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Kidney Week

Abstract: SA-OR109

A Population Study of Pregnancy Outcomes by Pre-Conception GFR

Session Information

Category: Women’s Health and Kidney Diseases

  • 2000 Women’s Health and Kidney Diseases


  • Tangren, Jessica Sheehan, Massachusetts General Hospital, Boston, Massachusetts, United States
  • Garg, Amit X., London Health Sciences Centre, London, Ontario, Canada
  • Dixon, Stephanie, Institute for Clinical Evaluative Sciences, London, Ontario, Canada
  • Dirk, Jade, Institute for Clinical Evaluative Sciences, London, Ontario, Canada
  • Mccallum, Megan K., Institute for Clinical Evaluative Sciences, London, Ontario, Canada
  • Akbari, Ayub, University of Ottawa, Ottawa, Ontario, Canada
  • Hladunewich, Michelle A., University of Toronto, Toronto, Ontario, Canada

Chronic kidney disease is a known risk factor for adverse pregnancy outcomes including preeclampsia and preterm delivery, however studies on CKD pregnancies are small, outdated and contain few subjects with moderate or advanced stage CKD. Our objective was to investigate the association of pre-conception GFR with the risk of adverse pregnancy outcomes in a large population-based cohort with more than 400 pregnancies in women with pre-existing moderate or advanced stage CKD.


A population-based cohort study of women in the province of Ontario, Canada, who had an obstetric delivery between 2007 and 2017. Administrative health databases linked using unique identifiers at ICES were used to capture all hospital births in Ontario and a majority of outpatient laboratory testing. Women with a serum creatinine measured within 2 years of conception were included for analysis.


The mean pre-conception eGFR among the 458,206 pregnancies included in the analysis was 114 ± 14 ml/min/1.73 m2, of which 28,232 were 60 to <90 ml/min/1.73 m2, 330 were 45 to <60 ml/min/1.73 m2 and 97 were <45 ml/min/1.73 m2. There were no maternal deaths among women with eGFR < 60 ml/min/1.73 m2. Rates of gestational hypertension, preeclampsia and preterm delivery increased monotonically across pre-conception eGFR categories (Figure 1). Maternal admission rate to the ICU during pregnancy or within 90 days after delivery was 7% among women with an eGFR < 45 ml/min/1.73 m2 compared with 1% in women with eGFR > 90 ml/min/1.73 m2.


In this population-based study of pre-conception CKD, low pre-conception eGFR was associated with high rates of maternal morbidity and adverse pregnancy outcomes. Absolute risk was highest in women with eGFR < 45 ml/min/1.73 m2, however even women with mildly impaired eGFR were at higher risk for adverse pregnancy outcomes.


  • NIDDK Support