Am J Perinatol 2018; 35(14): 1346-1351
DOI: 10.1055/s-0038-1626715
SMFM Fellowship Series Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The Utility of Repeat Midtrimester Anatomy Ultrasound for Anomaly Detection

S. Lindsay Wood
1  Center for Women's Reproductive Health, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama
,
John Owen
1  Center for Women's Reproductive Health, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama
,
Sheri M. Jenkins
1  Center for Women's Reproductive Health, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama
,
Lorie M. Harper
1  Center for Women's Reproductive Health, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama
› Author Affiliations
Funding None.
Further Information

Publication History

15 April 2017

29 December 2017

Publication Date:
08 February 2018 (online)

Abstract

Introduction Although guidelines recommend repeat ultrasound in the setting of an incomplete fetal anatomic survey, the clinical utility of this practice has not been established. As such, we aimed to assess the yield of repeat ultrasound for anomaly detection following an incomplete survey.

Materials and Methods This is a retrospective cohort study of all singletons who underwent a midtrimester anatomic ultrasound at University of Alabama at Birmingham (UAB) from 2006 to 2014. Patients with an incomplete ultrasound underwent repeat examinations until completion. The population was divided into cohorts FIRST, SECOND, and THIRD, corresponding to the ultrasound at which the exam was deemed complete. Each detected anomaly was tallied. The number of ultrasounds needed to detect an anomaly was then assessed per group.

Results Of 15,768 ultrasounds performed on 13,740 patients, 11,828 exams were completed on first attempt; 1,796 patients required a second, while 116 patients required a third scan or more. We detected 324 anomalies; 93.8% in FIRST, 5.9% in SECOND, and 0.3% in THIRD. The number of scans needed to detect an anomaly was 39, 189, and 348 for FIRST, SECOND, and THIRD, respectively.

Conclusion Over 90% of anomalies are detected on the initial fetal anatomic survey. The incremental diagnostic yield then decreases, requiring appreciably more repeat scans to detect one anomaly.

Note

This study was presented in part as an oral presentation at the Annual Convention of the American Institute of Ultrasound in Medicine (AIUM), New York City, NY, USA, March 17–21, 2016.