Diagnosis and management of fetal cardiac anomalies: 10 years of experience at a single institution

Perinatal outcomes of pregnancies with prenatally diagnosed foetal congenital heart disease

We aimed to assess the types of prenatally diagnosed congenital heart disease (CHD) and their association with structural and chromosomal abnormalities and to evaluate the perinatal outcomes according to the type of the heart defect. We retrospectively reviewed 377 pregnancies with prenatally diagnosed CHD. The main outcome measure was to evaluate the pregnancy outcomes of CHD according to the type of the heart defect and associated structural or chromosomal abnormalities. Of 377 foetuses with major structural CHD, 214 (56.8%) were isolated, 49 (13%) had additional cardiac anomalies, 58 (15.4%) had extracardiac malformations with normal karyotype and 56 (14.9%) had chromosomal abnormalities. The most common chromosomal abnormality was trisomy 21 (55.4%). Prenatal detection of CHD allows early workup to identify chromosomal abnormalities and detailed anatomic evaluation of extracardiac malformations. Prognostication of each heart defect at diagnosis and facilitating patients with isolated surgically correctable CHD for targeted postnatal care is essential.IMPACT STATEMENTWhat is already known on this subject? CHD is the most common structural anomaly and is strongly associated with chromosomal anomalies and genetic syndromes.What do the results of this study add? Survival of the prenatally diagnosed CHD depends on the type and severity of the condition and coexisting extracardiac structural or chromosomal abnormalities.What are the implications of these findings for clinical practice and/or further research? Prenatal detection of CHD allows early workup to identify chromosomal abnormalities, detailed anatomic evaluation of extracardiac malformations and time to refer the parents to tertiary cardiac care centres and prepare for planned delivery, as well as to establish an appropriate perinatal and postnatal therapeutic plan.

The Diagnostic Yield of Fetal Echocardiography Indications in the Current Era

BACKGROUND

The aim of this study was to examine the diagnostic yield of current fetal echocardiography (FE) indications representing a recent era.

METHODS

FE reports of all pregnancies referred to two provincial FE programs from 2009 to 2018 were examined, identifying the indication for FE (14 categories), gestational age at referral, and whether there was no fetal heart disease (FHD), mild or possible FHD (e.g., simple ventricular septal defect, possible coarctation), or moderate or severe FHD.

RESULTS

Over the study period, there were 19,310 unique FE referrals in Alberta (23.3 ± 5.4 weeks' gestation), including 1,907 (9.9%) with moderate or severe and 654 (3.4%) with mild or possible FHD. The most common referral indications included extracardiac pathology or markers (29.7%), maternal diabetes (18.3%), suspected FHD (17.7%), and family history of heart defects (17.7%). The highest yield for moderate or severe FHD was suspected FHD (41.1%; 95% CI, 39.4%-42.7%), followed by suspected or confirmed genetic disorder (15.4%; 95% CI, 12.6%-18.2%), twins or multiples (10.6%; 95% CI, 8.7%-12.5%), oligohydramnios (8.0%; 95% CI, 4.1%-11.9%), extracardiac pathology or markers (6.4%; 95% CI, 5.8%-7.1%), and heart not well seen (5.8%; 95% CI, 4.0%-7.6%). Lowest yields were observed for maternal diabetes (2.2%; 95% CI, 1.7%-2.7%) and family history of heart defects (1.7%; 95% CI, 1.3%-2.2%). Excluding suspected FHD, with two or more FE indications, all other indications demonstrated significant increases in yield of mild or possible (3.5% vs 1.9%, P < .001) and moderate or severe (7.2% vs 2.9%, P < .001) FHD.

CONCLUSIONS

Suspected FHD provides the highest diagnostic yield of moderate or severe FHD. In contrast, maternal diabetes and family history of heart defects, among the most common referral indications, had diagnostic yields approaching general population risks. Even in the absence of suspected FHD, having two or more referral indications importantly increases the diagnostic yield of all other FE indications.

