DANNER R1, MCMICHAEL L1, JESUDASON S1
1Central Northern Adelaide Renal and Transplantation Service, Renal Unit, Royal Adelaide Hospital, Adelaide, Australia
Background: Pregnancy outcomes in women with a solitary kidney and Chronic Kidney Disease (CKD) are poorly defined. Mild hydronephrosis is a common physiological phenomenon in pregnancy, occurring due to hormonal and mechanical changes, but may particularly affect women with a single kidney.
Case Report: We report a case of successful pregnancy outcome in a 30-year-old primiparous woman, with preconception stage 3b CKD (serum creatinine 160-180umol/L), due to a solitary kidney and previous pelvic-ureteric-junction obstruction requiring pyeloplasty. While she did not have preconception hypertension or proteinuria, her risk of maternal and foetal complications was assessed as being high, due to preconception CKD stage. The pregnancy was complicated by significant pelvicalyceal system dilatation identified at 28 weeks’ gestation during a routine fetal scan, with longitudinal kidney size increasing from 10cm to 26cm. The hydronephrosis exceeded the expected physiological change in pregnancy, generating concern for functional obstruction. The need for stent or nephrostomy insertion was considered. However, her serum creatinine remained stable at 180-210 umol/L in the second trimester, suggesting that her kidney was not functionally obstructed. She was therefore managed conservatively with regular clinical, biochemical and imaging surveillance. She was induced at 36+1 weeks’ gestation due to concerns the clinical situation might decline. The baby was healthy, with no placental vasculopathy. Post-partum, the hydronephrosis improved rapidly with reduction in kidney size to 12cm. Her creatinine remained stable between 160-190umol/L one-year post-partum. She remained normotensive throughout.
Conclusions: This case highlights that despite extreme physiological pelvicalyceal dilatation affecting a single kidney, this potentially high-risk patient had an excellent pregnancy outcome with no deterioration of renal function. Regular renal imaging during pregnancy in women with single kidneys should be undertaken.
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