Prenatal detection of congenital heart disease: factors affecting obstetric management and survival

Cardiac Axis in Early Gestation and Congenital Heart Disease

Congenital heart defects represent the most common structural anomalies observed in the fetal population, and they are often associated with significant morbidity and mortality. The fetal cardiac axis, which indicates the orientation of the heart in relation to the chest wall, is formed by the angle between the anteroposterior axis of the chest and the interventricular septum of the heart. Studies conducted during the first trimester have demonstrated promising outcomes with respect to the applicability of cardiac axis measurement in fetuses with congenital heart defects as well as fetuses with extracardiac and chromosomal anomalies, which may result in improved health outcomes and reduced healthcare costs. The main aim of this review article was to highlight the cardiac axis as a reliable and powerful marker for the detection of congenital heart defects during early gestation, including defects that would otherwise remain undetectable through the conventional four-chamber view.

A Compendium on Perinatal Autopsy in Neonats

Professionals who work in perinatal care must understand the advantages and disadvantages of perinatal autopsy since they are an essential tool for determining fetal and neonatal mortality. Perinatal is the period five months before one month after birth, while prenatal is before birth. The traditional prenatal autopsy is still the gold standard for establishing the cause of death and providing an accurate report, notwithstanding the development of new technology. The ideal locations for a prenatal autopsy are tertiary institutes that offer these procedures. It emphasizes the need for systematic histopathologic sampling, rigorous record-keeping, technological adaptation, and wise laboratory test use. When a laboratory does a microbiologic examination with a focus on the genital tract and neonatal problems, it is very beneficial. Karyotyping needs to be selective and works best when there are many aberrations if resources are to be saved. A perinatal autopsy is insufficient without examining the placenta, and severe lesions should be distinguished from deformities and abnormalities brought on by fetal death. In addition to providing epidemiology teams and auditing committees with high-quality data, the pathologist's role in perinatal medicine also includes participating in the multidisciplinary management of fetal abnormalities identified during pregnancy, monitoring the patterns of iatrogenic disease, and aiding the perinatal grief management process. Investigations into complicated multiple pregnancies, hydrops, bone dysplasias, and unexpected intrauterine fetal deaths provide unique obstacles and diagnostic difficulties. There hasn't been any research that contrasts postmortem computed tomography with postmortem x-rays in pregnant women, as far as we know. Histological analysis of many perinatal autopsies revealed healthy developing tissues. Only a tiny percentage of histological abnormalities can be expected in fetal anomaly terminations. On prenatal imaging, many organ abnormalities are commonly anticipated. A thorough database search was done in Pubmed, Medline, and Scopus using the phrases "fetal abnormalities," "karyotyping," "fetal abnormality," "postmortem," and "perinatal autopsy."

Efficacy of fetal cardiac axis evaluation in the first trimester as a screening tool for congenital heart defect or aneuploidy

Objective

To prove the efficacy of determining the abnormal fetal cardiac axis for screening congenital heart defects (CHDs) and predicting fetal aneuploidy at 11.0 to 13.6 weeks of pregnancy.

Methods

This retrospective study was performed at a single high-risk pregnancy center. The fetal cardiac axis was evaluated between 11.0 and 13.6 weeks of gestation in 142 fetuses. The cardiac axis in a 4-chamber view was measured as the angle between the line tracing the long axis of the heart and the line bisecting the thorax in the anteroposterior direction. A CHD was confirmed based on the second- to third-trimester fetal status or postnatal imaging. Aneuploidy was diagnosed using chorionic villus sampling, amniocentesis, or genetic testing after birth. Fisher's exact test was performed to assess the association between the fetal cardiac axis and the abnormal fetal status. A 2-way contingence table analysis was performed to confirm the efficacy of the fetal cardiac axis as a screening tool.

Results

Among the 142 fetuses, 10 had a CHD while 17 had aneuploidy. The abnormal fetal cardiac axis was significantly associated with CHDs (P=0.013) and aneuploidy (P=0.010). None of the fetuses with CHDs or aneuploidy had an isolated abnormal cardiac axis alone without other sonographic findings. The sensitivity of the fetal cardiac axis was 50.0% for CHDs and 41.2% for aneuploidy.

Conclusion

The fetal cardiac axis can be an additional helpful tool for prenatal screening of CHDs and aneuploidy in the first trimester.

Evaluation of fetal echocardiography as a routine antenatal screening tool for detection of congenital heart disease

BACKGROUND

Fetal echocardiography plays a pivotal role in identifying the congenital heart defects (CHDs) in utero. Though foetal echocardiography is mostly reserved for high risk pregnant women, its role as a routine prenatal screening tool still needs to be defined. Performing foetal echocardiography based on only these indications can lead to a significant numbers of CHD cases going undetected who will be deprived of further management leading to increased early neonatal mortalities. The aim of this study is to assess the incidence of CHDs by fetal echocardiography in an unselected population of pregnant women in comparison with pregnant women with conventional high risk factors for CHD.

METHODS

This study enrolled consecutive pregnant women who attended antenatal clinic between 2008 and 2012 in a tertiary care hospital. These pregnant women were categorized into two groups: high risk group included pregnant women with traditional risk factors for CHD as laid down by Pediatric Council of the American Society of Echocardiography and low risk group. Detailed fetal 2 D echocardiography was done.

RESULTS

A total of 1,280 pregnant women were included in study. The 118 women were categorized as the high risk group while remaining 1,162 were included in the low risk group. Twenty six cases of CHDs were detected based on abnormal foetal echocardiography (20.3 per 1,000). Two of the 26 cases of CHD occurred in high risk group whereas the remaining 24 occurred in low risk pregnancy. The difference in the incidence of CHDs between the two groups was not significant statistically (P=0.76).

CONCLUSIONS

Our study shows no difference in incidence of CHDs between pregnancies associated with high risk factors compared to low risk pregnancies. So we advocate foetal echocardiography should be included as a part of routine antenatal screening and all pregnant women irrespective of risk factors for CHDs.

[Prenatal screening of congenital heart defects in population at low risk of congenital defects. A reality today]

INTRODUCTION

We propose to demonstrate that it is possible to implement a valid (diagnostic sensitivity for major cardiac malformations 90%), and universal (applied to over 90% of pregnant women), prenatal screening method for congenital heart defects.

MATERIALS AND METHODS

Prospective study. A total of 12478 pregnant women were evaluated between January 2008 and December 2010. Congenital heart diseases were screened using fetal extended basic echocardiography (cardiac ultrasound).

