First-trimester detection of fetal anomalies in pregestational diabetes using nuchal translucency, ductus venosus Doppler, and maternal glycosylated hemoglobin.

Abstract

The frequency of fetal anomalies in women with pregestational diabetes correlates with their glycemic control. This study aimed to assess the predictive performance of first-trimester fetal nuchal translucency (NT), ductus venosus (DV) Doppler, and hemoglobin A1c (HbA1c) to predict fetal anomalies in women with pregestational diabetes. This was a prospective observational study of patients undergoing first-trimester NT with DV Doppler. Screening performance was tested for first-trimester parameters to detect fetal anomalies. Of 293 patients, 17 had fetal anomalies (11 cardiac, 7 major, 3 multisystem). All anomalous fetuses were suspected prenatally. One had NT >95th centile, 2 had reversed DV a-wave, and 13 had HbA1c >7.0%. The HbA1c was the primary determinant of anomalies (r(2), 0.15; P < .001) and >8.35% was the optimal cutoff for prediction of anomalies with an area under the curve of 0.72 (95% confidence interval, 0.57-0.88). Therefore, first-trimester prediction of anomalies was best in women with increased NT or HbA1c >8.3% (sensitivity 70.6%, specificity 77.4%, positive predictive value 16.2%, negative predictive value 97.7%, P < .001). In women with pregestational diabetes and poor glycemic control, an increased NT increases risks for major fetal anomalies. Second-trimester follow-up is required to achieve accurate prenatal diagnosis.