Poster Presentation Society of Obstetric Medicine of Australia and New Zealand and Australasian Diabetes in Pregnancy Society Joint Scientific Meeting 2017

Microalbuminuria as an early predictor of preeclampsia in the pre-gestational diabetic population (#113)

Monica Zen 1 2 , Suja Padmanabhan 2 3 , Ngai Wah Cheung 2 3 , Thushari I Alahakoon 1 2 , Vincent Lee 2 4
  1. Westmead Institute for Maternal & Fetal Medicine, Westmead Hospital, Westmead, NSW, Australia
  2. University of Sydney, Western Clinical School, Westmead, NSW, Australia
  3. Department of Endocrinology, Westmead Hospital, Westmead, NSW, Australia
  4. Department of Renal Medicine, Westmead Hospital, Westmead , NSW, Australia

Preeclampsia complicates 2-8% of all pregnancies and is a major cause of maternal and perinatal morbidity and mortality worldwide. At present, spot urinary protein to creatinine ratio (uPCR) forms part of the diagnostic criteria of preeclampsia and aids clinicians in the stratification of perinatal risk, guiding management decisions. Women with pregestational diabetes are at increased risk of preeclampsia and other adverse pregnancy outcomes. We hypothesize that in these women, many cases of nephropathy are missed if uPCR alone is used, and that mild diabetic nephropathy, as assessed by those with elevated urinary albumin to creatinine ratio (uACR), is associated with worse pregnancy outcome. This study aimed to establish whether uPCR and uACR can be used as independent predictive markers for preeclampsia and adverse outcomes, and compare their respective prognostic ability.

A prospective cohort study of 158 women with pre-gestational diabetes was conducted between 2013-2016, over three tertiary centres in Western Sydney. Urine was sampled in each trimester. The rate of preeclampsia within this cohort was found to be 17.1%. We found that both uPCR and uACR correlated with preeclampsia in trimester 3 (p-value 0.005, 0.012 respectively). While not statistically significant, there was a doubling in cases of preeclampsia in the microalbuminuric cohort compared to those with no albuminuria. This trend was not present with increasing uPCR levels in trimester 1. Subanalysis of the 113 patients with normal pregnancy uPCR (<30mg/mmol) in trimester 1 demonstrated that microalbuminuria was predictive of preeclampsia (p-value 0.01) and need for operative delivery (p-value 0.03). We conclude that in this high-risk obstetric cohort, both uPCR and uACR have similar diagnostic ability, but microalbuminuria appears to have prognostic ability at a much earlier gestation. Therefore we suggest that assessing microalbuminuria rather than overt proteinuria in the 1st trimester provides prognostically useful information in women with pregestational diabetes.