Which ultrasound finding is associated with a risk of hydronephrosis due to lower urinary tract obstruction?

The presence of lower urinary tract obstruction can lead to hydronephrosis, a condition where the kidneys become swollen due to a build-up of urine. Among the trisomies mentioned, certain conditions are more commonly associated with structural anomalies, including those affecting the urinary system.

Trisomy 21 (Down syndrome) is known to have a range of associated congenital anomalies, but the risk of hydronephrosis due to lower urinary tract obstruction is not as prominent compared to other trisomies. Trisomy 13 and Trisomy 18 are also known for a variety of severe anomalies, including those affecting renal development, but they do not have a significant established association with lower urinary tract obstruction leading to hydronephrosis.

The statement referring to trisomy affecting 10% indicates that a notable proportion of individuals with certain trisomies may have underlying issues that could contribute to complications like hydronephrosis. This suggests awareness of the prevalence and implications of structural defects observed in the context of these genetic conditions, highlighting the relevance for genetic counseling and prenatal diagnosis. Therefore, this choice captures the essence of understanding the broader implications of genetic conditions on renal health and associated risks.