Potential impact of population screening for prenatal diagnosis of congenital heart disease

Prenatal Diagnosis and Postnatal Outcome of Fetuses with Pulmonary Atresia and Ventricular Septal Defect

PURPOSE

 To assess the intrauterine course, associated conditions and postnatal outcome of fetuses with pulmonary atresia with ventricular septal defect (PAVSD).

METHODS

 All cases of PAVSD diagnosed prenatally over a period of 10 years with a minimum follow-up of 6.5 years were retrospectively collected in 3 tertiary referral centers.

RESULTS

 50 cases of PAVSD were diagnosed prenatally. 44.0 % of fetuses had isolated PAVSD, 4.0 % had associated cardiac anomalies, 10.0 % had extra-cardiac anomalies, 38.0 % had chromosomal anomalies, 4.0 % had non-chromosomal syndromes. Among the 32 liveborn children, 56.3 % had reverse flow in the patent arterial duct, 25.0 % had major aortopulmonary collateral arteries (MAPCAs) with ductal agenesis and 18.7 % had a double supply. 17 pregnancies were terminated (34.0 %), there was 1 intrauterine fetal death (2.0 %), 1 neonatal death (2.0 %), and 6 deaths (12.0 %) in infancy. 25 of 30 (83.3 %) liveborn children with an intention to treat were alive at the latest follow-up. The mean follow-up among survivors was 10.0 years (range 6.5-15.1). 56.0 % of infants underwent staged repair, 44.0 % had one-stage complete repair. After exclusion of infants with additional chromosomal or syndromal anomalies, 88.9 % were healthy, and 11.1 % had mild limitations. The presence of MAPCAs did not differ significantly between survivors and non-survivors (p = 0.360), between one-stage or staged repair (p = 0.656) and healthy and impaired infants (p = 0.319).

CONCLUSION

 The prognosis in cases without chromosomal or syndromal anomalies is good. MAPCAs did not influence prognosis or postoperative health. The incidence of repeat interventions due to recurrent stenoses is significantly higher after staged compared with single-stage repair.

Template-based Quality Assessment of the Doppler Ultrasound Signal for Fetal Monitoring

One dimensional Doppler Ultrasound (DUS) is a low cost method for fetal auscultation. However, accuracy of any metrics derived from the DUS signals depends on their quality, which relies heavily on operator skills. In low resource settings, where skill levels are sparse, it is important for the device to provide real time signal quality feedback to allow the re-recording of data. Retrospectively, signal quality assessment can help remove low quality recordings when processing large amounts of data. To this end, we proposed a novel template-based method, to assess DUS signal quality. Data used in this study were collected from 17 pregnant women using a low-cost transducer connected to a smart phone. Recordings were split into 1990 segments of 3.75 s duration, and hand labeled for quality by three independent annotators. The proposed template-based method uses Empirical Mode Decomposition (EMD) to allow detection of the fetal heart beats and segmentation into short, time-aligned temporal windows. Templates were derived for each 15 s window of the recordings. The DUS signal quality index (SQI) was calculated by correlating the segments in each window with the corresponding running template using four different pre-processing steps: (i) no additional preprocessing, (ii) linear resampling of each beat, (iii) dynamic time warping (DTW) of each beat and (iv) weighted DTW of each beat. The template-based SQIs were combined with additional features based on sample entropy and power spectral density. To assess the performance of the method, the dataset was split into training and test subsets. The training set was used to obtain the best combination of features for predicting the DUS quality using cross validation, and the test set was used to estimate the classification accuracy using bootstrap resampling. A median out of sample classification accuracy on the test set of 85.8% was found using three features; template-based SQI, sample entropy and the relative power in the 160 to 660 Hz range. The results suggest that the new automated method can reliably assess the DUS quality, thereby helping users to consistently record DUS signals with acceptable quality for fetal monitoring.

Neonates with critical congenital heart defects: Impact of fetal diagnosis on immediate and short-term outcomes

Background:

Fetal echocardiography is being increasingly used for prenatal diagnosis of congenital cardiac malformations, but its impact on the neonatal outcomes in low- and middle-income countries is still unknown.

