Introduction: Women with diabetes are at an increased risk of perinatal mortality. This applies in particular to women with pre-gestational diabetes, both type I (T1DM) and type II (T2DM) diabetes, who carry a nearly 4-fold increased risk of perinatal death than the general maternity population. The aim of our study was to describe perinatal mortality rates for women with pre-gestational and gestational diabetes.
Methods: Retrospective analysis of women with diabetes attending for antenatal care at the Royal Women’s Hospital, Melbourne, a quaternary maternity centre in Victoria, Australia, over an 11-year period (2010-2020). All perinatal deaths (stillbirths, neonatal deaths, terminations for congenital and/or genetic anomalies at or beyond 20 weeks gestation and a birthweight over 400g) were reviewed.
Results: This study included 7,772 women with diabetes; the vast majority of those had gestational diabetes (n=6,980; 89.8%); 10.2% had pre-gestational diabetes, comprising of 382 women with T1DM and 410 women with T2DM. There were 53 stillbirths, 10 neonatal deaths and 17 terminations of pregnancy for fetal anomalies in the GDM cohort; this correlates to a PNMR of 11.5:1,000 maternities (corrected PNMR 9:1,000). Women with pre-gestational diabetes had a 3.8-fold increased rate of perinatal mortality with 17 perinatal deaths among women with T1DM and 20 perinatal deaths among women with T2DM. Overall, women with T2DM had the highest PNMR (48.8:1,000 maternities) owing to an excess in congenital anomalies. The corrected PNMR for women with pre-gestational diabetes was 34:1,000.
Conclusion: Our study describes a 3.8-fold increase in perinatal mortality in women with pre-gestational diabetes when compared to women with gestational diabetes. In particular women with T2DM are at highest risk of perinatal death, due to an excess in congenital anomalies in this cohort of women. Women with T2DM should undergo the same surveillance and care (including pre-conception counselling) as women with T1DM.