Empty fetal renal fossa results of a tertiary center

Objective Our aim is to present the anomalies included empty renal fossa (ERF) in the ultrasonographic examination performed in the perinatology outpatient clinic of our hospital in 2020. Methods Ultrasonography requests were made in Kayseri City Hospital Perinatology Outpatient Clinic between January 1 and December 31, 2020, and 2405 ultrasonographic examinations were performed on 1961 pregnant women. The reports of the patients were analyzed retrospectively after the ethics committee approval of our hospital was obtained. All ultrasonographic examinations were performed by an experienced perinatologist using Samsung HS70A (Hampshire, UK), probe CA 1-7A. The fetuses diagnosed with empty renal fossa were screened in terms of accompanying anomalies and the detected anomalies were noted. Results Pregnant women were between 13 and 34 (mean 23.9) years old and their gestational ages were between 17 and 34 weeks. The incidence of empty renal fossa was found to be 0.75% for all pregnant women. An empty renal fossa finding was observed in a total of 15 fetuses. Horseshoe kidneys were present in four fetuses (0.20%), bilateral renal agenesis was present in five fetuses (0.25%), left renal agenesis was present in two fetuses (0.10%), pelvic kidneys (one on the right and two on the left) were present in three fetuses (0.15%), and crossed fused ectopic kidney was present in one fetus (0.05%). Conclusion The cause of ERF seen with anhydramnios is bilateral renal agenesis. In the presence of normal amniotic fluid, it should be considered that ERF may be due to various reasons and since the prognosis may change according to the accompanying anomalies, we must increase the accuracy of prenatal diagnosis.