Maternal Sirolimus Therapy for Fetal Cardiac Rhabdomyomas

Exploring Cardiovascular Involvement in Tuberous Sclerosis: Insights for Pediatric Clinicians

Tuberous sclerosis is a rare genetic disorder involving mainly the nervous and cardiovascular systems. The early recognition of the cardiovascular manifestations by the pediatrician allows an appropriate management and therefore enhances the quality of life of the affected children. Cardiac rhabdomyomas and the associated arrhythmias are the first cardiac features and they might represent a diagnosis challenge given their wide spectrum of clinical manifestations. We aimed to provide the paediatric practitioners with current knowledge regarding the cardiovascular complications in children with tuberous sclerosis. We overviewed the antenatal and postnatal evolution of cardiovascular manifestations, the systematic screening and long-term follow-up strategy of cardiac rhabdomyomas and arrhythmias in children with tuberous sclerosis.

Systematic Review of Lymphangioleiomyomatosis Outcomes in Pregnancy and a Proposed Management Guideline

OBJECTIVE

 Lymphangioleiomyomatosis (LAM) is a rare, multisystem disease that primarily affects women of reproductive age. Disease progression has been linked to estrogen exposure, and as such many patients are advised to avoid pregnancy. Data are limited regarding the interaction between LAM and pregnancy, and as such we performed a systematic review to summarize available literature reporting outcomes of pregnancies complicated by maternal LAM.

STUDY DESIGN

 This was a systematic review including randomized controlled trials, observational studies, systematic reviews, case reports, clinical practice guidelines, and quality improvement studies with full-text manuscripts or abstracts in the English language with primary data on pregnant or postpartum patients with LAM. The primary outcome was maternal outcomes during pregnancy as well as pregnancy outcomes. Secondary outcomes were neonatal outcomes and long-term maternal outcomes. This search occurred in July 2020 and included MEDLINE, Scopus, clinicaltrials.gov, Embase, and Cochrane Central. Risk of bias was ascertained using the Newcastle-Ottawa Scale. Our systematic review was registered with PROSPERO as protocol number CRD 42020191402.

RESULTS

 A total of 175 publications were identified in our initial search; ultimately 31 studies were included. Six (19%) studies were retrospective cohort studies and 25 (81%) studies were case reports. Patients diagnosed during pregnancy had worse pregnancy outcomes compared to those diagnosed with LAM prior to pregnancy. Multiple studies reported a significant risk of pneumothoraces during pregnancy. Other significant risks included preterm delivery, chylothoraces, and pulmonary function deterioration. A proposed strategy for preconception counseling and antenatal management is provided.

CONCLUSION

 Patients diagnosed with LAM during pregnancy generally experience worse outcomes including recurrent pneumothoraces and preterm delivery as compared to patients with a LAM diagnosis prior to pregnancy. Given that there are limited studies available, and that the majority are low-quality evidence and subject to bias, further investigation of the interaction between LAM and pregnancy is warranted to guide patient care and counseling.

KEY POINTS

· Data are limited on the effects of lymphangioleiomyomatosis on pregnancy outcomes.. · We performed a systematic review to summarize pregnancy outcomes complicated by LAM.. · Patients diagnosed with LAM during pregnancy experience worse outcomes..

Perinatal Results and Long-Term Follow-Up of Fetal Cardiac Tumors: A 30-Year Historical Cohort Study

BACKGROUND

This was a 30-year retrospective cohort study that approximates closely to the natural history of cardiac tumors diagnosed in the fetus, since there was no case of pregnancy interruption.

OBJECTIVE

To assess morbidity and mortality in the perinatal period and at long term in fetuses diagnosed with cardiac tumor. Our secondary objective was to assess the evaluating factors of perinatal and postnatal results.

METHODS

This was a retrospective cohort study with 74 pregnant women with an echocardiographic diagnosis of fetal cardiac tumor at two referral centers between May 1991 and November 2021. A descriptive analysis was performed, and data were expressed as absolute (n) and relative (%) frequencies, median and interquartile range. Fisher's exact test was used to evaluate the association of echocardiographic characteristics and clinical manifestations with perinatal and postnatal results. Global survival was calculated using the Kaplan-Meier method and the curves were compared by the log-rank test. The time of follow-up, calculated in months, corresponded to the time elapsed from hospital discharge to current status (survived/ censoring or death). The level of significance was set at 5% (p<0.05).

RESULTS

Rhabdomyoma is the most common type of cardiac tumor (85%), with a high morbidity (79.3%) and overall mortality of 17.4%. The presence of fetal hydrops was a predictor of death.

CONCLUSION

The presence of fetal hydrops had an impact on mortality, and hence is an important factor in counselling and determining the prognosis. Most deaths occurred before hospital discharge.

