Fetal Hydronephrosis in the Second and Third Trimester of Pregnancy and Six Months Follow-up after Birth

Background: Prenatal hydronephrosis (PNH) may be associated with congenital abnormalities in the urinary tract. This study aimed to determine and follow up on the fetus diagnosed with PNH until the first six months after birth.Methods: This prospective longitudinal study was conducted from May ۲۰۲۱ to July ۲۰۲۲ 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 ۸۰ ultrasound machine. If it is ≥ ۴ mm in the ۲nd and ≥ ۷ mm in the ۳rd trimesters, it is considered PNH. These infants were followed up until the first six months after birth. Data analysis was performed using SPSS ۲۰, Chi-square, Fisher's exact, and T-tests.Results: Of the ۵۶ eligible fetuses, ۵۰ fetuses were followed up. The mean gestational age at the time of diagnosis of PNH was ۲۰.۴۸ ± ۵.۳۷ weeks. Twenty cases of PNH (۴۵.۴۵%) spontaneously improved until birth. Thirty cases had hydronephrosis in the first week after birth, ۱۶ of which (۵۳.۳۳%) were bilateral. The cause of PNH in ۹۰% 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 six months, and ۶ cases (۱۲%) had adverse outcomes. The severity of PNH in the ۳rd trimester had a significant relationship with adverse outcomes (P=۰.۰۰۱). The APRPD in the ۳rd trimester has more sensitivity and specificity than in the ۲nd trimester for predicting adverse outcomes after birth.Conclusion: In most cases, the cause of PNH is idiopathic, and the resolution of PNH occurs up to ۶ months after birth. Moderate and severe PNH was associated with a poorer outcome and requires more follow-up and intervention.

کلیدواژه ها:

complication ، Fetal Hydronephrosis ، fetal pyelectasis ، Perinatal outcome