**8. Early evaluation of the fetal heart, at the first trimester (FT) morphogenetic scan**

Congenital heart defects appear during the first 8 weeks of the fetus development, thus cardiac sonography at the genetic scan, during 11–13 gestational weeks (GW) is feasible (**Figure 28**) and identifies numerous abnormalities (**Figures 29**–**35**) [59–61]. The rate of complete cardiac evaluation increases with gestational age, from 20% at 11GW, to more than 92% at 13–15 GW, especially when transvaginal route was used [62, 63].

**Figure 28.** FT cardiac sweep of a normal heart, duplex mode. (A): 4CV plane: gray-scale imaging shows, crux cordis and pulmonary veins entering left atrium; color Doppler imaging shows equal atrioventricular flow and no flow between ventricles. (B): LVOT plane with the aortic emergence, septoaortic continuity and aortic flow. (C): Crossing of the great vessels. (D): 3VT plane – the confluence of arterial arches on left of spine with normal direction and equal flow.

Regarding the *imaging technique*, gray scale is the basis of a reliable fetal cardiac scan in the ST,

**Figure 31.** Hypoplastic left heart. A diminutive left ventricle (A) and aorta (B) are identified with the aid of color Doppler.

**Figure 30.** Atrioventricular septal defect. Thickened common valve, large communication between the cardiac chambers,

Congenital Abnormalities of the Fetal Heart http://dx.doi.org/10.5772/intechopen.74077 137

For safety reasons, routine use of pulsed color Doppler is advised against in the FT [65], although tricuspid and ductus venosus flows are commonly used [66–72] and color Doppler improves early visualization of cardio-vascular features, due to the low discrimination of the heart structures in gray-scale mode [73–75], while respecting the ALARA principle (As Low

At a lesser extent, the FT *examination protocol* is similar to the second trimester cardiac scan [77, 78], as presented in **Figure 28**. 4D-STIC is feasible in the FT and likely to improve CHD

The *efficiency* of FT cardiac scan varies widely (detection rate 5.6–90%), depending on the protocol used, population risk and scanning route (TV, TA or both). High detection rates for major CHD were reported even in unselected or low risk population 80–90%, when using an extended standardized protocol [74, 75]. A systematic review of the literature [79] reported a pooled sensitivity and specificity of 85% (95% CI, 78–90%) and 99% (95% CI, 98–100%),

but much less informative in the FT [64].

RV, left ventricle; LV, left ventricle; PA, pulmonary artery; Ao, aorta.

As Reasonably Achievable) [76].

absence of crux cordis and regurgitation.

detection in expert hands.

**Figure 29.** Monoventricular heart.

on the scanning protocol, examiner experience, equipment quality and scanning conditions [18, 56–58]. It appears that the use of 4CV alone detects up to 77% of CHD, while adding OTV

Congenital heart defects appear during the first 8 weeks of the fetus development, thus cardiac sonography at the genetic scan, during 11–13 gestational weeks (GW) is feasible (**Figure 28**) and identifies numerous abnormalities (**Figures 29**–**35**) [59–61]. The rate of complete cardiac evaluation increases with gestational age, from 20% at 11GW, to more than 92% at 13–15 GW,

**Figure 28.** FT cardiac sweep of a normal heart, duplex mode. (A): 4CV plane: gray-scale imaging shows, crux cordis and pulmonary veins entering left atrium; color Doppler imaging shows equal atrioventricular flow and no flow between ventricles. (B): LVOT plane with the aortic emergence, septoaortic continuity and aortic flow. (C): Crossing of the great vessels. (D): 3VT plane – the confluence of arterial arches on left of spine with normal direction and equal flow.

increases prenatal detection to 83–92% of major abnormalities.

especially when transvaginal route was used [62, 63].

**morphogenetic scan**

136 Congenital Anomalies - From the Embryo to the Neonate

**Figure 29.** Monoventricular heart.

**8. Early evaluation of the fetal heart, at the first trimester (FT)** 

**Figure 30.** Atrioventricular septal defect. Thickened common valve, large communication between the cardiac chambers, absence of crux cordis and regurgitation.

**Figure 31.** Hypoplastic left heart. A diminutive left ventricle (A) and aorta (B) are identified with the aid of color Doppler. RV, left ventricle; LV, left ventricle; PA, pulmonary artery; Ao, aorta.

Regarding the *imaging technique*, gray scale is the basis of a reliable fetal cardiac scan in the ST, but much less informative in the FT [64].

