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

Objective: 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. Study Design: 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. Results: 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 (r², 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). Conclusion: 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.