RESULTS

The prevalence of birth defects in general and congenital heart disease was 2.5% (2.2-2.7%) and 0.9% (0.7-1%) respectively. Congenital heart disease had a higher rate of association with other structural abnormalities with 11.5% (5.6-17.4%), 21% for major congenital heart disease (9.9-32%), and chromosomal abnormalities of 15.9% (9.1-22.7%), with 32.6% for major congenital heart disease (19.8-45.3%). A fetal cardiac ultrasound assessment was performed on 99.2% of pregnant women. The fetal echocardiography is useful for the diagnosis of congenital heart disease in general, and major congenital heart disease, with a sensitivity of 42.8% (33.5-52.5%) and 90.4% (78.9-96.8%), respectively, and a specificity for both of 99.9% (99.8-99.9%).

CONCLUSIONS

It is possible to perform a valid prenatal and universal screening of major congenital heart disease.

Early fetal echocardiography: ready for prime time?

The objective of this study was to examine the performance of early fetal echocardiography as a screening tool for major cardiac defects in a high-risk population. Fetal echocardiograms performed at 12 to 16 weeks were reviewed. Cases that did not undergo a follow-up echocardiogram at 18 to 22 weeks were excluded. Results of the early and follow-up echocardiograms were compared. Over a 4-year period, 119 early fetal echocardiograms were recorded. Of those, 81 (68%) had follow-up fetal echocardiograms. Results of the early echocardiogram were normal in 77 of 81 (95.1%) cases. Of these, the follow-up was normal in 75 of these 77 cases; in the remaining 2, the follow-up raised suspicion for a ventricular septal defect (VSD) in one and persistent left superior vena cava in the other. On the other hand, the early echocardiogram was abnormal in 4 (4.9%) cases: (1) atrioventricular canal defect, with the follow-up demonstrating a VSD; (2) hypoplastic right ventricle and transposition of the great arteries, confirmed on follow-up; (3) VSD and coarctation of the aorta, confirmed on follow-up. In the fourth case, the early echocardiogram suspected a VSD and right-left disproportion, yet the follow-up was normal. In conclusion, early fetal echocardiography appears to be a reasonable screening tool for major cardiac defects.

Changing spectrum and outcome of 705 fetal congenital heart disease cases: 12 years, experience in a third-level center

INTRODUCTION

Congenital heart diseases are the most common prenatal and postnatal malformations. Nowadays, fetal echocardiography is a widely practiced technique; however, the impact of prenatal diagnosis on prognosis of the newborns affected by congenital heart disease remains uncertain.

OBJECTIVE

To assess the outcome and the changes in the spectrum of prenatally detected congenital heart disease in our tertiary care centre in 12 years of activity (1995-2006).

METHODS AND RESULTS

We detected 705 congenital heart diseases: 32% (223) were associated with extracardiac or chromosomal anomalies or both, and 68% (482) were isolated. Termination of pregnancy was chosen in 81% for associated anomalies and 37% for isolated anomalies (P<0.001). Of these, more than one-third occurred in hypoplasic left heart cases. The general survival rate was 72%; it was significantly lower in the group with associated heart diseases (46 vs. 80%, P<0.001). Over 12 years we noticed a reduction in the number of multimalformed fetuses and of the hypoplasic left heart cases, and a higher number of aortic arch anomalies detected. During the past 6 years of activity the survival rate obtained has significantly increased (55 to 84%, P<0.05), the termination rate has significantly decreased (35 to 14%, P<0.001) and the number of neonatal deaths has significantly decreased (39 to 10%, P<0.001).

CONCLUSION

The survival and the voluntary termination of fetuses with prenatally detected congenital heart diseases are strongly influenced by disease severity and by associated extracardiac or chromosomal anomalies, or both. Over 12 years, the spectrum of fetal congenital heart disease has changed and their outcome has significantly improved.

A systematic review of the accuracy of first-trimester ultrasound examination for detecting major congenital heart disease

OBJECTIVE

To evaluate the accuracy of first-trimester ultrasound examination in detecting major congenital heart disease (CHD) using a systematic review of the literature.

METHODS

General bibliographic and specialist computerized databases along with manual searching of reference lists of primary and review articles were used to search for relevant citations. Studies were included if a first-trimester ultrasound scan was carried out to detect CHD that was subsequently verified by a reference standard. Data were extracted on study characteristics and quality, and 2 x 2 tables were constructed to calculate sensitivity and specificity.

RESULTS

Ten studies (involving 1243 patients) were suitable for inclusion. Of these, four used transabdominal ultrasonography, four used transvaginal and two used a combination. Pooled sensitivity and specificity were 85% (95% CI, 78-90%) and 99% (95% CI, 98-100%), respectively.

CONCLUSION

Ultrasound examination of the fetus in the first trimester is feasible for accurately detecting major CHD. It may be offered to women at high risk of having children with CHD.

Fetal Echocardiography Service in Qatar: Establishment, Challenges and Outcome

A prospective observational study at the newly estab-lished Fetal Medicine Unit, Hamad Hospital, Qatar; evalu-ated the impact of the service on the detection rate of criti-cal congenital heart defects, patterns of referral and sub-sequent yield for structural congenital heart disease in a population with a significant proportion of high risk fac-tors.

Of 391 pregnant females examined between January 2003 and December 2004, 58 (14.8%) had fetal cardiac abnormalities of which 23 (5.8% of total referrals) had major structural malformations of the heart. Cases of fetal congenital heart disease had further evaluation us-ing real time three-dimensional echocardiography (RT3DE) which is new equipment in the paediatric cardi-ology department. All cases with cardiac defects whether minor or major had follow up fetal echocardiography. Neonatal echocardiography confirmed the diagnosis in all cases with major defects (100% specificity). False positive cases that were found to be normal post natal were 1% of the total cases referred (12% of cases with congenital mal-formation). False negative cases were 1% and all had a small ventricular septal defect (VSD) except for one Down's syndrome with a very large VSD.

Three patients needed urgent Caesarean section (CS) deliveries, one with complete heart block (HB) and two with supraventricular tachycardia (SVT). One patient traveled abroad as the fetus had left isomerism and major cardiac defects and complete HB. Fifteen newborns had to receive prostaglandin based on the fetal diagnosis before being seen by paediatric cardiologists. There was no termination of pregnancy due to major cardiac defects even in cases of HLHS.

The preliminary results of this clinic are very satisfac-tory and have affected favorably the outcome of the new-borns with congenital heart defects. It is hoped that the results of this study will encourage more referrals to the FMU.

Isolated ventricular septal defects detected by color Doppler imaging: evolution during fetal and first year of postnatal life

OBJECTIVE

To evaluate the development during gestation and up to 1 year postnatally of isolated small ventricular septal defects (VSDs) not visible by gray-scale imaging and detected only on color Doppler fetal echocardiography.

