Background
The purpose of this audit was to determine if the rate of large for gestational age neonates (LGA) and foetal adverse outcomes had improved after implementation of the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria for the diagnosis of gestational diabetes (GDM)1 in 2011 in Wollongong Public Hospital.
Methods
De-identified data from the midwife database for all births in Wollongong Public Hospital was obtained from 2008 to 2015. Patients in 2011, patients without diabetes and with pre-existing diabetes were excluded. The patients from 2008 to 2010 were classified as “Group 1”, and from 2012 to 2015 as “Group 2”.
Results
There was a significantly increased rate of GDM diagnoses in Group 2 (n=1958, 20.7%) compared to Group 1 there were (n=457, 6.5%) (p < 0.001). The median maternal body mass index (BMI) was significantly higher in Group 2 (28 kg/m2) than in Group 1 (26.7kg/m2) (p=0.002). There was also a greater need for insulin treatment in Group 2 (n=624, 31.7% vs. n= 115, 25.1%) (p=0.005).
The rate of LGA neonates was significantly reduced in Group 2 (n=269, 13.7%) compared to Group 1 (n=77, 16.8%) (p=0.027), however the rate of special care nursery admissions was greater in Group 2 (n=443, 22.6% vs. n=60, 13%) (p<0.001).
There was no significant difference in the mode of birth (p=0.067), neonatal hypoglycaemia (p=0.087) and respiratory distress (p=0.430) between the two groups.
Conclusions
Since the change in GDM diagnostic criteria, there was double the amount of women diagnosed with GDM than previously published data in 20112, possibly relating to a significant increase in median BMI. There were more women requiring insulin treatment. There was a significant decrease in the number of LGA infants. We could not find a significant change in other neonatal outcomes.