitus in China. Gestational diabetes mellitus women with normal prepregnancy body mass index in the same period of this prospective cohort study were divided into intervention group (n = 51) and control group (n = 55). The intervention group was managed rigorously, while the control group received conventional prenatal cares. The glucose profile, gestational weight gain and pregnancy outcomes were followed up and placental ultrastructures were observed and recorded by transmission electron microscopy. The blood glucose level and gestational weight gain in intervention group were significantly better controlled than those in control group (P < 0.01). The incidences of fetal distress, cesarean section and large for gestational age were significantly lower in intervention group than in control group (P < 0.05). There was a significant reduction in the incidence of abnormal placental ultrastructure in the intervention group (P < 0.01). After adjustment for confounding factors, the undesirable glycemic control and conventional management were related to abnormal placental ultrastructure (P < 0.05). Meanwhile, the undesirable glycemic control, abnormal placental ultrastructure and conventional management made sense in the incidence of fetal distress (P < 0.05), and the target glycemic control, recommend weight gain and active management were associated with reductions in the prevalence of cesarean delivery and large for gestational age (P < 0.05). The active management of gestational diabetes mellitus women with normal prepregnancy body mass index can improve pregnancy outcomes and placental ultrastructures, and the abnormal placental ultrastructure might be closely associated with the undesirable glycemic control and adverse pregnancy outcomes.