Clinical Monitoring of Sacrococcygeal Teratoma.

BACKGROUND: Sacrococcygeal teratomas (SCT) are often highly vascularized and may result in high-output cardiac failure, polyhydramnios, fetal hydrops, and demise. Delivery is guided by the SCT to fetus volume ratio (SCTratio), SCT growth rate, and cardiac output indexed for weight (CCOi). METHODS: We compared measurements and outcome in 12 consecutive fetuses referred with SCT. Adverse outcomes were: fetal surgery, delivery < 32 gestational weeks or neonatal demise. Only SCTratio and CCOi were used to manage the cases. SCT vascularization index (VI%) was derived from the 3D virtual organ computer-aided analysis (VOCAL) software. The SCTModel (modified from acardiac twins) calculated a hypothetical SCT draining vein size and derived a risk line, using diameters of the superior and inferior vena cava, the azygous and umbilical veins. VI% and a model of systemic and umbilical venous volumes (SCTModel) were tested as indicators for outcome in SCT. RESULTS: Fetuses were monitored from 20.1 to 36.4 gestational weeks and 5/12 had adverse outcomes: 1 had successful open fetal surgery at 23.8 weeks and delivered at term, 4 delivered at < 32 weeks with 3/4 having neonatal demise between 25 and 29 weeks. VI% was significantly higher in cases with adverse outcomes (mean 10.3 [8.9-11.6] vs. 4.4 [3.4-5.3], p < 0.0001). The additional fraction of the fetal cardiac output required to perfuse the SCT-draining vein (XSCO%) (p = 0.46), SCTratio (p = 0.08), and CCOi (p = 0.64) were not significant. All cases with adverse outcome had VI% > 8%. The SCTModel risk line predicted nonadverse outcomes well but lacked data in 2/5 cases with adverse outcomes. CONCLUSIONS: VI% is a significant indicator of SCT cases with adverse outcomes and combined with SCTratio may guide timing of delivery better than current measures.

In utero intervention for severe congenital heart disease.

The aim of foetal cardiac therapy is to treat an abnormality at the developmental stage so that the process of cardiac growth, which is complex and relies on the volume and direction of circulating blood as well as genetic determinants, can continue. In reality, most cardiac interventions are palliative; hence, major abnormalities are still present at birth. Nevertheless, tangible benefits following successful foetal intervention include improved haemodynamics and reduction in secondary damage leading to better postnatal outcomes. In cases of semilunar valve stenosis, or atresia, foetal valvuloplasty aims to achieve a biventricular, rather than univentricular, circulation. Opening and stenting a restrictive atrial foramen may preserve the pulmonary function in cases of hypoplastic left heart syndrome, thereby increasing the chances of successful postnatal surgery. More recent endeavours include percutaneous implantation of a miniaturised pacemaker to treat complete heart block and the promotion of left-sided heart growth by chronic maternal hyperoxygenation. The true clinical benefit of these interventions over natural history remains uncertain because of the paucity of appropriate randomised controlled trials (RCTs). Foetal cardiac therapy must now move from a pioneering approach to one that is supported by evidence, as has been done successfully for other foetal therapies.

Long-term outcomes for monochorionic twins after laser therapy in twin-to-twin transfusion syndrome.

Twin-to-twin transfusion syndrome typically occurs in the second trimester in 10-15% of monochorionic twin pregnancies. Vascular anastomoses of monochorionic placentae are the underlying cause of the development of the syndrome. If a blood flow imbalance occurs, one fetus becomes the so-called donor twin and the other the recipient. If untreated, perinatal mortality is 80-90%. Fetoscopic laser coagulation of the vascular anastomoses destroys the cause of the syndrome and leads to dual twin survival rates of around 70% and more than 90% of pregnancies with at least one survivor. However, unequal placental sharing, intrauterine death, and severe prematurity are still limiting factors for further improvement of survival rates and decreases in long-term morbidity. Prematurity and neurodevelopmental impairment affect the donor and recipient twins, whereas cardiovascular failure and obstruction of the right ventricular outflow tract are typical complications of recipients, which can lead to long-term morbidity. In this Review, we summarise the literature on follow-up data for survivors of twin-to-twin-transfusion syndrome after laser therapy, including neurodevelopmental outcomes, cardiovascular outcomes, growth, renal function, and ischaemic events, as well as the potential effects of intrauterine programming on later life.

