Embryonic and Fetal Heart Development Before 12 Weeks of Gestation

Objective: To assess embryonic and fetal cardiac growth and development using transvaginal 2-dimensional sonography before 12 weeks of gestation. Methods: Transvaginal scans for first-trimester dating were performed for 131 normal fetuses at 8-11 + 6 weeks of gestation. The basal-apical length (BAL), transverse length (TL), cardiac circumference (ECC), embryonic cardiac area (ECA), global sphericity index (GSI), and cardio-thoracic area ratio (CTAR) were able to be obtained in 105 normal embryos and fetuses. Results: Nomograms for several cardiac parameters including BAL, TL, ECC, ECA, GSI, and CTAR were constructed. BAL, TL, ECC, and ECA increased curvilinearly with advancing gestation (R-2 = 0.97406, 0.980396, 0.978359, and 0.920705, respectively, P < .001). GSI (mean, 1.14; SD, 0.10) and CTAR (mean, 15.7%; SD, 3.3%) values were constant at 8-11 + 6 weeks of gestation. There were significant curvilinear correlations between BAL, TL, ECC, and ECA, and crown-rump length (CRL) (R-2 = 0.975976, 0.983482, 0.980673, and 0.929936, respectively, P < .001). GSI and CTAR values were not changed with the increase of CRL during this period. Conclusion: Our results provide nomograms for several cardiac parameters which may improve the understanding of embryonic and fetal cardiac growth and development prior to 12 weeks of gestation.