Pregnancy in women with chronic kidney disease (CKD) continues to present a challenging clinical scenario. Over the past decade, there has been a substantial increase in data published, which has influenced the approach and management of CKD in pregnancy. However, pregnancy outcomes in women with a solitary kidney remain an under-researched phenomenon due to a scarcity of cases. Most of our knowledge stems from studies of living kidney donors, a group biased by strict selection criteria. Therefore, pregnancy outcomes in women with CKD and a solitary kidney remain an enigma, as the rarity of this unique clinical scenario has limited the opportunity for further research.
We report a case of successful pregnancy outcome in a 30-year-old primiparous woman, with stage 3b chronic kidney disease, on a background of a solitary kidney, with previous pelvic-ureteric-junction obstruction requiring pyeloplasty at the age of 15. Despite the absence of hypertension and minimal proteinuria, her risk of maternal and foetal complications was assessed as high, given her estimated Glomerular Filtration Rate (eGFR) of 31-37ml/min (creatinine 160-180umol/L) pre-conception. Her pregnancy was complicated by significant pelvicalyceal system dilatation, which exceeded the accepted physiological changes in pregnancy, and generated concern for obstruction and the need for stent or nephrostomy insertion. Her right kidney measured 26cm longitudinally with an AP pelvis measurement of 6.6cm. Her creatinine, which had increased to 180-200umol/L in her second trimester, remained stable, suggesting that her solitary kidney was not functionally obstructed. She was, therefore, able to be managed conservatively, with regular surveillance imaging and blood tests, and invasive intervention was avoided. Both her imaging and blood tests remained stable during her pregnancy and she delivered at 36 weeks' gestation without complications. Post-partum, her hydronephrosis improved significantly with repeat imaging showing a reduction in the size of her kidney to 12cm. Her creatinine remained stable between 160-190umol/L.
This case report not only adds invaluable data to the scarce CKD-pregnancy literature but also highlights the rare underlying pathophysiology and its impact on antenatal management and outcomes in this high-risk population.