Aims:

The objective of this study is to determine the impact of fetal echocardiography on immediate postnatal and short-term outcome in a tertiary pediatric cardiac center.

Study Design:

This is a prospective study.

Materials and Methods:

One hundred consecutive patients with critical congenital heart defects (CHD) requiring active medical or surgical interventions in the 1^st month of life were included in the study. The detailed history, postnatal examination findings, and fetal echocardiogram report were recorded. They were divided into two groups as antenatally diagnosed and postnatally diagnosed. Pre- and post-procedural variables were compared between the two groups.

Results:

Twenty-nine neonates were diagnosed antenatally while 71 were diagnosed postnatally. Totally, 10 babies (34.5%) among the antenatally diagnosed group were delivered in a tertiary health-care setup. The mean age at presentation was 0 day in the antenatally diagnosed group while 10 days (0–30 days) in the postnatally diagnosed group (P = 0.01). A total of 17 (58.6%) patients in the antenatal group had duct dependent CHD, and 15 (88.2%) of these patients were transported on prostaglandin E1. In comparison, 19/34 (55.9%) patients in the postnatal group were transported on prostaglandin. The pH on admission in the antenatal group was 7.32 ± 0.05 as compared to 7.28 ± 0.05 in the postnatal group (P = 0.0004). There were 4 (5.6%) deaths in the postnatal group during transfer. There was no significant difference in the postoperative variables in both groups.

Conclusions:

Fetal echocardiography identifies patients with complex CHD resulting in better parental counseling, thus facilitating delivery at a tertiary care center and preoperative stabilization. This results in improved preoperative mortality and better stabilization.

Diagnosis of congenital heart disease in an era of universal prenatal ultrasound screening in southwest Ohio

OBJECTIVES

Diagnostic ultrasound is widespread in obstetric practice, yet many babies with major congenital heart disease remain undiagnosed. Factors affecting prenatal diagnosis of major congenital heart disease are not well understood. This study aims to document prenatal detection rates for major congenital heart disease in the Greater Cincinnati area, and identify factors associated with lack of prenatal diagnosis.

METHODS

All living infants diagnosed with major congenital heart disease by 4 months of age at our centre were prospectively identified. Prenatal care data were obtained by parent interview. Neonatal records were reviewed for postnatal data. Obstetricians were contacted for diagnostic ultrasound data.

RESULTS

A total of 100 infants met the inclusion criteria. In all, 95 infants were analysed, of whom 94 were offered diagnostic ultrasound. In all, 41 had a prenatal diagnosis of major congenital heart disease. The rate of prenatal detection varied by cardiac lesion, with aortic arch abnormalities, semilunar valve abnormalities, and venous anomalies going undetected in this sample. Among subjects without prenatal detection, the highest proportion consisted of those having Level 1 diagnostic ultrasound only (66%). Prenatal detection was not significantly influenced by maternal race, education level, income, or insurance type.

CONCLUSIONS

Despite nearly universal diagnostic ultrasound, detection rates of major congenital heart disease remain low in southwest Ohio. An educational outreach programme including outflow tract sweeps for community-level obstetrical personnel may improve detection rates.

Prenatal detection of congenital heart disease in southern Nevada: the need for universal fetal cardiac evaluation

OBJECTIVE

Congenital cardiac malformations are common developmental anomalies. In the United States, congenital heart disease is the number one cause of infant mortality from congenital malformations. Prenatal diagnosis of congenital heart defects aids treatment coordination. Our aim was to evaluate prenatal detection of serious congenital heart malformations in Clark County, Nevada.

METHODS

We electronically searched our research department-maintained computer database for patients with serious congenital heart disease born in Clark County between May 2003 and April 2006. We excluded patients that did not have at least 1 local prenatal ultrasound examination. All pre-natal ultrasound studies were performed in obstetric offices, radiology imaging centers, or maternal-fetal medicine specialty practices. Fetal echocardiography was performed in maternal-fetal medicine specialists' offices under the supervision of a fetal cardiologist. Pediatric cardiologists performed all postnatal echocardiographic examinations.

