Ultrasound Link - increased nuchal translucency

Ventricular septal defect (VSD): difficult diagnosis at 11-13 weeks

Sun, 23 Sep 2012 16:44:59 GMT

This video clip describes echocardiographic features of ventricular septal defect (VSD) in fetus at 13 and 12 weeks' gestation.

VSD can be very difficult to detect and it can be easily not diagnosed even at 20 weeks scan.

The fetus has mildly increased nuchal translucency (NT) thickness. At 12 weeks' gestation there was ventricular disproportion (RV>LV) on fetal echocardiography and a congenital heart defect (CHD) was suspected. It was not possible to visualize ventricular septal defect at that stage. Repeated fetal echo at 13 weeks (one week later) clearly demonstrated subaortic VSD. Overriding aorta was more committed to the left ventricle. Both great arteries had similar size.

This type of VSD is frequently seen in the fetuses with trisomy 18 and trisomy 13. It worth to mention again that the diagnosis of this CHD can be very difficult, because in many cases 4 chamber view and 3 vessel-trachea view are normal.

An additional finding in the fetus was persistent left superior vena cava (PLSVC) which was the anatomical variant of bilateral SVC. PLSVC can be normal variation of the upper thoracic venous system, however it is very frequently associated with other cardiac anomalies.

Tricuspid regurgitation (TR) in fetus: tricuspid dysplasia at 12 weeks of pregnancy

Sun, 16 Sep 2012 07:48:37 GMT

This video clip describes sonographic features of tricuspid valve dysplasia at 12 weeks gestation.

The fetus with increased nuchal translucency thickness and hydrops fetalis had congenital tricuspid valve dysplasia:

severe tricuspid regurgitation (TR)
normal attachment of septal tricuspid valve leaflet
right atrial enlargement
cardiomegaly
mild pericardial effusion

In this case severe fetal TR was visible even of 2D scan. Color flow regurgitation jet of the valve was massive and there was aliasing. The TR in fetus was holosystolic. Regurgitation velocity on pulsed-wave doppler echocardiography was 150 cm/s. Normal attachment of septal tricuspid valve leaflet was clearly visible. In Ebstein's anomaly, another form of congenital tricuspid valve disease, there is apical displacement of the septal and posterior tricuspid valve leaflets.

Hypoplastic left heart syndrome (HLHS) at 12 weeks of pregnancy

Fri, 14 Sep 2012 17:21:09 GMT

This training video illustrates sonographic features of hypoplastic left heart syndrome (HLHS) at 12 weeks' gestation.

In the presented example the HLHS complex includes:

Aortic atresia
Obliterated left ventricle
Mitral atresia
Enlarged right ventricle
Large pulmonary artery
Retrograde flow from the ductus arteriosus in the aortic arch
Patent foramen ovale with normal forward flow in the pulmonary veins

An additional finding was large azygos vein, draining into superior vena cava and normal (not interrupted) inferior vena cava

Pleural effusion (hydrothorax) at 11-13 weeks of pregnancy

Sat, 11 Aug 2012 14:32:33 GMT

This ultrasound video demonstrates sonographic features of pleural effusion (hydrothorax) at 11-13 weeks of pregnancy.

Ectopia cordis: pentalogy of Cantrell

Sun, 27 May 2012 15:48:47 GMT

This video clip demonstrates sonographic features of ectopia cordis at 12 weeks of pregnancy. In this case ectopia cordis is a part of the pentalogy of Cantrell.

Congenital diaphragmatic hernia (CDH)

Sun, 29 Apr 2012 13:50:49 GMT

This video clip demonstrates left sided congenital diaphragmatic hernia (CDH) and intrathoracic stomach in the fetus with increased nuchal translucency (NT) thickness at 12 weeks' gestation.

The birth prevalence of diaphragmatic hernia is about 1 per 4,000 and the condition is usually sporadic. The prevalence of chromosomal defects, mainly trisomy 18, is about 20%.

In the case presented the fetus had multiple anomalies: CDH, brain abnormality, congenital heart defect (tetralogy of Fallot), echogenic kidneys with pyeloectasis and generalised edema.

Increased NT thickness is present in about 40% of fetuses with diaphragmatic hernia, including more than 80% of those that result in neonatal death due to pulmonary hypoplasia and in about 20% of the survivors (Sebire et al 1997). It is possible that in fetuses with diaphragmatic hernia and increased NT the intrathoracic herniation of the abdominal viscera occurs in the first trimester and prolonged compression of the lungs causes pulmonary hypoplasia. In the cases where diaphragmatic hernia is associated with a good prognosis, the intrathoracic herniation of viscera may be delayed until the second or third trimesters of pregnancy.

Early fetal echo: 31 clips of normal fetal heart (compilation)

Sun, 20 May 2012 14:33:42 GMT

This is a training video about the first trimester fetal echocardiograpy. The compilation video consists of 31 short clips from 18 patients scanned at 11-13 weeks of pregnancy due to high risk for congenital heat disease (CHD). All presented cases had normal heart anatomy, which was confirmed by 20 week fetal echocardiography.

The indications for early pregnancy fetal echocardiography include:

Increased nuchal translucency thickness
Tricuspid regurgitation
Reversed a-wave in ductus venosus
Extracardiac anomaly, such as exomphalos
Previous pregnancy complicated by fetal CHD

All the scans were performed using a Voluson 730 ultrasound scanner. In the video every clip is played twice. In order to provide the viewer with the real experience of heart scanning the clips are not annotated. For an annotated training video of fetal echocardiography please refer to our post ‘Fetal echocardiography at 11-13 weeks of pregnancy’.

