Pregnancy outcomes among multi-ethnic women with different degrees of hyperglycaemia during pregnancy in an urban New Zealand population and their association with postnatal HbA1c uptake

Background: Adverse pregnancy outcomes are more common in women with hyperglycaemia. Many women have suboptimal uptake of HbA1c testing postdelivery. Aims: To compare pregnancy outcomes among multi-ethnic women with different degrees of hyperglycaemia during pregnancy, and their association with postnatal HbA1c uptake after the introduction of email reminders. Materials and Methods: A retrospective and prospective single-centre study was conducted in South Auckland in 2639 women with early gestational diabetes mellitus (GDM) (diagnosed < 20 weeks), late GDM (diagnosed ≥ 20 weeks), overt diabetes in pregnancy, or known type 2 diabetes (T2DM) during pregnancy. Automated email reminders were sent to general practitioners to increase postnatal HbA1c screening. Results: HbA1c during pregnancy increased across the late GDM (n = 1425), early GDM (n = 148), overt diabetes (n = 573) and T2DM (n = 493) groups (P < 0.001). Stillbirth was least common in the late GDM group (0, 0.7, 0.5, and 1.9%, respectively, P < 0.001), as were caesarean delivery (32.7, 45.1, 39.4, and 53.5%, respectively, P < 0.001), large for gestational age (LGA) (14.7, 18.2, 22.3, and 30.5%, respectively, P < 0.001), small for gestational age (8.8, 16.7, 11.0, and 11.1%, respectively, P = 0.02), and preeclampsia/eclampsia (7.7, 9.2, 13.0, and 14.8%, respectively, P < 0.001). LGA and preeclampsia/eclampsia were more common among Pacific and Māori women than European women (LGA, 30.1, 22.7, 10.3%, respectively, P < 0.001; preeclampsia/eclampsia, 13.5, 14.0, and 8.1%, respectively, P < 0.001). Postpartum HbA1c screening increased among women with GDM/overt diabetes after the introduction of the reminder emails (39.6% vs 34.0%, P = 0.03). Conclusions: Women with late GDM are least likely to experience adverse outcomes. Email reminders to improve postpartum HbA1c screening warrant further investigation.