The natural history of fetal diagnosed isolated ventricular septal defect

OBJECTIVE

This study was undertaken to clarify the natural course of ventricular septal defect, and to find an index that would help in prenatal counseling.

METHODS

Between January 2010 and December 2014, 18 188 fetuses underwent echocardiographic examinations. Of these, 228 isolated ventricular septal defect cases were retrospectively reviewed.

RESULTS

In this retrospective study, the incidence of isolated ventricular septal defect was 1.25% (228/18 188). There were 146 patients who underwent echocardiography after delivery in order to confirm the natural course of patients with isolated ventricular septal defect. Of the 146 cases, 64 cases (43.84%) had the ventricular septal defect naturally closed in the fetal period. Of the 82 patients with ventricular septal defect at birth, 25 patients showed natural closure during follow-up. However, four patients (2.74%) required surgical treatment for ventricular septal defect. In case of perimembranous defects, natural closure is more frequent in the fetal period than in the postnatal period.

CONCLUSION

Our results indicate that 60.96% (89/146) of isolated ventricular septal defects diagnosed during the fetal life are closed naturally. Perimembranous type defect, small defect (<2 mm) and maternal age less than 35 years are the good prognostic factors for the natural closure during fetal life. © 2017 John Wiley & Sons, Ltd.

Prenatal diagnosis of congenital heart defects: accuracy and discrepancies in a multicenter cohort

OBJECTIVE

To examine the accuracy of fetal echocardiography in diagnosing congenital heart disease (CHD) at the fetal medicine units of three tertiary care centers.

METHODS

This was a multicenter cohort study of tertiary echocardiography referrals between 2002 and 2012. Prenatal and postnatal diagnoses were compared and the degree of agreement was classified as 'correct' (anatomy correct and the postnatal diagnosis led to a similar outcome as expected), 'discrepant' (anatomical discrepancies present but the severity and prognosis of the defect were diagnosed correctly) or 'no similarity' (the pre- and postnatal diagnoses differed completely).

RESULTS

We included 708 cases with CHD for which both prenatal and postnatal data were available. The prenatal diagnosis was correct in 82.1% of cases and discrepancies present were present in 9.9%; however, these did not result in a different outcome. In 8.1% there was no similarity between prenatal and postnatal diagnoses. Disagreement between pre- and postnatal diagnoses occurred significantly more frequently in cases that presented with a normal four-chamber view than in those with an abnormal four-chamber view (5.5% vs 1.9%). Incorrect identification of the outflow tracts and incorrect differentiation between unbalanced atrioventricular septal defect and hypoplastic left heart syndrome were relatively commonly encountered. In many cases with disagreement, trisomy 21, extracardiac anomaly or a high maternal body mass index was present.

CONCLUSIONS

The prenatal diagnosis and estimated prognosis of fetal echocardiography in our tertiary referral centers were appropriate in 92% of cases. Some types of CHD remain difficult to diagnose or rule-out prenatally, therefore awareness and education are of considerable importance. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Foetal congenital heart disease: obstetric management and time to first cardiac intervention in babies delivered at a tertiary centre

OBJECTIVES

The aim of this study was to determine the timing of neonatal cardiac intervention in babies with antenatally diagnosed congenital heart disease and the impact on obstetric management.

METHODS

A retrospective review of all deliveries between January, 2008 and December, 2009 was conducted in a tertiary centre with foetal and paediatric cardiology, maternal-foetal medicine, and obstetric units. All live births with antenatally detected congenital heart disease were included. Data were collected from foetal, paediatric cardiology, and maternity databases and records. Induction, delivery mode, and timing of the first cardiac intervention in the neonate were studied.

RESULTS

205 deliveries were included. Induction and elective Caesarean section rates were 51.2% (105/205) and 14.1% (29/205), respectively. The vaginal delivery rate was 56% (115/205). There was a non-significant trend towards a higher rate of vaginal delivery after spontaneous labour than after induction (75% versus 66%; p = 0.234). The rate of neonatal cardiac intervention during the initial stay was 59.5% (122/205); it was 18.5% (38/205) within 48 hours and 25.8% (53/205) within 72 hours. The median time to first intervention was 4 days (interquartile range 2-8). Babies with hypoplastic left heart syndrome (median 3, interquartile range 2-6), transposition of the great arteries (median 1, interquartile range 0-4.5), and arrhythmia (median 0.5, interquartile range 0-1) had a significantly earlier time to first intervention compared with those with other conditions (p = 0.001).