METHODS

This was a retrospective analysis of 146 fetuses with isolated VSDs detectable only on color Doppler echocardiography. Complete sequential gray-scale, color Doppler and spectral Doppler examination of the fetal heart were performed. The following variables were documented: site of the VSD, presence of extracardiac or chromosomal anomalies, outcome of the pregnancy and evolution of the defect up to 1 year postnatally.

RESULTS

A total of 113 fetuses reached their first year of postnatal life, 23 pregnancies were terminated, there were three stillbirths/neonatal deaths, and seven were lost to follow-up. It was observed that 32.7% (n = 37) of all defects in neonates alive after 1 year closed in utero, 44.3% (n = 50) of defects closed spontaneously within the first postnatal year, and 23.0% (n = 26) of defects did not close. In all, a comparable number of perimembranous and muscular septal defects closed spontaneously in utero and during the first year of postnatal life. Among 35 fetuses with extracardiac anomalies 51.4% (n = 18) were euploid.

CONCLUSION

Small VSDs, detectable only by color Doppler echocardiography, show a high spontaneous intrauterine and postnatal closure rate. These findings might be of value for prenatal parental counseling.

Prenatal detection of heart defects in a non-selected population of 30,149 fetuses--detection rates and outcome

OBJECTIVES

To evaluate the detection rate of congenital heart defects (CHD) in a non-selected population and to follow outcome after diagnosis.

METHODS

All 30,149 fetuses/newborns that were scheduled to deliver at our hospital between February 1991 and December 2001 were registered prospectively. Of these, 29,460 (98%) fetuses had a prenatal ultrasound scan at our center. The routine fetal examination at approximately 18 weeks' gestation included the four-chamber view and the great arteries of the fetal heart. The follow-up period was 2-13 years.

RESULTS

Of 97 major CHDs, 55 (57%) were detected prenatally, 16% (9/55) prior to, 66% (36/55) at and 18% (10/55) after the routine scan. Forty-four percent (19/43) of the isolated CHDs, 67% (36/54) of those with associated malformations and 48% (11/23) of the isolated ductal-dependent CHDs were detected. Thirty-eight percent (37/97) had an abnormal karyotype. Of the 55 major CHDs detected, 44% (24) of the pregnancies with lethal/serious fetal malformations were terminated, 15% (8) died in utero, 42% (23) were born alive and 27% (15) were still alive after 2 years. Of the 42 CHDs detected postnatally, 2% (1) were terminated for other reasons, 98% (41) were born alive and 81% (34) were still alive after 2 years.

CONCLUSIONS

Prenatal detection of CHD is still a challenge, with a 57% detection rate only. Isolated defects are detected less frequently. The overall outcome suggests that the most severe defects are detected with the present screening setting; only 27% of the babies with major CHDs detected were still alive after 2 years. Data from long-term follow-up will be of importance for the counseling process.

Accuracy of fetal echocardiography in the routine detection of congenital heart disease among unselected and low risk populations: a systematic review

OBJECTIVE

To determine among unselected and low risk populations the accuracy with which fetal echocardiography during the second trimester detects congenital heart disease.

DESIGN

A systematic review of studies that assess the accuracy of fetal echocardiography.

SETTING

District General Hospital and Tertiary referral centres.

POPULATION

Women during the second trimester attending for ultrasound assessment.

METHODS

General bibliographic databases (e.g. MEDLINE, EMBASE) and specialist computerised databases (e.g. Cochrane Library, National Research Register), grey literature, manual searching of reference lists of primary and review articles and personal contact with experts were used to identify studies. Studies were included if fetal echocardiography among unselected or low risk pregnant women was compared against a postnatal reference standard. Data were extracted on quality, study design and characteristics, and accuracy data to construct 2 x 2 tables. Data were synthesised qualitatively, and sensitivity and specificity with 95% confidence intervals were calculated.

MAIN OUTCOME MEASURE

Sensitivity and specificity.

RESULTS

Five primary studies met the inclusion criteria and comprised 60,901 subjects. One study assessed the accuracy of fetal echocardiography among an unselected population and four studies among low risk populations. All eligible studies found that fetal echocardiography helped to correctly diagnose normal fetus among unselected and low risk populations. Correct diagnosis of babies for congenital heart defects was higher among the unselected population (85%) than among the low risk populations (range from 35% to 86%); however, the potential for ascertainment bias and the choice of reference standard limits the validity of this finding. The variation in sensitivity across studies was not explainable by clinical factors such as scanning regime, operator skill and equipment.

CONCLUSIONS

The evidence from this review about the accuracy of fetal echocardiography does not lend support to its routine use among unselected and low risk populations during the second trimester to detect congenital heart disease.

Screening for congenital heart disease

Congenital heart disease has the characteristics of a disease that is suited to screening, and the four-chamber view is an effective screening tool with a sensitivity of 40% to 50%. The use of multiple cardiac views can increase the pre-natal detection to 60% to 80%. Given that most infants with congenital heart disease are born to low-risk women, routine screening is warranted. Early pre-natal diagnosis provides an opportunity to exclude associated extracardiac and chromosomal abnormalities, discuss pregnancy options, adjust obstetric management, prepare parents for delivery of an affected baby, and plan delivery in a tertiary care center. Despite the widespread use of ultrasonography, only 15% to 30% of infants with congenital heart disease are identified prenatally. There is a need to do better.

Four-dimensional ultrasonography of the fetal heart with spatiotemporal image correlation

OBJECTIVE

This study was undertaken to describe a new technique for the examination of the fetal heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC).

STUDY DESIGN

Volume data sets of the fetal heart were acquired with a new cardiac gating technique (STIC), which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage.

RESULTS

Volume datasets obtained with a transverse sweep were utilized to demonstrate the cardiac chambers, moderator band, interatrial and interventricular septae, atrioventricular valves, pulmonary veins, and outflow tracts. With the use of a reference dot to navigate the four-chamber view, intracardiac structures could be simultaneously studied in three orthogonal planes. The same volume dataset was used for surface rendering of the atrioventricular valves. The aortic and ductal arches were best visualized when the original plane of acquisition was sagittal. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. For example, the location and extent of a ventricular septal defect was imaged in a sagittal view of the interventricular septum. Furthermore, surface-rendered images of the atrioventricular valves were employed to distinguish between normal and pathologic conditions. Representative video clips were posted on the Journal's Web site to demonstrate the diagnostic capabilities of this new technique.

CONCLUSION

Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel method may assist in the evaluation of fetal cardiac anatomy.

Short-term outcome of isolated and associated congenital heart defects in relation to antenatal ultrasound screening

OBJECTIVE

To investigate the outcome of fetuses affected by congenital heart defects (CHD), either detected or undetected at ultrasound screening, according to their complexity and severity.

