Poster Presentation Society of Obstetric Medicine of Australia and New Zealand ASM 2026

ADEQUACY AND SAFETY OF RENAL BIOPSIES IN PREGNANCY –  A CASE-CONTROL STUDY (#156)

Tracy Li 1 2 , Soo Ying Ong 3 , Jun Mai 3 , Beata Zahorowska 3 , Daniela Potter 2 3 4 , Renuka Shanmugalingam 1 2 3 4 , Tim Spicer 2 3 , Angela Makris 1 2 3 4
  1. Department of Obstetrics and Gynaecology , Liverpool Hospital, Sydney, New South Wales, Australia
  2. South Western Sydney Clinical School, University of New South Wales , Sydney, New South Wales , Australia
  3. Department of Nephrology, Liverpool Hospital, Sydney, New South Wales , Australia
  4. Western Sydney Clinical School, University of Western Sydney, Sydney, New South Wales , Australia

Aim: To compare the adequacy and safety of renal biopsies performed during pregnancy with biopsies performed in non-pregnant women.

Background: Percutaneous renal biopsy is an invasive procedure with recognized risks. Renal biopsies are avoided during pregnancy due to concerns of increased procedural complications. There is limited data on the adequacy and safety of performing renal biopsies in pregnancy.

Methods: A single-centre retrospective case-control study compared women who underwent renal biopsy during pregnancy (including within 6 weeks postpartum) with women who underwent biopsy at other times. Cases were identified from a renal biopsy database (2007-2026). Non-pregnant controls were matched for age, gender, body mass index and year of biopsy. Clinical data was extracted from electronic medical records. Primary outcome was biopsy-related complications. Secondary outcomes included biopsy adequacy and pregnancy outcomes. Statistical analyses were performed using SPSS.

Results: 68 women were included (34 control and 34 pregnancy group), with no differences in baseline characteristics. There was no difference in complication rate (p=1.0). Biopsy inadequacy rates (<10 glomeruli or insufficient tissue for diagnosis) were comparable between the pregnancy and control groups (17.6%vs11.8%,p=0.734). On regression modelling, lower platelet counts independently predicted biopsy inadequacy (adjusted p=0.033), while higher proteinuria was associated with increased complication risk (adjusted p=0.019). Most pregnancy biopsies were performed postpartum (35.3%,n=12;median 4 days,IQR 3–12.5) or during the second trimester (32.4%,n=11;median gestation 16 weeks,IQR 10+2–21+6).

Conclusion: There was no difference in complication or adequacy rates for biopsies performed during pregnancy compared with non-pregnant controls. Pregnancy should not preclude renal biopsy when clinically indicated.