CONCLUSION

Vaginal delivery can be achieved in women delivering babies with major congenital heart disease at a tertiary centre. Delivery in or near a tertiary centre is recommended for patients requiring early intervention, of which many can be identified in advance.

Performance of different scan protocols of fetal echocardiography in the diagnosis of fetal congenital heart disease: a systematic review and meta-analysis

OBJECTIVE

The rapid progress in fetal echocardiography has lead to early detection of congenital heart diseases. Increasing evidences have shown that prenatal diagnosis could be life saving in certain cases. However, there is no agreement on which protocol is most adaptive diagnostic one. Thus, we use meta-analysis to conduct a pooled performance test on 5 diagnostic protocols.

METHODS

We searched PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials and WHO clinical trails registry center to identify relevant studies up to August, 2012. We performed meta-analysis in a fixed/random-effect model using Meta-disc 1.4. We used STATA 11.0 to estimate the publication bias and SPSS 17.0 to evaluate variance.

RESULTS

We use results from 81 studies in 63 articles to analyze the pooled accuracy. The overall performance of pooled sensitivities of spatiotemporal image correlation (STIC), extend cardiac echography examination (ECEE) and 4 chambers view + outflow tract view + 3 vessels and trachea view (4 CV+OTV+3 VTV) were around 0.90, which was significant higher than that of 4 chambers view + outflow tract view or 3 vessels and trachea view (4 CV+OTV/3 VTV) and 4 chambers view (4 CV). Unfortunately the pooled specificity of STIC was 0.92, which was significant lower than that of other 4 protocols which reached at 1.00. The area under the summary receiver operating characteristic curves value of STIC, ECEE, 4 CV+OTV+3 VTV, 4 CV+OTV/3 VTV and 4 CV were 0.9700, 0.9971, 0.9983, 0.9929 and 0.9928 respectively.

CONCLUSION

These results suggest a great diagnostic potential for fetal echocardiography detection as a reliable method of fetal congenital heart disease. But at least 3 sections view (4 CV, OTV and 3 VTV) should be included in scan protocol, while the STIC can be used to provide more information for local details of defects, and can not be used to make a definite diagnosis alone with its low specificity.

External aortic diameter ratios: a reliable method to diagnose preductal aortic coarctation

Aortic Coarctation (AC) is associated with sudden infantile death. Current pathological diagnosis depends on absolute vessel size which is prone to errors due to different rates of development. This study explores the use of ratios of the external diameter between the aortic isthmus (AI), ascending aorta (AA) and the descending aortas (DA). Our study found that while the vessel diameter increased with gestational age, the ratios remained constant and are therefore preferable than absolute size. This simple and highly reproducible method will allow more cases of AC that may be misdiagnosed to get a proper pathological diagnosis.

Screening fetal echocardiography in diabetic mothers with normal findings on detailed anatomic survey

OBJECTIVES

To evaluate the benefit of second-trimester fetal echocardiography for women with diabetes whose fetuses had no obvious heart disease on a detailed anatomic survey performed at skilled, high-volume obstetric centers, and to investigate the technical limitations of fetal echocardiography in this patient population.

METHODS

This was a retrospective descriptive review of fetal echocardiograms performed at Children's Hospital Boston from 2000 to 2005. All women referred during the second trimester for fetal echocardiography because of maternal diabetes were included. Those with severe heart disease suspected on obstetric ultrasound examination were excluded.