DESIGN

The study group comprised 3633 malformed fetuses entered into the Eurofetus database of which 798 had CHD. We compared the short-term outcome in cases where a CHD was detected by ultrasound screening with that in cases where a CHD was not detected. Isolated and associated CHD (ICHD and ACHD) and the degree of severity of defects were considered separately. Outcome data included termination of pregnancy (TOP), intrauterine fetal death, neonatal death (< 6 days after birth), gestational age at diagnosis and at delivery, mode of delivery and birth weight.

RESULTS

Of the 798 fetuses with CHD, 595 had ICHD and 203 had ACHD. The diagnosis of an anomaly was made significantly earlier in ACHD cases. TOP was chosen in 28% of cases with a prenatal diagnosis of CHD, 20% for ICHD and 37% for ACHD (P < 0.001). The survival rate of antenatally diagnosed fetuses was lower in those with ACHD than in those with ICHD (P < 0.001) and lower for fetuses with antenatal diagnosis than with postnatal diagnosis (P < 0.001); this was due to significant differences in the complexity and severity of the defect. Premature delivery (< 32 weeks) was more frequent in fetuses in which an antenatal diagnosis of CHD had been made. Severe CHD were diagnosed earlier and were associated with a higher rate of TOP and spontaneous loss.

CONCLUSIONS

The severity of CHD has a positive influence on the sensitivity of screening but a negative influence on the outcome. CHD that are not diagnosed antenatally include a high proportion of benign malformations. This explains the apparent paradox of a poorer outcome in fetuses in which a CHD was detected prenatally compared to those fetuses in which the defect was undetected prenatally. However, prenatal diagnosis provides parents with the option of TOP or of preventive care in specialized centers.

Evaluation and evolution during time of prenatal diagnosis of congenital heart diseases by routine fetal ultrasonographic examination

The objectives of this study were to evaluate routine prenatal diagnosis of congenital heart diseases (CHD) by fetal ultrasound examination in a well-defined population during the period 1994-1999 and to compare these results with the results from 1979 to 1993. This study included 80,076 consecutive pregnancies of known outcome from 1994 to 1999. CHD were classified as isolated or associated when at least one other major extra-cardiac malformation was present. Only 137 out of 688 malformed fetuses with CHD without chromosomal anomalies were detected (19.9%). The sensitivity of detection varied from 61.9% for malformations such as isolated hypoplastic left heart and single ventricle, to around 7-19% for atrial and ventricular septal defects. Prenatal detection rate of CHD was 11.4% for isolated cases, and 40.2% for multiple malformed with CHD. The gestational age at discovery varied from 16 to 36 weeks. There is no upper limit for termination of pregnancies in our country; 12.3% of all pregnancies were terminated after prenatal diagnosis. However, 62% of the pregnancies with a CHD detected prenatally were terminated. The detection rate of CHD increased during time from 9.2% during the period 1979-1988 to 13.7% during the period 1990-1993 and to 19.1% during the period 1994-1999. Our study shows large variation in the prenatal detection rate of CHD. Prenatal diagnosis of CHD is significantly higher when associated malformations are present. Cardiac defects affecting the size of the ventricles have the highest detection rate. Gestational age at discovery was 20-24 weeks for the majority of associated cardiac defects. The prenatal detection rate of CHD increased during time from 1979 to 1999.

Fetal echocardiography

Since the first report of fetal echocardiography in 1972 by Winsberg, several advances in ultrasound technology have occurred allowing detailed evaluation of cardiac anatomy in the second trimester fetus. Fetal echo is indicated in high risk pregnancies where the chances of fetus having a congenital heart disease (CHD) are likely to be high e.g., in fetus with extracardiac anomalies picked up on obstetric ultrasound, those with a history of CHD in family, maternal diabetes (especially insulin dependent), maternal connective tissue disorder etc. The reported sensitivity of fetal echo has ranged from 4-96% in various series depending upon the equipment, level of training, study design and examination technique. Although many CHD can be detected in four chamber view, an important group malformations that would need early intervention are likely to be missed. Hence a detailed echocardiographic examination including the outflow views must be done. Defects like atrial septal defect and patent ductus arteriosus cannot be diagnosed in fetal echo, as these are part of normal fetal physiology. Other CHD like coarctation of aorta, small ventricular septal defects, mild valvular stenosis, partial anomalous pulmonary venous drainage are also difficult to diagnose. Ultrasound assessment of fetus, however, has a clear role in the diagnosis, monitoring and management of fetuses with sustained arrhythmias. Prenatal diagnosis of CHD helps in planning the optimal management of the baby e.g. a fetus with a ductus dependent lesion can be planned to be delivered in a tertially care centre for stabilisation and early initiation of prostaglandin therapy to avoid acidosis and organ damage. Future of fetal medicine lies in fetal cardiac surgery for which echocardiography will play a very important role.

Prenatally diagnosed hypoplastic left heart syndrome--outcomes after postnatal surgery

OBJECTIVE

To identify prenatally diagnosed cases of hypoplastic left heart syndrome (HLHS) and then to determine postnatal outcomes after surgical interventions.

METHODS

An ultrasound and pediatric cardiology database was used to identify all fetuses diagnosed prenatally from 1991-1996 with HLHS. Fetal karyotypes were performed on cultured amniocytes. After diagnosis, parents were given several management options: pregnancy termination before 22 weeks, postnatal hospice care, or surgery using the Norwood procedure or cardiac transplantation. Ultrasound and echocardiography findings were later compared to karyotype results and postnatal outcome data.

RESULTS

Fifteen fetuses with HLHS were identified. Two (16%) chromosome abnormalities and three (20%) structural defects were detected. Three mothers (20%) opted for pregnancy termination, two (13%) chose postnatal hospice care, and one aneuploid fetus had an intrauterine death. Nine parents (60%) chose surgery for their infants; however, one infant was not an appropriate surgical candidate due to a coexisting diaphragmatic hernia. Eight infants underwent surgery and two survived (25%). Of the four infants scheduled to undergo the Norwood procedure, one died preoperatively, two died intraoperatively, and one infant survived and is doing well at age 8 months. Of the four infants scheduled for cardiac transplantation, two died awaiting transplant and one died postoperatively. One infant survived cardiac transplantation but has microcephaly and developmental delay at age two.

CONCLUSIONS

In prenatally diagnosed HLHS at our institution, the survival rate following surgery for infants felt to be the best candidates was only 25%.

Obstetric management of 219 infants with hypoplastic left heart syndrome

OBJECTIVE

The objective of this study was to describe the obstetric parameters from 219 deliveries of infants with hypoplastic left heart syndrome.

