Renal Diagnoses and Outcomes in Women with Disease Identified During Pregnancy Compared

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Renal Diagnoses and Outcomes in Women with Disease Identified During Pregnancy Compared with Non-Pregnant Controls: A 2 Centre Cohort Study of 1406 Women

P Webster1, K Bramham2, L Webster2, H. Terence Cook1, C Horsfield2, I Lydon2, M Homsy2, R Vaz1, C Santos1 & L Lightstone1.

1Imperial College Healthcare NHS Trust Renal & Transplant Centre, Hammersmith Hospital
2Maternal and Fetal Research Unit, King’s College London

Introduction: Chronic kidney disease (CKD) is estimated to affect 2% of women aged 16-54yrs in England. Pregnancy is frequently the first time women are seen by health services, and provides an opportunity to identify early disease. Our aims were i) To compare the aetiology of renal disease diagnosed during/after pregnancy with disease identified in non-pregnant women of child-bearing age; ii) To compare the long term renal outcomes of these two groups.

Methods: Native renal biopsies from 2tertiary centreswere studied (1997-2012). Renal disease identified in pregnancy-related (PR) biopsies included antenatal and postpartum biopsies investigating abnormalities recognised during pregnancy.Controls included biopsies from all women of childbearing age (16 to 49yrs). First biopsies were included. Repeat and inadequate biopsies were excluded.

Results: 174PR biopsies (19 antenatal, 155 postpartum) were identified; mean age at biopsy 32.5yrs. 1232 biopsies in control women; mean age 35.4yrs. PR women were younger than controls(p<0.0001). Follow-up time was similar between groups. Focal segmental glomerulosclerosis (FSGS) wasthe most common diagnosis in PR biopsiesand was more frequent than in controls(PR - 59/174, 33.9%; Controls - 143/1232, 11.6%; p<0.0001). Control patients had a higher incidence of lupus nephritis (p<0.001) and diabetic nephropathy (p=0.036). There were no significant differences inother diagnoses between PR and control biopsies. For women with FSGS, similar numbers reached end-stage renal disease requiring renal replacement therapy (p=0.281) and there was no difference in rate of change in creatinine between groups (median change in Cr/month PR = 0.17µmol/L (IQR 0.0, 1.2), control = 0.10µmol/L (IQR -.014, 0.71); p=0.228).

Conclusion: Renal diseases discovered during / after pregnancy occur at a younger age than in non-pregnant controls.FSGS is the most common diagnosis identified during or after pregnancy, but does not appear to be associated with worse long term renal outcomes compared with disease identified in non-pregnant controls. It is currently unclear whether pregnancy reveals or causes FSGS, or whether lesions are primary or secondary. Further work is needed to explore the nature of FSGS lesions, and to define risk factors for progression in order to optimise antenatal and postpartum management.