RESULTS

During the study period, we diagnosed serious congenital heart malformations in 161 patients among a total estimated 77,000 births (2/1000). Of the 161 patients, 58 (36%) had a prenatal diagnosis, and 103 (64%) had an exclusively postnatal diagnosis.

CONCLUSIONS

Standard prenatal ultrasound fails to show congenital heart disease in most fetuses.

Population-based study of antenatal detection of congenital heart disease by ultrasound examination

OBJECTIVES

Ultrasound-based screening is widely employed for the detection of congenital malformations in utero including congenital heart disease (CHD), but there is widespread variability in the efficacy of screening programs. We aimed to evaluate current antenatal detection rates of selected congenital heart defects in Victoria.

METHODS

Data were collected from the Victorian Perinatal Data Collection Unit and Birth Defects Registry. There were 631 209 births in Victoria (1993-2002), of which 4897 cases had CHD. Cases included live births, stillbirths and termination of pregnancies because of CHD. We reviewed all cases from 1999 to 2002 with atrioventricular septal defect, simple coarctation of the aorta, double-inlet or -outlet ventricle, hypoplastic left heart syndrome, simple transposition of the great arteries (TGA), tetralogy of Fallot and truncus arteriosus. Outcome measures were antenatal diagnosis, pregnancy outcome and associated malformations.

RESULTS

The overall birth prevalence of CHD from 1993 to 2002 in Victoria was 7.8/1000. The antenatal detection rate for the seven selected defects from 1999 to 2002 was 52.8%. All but 4.8% of the cases had an ultrasound examination at > 13 weeks' gestation. Antenatal detection was highest for hypoplastic left heart syndrome (84.6%) and lowest for simple TGA (17.0%).

CONCLUSIONS

This study shows wide variation in the antenatal detection rate of CHD in Victoria. The low antenatal detection rate of TGA, a defect that should be detected easily, demonstrates suboptimal routine obstetric anomaly scanning.

The impact of prenatal diagnosis of congenital heart disease on pediatric cardiology and cardiac surgery

Since the early 1980s prenatal diagnosis of congenital heart disease (CHD) has progressively impacted on the practice of pediatric cardiology and cardiac surgery. Fetal cardiology today raises special needs in screening programs, training of the involved staff, and allocations of services. Due to the increased detection rate and to the substantial number of terminations, the reduced incidence of CHD at birth can affect the workload of centers of pediatric cardiology and surgery. In utero transportation and competition among centers may change the area of referral in favor of the best centers. Echocardiography is a powerful means to diagnose and to guide lifesaving medical treatment of sustained tachyarrhythmias in the fetus. Prenatal diagnosis not only improves the preoperative conditions in most cases but also postoperative morbidity and mortality in selected types of CHD. Intrauterine transcatheter valvuloplasty in severe outflow obstructive lesions has been disappointing so far and this technique remains investigational, until its benefits are determined by controlled trials. Prenatal diagnosis allows counselling of families which are better prepared for the foreseeable management and outcome of the fetus. These benefits can reduce the risks of litigation for missed ultrasound diagnosis. As increased costs can be expected in institutions dealing with a large number of fetal CHD, the administrators of these institutions should receive protected funds, proportional to their needs.

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.

What to expect from routine midtrimester screening for congenital heart disease

The four-chamber view is the standard screening view of the fetal heart. However, it detects only about half of cardiac defects. Because this view does not show the great vessels, only conotruncal abnormalities with substantial septal defects will be seen. Second, septal defects may be too small at the time of screening to be detected. In addition, some defects such as pulmonic stenosis are late appearing. The addition of the aortic outflow tract view increases sensitivity by approximately 20%. Although all components of the four-chamber view may not be seen, there is still considerable information supplied by each of its parts.

Congenital heart disease: the impact of delivery in a tertiary care center on SNAP scores (scores for neonatal acute physiology)

OBJECTIVE

It has been hypothesized that delivery in a tertiary care center might improve the clinical condition and outcome of infants born with congenital heart disease. The purpose of this study was to determine the effect of delivery in a tertiary care center on SNAP scores (scores for neonatal acute physiology) of infants admitted to the neonatal intensive care unit with major structural cardiac defects.

