Hydronephrosis in Infancy and Early Childhood; Etiology, Follow-up, and Outcomes in the Northern Area of Jordan

Export Objective: Antenatal hydronephrosis (AHN) is the most common congenital genitourinary system anomaly detected by antenatal ultrasounds (US), follow up after birth is mandatory so that long-term morbidity can be avoided. The aim of this study was to determine the multiple outcomes of hydronephrosis (HN) diagnosed early in life and to identify the most common etiologies of AHN. Methods: A retrospective cohort study was conducted using data obtained from electronic charts, and we converted the collected data into electronic form. One hundred and twenty-five patients were included: those who were younger than 5 years and diagnosed or followed-up for HN in Princess Rahma Children Teaching Hospital during the period extending between March 2018 and March 2022. The severity and etiologies of postnatal HN were recorded. The relationship between postnatal HN severity, different etiologies, and outcomes was analyzed. Results: A total number of 125 patients were included in this study, 95 (76.0%) were males. HN was found to be mild in 66 (52.8%), moderate in 35 (28%), and severe in 18 (14.4%) of cases. A normal first postnatal ultrasound was found in 6 (4.8%) patients. The patient is considered to have transient HN if his condition resolves spontaneously during the period of follow-up, especially in the first year of life. A causative etiology was found in 41 (32.8%) patients; ureteropelvic junction obstruction (UPJO) in 18 (14.4%), vesicoureteral reflux (VUR) in 12 (9.6%), multicystic dysplastic kidney (MCDK) in 3 (2.4%), and other anomalies in 8 (6.4%). 49 (39.2%) had an isolated persistent HN without renal abnormalities. Twenty-four (19.2%) had spontaneous resolution during the follow-up period, 11 (8.8%) were misdiagnosed with HN as they were found to have extra renal pelvis. 22.4% of the patients developed urinary tract infection (UTI), which was higher in females. Males were more likely to have bilateral HN, but the need for surgery and the occurrence of chronic kidney disease (CKD) were higher in females. Eighty-nine (71.2%) were antenatally diagnosed, and 36 (28.8%) were diagnosed postnatally, either during the UTI investigation or incidentally. Upon follow-up, spontaneous resolution rate was 68%, surgery, or progressive course was evident in 35 (28%). Conclusions: HN during the neonatal and infancy periods can be a serious condition and end up with a CKD. PUJ stenosis is the most common etiology of severe HN. Spontaneous resolution may occur, especially in mild HN, while severe HN cases have higher rates of surgery and CKD. UTI can be the presenting symptom in missed, undiagnosed cases. Intrauterine diagnosis and proper follow-up are mandatory to avoid these complications.