First trimester echocardiographic screening is an increasingly common practice performed by skilled professionals; however, it requires more skills and experience to be acquired since the degree of visualization of different cardiac structures vary in a considerable fashion and rely on operator and machine related factors. First trimester screening for cardiac anomalies could be used as an adjunct to routine anomaly scanning performed from 18 to 22 gestational weeks [1, 2].
Fetal cardiac development could be affected by chronic medical disorders such as DM and could be observed more frequently in families with history of consanguinity and congenital heart disease. So, there is an increasing trend as regards the indications for early first trimester fetal echocardiography aided with advanced technology [13, 15].
A cornerstone issue that allows the parents to gain benefit from early diagnosis is to have time to make informed decisions concerning their pregnancy [16].
Furthermore, congenital defects observed within the first gestational trimester could be assessed for their developmental progress and possible prognosis that could be implemented in family discussion and counseling that denotes that more minor fetal cardiac anomalies diagnosed early could be followed up throughout gestation to determine the degree of progression providing clinical opportunities for earlier interventional management and provides a clue for the prognosis post-natal period [1, 3].
The current research study findings have interestingly revealed that color Doppler in comparison to 2D in observation of IVC, pulmonary veins, left and right outflow tracts, crossing of great arteries, aortic arch, ductal arch was statistically significant and more superior in detectability since most p values < 0.001. Denoting the privilege of color Doppler in detectability of fetal cardiac vessels at early gestational ages that permits detailed fetal cardiac scanning and increases the detectability of cardiac vascular anomalies. That was in agreement with other research group that showed improvement in detection rate with color Doppler than with 2D imaging for different structures as for example the IVC which was visualized by 2D imaging in only 4% in the eighth week, increasing to 13% by the 10th week and 80% by the 13th week where CD improved visualization of the inferior vena cava at earlier GAs to > 80% from 10 weeks [9]. Also, Wener et al. showed that visualization of the 4CV, outflow tract views, and three-vessel view was possible in 90% of fetuses at 12 to 14 weeks [14]. In our study at 13th gestational weeks, color Doppler did not show statistically significant difference in comparison to performance of echocardiography at 18th gestational weeks. Those findings denote that most severe congenital heart anomalies and structural flow abnormalities are feasible to detect at 13th gestational weeks permitting the obstetrician and pediatric cardiologist to counsel the case about the prognosis and progress of any observed malformation.
Prior research studies more than a decade ago have revealed and displayed that full echocardiographic examination of fetal heart could be performed at satisfactory level at 10th gestational weeks in most cases; however, a prior research study similar to the current research in approach and methodology have shown that color Doppler have a cornerstone value in elucidating the detailed fetal cardiac anatomy especially outflow tracts and venous systems from 10th to 14th gestational weeks; those research findings show great harmony and similarity to the current research study findings. Privilege of early sonographic diagnosis of fetal cardiac pathology also could be a trigger for detailed anomaly scanning for possible associated structural and chromosomal abnormalities [2, 4].
Prior research studies like the current research have mentioned that the best timing for fetal heart evaluation in a complete manner within the first trimester is between 12 + 0 and 13 + 6 gestational weeks [7].
Hutchinson and co-researchers verified the fact that to obtain a high rate of success for fetal anatomic cardiac evaluation, early fetal echo must be conducted after 11 gestational weeks [9]. On the other hand, in a smaller percentage of gestations, cardiac sonographic evaluation could be possible from 10th gestational week as sonographic researchers were in harmony with the current research study findings which have revealed that the real challenge is in the pulmonary vein evaluation in early fetal echocardiographic performance, with less than 50% successfully assessed by color Doppler even at 13 gestational weeks [10, 12].
Developmental changes in the morphology and function of the early heart need to be considered in early fetal echocardiographic performance. Since prior research groups in a similar approach and methodology have mentioned that at 10th gestational weeks, the cardiothoracic ratio is generous, the fetal cardiac axis nearly midline, with relatively large atrial chambers in comparison to the remaining cardiac mass, and a pericardial effusion is a frequent, findings interestingly research investigators have mentioned among their findings that assessment of atrioventricular valves is problematic at earlier gestational ages, especially before 12 gestational weeks. Those research findings could be justified by the fact that their thin anatomical nature besides the rapid fetal heart rate at earlier phases of intrauterine development impedes their proper sonographic resolution [8, 11].
