The Relationship Between Prenatal Hydronephrosis and Vesicoureteral Reflux in Children With a History of Prenatal Hydronephrosis in the Third Trimester of Pregnancy

Prenatal hydronephrosis is found in 1%-5% of pregnancies. Without well-timed diagnosis and treatment, it can lead to irreversible outcomes. Because little information is available on the indication of Vesicoureteral Reflux (VUR) regarding the antenatal diameter of the kidney pelvis, the current study aimed to determine the association between prenatal hydronephrosis and the VUR.

This cross-sectional study was conducted from 2011 to 2016 on 200 neonates with hydronephrosis detected in fetal life ultrasounds in the third trimester of pregnancy. We assessed the prenatal and postnatal kidney ultrasonography of 400 kidneys and Voiding Cystourethrogram (VCUG). We employed the Spearman correlation coefficient for determining the association between study variables. The obtained data were analyzed using SPSS 16.0 software at a significance level of less than 0.05.

Of 200 infants, 71.5% were males and 28.5% were females. No significant relationship was found between the degree of antenatal hydronephrosis and the VCUG severity (r=0.098, P=0.106). Despite antenatal hydronephrosis, the degree of postnatal hydronephrosis and the VCUG severity was correlated (r= 0.255, P=0.001).

There is no correlation between the severity of fetal hydronephrosis and VUR severity or the presence of a greater correlation between postnatal hydronephrosis and degree of VUR. Thus in cases of mild prenatal hydronephrosis, we suggest urinary tract ultrasonography three to seven days after birth and then cystography if postnatal sonography showed moderate or severe or progressive hydronephrosis.