Early Evaluation of the Fetal Heart

Abstract

Evaluation of the fetal heart at 11-13 + 6 weeks of gestation is indicated for women with a family history of congenital heart defects (CHD), a previous child with CDH, or an ultrasound finding associated with cardiac anomalies. The accuracy for early detection of CHD is highly related to the experience of the operator. The 4-chamber view and outflow tracts are the most important planes for identification of an abnormal heart, and can be obtained in the majority of fetuses from 11 weeks of gestation onward. Transvaginal ultrasound is the preferred route for fetal cardiac examination prior to 12 weeks of gestation, whereas, after 12 weeks, the fetal heart can be reliably evaluated by transabdominal ultrasound. Cardiac defects, such as ventricular septal defects, tetralogy of Fallot, Ebstein's anomaly, or cardiac tumors, are unlikely to be identified at ≤14 weeks of gestation. Additional ultrasound techniques such as spatiotemporal image correlation and the evaluation of volumes by a fetal-heart expert can improve the detection of congenital heart disease. The evaluation of the fetal cardiac function at 11-13 + 6 weeks of gestation can be useful for early identification of fetuses at risk of anemia due to hemoglobinopathies, such as hemoglobin Bart's disease.

Nomograms of Fetal Cardiac Dimensions at 18–41 Weeks of Gestation

“…We have provided standardized and comprehensive reference values for fetal cardiac morphometric parameters across gestation in a low-risk population. An accurate measurement of heart dimensions might be very useful to identify and monitor cardiac remodeling -change in shape, size, and structure -in response to pressure/volume overload or cardiac toxicity in many conditions, such as CHD [36,37], maternal diabetes [9], twin-to-twin transfusion syndrome [38], FGR [39], conception by ART [7], fetal anemia [40], congenital diaphragmatic hernia [41], or exposure to antiretroviral drugs [8]. A better understanding and follow-up of fetal cardiac adaptations could enable early interventions and minimize long-term cardiovascular consequences [42].…”

Obstetric ultrasound in tetralogy of Fallot

“…This period ensures that a full assessment of the developed cardiac anatomy can be performed whilst allowing time for further assessment with echocardiogram, amniocentesis, etc, whilst still previable . Whilst TOF has been detected with obstetric ultrasound earlier than 18‐week gestation, Hernandez‐Andrade et al demonstrated it was unlikely to be detected less than or equal to 14‐week gestation.…”

Cardiopatías congénitas, diagnóstico y manejo prenatal

“…El tamizaje del primer trimestre en las semanas 11-14, que comenzó con la evaluación de la TN para la detección de la trisomía 21 y otras aneuploidías, se fue extendiendo para el diagnóstico de varias malformaciones mayores. [19][20][21][22][23][24][25][26] La ecografía de las semanas 11-14 podría jugar un rol importante en la detección de CC por la visualización directa del defecto o por la presencia de marcadores ecográficos que incrementaran el riesgo.…”

“…Por ello, algunos autores sugieren la evaluación precoz del corazón fetal mediante el corte de 4 cámaras y los tractos de salida, que, luego de la semana 12, pueden obtenerse en la gran mayoría de los casos. 19 Otros cortes, en cambio, son más difíciles de obtener (Tabla 3). McAuliffe y col., reportaron que, a las 13 + 5 semanas, los arcos aórtico y ductal solo pudieron verse en el 45 % de los casos y las venas pulmonares, en el 16 % de los fetos estudiados.…”

“…22 Por último, hay que tener presente que el "ecocardiograma fetal precoz" tiene no solo una elevada tasa de falsos negativos, sino que también presenta una elevada tasa de falsos positivos, debido a que, entre otros factores, determinadas estructuras cardíacas podrían no encontrarse completamente desarrolladas. 19 Por ello, hay que ser cautos en el asesoramiento, ya que una proporción significativa de estudios anómalos van a tener, finalmente, un feto con corazón sano.…”