Healthcare provider recognition of pregnancy related risks and management considerations in patients with tuberous sclerosis complex

BACKGROUND

Patients with tuberous sclerosis complex (TSC) face an increased risk of maternal health complications and worsening disease manifestations during pregnancy. There are no established consensus guidelines that address the management of pregnancy in patients with TSC and healthcare providers rely on their individual experiences and preferences to derive treatment decisions. We sought to obtain provider opinion of pregnancy related maternal complications in patients with TSC, and the common evaluation and management strategies used to address these issues.

METHODS

We conducted a cross-sectional survey of healthcare providers with diverse areas of expertise related to the multisystem nature of involvement in TSC. Descriptive analyses were used to analyze our three primary variables: (1) provider recognition of maternal risks/complications; (2) provider recommendations before and during pregnancy; and (3) provider/clinic protocols.

RESULTS

We received responses from 87 providers from 11 countries, with 40.7% (n = 35) seeing > 30 TSC patients yearly. The majority of providers (n = 70, 88.6%) deemed that a patient with TSC needed expert care beyond the standard of care for a typical pregnancy, with over 25% of providers reporting that they have seen lymphangioleiomyomatosis (LAM) exacerbation, seizures, and preterm labor in pregnant patients with TSC. Providers who managed patients treated with mTOR inhibitors (mTORi) also agreed that mTORi use should be stopped prior to pregnancy (n = 45, 68.2%) but there was uncertainty about when to stop the mTORi (one month 28.9%, two months 11.1%, three months 42.2%, and 6-12 months 2.2%). Additionally, there were mixed opinions on restarting mTORi in response to disease progression during pregnancy. When asked about provider or clinic specific protocols, 71.6% (n = 53) of providers stated that they do not have a clear protocol for management decisions for patients with TSC before or during pregnancy.

CONCLUSION

Healthcare providers recognize that patients with TSC are at an increased risk for maternal health complications during pregnancy. However, there are wide inter-individual variances in practice, especially pertaining to decisions regarding mTORi use. There is a critical need to better understand the implications of pregnancy for patients with TSC, and to draft consensus recommendations to guide management decisions.

Mammalian target of rapamycin inhibitors: A new-possible approach for in-utero medication therapy

The mammalian/mechanistic target of rapamycin (mTOR) is a protein kinase that plays a crucial role in regulating cellular growth, metabolism, and survival. Although there is no absolute contraindication for the use of mTOR inhibitors during pregnancy, the specific fetal effects remain unknown. Available data from the past 2 decades have examined the use of mTOR inhibitors during pregnancy in patients with solid organ transplantation, showing no clear link to fetal complications or structural abnormalities. Recently, a handful of case reports and series have described transplacental therapy of mTOR inhibitors to control symptomatic and complicated pathologies in the fetus. The effect of these agents includes a significant reduction in lesion size in the fetus and a reduced need for mechanical ventilation in neonates. In this context, we delve into the potential of mTOR inhibitors as in-utero therapy for fetal abnormalities, with a primary focus on lymphatic malformation (LM) and cardiac rhabdomyoma (CR). While preliminary reports underscore the efficacy of mTOR inhibitors for the treatment of fetal CR and fetal brain lesions associated with tuberous sclerosis complex, chylothorax, and LMs, additional investigation and clinical trials are essential to comprehensively assess the safety and efficacy of these medications.

Cardiac problems in the fetus: a review for pediatric providers

PURPOSE OF REVIEW

The aim of this study was to provide pediatric providers with a review of the diagnosis and management of fetal cardiac disease in the current era.

RECENT FINDINGS

Prenatal detection of congenital heart disease (CHD) has improved but is still imperfect. In experienced hands, fetal echocardiography can detect severe CHD as early as the first trimester and a majority of more subtle conditions in the second and third trimesters. Beyond detection, a prenatal diagnosis allows for lesion-specific counseling for families as well as for development of a multidisciplinary perinatal management plan, which may involve in-utero treatment. Given the diversity of cardiac diagnoses and the rarity of some, collaborative multicenter fetal cardiac research has gained momentum in recent years.

SUMMARY

Accurate diagnosis of fetal cardiac disease allows for appropriate counseling, pregnancy and delivery planning, and optimization of immediate neonatal care. There is potential for improving fetal CHD detection rates. Fetal interventions are available for certain conditions, and fetal and pediatric cardiac centers have developed management plans specific to the expected postnatal physiology.