STUDY DESIGN

This retrospective cohort study included 195 infants with major congenital heart disease admitted to the neonatal intensive care unit at the New England Medical Center between July 1, 1992, and June 30, 1998. SNAP scores were abstracted from the medical record. The values of 97 neonates with major cardiac defects born at the New England Medical Center were compared with those of 98 neonates transferred to our center after delivery in a community setting. A 2-tailed Student t test for independent samples was used to compare the mean SNAP scores between the 2 cohorts.

RESULTS

The SNAP scores for infants with major cardiac defects who were born at the New England Medical Center ranged from 0 to 41, with a mean of 10.6 +/- 8.8. The values for infants with congenital heart disease who were transferred to our center after birth in community-based hospitals ranged from 0 to 34, with a mean of 11.1 +/- 7.0. There was no significant difference between the 2 populations (P =.646). A comparison of the mean SNAP scores of infants with prenatally diagnosed disease who were delivered at our center versus infants with postnatally diagnosed disease who were delivered in community hospitals was also statistically not significant (P =.824).

CONCLUSION

Delivery in a tertiary care center does not improve SNAP scores of infants with major structural cardiac defects.

Current and potential impact of fetal diagnosis on prevalence and spectrum of serious congenital heart disease at term in the UK. British Paediatric Cardiac Association

BACKGROUND

Assessment of the effect of fetal diagnosis on the prevalence of congenital heart disease at term requires national ascertainment because referral patterns are not rigorously structured.

METHODS

Between 1993 and 1995, all 17 paediatric cardiac centres in the UK submitted to a database lists of all fetuses diagnosed, and all infants needing surgery or interventional catheterisation or dying in the first year of life because of structural heart disease; details included the postal area of residence.

FINDINGS

There were 4799 affected pregnancies, 4165 babies born alive, 1124 fetal diagnoses, and 567 terminations of pregnancy because the fetus had structural heart disease. Thus, a fetal diagnosis was made in 23.4% of affected pregnancies (11.7% of all affected livebirths) with geographical variability in diagnostic rates.

INTERPRETATION

Fetal cardiac screening has an effect on the prevalence and types of congenital heart disease seen at term because many affected pregnancies are terminated. If detection rates of affected fetuses rose nationally to those seen in the 15 postal areas where detection rates were significantly higher than the national average in 1993-95, we would expect about 218 fewer affected individuals to be born annually.

Early diagnosis of major cardiac defects in chromosomally normal fetuses with increased nuchal translucency

OBJECTIVE

To determine the value of early ultrasound examination for prenatal diagnosis of cardiac defects in chromosomally normal fetuses with increased nuchal translucency thickness at 10-14 weeks of gestation.

DESIGN

Prospective audit.

SETTING

Fetal Medicine Centre.

METHODS

Specialist fetal echocardiography was carried out in 398 chromosomally normal fetuses with a nuchal translucency measurement above the 99th centile (> or = 3.5 mm). In the first 75 pregnancies the cardiac scan was carried out at 17-22 weeks and the next 323 cases had one scan at 13-17 weeks and another at 20-22 weeks. Pregnancy outcome was obtained in all of the cases.

RESULTS

Major cardiac defects were present in 29 (7.3% of 398) cases and in 28 of these the diagnosis was made by antenatal echocardiography. In 27 of the 29 fetuses with major cardiac defects echocardiography was carried out at 13-17 weeks and an abnormality was suspected in 24 of the cases (88%).

CONCLUSIONS

Increased nuchal translucency in chromosomally normal fetuses is associated with an increased prevalence of major cardiac defects and, as such, is an indication for specialist fetal echocardiography. Most of the cardiac abnormalities are detectable on antenatal fetal echocardiography and many can be excluded by early scanning.

Detection of transposition of the great arteries in fetuses reduces neonatal morbidity and mortality

BACKGROUND

Transposition of the great arteries (TGA) is a life-threatening malformation in neonates, but it is amenable to complete repair. Prenatal detection, diagnosis, and early management may modify neonatal mortality and mortality.