Advances in fetal echocardiography.

The development of fetal echocardiography and success in prenatal cardiac screening programs over the past 30 years has been driven by technical innovation and influenced by the different approaches of the various specialties practicing it. Screening for congenital heart defects no longer focuses on examining a limited number of pregnant women thought to be at increased risk, but instead forms an integrated part of a high-quality anatomical ultrasound performed in the second trimester using the 'five-transverse view' protocol. A prenatal diagnosis is feasible in almost all cardiac lesions and the advantages to parents and to health professionals are well recognized. Prenatal evaluation can usually determine the level of care required at delivery, thereby reducing perinatal morbidity. However, only half of the babies undergoing surgery within the first year of life have a prenatal detection, and practical training programs to support and provide feedback to sonographers remain essential for continued improvement.

The Influence of Blood Pressure on Fetal Aortic Distensibility: An Animal Validation Study.

BACKGROUND/AIMS: Aortic distension waveforms describe the change in diameter or cross-sectional area over the cardiac cycle. We aimed to validate the association of aortic fractional area change (AFAC) with blood pressure (BP) in a fetal lamb model. METHODS: Four pregnant ewes underwent open fetal surgery under general anesthesia at 107-120 gestational days. A 4-Fr catheter was introduced into the fetal femoral artery and vein, or the carotid artery and jugular vein. The thoracic aorta was imaged using real-time ultrasound; AFAC was calculated using offline speckle tracking software. Measurements of invasive BP and AFAC were obtained simultaneously and averaged over 10 cardiac cycles. BP was increased by norepinephrine infusion and the association of aortic distensibility with BP was assessed. RESULTS: Baseline measurements were obtained from 4 lambs, and changes in aortic distensibility with increasing BP were recorded from 3 of them. A positive correlation was found between AFAC and systolic BP (r = 0.692, p = 0.001), diastolic BP (r = 0.647, p = 0.004), mean BP (r = 0.692, p = 0.001), and BP amplitude (r = 0.558, p = 0.016) controlled for heart rate. No association was found between BP and maximum or minimum aortic area. CONCLUSION: AFAC provides a quantifiable measure of aortic distensibility and correlates with systolic BP, diastolic BP, mean BP, and BP amplitude in a fetal lamb model.

Acardiac twin pregnancies part IV: Acardiac onset from unequal embryonic splitting simulated by a fetoplacental resistance model.

BACKGROUND: Benirschke postulated that acardiac twinning occurs when markedly unequal embryonic splitting combines with arterioarterial (AA) and venovenous placental anastomoses. We tested this hypothesis by model simulations and by comparison of outcomes with 18 "pseudo-" (twin fetus with beating heart but otherwise with clear signs of an acardiac) and 3 "normal" acardiac cases. METHODS: The smaller/larger cell volume ratio at embryonic splitting becomes the smaller/larger embryonic/fetal blood volume ratio (a). From a, we derived nonpulsating blood pressures using normal values (larger twin) and normal values at an appropriate earlier gestational age (smaller twin). These unequal pressure sources were used in a linear resistance fetoplacental network to calculate umbilical venous diameter ratios. Acardiac onset occurs when the smaller twin has 50% left of its normal, singleton placenta. Comparison with clinical cases approximated a by crown-rump-length-ratio to the 3rd power. Input parameters are a and the AA-radius at 40 weeks. RESULTS: Acardiacs can be small or large, can occur early or late, earlier at smaller a and larger AA, with larger umbilical venous diameter ratios at smaller a and smaller AA. Comparison with the 21 clinical cases was good, except for 2. CONCLUSION: Our analysis supports Benirschke's hypothesis. The smaller twin has to share its placental perfusion with the larger twin, which is a novel finding. The AA size is essential for the future of both fetuses but complicates easy understanding of (pseudo-)acardiac clinical presentations. Late acardiac onset occurs infrequently. Using nonpulsating circulations may have caused our extensive predictions of late onset. An improved model requires including hypoxemia in the smaller twin from chronic placental hypoperfusion. Birth Defects Research 109:211-223, 2017. © 2016 Wiley Periodicals, Inc.

