关键词: 先兆早产, 地塞米松, 糖尿病, 妊娠, 动态血糖变化, 血药峰浓度

Abstract: Background　Preterm birth is a serious and common pregnancy complication.Immature development of physical function in premature infants causes the low survival rate，whose rescue results in a heavy burden on the family and society.Antenatal glucocorticoids treatment is an international recognized standard regimen benefiting fetal lung maturation.However，dexamethasone has a certain adverse effect on maternal glucose，and the mechanism that maternal glucose varies by peak blood concentration of dexamethasone is not clear.Objective　To explore the effect of antenatal administration of dexamethasone on blood glucose in pregnant women with threatened preterm birth.Methods　From October 2018 to February 2020，63 eligible hospitalized pregnant women with threatened premature birth were recruited from Foshan Women and Children Hospital，and divided into  GDM（gestational diabetes mellitus） group and non-GDM group according to the results of 75-gram oral glucose tolerance test （OGTT） at 24-28 weeks' gestation.Both groups received the same protocol to promote fetal lung maturation after admission：dexamethasone was injected intramuscularly 6 mg every 12 hours，4 times in total.The blood glucose 1 hour before and 3 hours after each injection of dexamethasone，and blood glucose at 1 hour before and after the peak blood concentration of dexamethasone after each injection of dexamethasone measured by the Medtronic MINIMED continuous glucose monitoring system as well as the chart of the trend of blood glucose over time were compared between the two groups Results　Finally，55 cases completed the study，including 16 with GDM and 39 without.There were no significant differences in blood glucose measured 1 hour before and 3 hour after each dexamethasone injection in both groups （P>0.05）.The first measured blood glucose at 1 hour before dexamethasone injection was lower than each of the latter three measured in GDM group （P<0.05）.The blood glucose 3 hours after each injection of dexamethasone showed no significant changes in GDM group （P>0.05）.The first measured blood glucose at 1 hour before dexamethasone injection was lower than that measured at the second or third time in non-GDM group （P<0.05）.The first measured blood glucose 3 hours after injection of dexamethasone was lower than each of the latter three measured in non-GDM group （P<0.05）.The blood glucose at 1 hour before or after peak blood concentration of dexamethasone after dexamethasone administration did not differ significantly by the times of injection of dexamethasone in both GDM and non-GDM groups （P>0.05）.Within 3 hours of injection of dexamethasone，the blood glucose of women without GDM was within the reference range，and there was no discernible trends，but the blood glucose of women with GDM showed greater fluctuation，and increased gradually 2 hours after each injection of dexamethasone.Conclusion　The blood glucose of singleton pregnant women may not be affected by the peak blood concentration of dexamethasone within 2 hours after injection of dexamethasone.The blood glucose significantly increased at 3 hours after dexamethasone injection.However，four times injections of dexamethasone had no cumulative effect on the increase of blood glucose.Within 3 hours of injection of dexamethasone，the blood glucose of women without GDM was within the reference range，and there was no discernible trends，but the blood glucose of women with GDM showed greater fluctuation，and increased gradually 2 hours after each injection of dexamethasone.

Key words: Threatened preterm birth；Dexamethasone；Diabetes, gestational；Dynamic glucose；Peak blood concentration