Abbreviations:

3VTV – three vessel-trachea view
4CV – four chamber view
LOT – left outflow tract
ROT – right outflow tract
Ao – aortic arch
Da – ductus arteriosus
PV – pulmonary valve
SVC – superior vena cava
RSA – right subclavian artery

Atrioventricular septal defect (AVSD) at 11 wks of pregnancy

Sun, 01 Apr 2012 14:57:17 GMT

This video clip demonstrates atrioventricular septal defect (AVSD) in the fetus with Down’s syndrome at 11 weeks' gestation.

AVSD, which comprises about 5% of congenital heart defects in infants, is strongly associated with trisomy 21. Another association of AVSD is with left atrial isomerism.

The classical sonographic feature of AVSD is absence of the crux or linear insertion of the atrioventricular (AV) valves. The presented case demonstrates a major defect of the AV septum and severe abnormality of the common AV valve. Color Doppler mapping with demonstration of abnormal not parallel filling of both ventricles through AVSD is essential in making the diagnosis in the first trimester. The condition is associated with severe holosystolic regurgitation, which is visible by colour Doppler as a jet with aliasing. Pulse Doppler is used for confirmation of regurgitation and for assessment of its severity.

Fetal echocardiography at 11-13 weeks of pregnancy

Sun, 22 Apr 2012 07:53:29 GMT

This is a transvaginal ultrasound video clip demonstrating examination of the fetal heart (echocardiography) at 13 weeks' gestation.

Major cardiac defects are responsible for about 50% of deaths in neonates and infants from all congenital abnormalities. It is therefore important to identify such defects as early in pregnancy as possible.

Early pregnancy echocardiography, performed at 11- 13 weeks' gestation, is used for screening and diagnosis of congenital heart defects. This is particularly important in the management of fetuses with increased nuchal translucency (NT) thickness.

Other indications include for early echocardiography include family history of congenital heart defects, detection of extracardiac defects, such as exomphalos or diaphragmatic hernia and the abnormal Doppler findings of reversed a-wave in the ductus venosus and tricuspid regurgitation.

Increased nuchal translucency (NT) and fetal outcome

Sun, 18 Dec 2011 11:25:53 GMT

This video clip describes the outcome of fetuses with increased nuchal translucency (NT) thickness. With increasing fetal NT there is a higher prevalence of chromosomal defects, miscarriage or stillbirth, major fetal abnormalities and congenital heart defects.

The data presented in this ultrasound video clip are based on The Fetal Medicine Foundation publication: Increased nuchal translucency with normal karyotype. Souka AP et al. Am J Obstet Gynecol. 2005; 192: 1005-21.

Early Pregnancy Anomaly Scan (EPAS) - Fetal ultrasound at 11-13 weeks

Sun, 18 Dec 2011 20:02:34 GMT

In the 1980's ultrasound examination for the diagnosis of fetal abnormalities was usually performed at 20 weeks' gestation. In the 1990's improved resolution of ultrasound machines and the introduction of transvaginal sonography made it possible to accurately examine the fetal anatomy earlier in pregnancy. Subsequently, the realisation that a high proportion of fetuses with trisomy 21 and other major aneuploidies have increased nuchal translucency (NT) thickness at 11-13 weeks and that the fetal karyotype could be obtained safely by chorionic villous sampling have shifted prenatal diagnosis to the first trimester of pregnancy.

Although the original objective of the 11-13 weeks scan was to measure the fetal NT it soon became obvious that at this scan it was possible to diagnose many major defects, including acrania-anencephaly, holoprosencephaly, exomphalos, gastroschisis, megacystis and lethal skeletal dysplasias. In addition, markers of aneuploidy, such as increased NT and abnormal Doppler blood flow across the tricuspid valve and in the ductus venosus, were suggestive of an underlying congenital cardiac defect. Recently, it has become apparent that abnormalities in the fetal brain, easily visible in the standard views used for measurement of NT, can identify open spina bifida and Dandy Walker malformation. In fetuses with increased NT and normal karyotype there is a wide range of associated malformations, dysplasias and genetic syndrome many of which can now be identified by detailed ultrasound examination at 11-13 weeks. Consequently, the 11-13 weeks scan has evolved to become the most important fetal anomaly scan in pregnancy.

In this site we will provide videos illustrating the methodology for the early pregnancy anomaly scan and a wide range of fetal abnormalities.

Echocardiography: Increased NT and normal heart at 11 weeks

Sun, 22 Apr 2012 08:01:13 GMT

This is a transvaginal video clip demonstrating examination of the fetal heart (echocardiography) at 11 weeks' gestation. The nuchal translucency (NT) thickness was increased at 11 weeks but the fetal karyotype and heart were normal. The stomach was not visible at 11 weeks but it became visible at 13 weeks. The increased NT resolved over the next 2 weeks, the pregnancy progressed normally and a normal neonate was born at term.

Early pregnancy echocardiography, performed at 11- 13 weeks' gestation, is important for screening and diagnosis of congenital heart defects in fetuses with increased NT and normal karyotype. For further information about the relation of nuchal translucency thicknes and fetal outcome please refer to our post "Increased nuchal translucency (NT) and fetal outcome".