Background: With introduction of the 2014 ADIPs criteria for GDM, a new model of care (MOC) was needed to manage the predicted 30% increase in women diagnosed with gestational diabetes mellitus (GDM) at Nepean Hospital. Following diagnosis, women attended an education session with diabetes educators and dietitians. They were then referred to either the diabetes in pregnancy clinic (DIPC) pathway if 75 g oral glucose tolerance (OGTT) levels were higher (fasting glucose ≥5.5mmol/l, 1 hour ≥10.5 or 2 hour ≥9.0 ) or continued their existing pre-GDM care pathway (EPGDM) with obstetrician or midwife if OGTT blood glucose levels (BGLs) were lower. EPGDM clinicians checked glycaemic control and referred to the DIPC for insulin therapy if BGLs were above targets.
Aim: To determine whether adverse neonatal outcomes are different for women managed via the 2 new MOC pathways.
Methods: 310 women were randomly selected from women referred to Nepean Hospital for GDM management between July 2018 and December 2019. Fifty two were excluded due to twin pregnancy, inadequate pregnancy or birth data available, or referral for hypoglycamia without GDM. Data were analysed for 257 women. Pregnancy data and adverse neonatal outcome data were collected from the electronic medical record.
Results: 127 women were triaged to the EPGDM and 126 to the DIPC pathway. Mean maternal age was 31.9 years. EPGDM pathway women were older, 33.6 ± 5.2 y compared with DIPC pathway women 32.3 ± 5.3 years (p=0.008). As expected, OGTT glucose levels were significantly higher at 1h and 2 h for DIPC women but not different for fasting venous glucose: 4.9±0.4 mmol/l for the EPGDM and 5.0±0.7mmol/l for the DIPC pathway (p=0.17). Fewer existing EPGDM pathway women received insulin 33.1% than DIP clinic pathway women 46.8% (p=0.03, OR 0.55, 95% CI 0.33-0.91). There was no significant difference between groups in mean parity (1.2) or gestational age at delivery (38.4 weeks). There was no significant difference in adverse neonatal outcomes between the EPGDM and the DIPC pathways for: neonatal LGA 16.5% versus 14.5%; SGA 2.4% versus 5%; hypoglycaemia 36.2% versus 38.1%; respiratory distress 22.1% versus 16.7%; NICU admission 37% versus 29.4% or jaundice 16.5% versus 23% (all p values > 0.2).
Conclusion: The new model of care using the EPGDM care pathway for women with lower glucose levels on OGTT is associated with less insulin use than the DIP clinic pathway but no significant difference in adverse neonatal outcomes.