Document Type : Original Article

Authors

1 Student Research Committee, Babol University of Medical Sciences, Babol, Iran.

2 Department of Pediatrics, Clinical Research Development Unit of Rouhani Hospital, Amirkola Children's Non-Communicable Diseases Research Center, Babol University of Medical Sciences, Babol, Iran.

3 Associate Professor, Department of Midwifery and Reproductive Health, Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences

4 Department of Pediatrics, Amirkla Children's Non-Communicable Disease Research Center, Babol University of Medical Sciences, Babol, Iran

5 Social Determinants of Health Research Center, Health Research Institute, Department of Biostatistics & Epidemiology, School of Public Health, Babol University of Medical Sciences, Babol, Iran

6 Perinatologist, Department of Gynecology and Obstetrics, Clinical Research Development Unit of Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran

7 Department of Pediatrics, Clinical Research Development Unit of Rouhani Hospital, Amirkola Children's Non-Communicable Diseases Research Center, Babol University of Medical Sciences, Babol, Iran

8 Department of Gynecology Oncology, Imam Hossein Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

9 Department of Radiology, Clinical Research Development Unit of Rouhani Hospital, School of Medicine, Babol University of Medical Sciences, Babol, Iran.

10.22038/ijn.2024.74690.2445

Abstract

Objective: Prenatal hydronephrosis (PNH) may be associated with congenital abnormalities in urinary tract. This study aimed to determine and follow up on the fetus diagnosed with PNH until the first 6 months after birth.

Methods: This prospective longitudinal study was conducted from May 2021 to July 2022 in fetuses who were diagnosed with PNH based on the size of the anterior-posterior diameter of the renal pelvis (APRPD) by a perinatologist with an S W 80 ultrasound machine. If it is ≥ 4 mm in the 2nd and ≥ 7 mm in the 3nd trimesters, it was considered PNH. These infants were followed up until the first 6 months after birth. Data analysis was performed using SPSS 20 and use Chi-square, Fisher's exact test and T Test.

Results: Of the 56 eligible fetuses, 50 fetuses were followed up. The mean gestational age at the time of diagnosis of PNH was 20.48 ± 5.37 weeks. Twenty cases of PNH (45.45%) spontaneously improved until birth. 30 cases had hydronephrosis in the first week after birth, 16 of which (53.33%) were bilateral. The cause of PNH in 90% is idiopathic. Other causes include polycystic kidney, vesicoureteral reflux, and posterior urethral valve. One case died in the first week after birth. Forty-three cases had spontaneous recovery of PNH by 6 months, and 6 cases (12%) had adverse outcomes. The severity of PNH in the 3nd trimesters had a significant relationship with adverse outcomes (P=0.001). The APRPD in the 3nd trimesters has more sensitivity and specificity than in the 2nd trimester for predicting adverse outcomes after birth.

Conclusion: In most cases, the cause of PNH was idiopathic, and the resolution of PNH occurs up to 6 months after birth. Moderate and severe PNH was associated with a poorer outcome and requires more follow-up and intervention.

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