Objective To assess the uptake of postnatal oral glucose tolerance test and to determine the sensitivity of fasting postnatal blood sugar in predicting 2-h impaired glucose tolerance. Methods Retrospective study of 1961 women diagnosed with gestational diabetes mellitus. All women were offered oral glucose tolerance test six weeks post-delivery. Results Of 1961 women, 1090 (56%) returned for postpartum oral glucose tolerance test. A fasting plasma glucose of ≥6.1 mmol/l identified only 76 of 167 women with impaired glucose tolerance detected by a 2-h oral glucose tolerance test (sensitivity of 45.5%; 95%CI: 38.1–53.1). We observed a normal fasting glucose but an impaired 2-h glucose tolerance in 91 out of 968 (9.4%) women. Asian ethnicity, admission on special care baby unit and antenatal insulin therapy strongly predicted 2-h impaired postnatal blood glucose levels (P < 0.05). Conclusion Although fasting plasma glucose is a convenient method, it lacks sensitivity in identifying women with impaired glucose tolerance postnatally.
Utility of Screening Fasting Plasma Glucose and Glycated Hemoglobin to Circumvent the Need for Oral Glucose Tolerance Test in Women with Prior Gestational Diabetes