For safety reasons, routine use of pulsed color Doppler is advised against in the FT [65], although tricuspid and ductus venosus flows are commonly used [66–72] and color Doppler improves early visualization of cardio-vascular features, due to the low discrimination of the heart structures in gray-scale mode [73–75], while respecting the ALARA principle (As Low As Reasonably Achievable) [76].

At a lesser extent, the FT *examination protocol* is similar to the second trimester cardiac scan [77, 78], as presented in **Figure 28**. 4D-STIC is feasible in the FT and likely to improve CHD detection in expert hands.

The *efficiency* of FT cardiac scan varies widely (detection rate 5.6–90%), depending on the protocol used, population risk and scanning route (TV, TA or both). High detection rates for major CHD were reported even in unselected or low risk population 80–90%, when using an extended standardized protocol [74, 75]. A systematic review of the literature [79] reported a pooled sensitivity and specificity of 85% (95% CI, 78–90%) and 99% (95% CI, 98–100%),

**Figure 32.** Transposition of great arteries. Inapparent four-chamber view (A), with parallel course of the arterial arches (B) and the impression of only one arterial arch at the level of 3VT view (C).

respectively. Thus, FT cardiac scan has a high accuracy in major CHD detection and a reasonable accuracy to diagnose normal heart. We should underline during parents counseling that normal fetal cardiac features examinations at any time of pregnancy do not exclude CHD, as some diseases evolve in utero and become apparent later during pregnancy: coarctation of aorta, pulmonary stenosis, tetralogy of Fallot, hypoplastic left heart syndrome, cardiomyopathy or cardiac tumors [80–83]. Ventricular septal defects are the earliest missed lesions because of the small size of the lesion and low flow velocities in the FT. A normal cardiac scan in the FT should not be considered a replacement for the second trimester echocardiography.

*Markers for cardiac abnormalities* (**Figure 36**) may also be useful in early pregnancy, as increased nuchal translucency (NT) and abnormal ductus venosus and tricuspid flows. Increased *NT* was associated with cardiac dysfunction and abnormalities, even in chromosomally normal fetuses, but not obviously related to any particular type of cardiac anomaly [84–86]. The prevalence of CHD when NT is the 95th percentile is up to 20% [87] and about six times higher

**Figure 34.** Tetralogy of Fallot with right aortic arch. (A): Normal appearance of atrioventricular flows; (B): overriding

**Figure 33.** Double aortic arch. Four-chamber view with normal appearance (A), normal emergence of the aorta (B) and pulmonary artery (C), with the aorta coursing to the right of the spine and dividing in two branches that form a vascular

Congenital Abnormalities of the Fetal Heart http://dx.doi.org/10.5772/intechopen.74077 139

aorta; (C): aorta coursing to the right of the spine along the diminutive pulmonary artery.

ring around the trachea (D).

**Figure 33.** Double aortic arch. Four-chamber view with normal appearance (A), normal emergence of the aorta (B) and pulmonary artery (C), with the aorta coursing to the right of the spine and dividing in two branches that form a vascular ring around the trachea (D).

respectively. Thus, FT cardiac scan has a high accuracy in major CHD detection and a reasonable accuracy to diagnose normal heart. We should underline during parents counseling that normal fetal cardiac features examinations at any time of pregnancy do not exclude CHD, as some diseases evolve in utero and become apparent later during pregnancy: coarctation of aorta, pulmonary stenosis, tetralogy of Fallot, hypoplastic left heart syndrome, cardiomyopathy or cardiac tumors [80–83]. Ventricular septal defects are the earliest missed lesions because of the small size of the lesion and low flow velocities in the FT. A normal cardiac scan in the FT should not be considered a replacement for the second trimester echocardiography. *Markers for cardiac abnormalities* (**Figure 36**) may also be useful in early pregnancy, as increased nuchal translucency (NT) and abnormal ductus venosus and tricuspid flows. Increased *NT* was associated with cardiac dysfunction and abnormalities, even in chromosomally normal fetuses, but not obviously related to any particular type of cardiac anomaly [84–86]. The prevalence of CHD when NT is the 95th percentile is up to 20% [87] and about six times higher

**Figure 32.** Transposition of great arteries. Inapparent four-chamber view (A), with parallel course of the arterial arches

(B) and the impression of only one arterial arch at the level of 3VT view (C).