STUDY DESIGN

The Pediatric Cardiovascular Surgery Database at the University of Michigan was searched, and cases of neonates with the diagnosis of hypoplastic left heart syndrome were found. Obstetric records were then reviewed.

RESULTS

One hundred sixty-one infants (74%) were delivered vaginally and 58 (26%) were delivered by the cesarean route. The mean gestational age at delivery was 38.9 weeks. Mean Apgar scores at 1 and 5 minutes were 7 and 8, respectively. Ninety percent were delivered at term and 10% were delivered before 37 weeks. The diagnosis of hypoplastic left heart syndrome was made antenatally in 82 cases (37%) and neonatally in 137 cases (63%). In the antenatal group the mean gestational age at diagnosis was 27 weeks. Karyotype analysis was performed in 32 of all cases (15%), with 8 fetuses revealing an abnormal karyotype. Seven cases were 45,X and 1 was trisomy 21.

CONCLUSION

Staged reconstruction surgery has markedly improved survival for neonates born with isolated hypoplastic left heart syndrome. Our review suggests that, aside from determining the karyotype, no further obstetric interventions seem warranted. While awaiting spontaneous labor at term, the planned mode of delivery should be vaginal, with cesarean delivery performed for routine obstetric indications only.

[Fetal echocardiography]

Cardiac malformations are the most frequent and serious fetal malformations. However their prenatal diagnosis is the less easy. Fetal echocardiography is the main diagnostic tool; in addition it is helpful for the therapeutic orientation. Only 30% of fetal heart diseases are detected on account of maternal or fetal indications, most of them being discovered without any known risk factor. In order to improve its diagnostic sensitivity, fetal echocardiography must include a four chambers view and a study of ventricular and arterial connection. Nevertheless, many heart diseases remain undetected, most of them being minor with favorable prognosis. Search of an extracardiac abnormality and karyotype analysis must be performed in order to explicit the prognosis. Fetal arrhythmias can be analyzed by study of the atrial and ventricular contraction using M-mode echocardiogram or Doppler mode; most of them are supraventricular and accessible to maternal therapy. The sustained fetal bradycardia is frequently a complete heart block whose prognosis depends upon its association with a heart defect and/or a ventricular escape. Antibodies SS-A and SS-B are frequently associated with complete heart block without structural heart defects. Hypertrophic cardiomyopathy may be observed in fetus of diabetic mothers needing an accurate evaluation of the thickness of the interventricular septum. Echocardiography is a part of fetal medicine, which includes the different specialties devoted to the fetus.

Prognosis following prenatal diagnosis of heart malformations

Our objective was to document the prognosis of cases with fetal heart malformations (FHM). Forty-two fetuses assessed both in a regional fetal medicine and paediatric cardiology unit were classified prenatally into isolated FHM or those associated with extra-cardiac structural or karyotypic anomalies (ECA) and this classification was not changed subsequently (analogous to an intention to treat analysis). The end points studied included chromosomal abnormality, pregnancy outcome and follow-up at one year of age. FHM were isolated in 16 (38%) and associated with ECA in 26 (62%) of cases. The karyotypic abnormality rate was 8/42 (19%) overall and 8/26 (31%) in ECA cases. The pregnancy outcome included termination of pregnancy in 19 (45%), intrauterine death of two (5%) and live birth in 21 (50%). 12/16 (75%) of isolated FHM cases were live born compared with 9/26 (35%) of ECA cases (P < 0.03). Of the isolated FHM live born babies, 8/12 (67%) were alive at the end of the first year and seven of these were growing normally and did not require cardiac medication. However, a considerable proportion of their first year was spent in hospital (median 8%, interquartile range 5-10). Only one of nine ECA live born cases was alive but with poor growth and dependence on cardiac drugs at one year. These data confirm previous findings in prenatal diagnosis series that the prognosis for FHM is worse than that reported in studies of congenital heart disease at birth and is strongly dependent upon the presence of ECA. In their absence, outcome is better than previously published. Counselling must take place only after full fetal medicine assessment and should be based upon prenatal data.

Prenatal diagnosis of congenital heart disease

Owing to the widely different levels of experience of examiners, there is a large discrepancy in study results of second trimester ultrasound screening for fetal malformations, which is a result of varying levels of obstetric scanning expertise prevalent at the reporting centre. This holds particularly true for the prenatal diagnosis of congenital heart disease where detection rates ranging from 0 per cent to 60 per cent are being reported. On the other hand, congenital heart disease affects about 4-8 per 1000 live births and is a leading cause of infant mortality, whereas prenatal diagnosis could possibly prevent death and long-term morbidity in some of these neonates. Various screening concepts for more effective detection of congenital heart diseases are analysed in this article, including the more recent technique of early echocardiography between 13 and 15 weeks of gestation. High-risk groups are defined and the group of fetuses with increased thickness of nuchal translucency seems to be of particular interest.

Routine prenatal screening for congenital heart disease: what can be expected? A decision-analytic approach

OBJECTIVES

This study assessed the potential impact of fetal ultrasound screening on the number of newborns affected by cardiac anomalies.

METHODS

A decision model was developed that included the prevalence and history of congenital heart disease, characteristics of ultrasound, risk of abortion, and attitude toward pregnancy termination. Probabilities were obtained with a literature survey; sensitivity analysis showed their influence on expected outcomes.

RESULTS

Presently, screening programs may prevent the birth of approximately 1300 severely affected newborns per million second-trimester pregnancies. However, over 2000 terminations of pregnancy would be required, 750 of which would have ended in intrauterine death or spontaneous abortion. Further, 9900 false-positive screening results would occur, requiring referral. Only the sensitivity of routine screening and attitude toward termination of pregnancy appeared to influence the yield substantially.

CONCLUSIONS

The impact of routine screening for congenital heart disease appeared relatively small. Further data may be required to fully assess the utility of prenatal screening.

Reversed shunting across the ductus arteriosus or atrial septum in utero heralds severe congenital heart disease

OBJECTIVES

This study was performed to define the significance of Doppler color flow mapping in demonstrating reversal of the direction of the normal physiologic flow across the atrial septum and ductus arteriosus in the human fetus.

BACKGROUND

Reversal of the physiologic shunting across the ductus arteriosus or atrial septum in utero (i.e., left to right) can be readily identified by Doppler color flow mapping, complemented by pulsed and continuous wave Doppler information.

METHODS

We reviewed echocardiograms recorded at our three institutions from 1988 to 1993, which displayed reversal of flow by Doppler color flow in 53 fetuses of gestational age 18 weeks to term. The diagnoses were confirmed by postnatal echocardiography, operation or autopsy. Reversal of shunting was consistently associated with severe heart disease.

