Diagnostic yield and safety of percutaneous native kidney biopsy in pregnancy: 20-years of single-center experience

Background Percutaneous kidney biopsy is a fundamental procedure in nephrology. Although pregnancy is not a contraindication, a careful risk–benefit assessment is mandatory in pregnancy. We aimed to evaluate safety and diagnostic accuracy of percutaneous kidney biopsy in pregnancy in a single-center retrospective study. Methods Percutaneous kidney biopsy was performed in 19 pregnant patients. Demographics, estimated glomerular filtration rates, serum albumin levels, and proteinuria levels at the time of biopsy were evaluated. Biopsy-related complications, diagnoses, and treatments during the follow-up were analyzed. In addition, delivery success, preeclampsia, early delivery, low birth weight rates, and long-term outcomes of the patients were retrieved and analyzed. Results Mean patient age was 27 (range 16–41) years. Median gestational week at kidney biopsy was 20th. All but one biopsies were diagnostic. Median gestational week of delivery was 35 (range 23–39) gestational weeks. Preterm delivery (< 37 gestational weeks) and low birth weight (< 2500 mg) occurred in 73.7% and 52.6% of cases, respectively. Median weight at birth was 2500 mg. The incidence of preeclampsia was 57.9%. Overall 89.5% of the children survived. Median post-biopsy follow-up was 64 months. Maternal mortality was not observed during the follow-up period. End stage kidney disease developed in one patient. The results of percutaneous kidney biopsy led to therapeutic decisions in 73.7% of cases. Conclusions Although percutaneous kidney biopsy is not frequently performed during pregnancy, it is relatively safe and usually diagnostic, and may guide further follow-up. Graphical abstract