Methods for prenatal assessment of fetal cardiac function

Fetal cardiac function is increasingly recognized as a marker of disease severity and prognosis in selected fetal conditions. Magnetic resonance imaging (MRI) has been used in experimental (animal) fetal cardiology but the lack of a noninvasive fetal electrocardiogram (ECG) to trigger image acquisition remains a major limiting factor precluding its application in humans. Fetal medicine specialists are therefore limited to ultrasound to evaluate human fetal cardiac function. In this review, we aim to provide a complete overview of the different ultrasound techniques that can be used for fetal cardiac function assessment and we discuss their (theoretical) strengths and shortcomings. Conventional methods include M-mode assessment of ventricular contractility and Doppler assessment of the precordial veins and cardiac output (CO). More recent techniques such as the measurement of the myocardial performance index (MPI), myocardial motion analysis with tissue Doppler, speckle tracking and three-dimensional (3D) ultrasound techniques are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

The fetal cerebellum. Pitfalls in diagnosis and management

Prenatal diagnosis of congenital and acquired cerebellar disorders is possible by the use of ultrasound (US) and magnetic resonance imaging (MRI). Although numerous studies have been conducted in this field, diagnostic uncertainties are still common in daily clinical practice. This review outlines five possible pitfalls in the diagnosis of fetal cerebellar disorders: confusion between different entities describing vermian pathologies (Dandy–Walker variant, vermian hypoplasia and vermian agenesis); premature diagnosis of abnormal vermian formation; difficulties in the ultrasonographic differentiation between the cerebellar hemispheres and the vermis; late development of cerebellar hypoplasia/atrophy and differential diagnosis of unilateral cerebellar findings. Copyright © 2009 John Wiley & Sons, Ltd.     

Shortened fetal long bones: a possible in utero manifestation of placental function

Shortened fetal long bones (SFLB) are usually indicative of a skeletal dysplasia. Our aim in this observational retrospective study was to describe a new association between SFLB, small for gestational age (SGA) fetuses and placental abnormalities, and to suggest an aetiologic explanation. During the last decade we have evaluated nine cases in which SFLB (more than 2SD below the mean) was associated with SGA, abnormal maternal serum placental hormones and abnormal placental sonography. Six cases had significantly increased second trimester maternal serum βhCG and four developed toxaemia of pregnancy or had chronic hypertension. On histology, mature placentas with vascular abnormalities, including chorangiosis, large infarcts and slightly increased syncytial knots were noted. The combination of SFLB, SGA fetuses and placental abnormalities (sonographic, as well as histological) suggested a possible common pathway in the aetiology of this association. Copyright © 2002 John Wiley & Sons, Ltd.     

First-trimester fetal heart block and increased nuchal translucency: an indication for early fetal echocardiography

Prevalence of congenital heart disease increases with nuchal translucency (NT) thickness. First-trimester fetal bradycardia may result from heart block associated with complex congenital heart disease. We report two cases detected in the first trimester of pregnancy, in which both fetuses showed an increased nuchal translucency and bradycardia. Fetal karyotype was normal in both fetuses. First-trimester fetal echocardiography was performed and, in both cases, complex congenital heart disease was diagnosed. We discuss the added role of fetal heart rate in first-trimester ultrasound screening, in fetuses with increased nuchal translucency and normal karyotype. We stress, as well, the importance of echocardiography performed in the first trimester as a potential tool for early diagnosis in selected cases. Copyright © 2005 John Wiley & Sons, Ltd.     

Evaluation of prenatal diagnosis of associated congenital heart diseases by fetal ultrasonographic examination in Europe