138 Congenital Anomalies - From the Embryo to the Neonate

**Figure 34.** Tetralogy of Fallot with right aortic arch. (A): Normal appearance of atrioventricular flows; (B): overriding aorta; (C): aorta coursing to the right of the spine along the diminutive pulmonary artery.

**Author details**

Dominic Gabriel Iliescu<sup>1</sup>

Marius Calomfirescu Vicea<sup>7</sup>

"Gr.T.Popa", Iasi, Romania

Ciprian Laurentiu Patru<sup>1</sup>

Simona Vlădăreanu<sup>4</sup>

Craiova, Romania

Bucharest, Romania

Targu-Mures, Romania

Hatieganu", Cluj-Napoca, Romania

Babes", Timisoara, Romania

2000;**54**:660-666

2014;**129**:2183-2242

Romania

Romania

**References**

, Ștefania Tudorache<sup>1</sup>

, Mona Elena Zvanca<sup>3</sup>

, Roxana Cristina Drăgușin<sup>1</sup>

1 Department of Obstetrics and Gynaecology, University of Medicine and Pharmacy,

2 Department of Obstetrics and Gynaecology, University of Medicine and Pharmacy,

4 Department of Neonatology, University of Medicine and Pharmacy, "Carol Davila",

5 Department of Obstetrics and Gynaecology, University of Medicine and Pharmacy,

7 Secretary, Romanian Society of Ultrasound in Obstetrics and Gynecology, Bucharest,

6 Department of Obstetrics and Gynaecology, University of Medicine and Pharmacy, "Iuliu

8 Department of Obstetrics and Gynaecology, University of Medicine and Pharmacy, "Victor

[1] Rosano A, Botto LD, Botting B. Infant mortality and congenital anomalies from 1950 to 1994: An international perspective. Journal of Epidemiology and Community Health.

[2] Donofrio MT, Moon-Grady AJ, Hornberger LK, et al. Diagnosis and treatment of fetal cardiac disease a scientific statement from the American Heart Association. Circulation.

[3] Chenni N, Lacroze V, Pouet C, Fraisse A, Kreitmann B, Gamerre M, Boubli L, D'Ercole C. Fetal heart disease and interruption of pregnancy: Factors influencing the parental decision-making process. Prenatal Diagnosis. 2012 Feb;**32**(2):168-172. DOI: 10.1002/pd.2923

9 Department of Public Health, University of Medicine and Pharmacy, Craiova, Romania

3 Department of Obstetrics-Gynecology, University of Medicine and Pharmacy, Bucharest,

, Claudiu Marginean<sup>5</sup>

\*Address all correspondence to: dnemescu@yahoo.com

, Dragos Nemescu2

, Cezara Muresan<sup>8</sup>

, Iuliana Ceausu<sup>3</sup>

\*, Monica Mihaela Cirstoiu<sup>3</sup>

, Laura Monica Cara<sup>9</sup>

,

Congenital Abnormalities of the Fetal Heart http://dx.doi.org/10.5772/intechopen.74077

, Daniel Muresan<sup>6</sup>

and Maria Sorop-Florea<sup>1</sup>

,

141

,

**Figure 35.** Hypoplastic right heart syndrome. Tricuspid atresia with intact septum. (A): Dysplastic thickened tricuspid valve in 4CV assessment, with lack of antegrade blood flow (B) and regurgitation (C). Normal aortic flow is visualized (D), and reversed ductal flow (E), by using color Doppler.

**Figure 36.** Normal flows at the pulsed Doppler interrogation of ductus venosus (A) and tricuspid valve (B). Ductus venosus with reversed a-wave (C) and tricuspid regurgitation (D) in fetus with atrioventricular septal defect (E).

than unselected population for NT ≥99th percentile [88]. Still, NT measurement is not a reliable screening test for CHD during FT, because of the overall low detection rates for CHD (around 15%) in unselected or low-risk populations [89, 90].

The performance of early screening for CHD achieved by measurement of fetal NT is improved by the assessment of ductus venosus and tricuspid valve flow pattern. In fetuses with enlarged NT (above 95 centile) and *absent or reversed a-wave in DV flow* the risk for major CHD is tripled [91]. The finding of reversed a-wave in chromosomally normal fetuses increases by almost 10 times the risk of CHD, with a predominance of right-heart anomalies regardless of the measurement of NT [86]. Also, chromosomally normal fetuses with *tricuspid valve regurgitation* have an 8-fold increased risk for CHD [92, 93].