METHODS AND RESULTS

Preoperative and postoperative morbidity and mortality were compared in 68 neonates with prenatal diagnosis and in 250 neonates with a postnatal diagnosis of TGA over a period of 10 years. The delay between birth and admission was 2+/-2.8 hours in the prenatal group and 73+/-210 hours in the neonatal group (P<0.01). Clinical condition at arrival, including metabolic acidosis and multiorgan failure, was worse in the neonatal group (P<0.01). Once in the pediatric cardiology unit, the management was identical in the 2 groups (atrioseptostomy, PGE1 infusion, operation date). Preoperative mortality was 15 of 250 (6%; 95% CI, 3% to 9%) in the neonatal group and 0 of 68 in the prenatal group (P<0.05). Postoperative morbidity was not different (25 of 235 versus 6 of 68), but hospital stay was longer in the neonatal group (30+/-17 versus 24+/-11 days, P<0.01). In addition, postoperative mortality was significantly higher in the neonatal group (20 of 235 versus 0 of 68, P<0.01); however, the known risk factors for operative mortality were identical in the 2 groups.

CONCLUSIONS

Prenatal diagnosis reduces mortality and morbidity in TGA. Prenatal detection of this cardiac defect must be increased to improve early neonatal management. In utero transfer of fetuses with prenatal diagnosis of TGA in an appropriate unit is mandatory.

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.

The antenatal diagnosis of fetal abnormalities: a 10 year audit of influencing factors

During the 10 years 1984-1993, a total of 438 fetuses and children with a congenital abnormality, identified antenatally or in the first year of life, were registered from the North Tees Health District with the Northern Region Congenital Abnormality Survey (NorCAS). This represented an abnormality rate of 2% of all births. In total, 252 structural abnormalities (57.5%) were detected by antenatal ultrasound examination. In spite of a targeted education programme, identification of cardiac lesions remained poor. The detection of structural abnormality by antenatal scan rose from 52% in 1984 to 85% in 1993, due mainly to improvements in image quality and resolution of ultrasound equipment. Also important was audit, based both on review of images and feedback from a comprehensive central register (NorCAS).

Hypoplastic left heart syndrome in the second trimester

Hypoplastic left heart syndrome is a relatively common congenital anomaly with a high mortality even after palliative postnatal surgery. The case presented had a normal cardiac cavity and great artery dimensions at 19 weeks of gestation but bright left ventricular myocardial echoes, impaired left ventricular shortening, and no detectable forward flow in the left ventricular outflow tract. Autopsy showed left ventricular subendocardial calcification. This demonstrates a likely early stage in the evolution of hypoplastic left heart syndrome, which has a variable time course. The abnormal left ventricular myocardial performance associated with low left ventricular output results in a failure of growth of the left heart rather than there being a primary failure of embryogenesis.

[Management of newborn infants in maternity-neonatal intensive care units]

BACKGROUND

Although in utero transfer seems actually the safest option when risk factors are identified, specialized transport teams remain important to consider for the neonatal overall management.

SUBJECTS

From January 1988 through December 1992, 692 transports of 838 neonates were prospectively studied to determine effectiveness and safety of the Hospital Lenval's neonatal transport team.

RESULTS

Neonatal transports were required respectively for prematurity (46.4%), acute fetal distress (13.8%), respiratory distress (10.1%), intrauterine growth retardation (7.8%), multiple pregnancies (5.2%), perinatal asphyxia (3.1%) and life-threatening congenital abnormalities (2%). Pediatric assistance was unplanned in most of the cases (80%). Assistance with a pediatrician before delivery was performed more frequently (70%) for premature babies (mean gestational age 34.1 +/- 3.1 wk) delivered by cesarean section in 66.4% of the cases; in this group, delivery room resuscitation was less aggressive. Assistance was performed after delivery less frequently (30%), approximately in one-half of the cases for neonatal distress: respiratory (33.9%) or neurologic (17.1%); in this group, delivery room resuscitation was more aggressive. In transit, ventilation support via endotracheal intubation was given to 17.9% of the babies. Neither death nor heavy complication occurred during transport. On arrival in the neonatal intensive care unit, hypothermia was noted in 9.6% of the cases, hypotension in 4.3%, hypoglycemia in 13.1% and metabolic acidosis in 10.4%. In our series, the overall mortality rate was 6%, and incidence of neurologic damage 3.3%.

