Correlation between prenatal ultrasound and fetal autopsy findings on urinary system anomalies terminated in the second trimester.

Objective: This prospective study was designed to compare ultrasound and autopsy findings on fetal urinary system malformations in second trimester terminations of pregnancy to evaluate the degree of agreement of such findings.

Methods: From January 2003 to October 2012, a total of 308 second trimester terminations of pregnancy were performed because of fetal malformation diagnosed through second trimester ultrasound examination at a tertiary referral center.

Result: Among 308 second trimester fetuses with congenital anomalies, 62 (20.1%) had urinary anomalies. Ultrasound and fetal autopsy findings were in full agreement for urinary system malformations in 45 (72.6%) of 62 cases. In six (9.7%), autopsy confirmed the malformations detected by ultrasound but showed additional lesser urinary anomalies. In 10 (16.1%) cases, autopsy revealed major urinary anomalies not determined by ultrasound. In one case (1.6%), ultrasound reported bilateral renal agenesis; however, autopsy revealed a horseshoe kidney. The ultrasound screening sensitivity was 83.8%, and specificity was 99.5%.

Conclusion: The results showed that prenatal ultrasound achieved a high accuracy in diagnosing fetal urinary malformations. However, fetal autopsy occasionally adds valuable information to prenatal ultrasound findings.