RESULTS

There were 584 initial fetal echocardiograms. No patients were diagnosed with severe heart disease prenatally. Nineteen were diagnosed with suspected mild heart disease (such as small ventricular septal defect), five of whom had normal follow-up fetal evaluation and five of whom had normal postnatal evaluation. Most of these pregnancies did not have a postnatal cardiac evaluation. Forty-seven fetuses had benign cardiac findings. Nearly one third of patients had imaging that was felt to be limited or incomplete, mostly due to poor acoustic windows. Forty-eight patients were asked to return for at least one follow-up visit, most due to the inability to complete the exam at the initial visit.

CONCLUSIONS

In an environment with access to high-volume, skilled comprehensive ultrasound services, fetal echocardiography by a pediatric cardiology program adds little to the care of women with diabetes and no suspected heart disease on a detailed anatomic survey. Poor acoustic windows frequently necessitate multiple visits.

Reducing the cost of detection of congenital heart disease in fetuses of women with pregestational diabetes mellitus

OBJECTIVE

To provide a cost minimization analysis to support a paradigm shift in the use of comprehensive ultrasound and echocardiography in the prenatal diagnosis of congenital heart disease (CHD) in fetuses of women with diabetes mellitus (DM).

METHODS

In this retrospective cohort study, the diabetic clinic service database of the University of California San Diego was searched from January 2001 to June 2004 for pregnant women with Type I or II DM and HbA1c >6.3%. Subjects underwent comprehensive ultrasound examination (with four-chamber views and outflow tracts) and fetal echocardiography according to a standard protocol. Newborns were examined for cardiac defects and underwent postnatal echocardiography as indicated. The cost of screening was evaluated.

RESULTS

Of 115 neonates and two terminations of pregnancy there were 20 (17%) cases of CHD. Six of these CHD were major and all six were detected prenatally by both ultrasound and echocardiography. Three additional clinically insignificant cases of CHD were identified by fetal echocardiography. Eleven cases of CHD were identified by postnatal echocardiography only, all of which were clinically insignificant lesions. The prenatal detection rate of major CHD was 100% (6/6) for both ultrasound and echocardiography. The sensitivites of ultrasound (30% (95% CI, 13-54%)) and echocardiography (45% (95% CI, 24-68%)) were similar (P = 0.32). A cost minimization analysis was done using the published Medicaid (California) system's relative value unit and conversion factors. Accordingly, our current protocol costs $6503.43 per case of major CHD detected. If echocardiography had been performed only as indicated and postnatal echocardiography had been performed on all neonates, the cost would have been $7056.83 per case of major CHD detected. Alternatively, combined targeted ultrasound with indicated prenatal and postnatal echocardiography would have been associated with a cost of $4996.05 per case of major CHD detected.

CONCLUSION

Detection of major CHD was excellent with both comprehensive prenatal ultrasound and echocardiography. Echocardiography added little to the prenatal diagnosis of CHD if the comprehensive ultrasound examination was normal. The highest cost-benefit ratio and most efficacious protocol for screening based on our data would be comprehensive ultrasound with prenatal and postnatal echocardiography only as indicated. Further prospective studies are warranted.

Delivery room management of the newborn

Neonatal resuscitation is an attempt to facilitate the dynamic transition from fetal to neonatal physiology. This article outlines the current practices in delivery room management of the neonate. Developments in cardiopulmonary resuscitation techniques for term and preterm infants and advances in the areas of cerebral resuscitation and thermoregulation are reviewed. Resuscitation in special circumstances (such as the presence of congenital anomalies) are also covered. The importance of communication with other members of the health care team and the family is discussed. Finally, future trends in neonatal resuscitation are explored.

Prenatal diagnostic accuracy in South Carolina demonstrated by autopsy

Fully 150 consecutive fetal/neonatal autopsies were reviewed to determine to what extent they confirmed or altered the impressions gained through prenatal ultrasonographic fetal examination. Distinctions were made between features that may or may not be assessable by prenatal ultrasound. Analyses of weights and measures were based on recently published regressions derived from a worldwide review of normative data. Our analysis indicated a high level of correspondence between prenatal ultrasound findings and later observations of independent persons at autopsy (85% positive predictive value and 44% sensitivity). We concluded that skills of maternal-fetal medicine specialists, located at several geographically divergent centers, are confirmed by a high level of correspondence between prenatal ultrasound and autopsy findings. The low sensitivity was due in large part to the relatively subtle nature of many autopsy findings that had not been predicted by prenatal examination.

