Antenatal oral glucose-tolerance test values and pregnancy outcomes

Objective: The aim of the present study was to explore the impact of individual blood glucose values (n = 4; i.e. fasting and 1, 2 and 3 h following oral glucose administration) obtained during antenatal oral glucose-tolerance testing, together with two different sets of criteria used for diagnosis of gestational diabetes mellitus (GDM) - Carpenter and Coustan Criteria (CCC) and National Diabetes Data Group (NDDG) criteria - in predicting pregnancy outcomes and maternal insulin need. Setting: Al Ain Hospital, United Arab Emirates. Method: This observational uncontrolled cohort study gained its study subjects from a randomised, controlled, longitudinal, prospective clinical trial performed at Al Ain Hospital, Al Ain, United Arab Emirates. The eligible population was made up of all women (n = 720) who participated in an early screening programme for GDM. Those who had a positive oral glucose-tolerance test (OGTT) based on CCC were included in the study (n = 165). All recruited women with GDM were followed from time of recruitment to 6 months postpartum. The sources of information used were maternal and neonatal medical records and laboratory findings for women both antenatally and postnatally. Results: The maternal and neonatal outcomes indicated that the number of abnormally elevated antenatal OGTT values obtained during the diagnosis of GDM was significantly correlated with development of a number of pregnancy complications. Data analysis also indicated that the number of abnormal diagnostic antenatal OGTT values using CCC was significantly correlated with development of postpartum diabetes mellitus (P = 0.044) within 6 months of delivery. The number of abnormal OGTT values significantly contributed to insulin need during the index pregnancy (P < 0.05). The CCC approach was more sensitive than the NDDG methodology for predicting the onset of GDM and a number of the associated complications. Conclusions: The study highlighted the importance of abnormal values for antenatal OGTT in identifying the need for insulin management in women with GDM. © 2008 The Authors.