Significant kidney disease in pregnancy: Feasibility and outcomes of a national population-based study using the Australasian Maternity Outcomes Surveillance System

Background: Current understanding of clinical practice and care for maternal kidney disease in pregnancy in Australia is hampered by limitations in available renal-specific datasets.

Aims: To capture the epidemiology, management, and outcomes of women with significant kidney disease in pregnancy and demonstrate feasibility of a national cohort study approach.

Materials and methods: An Australian prospective study (2017-2018) using a new kidney disease-specific survey within the Australasian Maternity Outcomes Surveillance System (AMOSS). Women who gave birth with acute kidney injury (AKI), advanced chronic kidney disease (CKD), dialysis dependence or a kidney transplant were included. Demographic data, renal and obstetric management, and perinatal outcomes were collected.

Results: Among 58 case notifications from 12 hospitals in five states, we included 23 cases with kidney transplant (n = 12), pre-existing CKD (n = 8), newly diagnosed CKD (n = 2) and dialysis (n = 1). No cases of AKI were reported. Reporting rates were better in states with study investigators and, overall, cases were likely under-reported. Nearly 35% of women had a non-delivery-related antenatal admission. Nephrology involvement was 78.3% during pregnancy and 91% post-partum. Adverse events were increased, including pre-eclampsia (21.7%), and preterm birth (60.9%). Women had high rates of aspirin (82.6%) and antihypertensive (73.9%) use, indwelling catheter for labour/delivery (65.2%), caesarean delivery (60.9%), and blood transfusion (21.7%).

Conclusions: This first-ever Australian prospective study of significant kidney diseases in pregnancy provided novel insights into renal-specific clinical patterns and practices. However, under-reporting was likely. Future studies need to overcome the challenges of case identification and data collection burden.