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.

Immediate and long-term outcomes in children with prenatal diagnosis of selected isolated congenital heart defects

OBJECTIVES

To compare the immediate postinterventional and long-term outcomes of children with a prenatal and those with a postnatal diagnosis of isolated congenital heart defects.

METHODS

This was a retrospective study of 257 children admitted over a 10-year period to our pediatric cardiology unit with one of four different cardiac lesions: transposition of the great arteries, atrioventricular canal defect, tetralogy of Fallot and pulmonary atresia; 208 were diagnosed postnatally and 49 prenatally. Management was identical in the two patient groups.

RESULTS

The median age at admission was 22 days in the postnatal group and 10 days in the prenatal group. In the prenatal group there was a higher median preoperative O2 saturation level (P=0.07), fewer cases of preoperative cardiac failure (P=0.03), fewer cases of preoperative closure of the duct (P=0.04), a shorter median duration of postoperative mechanical ventilation (P=0.03), less need for resurgery (P=0.02) and a shorter median duration of stay in the intensive care unit (P=0.05). Postoperative survival was 96% in the prenatal group and 90% in the postnatal group. Assessment of long-term survival revealed a longer catheter intervention-free interval in the prenatal group (P=0.03). At the 1-year follow-up, residual impaired cardiac function was less frequent in the prenatal than in the postnatal group (P=0.04). Overall survival at maximum follow-up was 92% in the prenatal and 84% in the postnatal group.

CONCLUSIONS

Prenatal diagnosis of isolated congenital heart defects allows admission for surgery in a more stable condition and is associated with lower short-term and long-term morbidity and mortality.

Outcome of fetal cardiac defects

PURPOSE OF REVIEW

The present review summarizes the prenatal and postnatal outcome of cardiac anomalies and sustained arrhythmias diagnosed during fetal life.

RECENT FINDINGS

The outcome of sustained fetal arrhythmias has improved with greater experience using Sotalol for atrial flutter, and digoxin and amiodarone for 1: 1 reciprocating tachycardia. The outcome of fetal conduction system disease secondary to maternal Sjögren's antibodies has noticeably improved with transplacental dexamethasone. The postnatal prognosis for atrioventricular block associated with left atrial isomerism, however, remains very bleak. Assessing the effect of prenatal diagnosis on the outcome of structural defects remains difficult because of the high number of extracardiac anomalies and chromosome defects in this group. Preoperative survival is improved, but postoperative mortality has not improved. One clear advantage of prenatal diagnosis is the selection of fetuses that may benefit from in-utero intervention to limit the progression of their disease or lessen its severity at birth.

SUMMARY

For the most part, postoperative mortality of structural cardiac defects is not significantly improved by prenatal diagnosis. In-utero management of tachyarrhythmias and conduction system disease has improved postnatal outcome, except for the fetus with atrioventricular block and left atrial isomerism.

Factors affecting technical success of fetal aortic valve dilation

OBJECTIVE

We have reported previously that valve dilation enhances growth of cardiac structures and may prevent hypoplastic left heart syndrome (HLHS) in fetuses with critical aortic stenosis. We aimed to investigate maternal/fetal factors which may affect the technical success of fetal valvuloplasty, and to describe perinatal complications of the procedure.

METHODS

This was a descriptive series of 22 fetuses diagnosed with critical aortic stenosis developing into HLHS which underwent intervention by valvuloplasty. Initially this was attempted using a percutaneous approach; reassessment after our first five attempts, only one of which was successful, led to the introduction of the option of laparotomy. Technical success was defined as balloon inflation across the aortic annulus and a broader jet through the aortic valve as assessed by Doppler. Data collected included body mass index, demographic variables, ultrasound findings and postprocedure interventions.

