Fetal Heart Ultrasound
Fetal heart abnormalities are one of the commonest forms of abnormality detected prior to birth. Just under 1 in 100 babies are born with heart problems (Congenital Heart Disease). Many of these problems are isolated to the heart, however, some are part of more complex fetal abnormalities or syndromes involving other organ systems.
Fetal heart screening is part of the Mid Trimester Ultrasound examination that most women have at 19-20 weeks of gestation. It aims to identify that the heart is in a normal position, has 4 normal sized chambers, normal heart valves and large arteries arising from the heart. A normal screening heart ultrasound examination rules out the majority of complex Congenital Heart Disease abnormalities.
Fetal Echocardiography is a focused ultrasound examination of the fetal heart when an abnormality is suspected on screening, or if a pregnancy is at a higher than normal risk of fetal heart abnormality. Fetal Echocardiography is performed by a Fetal Cardiologist (Children’s Heart Specialist) or Obstetric Ultrasound Specialist. A detailed Fetal Echocardiogram can identify normal heart structure and function from early in the second trimester (from approximately 14 weeks of pregnancy).
It differs from a screening ultrasound in that it aims to identify the structure and function of the heart chambers and valves, all of the artery and vein connections to and from the heart, and their relationships within the fetal chest. It also looks at the functioning of the fetal-placental circulation. A Fetal Echocardiogram takes 30-40 minutes depending on fetal position and the complexity of any abnormalities identified.
A Fetal Cardiologist can immediately give the results of the scan and help the family plan further management throughout the pregnancy and after delivery as required.
Why is Fetal Echocardiography important?
Fetal Cardiology is a growing area of Cardiology practice. Identification of Congenital Heart Disease prior to birth gives the best chance of survival for certain abnormalities and allows planning for delivery in a center capable of managing babies with complex heart disease.
Diagnosis early in a pregnancy provides families with choice, and time to prepare for a very different start to life with their child, who in some cases may need early medical or surgical intervention.
Reasons for Fetal Echocardiography
Not every fetus requires Fetal Echocardiography. For low risk pregnancies with a normal screening Mid Trimester Ultrasound examination no further testing is required.
Reasons for which a focused Fetal Echocardiogramis performed include:
- Suspected Congenital Heart Disease on screening Ultrasound examination
- Family history of Congenital Heart Disease,Chromosomal
- Abnormalities or Cardiomyopathy in a first degree relative
- Fetal Chromosomal Abnormalities including Downsyndrome (Trisomy 21), Trisomy 13 and 18, andTurner syndrome
- Fetal Malformations outside the heart (kidney, lung,gut and brain)
- Increased Nuchal Translucency on first trimester screening
- Maternal Metabolic Disorders including Diabetes Mellitus and Phenylketonuria
- Fetal Arrhythmias (abnormal fetal heart rhythm)
- Monochorionic (identical) Twin pregnancies
- Maternal exposure to certain medications or viruses during pregnancy
- Fetal Hydrops (accumulation of fluid within the fetal body cavities)
Congenital Heart Disease is often associated with abnormalities outside the heart, or part of a larger Chromosomal or Syndromic abnormality affecting the whole baby. Women whose fetuses are identified to have significant Congenital Heart Disease will potentially need to see multiple specialists during the pregnancy and beyond. At Siles Health we have a Genetic Counsellor who can help support and guide families through this difficult time with the assistance of the Fetal Cardiologist and other sub-specialties if required.