Physiological subtypes of gestational glucose intolerance and risk of adverse pregnancy outcomes

BACKGROUND: Women with gestational glucose intolerance, defined as an abnormal initial gestational diabetes screening test, are at risk for adverse pregnancy outcomes even if they do not have gestational diabetes. We previously defined gestational diabetes physiologic subtypes based on the primary underlying physiology leading to hyperglycemia and found that women with different subtypes had differential risk of adverse outcomes. Physiologic subclassification has not yet been applied to women with gestational glucose intolerance. OBJECTIVE: We defined gestational glucose intolerance physiologic subtypes based on the presence of insulin resistance, insulin deficiency, or mixed pathophysiology, and aimed to determine if these subtypes are at differential risk for adverse outcomes. We hypothesized that women with the insulin resistant subtype of gestational glucose intolerance would have the greatest risk of adverse pregnancy outcomes. STUDY DESIGN: In a hospital-based cohort study, we studied women with gestational glucose intolerance (glucose loading test 1-hour glucose ≥140 mg/dL, N=236) and normal glucose tolerance (glucose loading test 1-hour glucose