RESULTS

Technical success increased significantly if maternal laparotomy was an option (83.3% vs. 20.0%, P = 0.017). Laparotomy was performed in 66.6% (12/18) of cases. There was a learning curve that showed an increase in success rate and decrease in need for laparotomy over the 3-year study period. Neither the need for laparotomy nor the chances of technical success were predictable by gestational age, body mass index or placental location. Tocolysis was limited to perioperative prophylaxis; one woman experienced wound infection and fluid overload. Postoperatively, three fetuses died and two delivered prematurely, 2 and 7 weeks after intervention.

CONCLUSION

Fetal aortic valvuloplasty can be performed with technical success, with low fetal loss rate and few maternal complications. While the need for laparotomy cannot be predicted, having it available as an option improves the technical success rate.

Delivery room and early postnatal management of neonates who have prenatally diagnosed congenital heart disease

Advances in fetal echocardiography are providing highly accurate diagnoses of congenital heart disease prior to delivery, making it possible to plan the delivery-room management of these newborns. Knowledge of the expected transitional circulation occurring with birth and the pathophysiologic implications of congenital heart disease increases the likelihood of providing efficient and effective therapies. The majority of neonates who have congenital heart disease will not require delivery room resuscitation in excess of routine care; however, a small number of prenatally diagnosed cardiac lesions are more likely to require urgent postnatal intervention immediately following delivery. These cardiac lesions include transposition of the great arteries with intact ventricular septum and restrictive atrial septum, hypoplastic left heart syndrome with intact atrial septum, obstructed total anomalous pulmonary venous return, and complete congenital heart block. Prenatal diagnosis allows for coordination of care surrounding delivery and during the early postnatal hours.

Diagnosis and outcome of congenital heart disease in fetuses from multiple pregnancies

OBJECTIVES

(1) To assess the diagnostic accuracy of fetal echocardiography and (2) to evaluate the type and the outcome of congenital heart disease (CHD) detected in fetuses from multiple pregnancies.

METHOD

SETTING

tertiary referral center for prenatal diagnosis of CHD.

DESIGN

observational study. In the period 1994-2003, 711 fetuses from 330 multiple pregnancies (282 twins, 45 triplets and 3 quadruplets) underwent fetal echocardiography at our unit. CHD were present in 45 of them. Diagnostic accuracy (sensitivity, specificity, positive and negative predictive values) was calculated for fetal echocardiography. For the fetuses with CHD, the following variables were analysed: gestational age at diagnosis, type of CHD, associated anomalies, fetoneonatal outcome. Confirmation of the diagnosis was obtained in 45/48 cases with CHD and in 580/610 without CHD. Mean follow-up time for diseased neonates was 52 months (range 6-127).

RESULTS

In the study population, there were 40 true positives, 5 false negatives, 1 false positive and 632 true negatives, which yields the following figures: sensitivity 88.8% (40/45), specificity 99.8% (632/633), positive predictive value 97.6% (40/41) and negative predictive value 99.2% (632/637). As for the 45 cases with CHD, type of CHD was evenly distributed among left and right heart, conotruncal and septal defects, with 6/7 right heart lesions occurring in recipient fetuses of pregnancies complicated by TTTS. The aneuploidy rate was 7.0% (3/43). As for the outcome, 26 (57.8%) neonates survived and 17 (37.7%) died prior to or after surgery. Very low birthweight accounted for 7 of the 17 perinatal deaths.

CONCLUSIONS

Our data show that the diagnostic performance of fetal echocardiography in multiple gestations is comparable with that obtained in singletons, as far as twin pregnancies are concerned. Data on triplets and quadruplets are too scant to be of statistical relevance. In addition, the importance of prematurity as primary cause of death in this subset of fetuses should be considered when counseling couples with multiple pregnancies and a fetus with CHD.