RESULTS

Reversed atrial shunting was found with severe left heart obstructive lesions, including 19 with hypoplastic left heart syndrome, 3 with critical aortic stenosis, 2 with double-outlet right ventricle and 1 each with an interrupted aortic arch, atrioventricular septal defect and severe left ventricular dysfunction due to dilated cardiomyopathy. Reversed ductus arteriosus shunting was found with severe right heart obstructive lesions, including nine fetuses with pulmonary atresia, six with severe obstructive tricuspid valve abnormalities, five with severe tetralogy of Fallot, four with Ebstein's anomaly and two with single ventricle and pulmonary stenosis. Associated cardiac lesions were common in both groups. Only 3 of the 15 infants who were delivered alive from the reverse ductus arteriosus shunt group and 4 of 12 from the reverse atrial shunt group still survive.

CONCLUSIONS

The finding of reversed flow by Doppler color flow mapping during fetal life provides a key to subsequent accurate diagnosis and denotes a spectrum of diseases with a very poor prognosis.

Cardiac abnormalities associated with hydrops fetalis

Cardiovascular abnormalities are associated with hydrops fetalis in 26% of cases reported in the modern era. These include not only structural abnormalities, but also cardiac arrhythmias, failure, tumors, myopathy, infection, inflammation, infarction, and arterial calcification. Cardiac structural abnormalities may be causative or seen only in association with hydrops fetalis. Structural lesions that result in right atrial pressure or volume overload seem to be most commonly associated with hydrops fetalis. Fetal cardiac tumors, cardiomyopathy, myocarditis, myocardial infarction, and arterial calcification probably result in hydrops fetalis by a similar mechanism. Fetal tachyarrhythmia has been shown to result in elevation of atrial pressure and atrial natriuretic peptide. Fetal tachyarrhythmias are the most treatable of cardiac causes of hydrops fetalis. Fetal bradyarrhythmias are less easily treatable and less certainly a causative mechanism of hydrops fetalis.

The delivery room resuscitation of the hydropic neonate

Hydrops fetalis is a relatively rare disorder that will be encountered occasionally in all obstetric centers. The prognosis for infants with hydrops fetalis is poor, with mortality reported in the range of 50% to 98%. The effectiveness of delivery room resuscitation and the ability to achieve early adequate gas exchange in affected infants may be related to survival. Successful resuscitation requires an understanding of transitional neonatal physiology and the potential impact of hydrops fetalis, an experienced and well-prepared resuscitation team, meticulous attention to technical aspects of resuscitation, and careful assessment and monitoring of the infant during resuscitation.

The accuracy of antenatal fetal echocardiography screening in high- and low-risk patients

OBJECTIVE

The purpose of this study was to evaluate the accuracy of four-chamber and left ventricular outflow tract views in low-risk patients and comprehensive fetal echocardiographic examinations in high-risk patients to diagnose structural heart disease or thoracic anomalies.

STUDY DESIGN

A prospective outcome study of two cohorts was performed; 1136 low-risk patients and 886 high-risk patients were evaluated during a 2-year period. Low-risk patients underwent routine four-chamber and left ventricular outflow tract evaluation whereas high-risk patients had detailed fetal echocardiographic examinations. Accuracy of the ultrasonographic diagnosis was evaluated from neonatal discharge data.

RESULTS

Only 2 of 14 patients with congenital heart disease in the low-risk group were correctly identified (sensitivity 14.3%) whereas 10 of 16 patients with congenital heart disease or thoracic anomalies were correctly identified in the high-risk group (sensitivity 62.5%).

CONCLUSION

The current study showed poor diagnostic accuracy of the standard four-chamber and left ventricular outflow tract views in low-risk patients for the diagnosis of structural cardiac anomalies. Patients with risk factors for congenital heart disease should be referred for comprehensive fetal echocardiographic examination.

Prenatal diagnosis of congenital heart disease; prospects and problems

Routine fetal echocardiography has been submitted as an antenatal screening test for congenital heart disease despite a wide range of efficacy reported. Hence, evaluation of the variable results of prenatal ultrasound screening programs was pursued. As the studies appeared to have a heterogeneous design, the originally reported figures have been corrected for one plausible prevalence of cardiovascular anomalies. Clinical setting (general hospitals vs. teaching hospitals), case ascertainment (retrospective vs. prospective; follow-up on (suspected) cases only vs. routine follow-up) and length of follow-up (< 1 year vs. a longer period) all have similar effects on the reported yield of cases and sensitivity of the proposed screening test. Notably, a relatively low yield of cases causes a seemingly high sensitivity, whereas a higher yield of cases causes a seemingly low sensitivity. Additional factors of study design, e.g. case definition, diagnostic procedures and appliances used, were usually not described in detail, yet may also have affected the results. Evaluating diagnostic tests apparently demands a rigorous study design to overcome biased results. Furthermore, no sufficient evidence could be found meriting current routine prenatal screening for congenital heart disease.

Fetal echocardiography in detecting anomalous pulmonary venous connection: four false positive cases

Prenatal detection of congenital heart disease is possible from the 16th week of pregnancy, the ideal time being the mid-trimester, when most cardiac abnormalities can be detected. However, identification of anomalous pulmonary venous connection is difficult before birth and the sensitivity of fetal echocardiography in detecting this anomaly is low. Four cases are reported in which fetal echocardiographic findings obtained during the third trimester of pregnancy were highly suggestive of anomalous pulmonary venous connection. Right ventricular and atrial dominance associated with an enlarged coronary sinus or dilated superior vena cava were identified and considered to be indirect markers of the anomaly. No other cardiac anomaly was detectable. In all cases right ventricular and atrial dominance with dilated coronary sinus or superior vena cava were confirmed after birth despite the presence of normal pulmonary venous connections. These results confirm that the prenatal detection of this condition is difficult and should be based on the direct visualisation of anomalous pulmonary venous connections. The sole detection of indirect signs, such as right atrial and ventricular dominance with or without a dilated coronary sinus, superior vena cava, or inferior vena cava, does not warrant the diagnosis of anomalous pulmonary venous connection. Since the pulmonary venous flow in the human fetus is not as small as is commonly assumed, an anomalous drainage should be detectable when present and therefore should be specifically sought if the anomaly is suspected. The reasons for the presence of such transient cardiac anomalies remain obscure, but they might be related to functional or morphological rearrangement of the heart during fetal and perinatal life.