Acardiac twin pregnancies part II: Fetal risk of chorangioma and sacrococcygeal teratoma predicted by pump/acardiac umbilical vein diameters.

BACKGROUND: We recently published pump/acardiac umbilical venous diameter (UVD) ratios, representing the pump twin's excess cardiac output fraction, of 27 acardiac twin pregnancies. There was a clear separation between the 17 pump twins that had life-threatening complications and the 10 that did not. The hypothesis of this study is that placental chorangioma and sacrococcygeal teratoma (SCT), tumors whose perfusion also causes high-output complications, have the same fetal outcome as pump twins when perfusion of the tumor requires the same excess cardiac output fraction. METHODS: We compared the three fetoplacental circulations. Fetuses with a placental chorangioma and acardiac twin pregnancies both have their feeding artery and draining vein located at the placental cord insertion. In contrast, SCT lacks a prescribed feeding artery and draining vein. We, therefore, had to modify our model to assume that the diameter of the hypothetical draining vein is related to the flow difference between inferior vena cava and superior vena cava. The latter flow has been estimated sonographically and is the same as the inferior vena cava flow in the absence of an SCT. Furthermore, a simple modification accounts for the different location of the tumor with respect to the placental cord insertion. RESULTS: We propose to apply the clinical pump/acardiac UVD ratios to pregnancies complicated by placental chorangiomas and the modified pump/acardiac UVD ratios for SCT. CONCLUSION: Risk prediction of these rare fetal tumors may be possible based on application of data on excess cardiac output fractions from pump/acardiac UVD ratios and will require future clinical validation. Birth Defects Research (Part A) 106:733-738, 2016. © 2016 Wiley Periodicals, Inc.

Fetal cardiovascular hemodynamics in twin-twin transfusion syndrome.

Twin-twin transfusion syndrome (TTTS) complicates 10-15% of monochorionic-diamniotic (MCDA) pregnancies. It originates from unbalanced transfer of fluid and vasoactive mediators from one twin to its co-twin via placental anastomoses. This results in hypovolemia in the donor and hypervolemia and vasoconstriction in the recipient twin. Consequently, the recipient demonstrates cardiovascular alterations including atrioventricular valve regurgitation, diastolic dysfunction, and pulmonary stenosis/atresia that do not necessarily correlate with Quintero-stages. Selective fetoscopic laser photocoagulation of placental vascular anastomoses disrupts the underlying pathophysiology and usually improves cardiovascular function in the recipient with normalization of systolic and diastolic function within weeks after treatment. Postnatal studies have demonstrated early decreased arterial distensibility in ex-donor twins, but 10-year follow up is encouraging with survivors showing normal cardiovascular function after TTTS. However, prediction and appropriate early management of TTTS remain poor. Assessment of the cardiovascular system provides additional insight into the pathophysiology and severity of TTTS and may permit more targeted early surveillance of MCDA pregnancies in future. It should form an integral part of the diagnostic algorithm.

Foetal cardiac function: assessing new technologies.

Assessment of foetal cardiac function is more challenging than in the adult, in whom emerging technologies are tested. The postnatal cardio-respiratory interaction is replaced by the cardio-placental circulation and impedance of the brain, and distal vascular beds play an important role in modulating flow to enable its redistribution in the foetal body. Prenatal specialists, comprising obstetricians and cardiologists, have tested a variety of traditional methodologies, as well as non-Doppler offline ultrasound methods in the foetus. This article reviews the development of techniques, outlines their use, and draws attention to pitfalls in adapting technologies validated in the adult heart to the small, fast beating, remote, and largely ungated foetal heart.

Prenatal screening for major congenital heart disease: assessing performance by combining national cardiac audit with maternity data.

