Accuracy of Polyhydramnios for Detection of Fetal Anomalies on Ultrasound

Abstract

Objective: To determine the diagnostic accuracy of polyhydramnios for detecting fetal anomalies on ultrasound in singleton pregnancies.

Study Design: Cross-sectional study.

Place and Duration of Study: Armed Forces Institute of Radiology and Imaging, Military Hospital, Rawalpindi Pakistan, from Oct 2018 to Apr 2019.

Methodology: A total of 145 pregnant females coming for antenatal/anomaly scans, aged 18 to 45 years, were included. All scans were obtained with a 3.5-5 MHz curvilinear transducer and obstetric settings of the ultrasound machine. AFI was calculated as the sum of the deepest, unobstructed, vertical length of each pocket of fluid measured in cm in all four quadrants and then added to the others. The radiologist observed fetal structural anomalies.

Results: Polyhydramnios was present in 15(10.34%) patients. The congenital fetal anomaly on ultrasound was present in 6(4.14%) cases. In polyhydramnios-positive patients, 05(3.4%) had a congenital fetal anomaly, and 10(6.8%) had no congenital fetal anomaly. Among 130 polyhydramnios-negative patients, 01(0.7%) had a congenital fetal anomaly, whereas 129(88.9%) had no congenital fetal anomaly. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of polyhydramnios for detecting fetal anomalies on ultrasound were 83.33%, 91.41%, 29.4%, 99.23% and 92.41%, respectively.

Conclusion: This study concluded that the diagnostic accuracy of polyhydramnios¸, significantly moderate to severe forms, is relatively high for detecting fetal anomalies on ultrasound.
Keywords: Fetal anomalies, Polyhydramnios, Ultrasonography.