Diagnostic Accuracy of Early Ultrasound for Congenital Anomalies

Abstract

ABSTRACT

Detection of fetal anomalies on antenatal scan is very important as it may help the couple to decide whether they want continuation of pregnancy or termination and it also helps them to get the delivery in appropriate settings suitable for the resuscitation and management of the abnormal baby. Early detection even before 20 weeks if reliable may help reduce the anxiety of couple having previous history of congenital anomalies and early management with lesser morbidity. Objective: To find the diagnostic accuracy of 11-14 weeks ultrasound in fetal anomalies detection among high risk women taking 20 weeks scan as gold standard. Study Design: The study adopted a cross-sectional design which consisted of validation.

Setting: The study is conducted in “Fatima Ward, Gynaecology & Obstetrics Department, Allied Hospital, Faisalabad” in collaboration with “Allied Hospital, Faisalabad Radiology Department”. Duration of Study: Six months after the approval of research proposal. Period: August 2015 to January 2016. Methodology: After the approval of the study by the ethical committee of the Allied Hospital and written informed consent, the cases fulfilling the inclusion criteria were registered through OPD of Allied Hospital, Faisalabad. Patients were counseled and referred to ultrasound department of this same hospital, for trans-abdominal scan. A single operator performed all the scans after obtaining a verbal consent. Ultrasound was done on the Siemens machine using 2.5 – 3.5 MHz probe. To assess the diagnostic accuracy of 11 – 14 weeks scan, for anomaly detection; the screening was done and sensitivity was evaluated; patients were followed by taking contact numbers and a detailed anomaly scan at 20 weeks was done. Results: In our study, out of 611 cases, 22.91%(n=140) were between 18-25 years of age while 77.09%(n=471) were aged between 26-35, with a mean+sd value of 28.33+3.71 years, the occurrence of fetal anomalies (on gold standard) was documented in 9% presenting (n=55). However, 91% respondents (n=556) had no morbidity. The Diagnostic precision of 11-14 weeks ultrasound in fetal anomalies detection among high risk women taking 20 weeks scan as gold standard was calculated, it is showing that 7.36%(n=45) had true positive, while 1.80%(n=11) presented a false +ive outcome. 89.20% (n=545) had true -ive and 1.64% (n=10) had false -ive, sensitivity is calculated as 81.80%, specificity is calculated as 98.02%, positive predictive value (PPV) is calculated as 83.35%, negative predictive value (NPV) is calculated as 98.19% and overall accuracy rate is calculated as 96.56%. Conclusion: We finalized that the diagnostic accuracy of 11-14 weeks ultrasound in fetal anomalies detection among high risk women taking 20 weeks scan as gold standard is higher and useful in our population.