Relationship between Positive Glucose Screening, Obesity and Pregnancy Outcome in the Absence of Gestational Diabetes: A Retrospective Cohort Study

Background: Currently pregnant women with abnormal glucose screening test (GCT), performed at 26 28 weeks gestation with a subsequent normal glucose tolerance test (GTT) receive routine care. Could these women be at risk of adverse pregnancy? Objective: Compare rate of caesarean section (CS), induction of labour (IOL), macrosomia, admission to special care nursery and neonatal hypoglycaemia. Designs: Retrospective cohort study. Setting: Ipswich Hospital, Ipswich, Queensland. Participants: Pregnant women having had the test at the hospital laboratory. Methods: Charts review of outcome measures including induction of labour, caesarean section, macrosomia, RDS and short-term neonatal morbidity. Results: We reviewed 882 charts (441 cases and 441 controls). There was a higher IOL rate among cases 21.1% versus 16.6% (OR and 95% CI 1.45; 1.03 2.06) and a higher CS rate, 30.4 versus 23.6 (OR and 95% CI 1.41; 1.05 1.91). Compared to women with BMI 18.5 24.9, women with BMI of 30 and above had a significantly higher IOL rate (47.1% versus 22.6%), higher CS rate (47.2% versus 25.7%) and higher rate of macrosomic baby (79.2% versus 4.2%). There were more women amongst the cases who were older, smoked, had a BMI 30 and above and had previous history of GDM. After adjusting for maternal age, BMI and smoking status, there was still an increased odds of CS, IOL and macrosomia, but this did not reach statistical significance. Conclusion: Abnormal glucose screening test in the absence of gestational diabetes is associated with adverse pregnancy outcome. This is largely contributed by maternal obesity. Corresponding author.