The value of the first trimester ultrasound in the era of cell free DNA screening

• Published in: Prenatal diagnosis 2016-12, Vol.36 (13), p.1192-1198
• Main Authors: Rao, Rashmi R., Valderramos, Stephanie G., Silverman, Neil S., Han, Christina S., Platt, Lawrence D.
• Format: Article
• Language: English
• Subjects: Adult; Diagnostic Errors - statistics & numerical data; DNA - blood; Female; Fetus - chemistry; Gestational Age; Humans; Maternal Serum Screening Tests - methods; Middle Aged; Pregnancy; Pregnancy Trimester, First; Prenatal Diagnosis - methods; Prenatal Diagnosis - statistics & numerical data; Retrospective Studies; Ultrasonography, Prenatal
• ISSN: 0197-3851; 1097-0223
• DOI: 10.1002/pd.4955

Objective To describe the clinically relevant findings detected by the first trimester ultrasound (FTU) and to determine the additional value of the FTU compared to cell free DNA (cfDNA) alone. Method Retrospective cohort study of patients undergoing a FTU at a maternal–fetal medicine referral practice. Fetal, gynecologic, and placental findings detected by ultrasound were analyzed with available cfDNA and diagnostic testing results. A subgroup analysis of positive ultrasound findings and cfDNA results was performed to assess the additional benefit of ultrasound evaluation in FT prenatal screening. Results There were 1906 FTU between 1 October 2013 and 1 October 2014. CfDNA results were available for 959 (50%) patients. FTU detected: 42 fetal (2.2%), 286 gynecologic (15.0%), and 317 placental (16.6%) findings. CfDNA results were discordant with invasive testing results in 8/61 cases (13%) and with ultrasound findings in 18/42 (42%) cases. There were six false positive and two false negative cfDNA results confirmed by diagnostic testing. Subgroup analysis revealed that cfDNA as the sole method of prenatal screening in the FT would miss 95% of the fetal findings detected with ultrasound. Conclusion The comprehensive FTU provides valuable clinical information about fetal and maternal anatomy that cannot be detected with cfDNA alone. © 2016 John Wiley & Sons, Ltd. What's already known about this topic? Cell free fetal DNA (cfDNA) is widely used as a primary screening tool for aneuploidy in the general obstetric population CfDNA can detect trisomy 21 with excellent sensitivity; however, detection rates for cfDNA and other less common aneuploidies and microdeletions are not well studied. CfDNA is not designed to detect some congenital and placental abnormalities. There is suboptimal counseling regarding the role of cfDNA in prenatal screening What does this study add? The comprehensive first trimester ultrasound should be used in conjunction with cfDNA as it provides valuable clinical information about fetal and maternal anatomy and clinically relevant placental findings that cannot be detected with cfDNA alone.