Can early ultrasound reduce the gestational age at abortion for fetal anomalies?

A significant proportion of second-trimester abortions are done for fetal anomalies. Our objective was to evaluate the impact of ultrasound at <14 weeks on the gestational age at abortion for structural fetal abnormalities.

Retrospective review identified all patients undergoing abortion following sonographic diagnosis of structural fetal anomalies at a single institution from 2004-2011. First-trimester ultrasound findings were reviewed, and abnormalities were categorized as "diagnostic" or "nondiagnostic." Chi-square analysis and Mann-Whitney U test were used for statistical comparison.

One hundred thirty-two patients who underwent abortion due to structural fetal abnormalities were included, 109 of whom underwent ultrasound at 11-13 weeks. In those scanned at <14 weeks, there were diagnostic findings in 36 cases (33.0%) and abnormal nuchal translucency or other nondiagnostic finding leading to early second-trimester ultrasound in 16 cases (14.7%). In those scanned at <14 weeks, median gestational age at abortion was earlier compared to those who underwent initial anatomic evaluation in the second trimester, 19 weeks (13.5-21) versus 21 weeks (19-22), p=.001.

Ultrasound at <14 weeks was associated with an earlier gestational age at abortion in pregnancies with structural fetal abnormalities.