THE PROGNOSTIC VALUE OF HEMOGLOBIN-A1C IN PREDICTING FETAL HEART-DISEASE IN DIABETIC PREGNANCIES

Objective: To evaluate detailed fetal echocardiography for predicting congenital heart disease in overt diabetic pregnancies. Methods: Overt diabetic gravidas with initial hemoglobin Alc (HbA1c) at or above 8.5 %, a family history of congenital heart disease, or fetal cardiac anom aly suspected on screening sonography were referred to a pediatric car diologist for detailed fetal echocardiography. After 7 years, the resu lts of the protocol were reviewed retrospectively. The sensitivity and specificity of the initial HbA1c in predicting congenital heart disea se were assessed. Results: During the study period, 193 patients recei ved care in the diabetes and pregnancy service. Sixty-four received fe tal echocardiography, 47 because of initial HbA1c levels at or above 8 .5% and 17 for other indications. Twenty fetuses had major anomalies, eight of which were cardiac (40%). Six of the cardiac anomalies had be en studied by fetal echocardiography, and four were diagnosed correctl y. The initial HbA1c was not different among pregnancies with major an omalies, cardiac anomalies, or no anomalies. No malformations were not ed in patients with normal initial HbA1c values. The overall sensitivi ty of the protocol for identifying congenital heart disease was 50% (f our of eight) and specificity was 54% (90 of 167). Detailed fetal echo cardiography had a sensitivity of 66% (four of six) and a specificity of 100% (58 of 58) for correctly identifying fetal congenital heart di sease. Conclusions: No cases of congenital heart disease were observed in patients with a normal initial HbA1c value. Among patients with ab normal HbA1c values, no critical level of glycohemoglobin was identifi ed that provided optimal predictive power for congenital heart disease screening. We recommend detailed fetal echocardiographic imaging in a ll patients with initial HbA1c levels above the upper limit of normal of 6.1%.