CONCLUSION

A skilled person in neonatal resuscitation available at every referring maternity and regional high-risk obstetric/neonatal combined centre are two recommendations which could provide improved neonatal management.

Fetal echocardiography

Fetal echocardiography has provided a means for the detailed assessment of cardiac structure and function from early prenatal life. Indications for a fetal echocardiographic examination and the potential implications for individuals caring for newborns with cardiac malformations are discussed.

Antenatal diagnosis of congenital heart disease and Down's syndrome: the potential effect on the practice of paediatric cardiology

OBJECTIVE

To predict the effect of antenatal ultrasound screening for congenital heart disease and maternal serum screening of Down's syndrome on the practice of paediatric cardiology and paediatric cardiac surgery.

DESIGN

A retrospective and prospective ascertainment of all congenital heart disease diagnosed in infancy in 1985-1991.

SETTING

One English health region.

PATIENTS

All congenital heart disease diagnosed in infancy by echocardiography, cardiac catheterisation, surgery, or necropsy was classified as "complex", "significant", or "minor" and as "detectable" or "not detectable" on a routine antenatal ultrasound scan.

RESULTS

1347 infants had congenital heart disease which was "complex" in 13%, "significant" in 55%, and "minor" in 32%. 15% of cases were "detectable" on routine antenatal ultrasound. Assuming 20% detection and termination of 67% of affected pregnancies, liveborn congenital heart disease would be reduced by 2%, infant mortality from congenital heart disease by 5%, and paediatric cardiac surgical activity by 3%. Maternal screening for Down's syndrome, assuming 75% uptake, 60% detection, and termination of all affected pregnancies, would reduce liveborn cases of Down's syndrome by 45%, liveborn cases of congenital heart disease by 3.5%, and cardiac surgery by 2.6%.

CONCLUSIONS

Screening for congenital heart disease using the four chamber view in routine obstetric examinations and maternal serum screening for Down's syndrome is likely to have only a small effect on the requirements for paediatric cardiology services and paediatric cardiac surgery.

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.

Use of autologous umbilical artery and vein for vascular reconstruction in the newborn

Autologous umbilical artery and vein were evaluated as vascular conduits in newborn lambs. Eight newborn lambs were delivered transabdominally under sterile conditions at term. The umbilical artery and vein were dissected from the cord and stored in culture media. On the same day, each lamb underwent bilateral superficial femoral artery transection and reconstruction. Nine arteries were reconstructed with autologous umbilical vein interposition grafts, five with umbilical artery interposition grafts, and two by primary native artery anastomosis. After the birth weight of the lambs quadrupled (37 to 45 days), they were killed and all grafts and anastomoses were examined grossly and histologically. At the conclusion of the study, both native artery anastomoses (2/2) were patent. Five umbilical vein (5/9) and two umbilical artery (2/5) autografts were also widely patent. Patent autografts retained an intact endothelium supported by a viable media. The nonpatent autografts had become atrophic remnants displaying histologic signs of early closure. Graft failures are attributed to the extreme vasoactive nature of the umbilical vessels. These preliminary results suggest that umbilical vessels may be useful as a vascular autograft if the vasoactive nature of these vessels can be overcome during the immediate perioperative period.

Temporary iatrogenic fetal tricuspid valve atresia in a case of twin to twin transfusion syndrome

This report describes the sequence of events in the development and subsequent spontaneous resolution of functional tricuspid valve atresia in the donor fetus in a case of twin to twin transfusion syndrome. Fetoscopic laser coagulation of the placental anastomoses was performed at 20 weeks' gestation. Subsequently, there was evidence of increased placental vascular resistance in the donor twin and major impairment of right ventricular function with no forward flow through the tricuspid valve. During the next four weeks, however, there was spontaneous and complete recovery of ventricular function and resolution of the functional tricuspid valve atresia. These findings suggest that alterations in fetal haemodynamics may result in structural cardiac abnormality and may be the precursors of some forms of congenital heart disease.

Screening for fetal cardiac malformations

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