Pregravid HbA1c and Glucose Measurement to Rule Out Future Gestational Diabetes Mellitus and Reduce the Need for Oral Glucose Tolerance Testing in Pregnancy.

Abstract

The International Association of the Diabetes and Pregnancy Study Groups (IADPSG) has recommended universal screening for gestational diabetes mellitus (GDM) by oral glucose tolerance test (OGTT) in all pregnant women (1). However, concern has been raised that this recommendation may pose a resource challenge for health care systems (2). Recognizing that women who develop GDM have chronic metabolic dysfunction that predates their pregnancy (3), we hypothesized that measurement of pregravid HbA1c or glucose may provide the capacity to rule out GDM in low-risk women and thereby reduce the overall OGTT burden in pregnancy. To test this hypothesis, we conducted a population-based retrospective cohort study using real-world data for Ontario, the most populous province in Canada. With administrative databases that track health care utilization, we identified all women in Ontario without preexisting diabetes who had pregravid measurement of HbA1c or glucose before singleton live-birth pregnancies between January 2008 and December 2015. Pregravid HbA1c or glucose was measured at median 1.4 years (interquartile range 1.03–2.05 years) before pregnancy in 334,829 women, including 20,221 who developed GDM. For this study, the women were randomly assigned to either derivation ( n = 167,401) or validation ( n = 167,428) cohorts to evaluate the capacity of these pregravid glycemic measurements for predicting GDM. In the derivation cohort, pregravid …