Postprandial Hyperglycaemia Screening and Pregnancy Outcomes-Lessons From COVID -19.

Background: During COVID-19, the diagnosis and treatment of GDM differed from conventional criteria. In Australia, during the alternative testing period, women with fasting glucose < 4.7 mmol/L were not diagnosed with GDM.

Aim: To describe the maternal and neonatal outcomes of pregnant women with fasting blood glucose < 4.7 mmol/L for whom the diagnosis and treatment pathways differed before and during COVID-19.

Materials and methods: An Australian population-based data linkage study involving 3891 women with fasting blood glucose < 4.7 mmol/L between 24 and 32 weeks of gestation categorised into three groups: women diagnosed with GDM by postprandial hyperglycaemia (PPGDM; n = 226); normal glucose tolerance group (NGT; n = 3125) and women not tested for postprandial hyperglycaemia, mostly during COVID-19 (LFBG; n = 540). Perinatal outcomes were compared using generalised linear models.

Results: There were no differences between PPGDM and NGT groups in the risk of large for gestational age infants (RR 0.98, 95% CI: 0.63-1.52) although the mean birth weight (MD -103.43, 95% CI: -175.46 to -31.40)) was lower in the PPGDM group. The maternal and neonatal outcomes in the LFBG group were mostly comparable to the NGT group.

Conclusion: In our study, the Australian COVID-19 GDM screening protocol, which includes initial fasting glucose testing, reduced the need for an OGTT in 67% of pregnant women. Diagnosis and treatment for postprandial hyperglycaemia in women with lower FBG should consider the benefits, as well as the financial, logistical and psychological costs involved.