In utero pulmonary artery and aortic growth and potential for progression of pulmonary outflow tract obstruction in tetralogy of Fallot

OBJECTIVES

This study was designed to define patterns of pulmonary artery and aortic growth in fetuses with tetralogy of Fallot and to determine the potential for in utero progression of right ventricular outflow tract obstruction.

BACKGROUND

Despite an abundance of reports documenting the prenatal diagnosis of tetralogy of Fallot, there is little information about its course in utero.

METHODS

Pulmonary artery and ascending aortic diameters were measured from prenatal and postnatal echocardiograms of 16 fetuses with tetralogy of Fallot, initially studied at 23.6 +/- 6.0 (mean +/- SD) weeks of gestation. Fetuses were classified retrospectively as having mild and severe tetralogy of Fallot according to whether the pulmonary artery circulation was (severe, n = 5) or was not (mild, n = 11) ductus arteriosus dependent at birth.

RESULTS

Initial main pulmonary artery diameter was small for gestational age in 9 fetuses, large in 2 and normal in 5 compared with data from 57 gestational age-adjusted normal fetal studies; it was significantly smaller in the group with severe tetralogy of Fallot (p = 0.05). The initial main pulmonary artery/aortic diameter ratio was also smaller for the group with severe tetralogy of Fallot (0.50 +/- 0.15 vs. 0.73 +/- 0.14 in the group with mild tetralogy of Fallot, p = 0.01). Initial aortic and branch pulmonary artery diameters tended to be normal or near normal for age. In eight fetuses serially studied, main and branch pulmonary artery growth was normal or reduced during prenatal follow-up. Pulmonary artery growth was most reduced in two fetuses in the group with severe tetralogy of Fallot, resulting in pulmonary artery hypoplasia at birth. Two fetuses with valvular pulmonary atresia at birth had previously shown anterograde pulmonary outflow in midgestation, suggesting progression of pulmonary outflow obstruction.

CONCLUSIONS

The postnatal spectrum of pulmonary artery size in tetralogy of Fallot can be attributed to variable patterns of growth in utero. Main pulmonary artery size, main pulmonary artery/aortic diameter ratio and pattern of pulmonary artery growth may be predictive of the severity of postnatal pulmonary outflow obstruction. Pulmonary atresia can develop in utero in some fetuses with tetralogy of Fallot.

Prenatal Diagnosis of Critical Aortic Stenosis

Critical aortic stenosis in the infant can lead to endocardial fibroelastosis and congestive heart failure. Prenatal sonographic findings in a case of endocardial fibroelastosis and a review of the pathophysiology of this condition are presented.

Assessment of changes in blood flow through the lungs and foramen ovale in the normal human fetus with gestational age: a prospective Doppler echocardiographic study

OBJECTIVE

To measure lung blood flow and flow through the foramen ovale in the normal human fetus and to assess the changes in each with gestational age and the proportions of combined ventricular output that the respective flows represent.

PATIENTS AND DESIGN

38 normal fetuses (gestational age 18-37 weeks) were studied prospectively with Doppler echocardiography.

METHODS

Echocardiographic images and Doppler velocity signals were obtained from the ascending aorta, main pulmonary artery, and ductus arteriosus from each fetus and digitised to obtain arterial diameters, heart rates, and velocity-time integrals. Blood flow in each artery was calculated as the product of heart rate, flow-velocity integral, and arterial cross sectional area. Blood flow through the lung was assessed as the difference between flow in the pulmonary artery and ductal flow; combined ventricular output as the sum of aortic and pulmonary artery flows; and flow through the foramen ovale as the difference between flows through the aorta and lungs.

RESULTS

Blood flow through the lungs increased exponentially with gestational age (r = 0.89, p < 0.001), by almost four-fold over the period of gestation studied, and was a mean (SD) of 22% (7%) of combined ventricular output. Blood flow through the foramen ovale increased exponentially by threefold (r = 0.77, p < 0.001), representing between 17% and 31% of combined ventricular output.

CONCLUSIONS

Blood flow through the lungs and across the foramen ovale can be calculated non-invasively in the normal human fetus. Both flows increase exponentially with age and comprise between one fifth and one quarter of the combined ventricular output, proportions that remain unchanged through the second and third trimesters of pregnancy.

The ultrasound markers of chromosomal disease: a retrospective study

Over a 3 year period 37 pregnancies were complicated by a chromosomal abnormality. In the two cases of trisomy 13, holoprosencephaly, facial clefting, polydactyly and growth retardation were seen. In the seven cases of trisomy 18, abnormalities of the extremities, face and heart were common. Growth retardation and diaphragmatic hernia were also demonstrated. In the 21 cases of Down's syndrome the main abnormalities were cardiac, duodenal atresia and subtle digital anomalies. The two fetuses with triploidy showed a large hydropic placenta and holoprosencephaly respectively, and all five cases of Turner's syndrome demonstrated a cystic hygroma two of which were associated with hydrops. From the antenatal scans major anomalies were detected in 18 fetuses, however, chromosomal disease was suspected in only 15 cases. This was in part owing to a high false negative rate for cardiac anomalies (14 cases) in both routine and detailed scans. Owing to the diversity of anomalies present in chromosomal disease full assessment of the fetus is recommended with particular attention to the fetal heart, face, hands and feet. Specific anomalies are suggested for karyotype.

Value of routine ultrasound scanning at 19 weeks: a four year study of 8849 deliveries

OBJECTIVE

To evaluate the effectiveness of routine ultrasound scanning at 19 weeks' gestation in an unselected population in terms of accuracy of detection of fetal structural abnormality and the effect on obstetric and neonatal care.

DESIGN

Prospective study over four years. Scans performed by radiographers with overall supervision by a radiologist.

SETTING

Ultrasound department of district general hospital.

SUBJECTS

All pregnant women were offered scans; 8523 of 8849 (96%) accepted.

MAIN OUTCOME MEASURES

Information obtained from hospital records, genetic analysis, and post-mortem findings.

RESULTS

166 fetal anomalies occurred; 140 were detected at 19 weeks (sensitivity 85%; specificity 99.9%). In 27 cases fetuses were shown to have severely crippling or lethal abnormalities; termination of pregnancy was requested in 25. Early diagnosis influenced timing and place of delivery in babies with severe cardiac or gastrointestinal anomalies.

CONCLUSION

Scanning at 19 weeks with availability of termination can reduce perinatal morbidity and mortality. Scanning can be performed in a general ultrasound department with adequate counselling facilities and close cooperation between radiographers, midwives, obstetricians, paediatricians, and the radiologist.

Fetal echocardiography: accuracy and limitations in a population at high and low risk for heart defects

OBJECTIVE

Our objective was to assess the accuracy of prenatal echocardiography in detecting congenital heart defects in patients at high and low risk for structural cardiac anomalies.

