What is the role of the 11- to 14-week ultrasound in women with negative cell-free DNA screening for aneuploidy?

OBJECTIVE

This study aimed to examine the role of the 11- to 14-week ultrasound in women with negative cell-free DNA screening.

METHODS

A retrospective cohort study of women at increased risk for aneuploidy based on age or medical history and negative cell-free DNA screening between March 2012 and March 2014 was conducted. Patients were included if they had an 11- to 14-week ultrasound and obstetrical care at our center(s). Primary outcome was an unexpected finding at ultrasound. Imaging findings were compared with obstetrical outcome by medical record review.

RESULTS

Study group was composed of 1739 patients. An unexpected finding was identified in 60/1739 (3.5%). An abnormal fetal finding occurred in 37 living fetuses (2.1%); 33 had a nuchal translucency (NT) ≥ 3 mm, including four 'isolated' cystic hygroma and three with a structural abnormality. Four fetuses had a structural anomaly without a thick NT. Karyotype confirmed euploidy in 98.7% of available cases. Pregnancy termination was chosen by 63.6% of those with cystic hygroma or anomaly at the 11- to 14-week scan. Unexpected multiples were identified in 13 (0.7%) women and a fetal demise in 10 (0.6%).

CONCLUSION

Unexpected findings at the 11- to 14-week scan occur in 3.5% of patients with negative cell-free DNA. Recognition provides options for comprehensive testing, consultation, and management.