OBJECTIVE: Determine maternity hospital and lesion-specific prenatal detection rates of major congenital heart disease (mCHD) for hospitals referring prenatally and postnatally to one Congenital Cardiac Centre, and assess interhospital relative performance (relative risk, RR). METHODS: We manually linked maternity data (3 hospitals prospectively and another 16 retrospectively) with admissions, fetal diagnostic and surgical cardiac data from one Congenital Cardiac Centre. This Centre submits verified information to National Institute for Cardiovascular Outcomes Research (NICOR-Congenital), which publishes aggregate antenatal diagnosis data from infant surgical procedures. We included 120 198 unselected women screened prospectively over 11 years in 3 maternity hospitals (A, B, C). Hospital A: colocated with fetal medicine, proactive superintendent, on-site training, case-review and audit, hospital B: on-site training, proactive superintendent, monthly telemedicine clinics, and hospital C: sonographers supported by local obstetrician. We then studied 321 infants undergoing surgery for complete transposition (transposition of the great arteries (TGA), n=157) and isolated aortic coarctation (CoA, n=164) screened in hospitals A, B, C prospectively, and 16 hospitals retrospectively. RESULTS: 385 mCHD recorded prospectively from 120 198 (3.2/1000) screened women in 3 hospitals. Interhospital relative performance (RR) in Hospital A:1.68 (1.4 to 2.0), B:0.70 (0.54 to 0.91), C:0.65 (0.5 to 0.8). Standardised prenatal detection rates (funnel plots) demonstrating inter-hospital variation across 19 hospitals for TGA (37%, 0.00 to 0.81) and CoA (34%, 0.00 to 1.06). CONCLUSIONS: Manually linking data sources produced hospital-specific and lesion-specific prenatal mCHD detection rates. More granular, rather than aggregate, data provides meaningful feedback to improve screening performance. Automatic maternal and infant record linkage on a national scale, requires verified, prospective maternity audit and integration of health information systems.

The cost-effectiveness of prenatal detection for congenital heart disease using telemedicine screening.

We estimated the longer-term cost-effectiveness of using telemedicine screening for prenatal detection of congenital heart disease (CHD). One hospital in south-east England with a telemedicine service was connected to a fetal cardiology unit in London. A UK health service perspective was adopted. Evidence on costs and outcomes for standard-risk pregnant women during the antenatal period was based on patient-level data. Extrapolation beyond the end of the study (just after delivery) was carried out for the lifetime of children born with and without CHD. Expert opinion and data from published sources was used to populate a decision model. Future costs and benefits were discounted. The main outcome was quality-adjusted life years (QALYs) and results were expressed as cost per QALY gained. Various one-way sensitivity analyses were conducted. The model showed that offering telemedicine screening by specialists to all standard-risk pregnant women was the dominant strategy (i.e. cheaper and more effective). The sensitivity analyses found that the model was robust, and that telemedicine remained the most cost-effective strategy. The study showed that it would be cost-effective to provide telemedicine examinations as part of an antenatal screening programme for all standard-risk women.

Ventricular strain changes in monochorionic twins with and without twin-to-twin transfusion syndrome.

OBJECTIVE: The objective of the study was to investigate whether vector velocity imaging (VVI), a non-Doppler speckle tracking ultrasound technology, is feasible in twin pregnancies and can aid management of twin-twin transfusion syndrome (TTTS). STUDY DESIGN: Twenty-seven women pregnant with monochorionic diamniotic twins affected by TTTS and 28 monochorionic pregnancies that did not develop TTTS were included in a prospective case-control study at a fetal medicine center. Fetal echocardiograms were recorded with dummy electrocardiography to retain original frame rates when exported for offline speckle tracking analysis using Syngo-VVI software (Siemens Corp, Munich, Germany). Right and left ventricular (LV) free wall Lagrangian strain was measured from the original coordinates. Within-twin pair ventricular strain differences including relationship to Quintero staging and response to laser therapy for TTTS were analyzed by Wilcoxon signed-rank test. RESULTS: The VVI strain measurements could be analyzed in 182 of 200 TTTS and 96 of 112 non-TTTS control ventricles. Within-pair strain was concordant in non-TTTS controls. Recipient LV strain was reduced at all Quintero stages compared with donors (P < .01). Recipient right ventricular strain was reduced only in stages 3 and 4 (P < .01). Strain improved at a median of 2 weeks following successful laser therapy. Intertwin differences in strain were independent of weight discordance. CONCLUSION: Recipient LV strain is reduced in stages 1 and 2 TTTS. Within-pair strain discordance may distinguish early TTTS from growth discordance and guide timing of and management following treatment.

Myocardial strain abnormalities in fetal congenital heart disease assessed by speckle tracking echocardiography.

