Study Population and Design
Data for this study come from a prospective cohort study of pregnant
women with GDM, diagnosed by a 1-hour glucose challenge test value ≥ 200
mg/dl or by the Carpenter-Coustan criteria for the 3-hour 100-gram OGTT,
in care at a single academic medical center in the United States.
Details of the study have been published previously.14Briefly, postpartum women with recent GDM were recruited between January
2017 and July 2018 and were eligible for enrollment if they were≥ 18 years of age and fluent in English or Spanish. Women were
excluded if they intended to move outside of the state in the coming
year, could not tolerate a 75-gram glucose tolerance test (e.g., women
with a history of gastric bypass), or had a known hemoglinopathy. At 2
days postpartum, all participants underwent a 2-hour 75-gram OGTT.
Participants and their providers were blinded to the results of this
OGTT. Postpartum care was otherwise not altered. Women were contacted to
receive an OGTT at 4-12 weeks postpartum, in accordance with current
clinical guidelines. Participants were followed through 1 year
postpartum. In this analysis we included women that had an HbA1C measure
at 1 year postpartum (+/- 4 months) to assess glucose metabolism
(n=203/300, 68%; Figure 1). All study participants provided written
informed consent prior to data collection and ethical approval was
provided by the Institutional Review Board Women and Infants Hospital in
Providence, Rhode Island (IRB #836907).