Cardiopulmonary Bypass in Ewe’s Fetus: Advances and Setbacks in Our Learning Curve

Fetal cardiac surgery represents a surgical challenge and several centers are attempting to establish a suitable methodology in animals. We present our experience with extra-corporeal bypass procedures in preterm and term sheep fetuses. Twenty-two fetuses (103-139 days gestation, mean 115 days gestation) underwent a 1-hour period of right heart-to-pulmonary artery extracorporeal circulation followed by 1 hour of observation. Animals were divided into group 1 and group 2, according to gestational age (above and below 0.85). Three pumps were used: centrifugal without (group 1) reservoir, centrifugal with (group 2) reservoir, and roller with reservoir (group 2). Experiments were completed in 75% of fetuses in group 1 and in 37% of fetuses in group 2. Bleeding was the main cause of failure, especially for group 2. A slow deterioration of blood gas status was noted in group 1, while this trend could be partially reversed in group 2 with corrective measures. Complete heart bypass could not be achieved in either group, and residual fluctuations in arterial pressure were observed. During bypass, body temperature decreased more in group 2 than in group 1. We conclude that cardiac bypass is feasible over a short period in near-term fetuses. A successful outcome may also be obtained in younger fetuses, but better measures need to be implemented for the prevention of surgical bleeding.

Successful repair of aorto-left ventricular tunnel diagnosed prenatally

Aorto-left ventricular tunnels are anomalous communications between the ascending aorta and the left ventricle. Prenatal diagnosis, followed by successful surgical management, is rare. We describe a fetus diagnosed with aorto-left ventricular tunnel at 35 weeks who achieved a favourable outcome after immediate postnatal surgical repair.

Should all pregnant diabetic women undergo a fetal echocardiography? A cost-effectiveness analysis comparing four screening strategies

OBJECTIVE

To determine if a policy of universal fetal echocardiography for all pregnant diabetic women is cost-effective as a screening tool for congenital heart defects.

STUDY DESIGN

Using a decision-analysis model, we compared the cost-effectiveness of four screening strategies: (1) none--no ultrasound is performed; (2) selective fetal echocardiography after abnormal detailed anatomic survey; (3) fetal echocardiography for only high hemoglobin A1C, and (4) universal fetal echocardiography for all diabetics. The sensitivity and specificity for each strategy were derived by literature search. The analysis was from a societal perspective using a willingness-to-pay threshold (50,000 dollars) and a theoretic cohort of 40,000 pregnant diabetics. Costs included costs of tests and the costs of complications and of raising a child with a cardiac defect. Outcomes were reported as cost per quality-adjusted life years (QALY) gained for each congenital heart defect prevented by each strategy and the number of congenital heart defects detected. One-way, multiway and probabilistic sensitivity analyses were performed.

RESULTS

Compared with the other strategies, selective fetal echocardiography after abnormal detailed anatomic survey costs less per QALY gained for cardiac defect screening. Although universal fetal echocardiography was associated with a higher detection rate for cardiac defects, it was more costly. The sensitivity analyses revealed a robust model over a wide range of values.

CONCLUSION

Under the baseline assumptions, selective fetal echocardiography after an abnormal detailed anatomic survey is more cost-effective compared with universal fetal echocardiography as a screening strategy for cardiac defects in pregnant diabetics.

Fetal echocardiography: are we getting it right?

OBJECTIVE

To determine the diagnostic accuracy of prenatal fetal echocardiography.

METHODS

The study was a retrospective chart review of 190 consecutive patients over a 3-year period from November 1998 to February 2002 of all women referred to the Maternal Fetal Medicine unit, Mater Mothers Hospital, for fetal echocardiography. The prenatal diagnosis was compared with the postnatal diagnosis made by postnatal echocardiography, surgical findings or post-mortem. The accuracy of prenatal diagnosis was described on a predetermined 4-point scale.

RESULTS

Of the 89 patients, for whom complete diagnostic follow-up was available, there was complete agreement between the prenatal and postnatal diagnosis in 63 cases, minor discrepancies in 25 cases and major disagreement in 1 case.

CONCLUSIONS

In experienced hands, fetal echocardiography is accurate and allows medical staff and patients information in order manage a pregnancy appropriately.