OBJECTIVES: To compare myocardial deformation patterns in fetuses with congenital heart disease (CHD) with our reference range using speckle tracking echocardiography. METHODS: We prospectively stored and analyzed 4-chamber loops of 28 fetuses with CHD (median gestation 27 weeks, range 20.9-37.0). The peak longitudinal left (LVs) and right (RVs) ventricular free wall Lagrangian strain and LV/RV strain ratio were measured from Syngo VVI software- (Siemens) derived original coordinates. Strain values from the first examination were compared with normative data from the same population using ANOVA with post hoc tests and serial examinations described in 14 fetuses. RESULTS: Simple shunt lesions (0.82) and shunts with pulmonary stenosis or atresia (0.93) had reduced mean LV/RV strain ratios compared to normal fetuses (1.01; 95% CI 0.97-1.05). Fetuses with hypoplastic left heart had the lowest (0.29), and those with Ebstein the highest (1.55), LV:RV ratio. Serial measurements showed increased LVs in aortic coarctation and aortic stenosis, but not in one developing important mitral regurgitation. Increased right ventricular loading in a fetus developing pulmonary regurgitation was associated with increasing RVs. CONCLUSIONS: Myocardial strain reflects the changing physiology of fetal CHD. Speckle tracking might be a useful tool to study the progress of myocardial function in affected fetuses.

Isolated atrioventricular block in the fetus: a retrospective, multinational, multicenter study of 175 patients.

BACKGROUND: Isolated complete atrioventricular block in the fetus is a rare but potentially lethal condition in which the effect of steroid treatment on outcome is unclear. The objective of this work was to study risk factors associated with death and the influence of steroid treatment on outcome. METHODS AND RESULTS: We studied 175 fetuses diagnosed with second- or third-degree atrioventricular block (2000-2007) retrospectively in a multinational, multicenter setting. In 80% of 162 pregnancies with documented antibody status, atrioventricular block was associated with maternal anti-Ro/SSA antibodies. Sixty-seven cases (38%) were treated with fluorinated corticosteroids for a median of 10 weeks (1-21 weeks). Ninety-one percent were alive at birth, and survival in the neonatal period was 93%, similar in steroid-treated and untreated fetuses, regardless of degree of block and/or presence of anti-Ro/SSA. Variables associated with death were gestational age < 20 weeks, ventricular rate ≤ 50 bpm, fetal hydrops, and impaired left ventricular function at diagnosis. The presence of ≥ 1 of these variables was associated with a 10-fold increase in mortality before birth and a 6-fold increase in the neonatal period independently of treatment. Except for a lower gestational age at diagnosis in treated than untreated (23.4 ± 2.9 versus 24.9 ± 4.9 weeks; P=0.02), risk factors were distributed equally between treatment groups. Two-thirds of survivors had a pacemaker by 1 year of age; 8 children developed cardiomyopathy. CONCLUSIONS: Risk factors associated with a poor outcome were gestation < 20 weeks, ventricular rate ≤ 50 bpm, hydrops, and impaired left ventricular function. No significant effect of treatment with fluorinated corticosteroids was seen.

Cost implications of introducing a telecardiology service to support fetal ultrasound screening.

A district hospital in south-east England used a telecardiology service for fetal cardiac diagnosis alongside an existing arrangement for referring pregnant women directly to perinatal cardiologists in London for detailed fetal echocardiography. Women were identified for referral according to local protocols when having a second trimester anomaly scan. For the telemedicine referrals, the sonographers video-recorded images from the anomaly scans for transmission during monthly videoconferences. The cost of the women's antenatal care was calculated from the specialist assessment until delivery, while family costs were collected in a postal survey. Over 15 months, telemedicine was used in 52 cases, while 24 women were seen in London. The London women were more likely to have had an ultrasound abnormality (29% v 10%, P = 0.047). A telemedicine assessment of 5 min duration was more costly than an examination in London (mean cost per referral of pound206 v pound74, P < 0.001). However, the telecardiology service was cost neutral after 14 days and for the extended period until delivery. Travel costs for London women averaged pound37 compared with pound5.50 for the telemedicine referrals. Telemedicine may be useful to support perinatal cardiologists in the UK whose workloads are expanding in response to improved standards in antenatal ultrasound screening.