Glycemia in early pregnancy and pregnancy outcomes

  • Jincy Immanuel

Western Sydney University thesis: Doctoral thesis

Abstract

Detecting and managing mild hyperglycemiain early pregnancy is a research priority. Currently, there is no solid evidence for suitable diagnostic criteria, screening methods, and approaches for treating mild hyperglycemiain early pregnancy. Despite the absence of universally accepted guidelines, women who develop dysglycemia in early pregnancy have been diagnosed and treated as having early gestational diabetes mellitus (GDM)using the standard (24-28-week) criteria, which varies globally. That many women diagnosed with GDM in early pregnancy using the standard criteria do not have hyperglycemia in late gestation calls into question the suitability of this approach. Regardless, in my meta-analysis, women who developed GDM in early pregnancy were found to have a higher risk of perinatal mortality and neonatal hypoglycemia and were more likely to receive insulin therapy than those with late GDM. This urgently necessitates addressing GDM not just in late gestation but from the beginning of pregnancy. This thesis includes a range of research objectives, including investigating the utility of early pregnancy HbA1c for detecting GDM, defining and characterizing metabolic phenotypes of early GDM, comparing pregnancy outcomes among women with different degrees of hyperglycemia during pregnancy, and evaluating the accuracy of blood glucose meters in pregnancy. The analysis of the early pregnancy data of women enrolled in the Vitamin D and lifestyle intervention for GDM prevention (DALI) trial showed that HbA1c measured before 20 weeks of gestation had limited value for identifying GDM and predicting adverse pregnancy outcomes. This thesis refutes the current practice of using HbA1c to identify and treat GDM in early pregnancy. Apart from identifying major gaps in the knowledge of women with early hyperglycemia, this research provides insight into the metabolic heterogeneity of early GDM and highlights the need for a new model of care for women with early dysglycemia. This research provides future direction in GDM care by including insulin resistance screening for high-risk women and emphasizes the importance of using glucose meters that adjust for hematocrit interferences during pregnancy. This thesis has also shown the significance of early GDM and suggests that it should be considered as a separate but related clinical entity to GDM diagnosed later in pregnancy.
Date of Award2020
Original languageEnglish

Keywords

  • diabetes in pregnancy

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