The Utility of Glycated Hemoglobin, Determined in the Second Trimester of Pregnancy, in Diagnosing Gestational Diabetes

Abstract

Background and Aims: Gestational diabetes (GD) identifies a pregnancy with high obstetrical risk due to the possible complications that may appear and which are associated with significant perinatal mortality and morbidity. The role of HbA1c in diagnosing GD is still debatable. Our aim was to evaluate the clinical utility of HbA1c assessed in the second trimester of pregnancy (before performing the oral glucose tolerance test - OGTT) in establishing the macrosomia risk, and also for diagnosing GD. Material and methods: This was an observational study on a group of 165 pregnant women followed from the first trimester of pregnancy in whom we measured HbA1c in the second trimester, before running an OGTT with 100 grams of glucose and who delivered at term (37 - 41 weeks of pregnancy). Finally, HbA1c and OGTT were performed only in 132 women, these being the subjects of our study. Results: The average value of HbA1c was 4.85±1.23%. HbA1c was higher in the group having gestational diabetes (6.58±0.74%) in comparison to the group not having GD (4.52±0,80%). The Receiver Operating Characteristic (ROC) curve for HbA1c determined in the second trimester, for diagnosis of GD, has an area under the curve (AUC) of 0.939. Conclusions: HbA1c value could be considered as a sensitive and specific predictive factor in appreciating the macrosomia risk and could be set as an extra criterion in GD diagnosis.

The accuracy of haemoglobin A1c as a screening and diagnostic test for gestational diabetes: a systematic review and meta-analysis of test accuracy studies

“…An additional eligible article was excluded for not stating the trimester of HbA1c or OGTT testing. Twenty-three eligible studies were subsequently included in the review and meta-analysis [11][12][13][15][16][17]19,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] (Fig. 1).…”

“…Two population subgroups were included across the 23 studies. Seventeen studies sampled pregnant women with risk factors for gestational diabetes [11][12][13][15][16][17]19,22,23,25,26,31,32,[34][35][36][37] as defined by the NICE guidelines [38] and six studies included women without risk factors [24,[27][28][29][30]33]. Studies in settings with an 'at risk' population based on their ethnic origin (South Asians, Africans/Black Caribbean and Middle Eastern) as defined by the NICE guidelines [38] have been classified as having included a population 'at risk' of gestational diabetes even if not explicitly stated or described in the individual studies [16,22,23,35].…”

“…Fourteen different diagnostic criteria for the OGTT have been used across all studies [11][12][13]15,[24][25][26][28][29][30][31][32][33][34]36,37]. Six studies have each used two different diagnostic criteria [16,17,19,22,27,35].…”

Relationship between Glycosylated Haemoglobin Levels and Perinatal Outcome among Women with Gestational Diabetes Mellitus at the University of Port Harcourt Teaching Hospital, Nigeria

“…The risk factors for GDM include a family history of type 2 DM, obesity, previous history of GDM, increasing maternal age, Afro Caribbean or Asian ethnicity, unexplained perinatal death, previous macrosomic baby and previous delivery of an infant with congenital anomaly [1, 3,7,12,13].…”

“…Perinatal effects may include congenital anomalies, intra uterine fetal death, fetal macrosomia, premature rupture of fetal membranes, preterm delivery, birth injuries due to macrosomia with subsequent difficult delivery, respiratory distress syndrome and hyperbilirubinaemia [3,10,12,14,15]. Maternal and childhood obesity as well as cardiovascular disease are also potential long term consequences of GDM [13,[16][17][18].…”