Transient hyperglycemia, impaired glucose tolerance and gestational diabetes mellitus (GDM) in preterm pregnant women receiving antenatal steroids

OBJECTIVE:To determine the frequency of transient hyperglycemia, impaired glucose tolerance and gestational diabetes mellitus(GDM) in preterm pregnant women receiving antenatal steroids. METHODOLOGY:This descriptive cross-sectional study was carried out in Maternal and Child Health Center unit 1 (MCH-1) at Pakistan Institute of Medical Sciences Islamabad Pakistan from January 2017 till August 2017. A total of 365 pregnant women presenting to emergency and outpatient department with preterm labor (alive morphologically normal babies), with preterm premature rupture of membranes (PPROM) and other conditions which require early delivery including preeclampsia, IUGR requiring preterm delivery, severe oligohydramnios, antepartum hemorrhage(APH), women receiving two doses dexamethasone and all those with BSR>126mg/dl were included in the study. Multiple pregnancies, advanced preterm labor (cervix > 5cm dilated), gestational diabetes mellitus (GDM) or type I/II diabetes mellitus (DM), chorioamnionitis and taking any medication that affects glucose metabolism were excluded from the study. After ethical approval, informed consent was taken from study participants. Blood sugar levels before the commencement of 1st dose of dexamethasone were noted. Blood sugar profile (fasting, 2 hours after lunch, 2 hours after dinner) were carried out. 2nd dose of dexamethasone was given after 12 hours of 1st dose. Profile was carried out till euglycemia or 5 days if sugars remain deranged.  Patients having deranged levels for greater than 5 days were advised 75 g oral glucose tolerance test(OGTT) and labelled as having impaired glucose tolerance or gestational diabetes mellitus. RESULTS: In our study, 57.57%(n=213) were between 18-30 years, 42.43%(n=157) were between 31-40 years of age, mean age was calculated as 28.92+5.54 while mean gestational age was 31.19+1.92 weeks. Frequency of transient hyperglycemia, impaired glucose tolerance and gestational diabetes mellitus(GDM) in preterm pregnant women receiving antenatal steroids revealed 62.16%(n=230) had transient hyperglycemia, 9.46%(n=35) had impaired glucose tolerance, 2.16%(n=8) had gestational diabetes and 26.22%(n=97) had no blood glucose abnormality.   CONCLUSION: We concluded that the frequency of abnormal glucose levels increases in preterm pregnant women receiving antenatal steroids. Therefore, single blood sugar level done routinely before dexamethasone therapy are insufficient to judge the glucose metabolic status and should be closely monitored during the use of antenatal corticosteroids. KEYWORDS: Preterm delivery, antenatal steroids, transient hyperglycemia, impaired glucose tolerance and gestational diabetes mellitus(GDM)