Ultrasound scans in the mid trimester of pregnancy are now a routine part of antenatal care in most European countries. With the assistance of Registries of Congenital Anomalies a study was undertaken in Europe. The objective of the study was to evaluate prenatal detection of congenital heart defects (CHD) by routine ultrasonographic examination of the fetus. All congenital malformations suspected prenatally and all congenital malformations, including chromosome anomalies, confirmed at birth were identified from the Congenital Malformation Registers, including 20 registers from the following European countries: Austria, Croatia, Denmark, France, Germany, Italy, Lithuania, Spain, Switzerland, The Netherlands, UK and Ukrainia. These registries follow the same methodology. The study period was 1996–1998, 709 030 births were covered, and 8126 cases with congenital malformations were registered. If more than one cardiac malformation was present the case was coded as complex cardiac malformation. CHD were subdivided into ‘isolated’ when only a cardiac malformation was present and ‘associated’ when at least one other major extra cardiac malformation was present. The associated CHD were subdivided into chromosomal, syndromic non-chromosomal and multiple. The study comprised 761 associated CHD including 282 cases with multiple malformations, 375 cases with chromosomal anomalies and 104 cases with non-chromosomal syndromes. The proportion of prenatal diagnosis of associated CHD varied in relation to the ultrasound screening policies from 17.9% in countries without routine screening (The Netherlands and Denmark) to 46.0% in countries with only one routine fetal scan and 55.6% in countries with two or three routine fetal scans. The prenatal detection rate of chromosomal anomalies was 40.3% (151/375 cases). This rate for recognized syndromes and multiply malformed with CHD was 51.9% (54/104 cases) and 48.6% (137/282 cases), respectively; 150/229 Down syndrome (65.8%) were livebirths. Concerning the syndromic cases, the detection rate of deletion 22q11, situs anomalies and VATER association was 44.4%, 64.7% and 46.6%, respectively. In conclusion, the present study shows large regional variations in the prenatal detection rate of CHD with the highest rates in European regions with three screening scans. Prenatal diagnosis of CHD is significantly higher if associated malformations are present. Cardiac defects affecting the size of the ventricles have the highest detection rate. Mean gestational age at discovery was 20–24 weeks for the majority of associated cardiac defects. Copyright © 2001 John Wiley & Sons, Ltd.     

New and/or improved aspects of fetal surgery

Open fetal surgery through a wide hysterotomy is no longer a real option for prenatal intervention, but a minimally invasive approach has emerged as treatment for a small number of indications. Endoscopic ablation of placental vessels is the preferred treatment for severe twin-to-twin transfusion syndrome and it may be the only chance to salvage the most severe forms of congenital diaphragmatic hernia. Several other indications are currently under review and may become justified in the future, provided that diagnostic accuracy and patient selection become more accurate. Before invasive fetal intervention becomes widely accepted, however, we need to better define outcome. It is no longer acceptable to express results in terms of survival at birth. Survival at discharge and long-term morbidity must be considered as well. Copyright © 2011 John Wiley & Sons, Ltd.     

Successful early in utero management of fetal hydrothorax in a twin pregnancy

We present a case of dichorionic diamniotic twin pregnancy in which one of the fetuses was found to have a major pleural effusion at 15 weeks of gestation. A single-needle pleural fluid aspiration was performed at 15 and 16 weeks, but the fluid reaccumulated quickly after each procedure and at 16 weeks, the fetus was found to become progressively hydropic. A shunt was then successfully inserted at 17 weeks, which is the earliest gestation reported so far in the literature for such a procedure to treat isolated hydrothorax. Because we felt that the fetus would be too small for a classical double-pigtail pleuroamniotic shunt, we used a multilength double-pigtail bladder stent (Harrison drain; Cook; Spencer; Indiana; USA) via a 13-gauge echo tip trocar. This shunt could be used for both singleton and twin pregnancies presenting with fetal pleural effusion from as early as 16 to 17 weeks to prevent the development of fetal hydrops and polyhydramnios and subsequent premature delivery. Treatment at this stage of gestation would also minimize the risk of lung hypoplasia, which is the main clinical issue when shunts are inserted after 24 weeks. Copyright © 2003 John Wiley & Sons, Ltd.     

The nuchal translucency and the fetal heart: a literature review

In this overview the current knowledge of the relationship between an increased nuchal translucency (NT) measurement and fetal heart structure and function in chromosomally normal fetuses is reviewed. Relevant pathophysiological theories behind the increased NT are discussed. Fetuses with an increased NT have an increased risk for congenital heart disease (CHD) with no particular bias for one form of CHD over another. This risk increases with increasing NT measurement. Although the NT measurement is only a modestly effective screening tool for all CHD when used alone, it may indeed be effective in identifying specific CHD “likely to benefit” from prenatal diagnosis. The combination of an increased NT, tricuspid regurgitation and an abnormal ductus venosus (DV) Doppler flow profile, is a strong marker for CHD. A fetal echocardiogram should be performed at 20 weeks' gestation in fetuses with an NT ≥ 95th percentile but < 99th percentile. When the NT measurement is ≥ 99th percentile, or when tricuspid regurgitation and/or an abnormal DV flow pattern is found along with the increased NT, an earlier echocardiogram is indicated, followed by a repeat scan at around 20 weeks' gestation. The resultant increased demand for early fetal echocardiography and sonographers with this special expertise needs to be planned and provided for. Copyright © 2009 John Wiley & Sons, Ltd.