Prenatal Growth in Fetuses with Isolated Cyanotic and Non-Cyanotic Congenital Heart Defects

Background: Fetal growth may vary significantly in different congenital heart defects (CHDs). Objectives: To investigate prenatal growth of CHD fetuses and its correlation with classifications based upon expected oxygen delivery to the fetal brain or structural findings. Methods: Seventy-nine euploid fetuses with isolated CHD were recruited prospectively and categorized by the expected oxygen supply to the brain (low, intermediate, and high) or by the expected arterial mixing considering two categories (cyanotic or non-cyanotic). Biometry and Doppler were recorded, and Z-scores (Zs) calculated. Growth changes at different time points were analyzed and compared with 150 controls. Results: A total of 664 exams were performed on 229 fetuses. Median head circumference (HC) Zs were lower in all CHD fetuses from the second trimester onwards and in cyanotic CHD fetuses from the first onwards, with associated smaller abdominal circumference (AC) in the third trimester (first-trimester biparietal diameter Zs cyanotic: -1.3 [-2.36; -0.98], non-cyanotic -0.72 [-1.25; -0.6], p = 0.044, second-trimester HC Zs cyanotic: -1.47 [-2.3; -0.84]; non-cyanotic -0.45 [-0.83; -0.02], p < 0.0001; AC Zs cyanotic 0.0 [-0.44; 0.86]; non-cyanotic 0.65 [0.31; 1], p = 0.0006). Birth-weight centiles were smaller in CHDs (particularly in cyanotic) with no differences between categories of brain oxygen delivery. Conclusions: Fetuses with cyanotic CHD have fetal growth restriction, impaired head growth, yet normal posterior fossa dimensions and fetal-placental Doppler.