STUDY DESIGN

Sixty-nine consecutive fetuses with congenital heart defects who had had prenatal ultrasonography at greater than or equal to 18 weeks' gestation were evaluated to determine the accuracy of prenatal ultrasonography in identifying structural cardiac defects. Thirty-nine patients were at high risk and 30 patients were at low risk for cardiac anomalies. All fetuses were scanned with standard four-chamber and outflow tract views. Data concerning extracardiac anomalies and karyotypic abnormalities were tabulated. The accuracy of the four-chamber view alone in identifying congenital heart defects was evaluated.

RESULTS

Fifty-seven of 69 fetuses (83%) were prenatally identified ultrasonographically as having a heart defect. There was no difference in the sensitivity of detecting cardiac anomalies between high-risk and low-risk groups. When the four-chamber view was used, only 63% of fetuses were recognized as having an abnormal heart. Extracardiac anomalies were noted in 36% and karyotypic abnormalities in 17% of patients.

CONCLUSION

The four-chamber and outflow tract views done routinely in an ultrasonography laboratory seeing a mixed population of patients was successful in detecting 83% of fetuses with structural cardiac malformations. Because 43% of the fetuses with heart defects were referred for low-risk indications, systematic ultrasonographic examination of the fetal heart should not be reserved only for those at high risk.

Hypoplastic left heart syndrome: prenatal diagnosis, clinical profile, and management

We diagnosed hypoplastic left heart syndrome, generally regarded as a lethal congenital heart defect, by fetal echocardiography in 20 pregnancies in the last 5 years. The clinical profile, management, and outcome of these pregnancies were reviewed. We found a 40% association of karyotype and extracardiac malformations. Elective abortion was performed in nine pregnancies. Two of seven live-born babies had early neonatal assessment and intervention as a result of in utero diagnosis and counseling. Prolonged survival was achieved in both infants. We conclude that prenatal diagnosis of the hypoplastic left heart syndrome necessitates complete evaluation of the fetus for associated genetic and extracardiac malformations. Prenatal diagnosis of this defect provides opportunities for in depth counseling of parents and obtaining informed consent for either postnatal intervention or nonintervention before the medical and emotional complexities associated with the neonatal intensive care setting are encountered.

Tricuspid valve dysplasia or displacement in intrauterine life

In 450 cases of structural heart disease diagnosed prenatally, 38 fetuses (8.5%) had either a dysplastic or a displaced tricuspid valve. The tricuspid valve was dysplastic in 22 fetuses, all of which had evidence of tricuspid regurgitation resulting in right atrial dilation and increased cardiothoracic ratio. An associated abnormality of the pulmonary valve occurred in 16 fetuses. The remaining 16 fetuses had Ebstein's malformation, 14 with evidence of tricuspid incompetence at presentation and 10 with an associated abnormality of the pulmonary valve. Of the 38 cases, the pregnancy was interrupted in 17, spontaneous intrauterine fetal death occurred in 8, 11 infants died postnatally and 2 infants are still alive; additional abnormalities were found in 8 cases (chromosomal anomalies in 2, ventricular septal defects in 2, corrected transposition in 2, the Chiari malformation in 2, supraventricular tachycardia in 1 case and coarctation of the aorta in 1). Fetuses with severe abnormalities are selected for fetal echocardiography by the four chamber screening program and a high rate of natural loss both in intrauterine life and immediately after birth was observed in the 21 cases in which pregnancy was continued. This would explain the higher incidence of tricuspid valve disease in our prenatal compared with postnatal series. Although increased cardiothoracic ratio and associated lesions of the right ventricular outflow tract contribute to the poor outcome in the cases detected prenatally, the absence of these features does not always indicate a good prognosis because progression of disease can occur with advancing gestational age. No absolute measurement or single echocardiographic feature emerged as a consistent predictive factor of prognosis.

Fetal echocardiography: the role of the screening procedure

1841 pregnant women without any risk factor for heart malformation of the fetus underwent an echocardiographic screening at an average gestational age of 23 weeks. Seven cases of heart diseases were diagnosed (0.38%), of which one died in utero at 28 weeks and another one was interrupted. In four cases the karyotype was carried out prenatally, while in the remaining three it was performed only after birth. There were 11 false-negative (0.59%), mainly concerning anomalies of minor clinical significance. Within this group, two newborns with interatrial defect of the ostium secundum type appeared to be affected by trisomy 21. Therefore, the rate of congenital heart diseases in live births not at risk (0.86%) was in line with the data reported in paediatric literature. On the other hand, the association with chromosomal anomalies was surprisingly frequent (4 out of the 9 karyotypes performed were anomalous). Such finding should be verified by studying a larger non-selected population. However, a fetal karyotype should be offered, for its practical consequences, also in those cases of cardiac anomalies of lesser clinical significance.

Prenatal diagnosis of aortic atresia by colour Doppler flow mapping

A case of aortic atresia with insufficiency of mitral valve diagnosed prenatally at 33 weeks of gestation is presented. An accurate diagnosis of this fetal cardiovascular malformation was possible by application of Doppler colour flow mapping, which demonstrated (a) the absence of forward flow in the hypoplastic ascending aorta, (b) reverse flow of blood from the ductus arteriosus into the severely hypoplastic ascending aorta in the late systole, (c) pansystolic mitral valve regurgitation, and (d) absent flow across the foramen ovale as a result of premature closure of the foramen ovale.

Hydrops revisited: literature review of 1,414 cases published in the 1980s

This paper reviews 47 series of hydrops fetalis (804 cases) and 610 individual cases published since 1980. From this large number of cases, guidelines are derived for prenatal diagnosis and management.

Cardiac and extra-cardiac anomalies as indicators for trisomies 13 and 18: a prenatal ultrasound study

The purpose of the present study was to establish sonographic markers for prenatal diagnosis of trisomies 13 and 18. Retrospective analysis of sonographic morphology was therefore carried out in seven fetuses with trisomy 13, and 16 fetuses with trisomy 18. Gestational age ranged between 17 and 39 weeks (median 28 weeks). Polyhydramnios and symmetrical growth retardation were present in 14 of 23 fetuses. A cardiac anomaly was diagnosed in all 23 fetuses, the majority representing a ventricular septal defect (n = 8) or double outlet right ventricle (n = 8). Extra-cardiac anomalies were characterized by a high incidence of limb deformities (polydactyly, clenched hands, club feet; n = 15) and omphalocele (n = 7). We conclude that the combined appearance of cardiac and extra-cardiac anomalies should prompt fetal karyotyping. Cardiac anomalies in combination with fetal limb deformities and omphalocele are suspicious for trisomies 13 and 18.