Glycated hemoglobin in the first trimester of pregnancy as a predictor of gestational diabetes mellitus

• Grant number: 19/26332-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2020
• End date: February 28, 2022
• Field of knowledge: Health Sciences - Medicine - Maternal and Child Health
• Principal Investigator: Roberto Antonio de Araujo Costa
• Grantee: Beatriz dos Santos Luz
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Some questions are raised about the screening and diagnosis of diabetes mellitus in pregnancy. Others are using glycated hemoglobin (HbA1C) routinely in the first trimester of pregnancy to diagnose pre-existing diabetes in the first trimester. For confirmation of this diagnosis, either the HbA1C value is well established (6.5% or greater). However, it does not consider the management of HbA1c values between 5.7 and 6.4%, which the general population considers as prediabetes and a change in lifestyle is recommended and may use the association with medications. Objective: (I) to determine the incidence of GDM between 24 and 28 weeks of gestation and (II) to estimate the risk of developing this disease in pregnant women with HbA1c levels between 5.7-6.4% used and normal fasting glucose, until 14 weeks of gestation. Method: observational study, retrospective cohort. Being eligible for the study as pregnant women who dosed glycated hemoglobin and fasting glucose in the first trimester of pregnancy and underwent glucose tolerance testing at 75g (oTTG-75g) between 24 and 28 weeks of pregnancy. In the laboratory evaluation of the first trimester of pregnancy, women will be classified into three groups: (I) normal, with glycated hemoglobin (HbA1c) below 6.5% and fasting glucose (GJ) below 92 mg / dL; (II) DMG, with HbA1c below 6.5% and GJ between 92 and 125 mg / dL; and (III) "overt diabetes" with HbA1c of 6.5% or greater and / or GJ of 126 mg / dL or greater. The selected managers will be further divided into two groups according to glycated hemoglobin: (Group 1) normal with HbA1c lower than 5.7%; and (Group 2) prediabetes with HbA1c equal to or greater than 5.7% and less than 6.5%. Only as normal patients (groups A and B) and undergoing oTTG-75g will be included in the research. From this information, the incidence of pregnant women with GDM (diagnosed by oTTG-75g between 24 and 28 weeks of gestation) who have HbA1C levels between 5.7-6.4% used up to 14 weeks of gestation will be estimated. Also, calculate the risk of developing GDM, with 95% confidence intervals. It will be considered a significance level of 5%. (AU)