Successful Prenatal Treatment of Cardiac Rhabdomyoma in a Fetus with Tuberous Sclerosis

Cardiac rhabdomyomas are a possible early manifestation of the Tuberous Sclerosis Complex (TSC). They often regress spontaneously but may grow and cause cardiac dysfunction, threatening the child's life. Treatment with rapalogs can stop the growth of these cardiac tumors and even make them shrink. Here, we present the case of a successful treatment of a cardiac rhabdomyoma in a fetus with TSC by administering sirolimus to the mother. The child's father carries a TSC2 mutation and the family already had a child with TSC. After we confirmed the TSC diagnosis and growth of the tumor with impending heart failure, we started treatment at 27 weeks of gestation. Subsequently, the rhabdomyoma shrank and the ventricular function improved. The mother tolerated the treatment very well. Delivery was induced at 39 weeks and 1 day of gestation and proceeded without complications. The length, weight, and head circumference of the newborn were normal for the gestational age. Rapalog treatment was continued with everolimus. Metoprolol and vigabatrin were added because of ventricular preexcitation and epileptic discharges in the EEG, respectively. We provide the follow-up data on the child's development in her first two years of life and discuss the efficacy and safety of this treatment.

Reproductive health after thoracic transplantation: An ISHLT expert consensus statement

Pregnancy after thoracic organ transplantation is feasible for select individuals but requires multidisciplinary subspecialty care. Key components for a successful pregnancy after lung or heart transplantation include preconception and contraceptive planning, thorough risk stratification, optimization of maternal comorbidities and fetal health through careful monitoring, and open communication with shared decision-making. The goal of this consensus statement is to summarize the current evidence and provide guidance surrounding preconception counseling, patient risk assessment, medical management, maternal and fetal outcomes, obstetric management, and pharmacologic considerations.

Propranolol Therapy for Congenital Chylothorax

Congenital chylothorax is a rare and often severe anomaly without well-established medical therapies. Previously, propranolol use in patients with lymphatic malformations and secondary chylothorax was associated with improvement in clinical signs. We hypothesized that propranolol treatment would be beneficial for severe congenital chylothorax. We reviewed medical records of neonates born from 2015 to 2019 at our tertiary center with a prenatal diagnosis of congenital chylothorax for whom either prenatal or postnatal propranolol therapy was initiated. Inclusion was limited to fetuses diagnosed with severe congenital chylothorax without significant genetic, infectious, or cardiac anomalies, and who underwent prenatal interventions to mitigate consequences of the condition. Propranolol was administered orally to pregnant women at 20 mg 4 times daily and increased to a maximum dose of 40 mg 4 times daily, or to infants at 0.3 mg/kg/d and increased to 1 to 2 mg/kg/d. Primary outcomes were the time course of resolution of ultrasonographical, clinical, and/or radiologic signs of chylothorax after treatment with propranolol. Four neonates met the inclusion criteria. In 2 cases, prenatal initiation of propranolol led to resolution of the chylothoraxes before delivery (38 and 32 days after treatment) on a dose of 40 mg/day 4 times daily. Neonates had a normal postnatal course. Postnatal propranolol was initiated in 2 neonates with respiratory failure when chylothoraces were refractory to standard management. Stabilization and improvement of their pleural effusion was observed by imaging at 29 and 13 days after initiation of propranolol. There were no significant maternal or neonatal complications from prenatal or postnatal propranolol use. Propranolol may be efficacious in treating severe fetal congenital chylothorax.

Fetal Tuberous Sclerosis: Sirolimus for the Treatment of Fetal rhabdomyoma

BACKGROUND

Sirolimus constitutes a safe and effective treatment for cardiac manifestations of tuberous sclerosis complex (TSC) in children but only four cases describing prenatal treatment of rhabdomyomas with mTOR inhibitors have been published.

CASE

In this case, sirolimus was initiated at 26 weeks´ gestation in a pregnant woman with TSC with a fetus with a large rabdomyoma conditioning severe arrythmia. There was a significant reduction in the tumor size with ongoing treatment and a partial reversion of the arrythmia.

CONCLUSION

m-TOR inhibitors can be considered for severe cases of fetal rhabdomyomas with poor prognosis given its potencial benefits.

Prenatal diagnosis and intervention improve developmental outcomes and epilepsy prognosis in children with tuberous sclerosis complex

AIM

To assess whether prenatal diagnosis and early intervention are beneficial for developmental outcomes and epilepsy prognosis in individuals with tuberous sclerosis complex (TSC).

METHOD

This retrospective study originated from a single-centre TSC-specific cohort. We enrolled 273 individuals (138 males, 145 females; 2 years-7 years 6 months, mean 4 years 5 months, SD 1 year 6 months) with definitive TSC who completed TSC1/TSC2 genetic testing and were followed up to 2 years of age. The benefits of early attention and intervention were assessed by comparing epilepsy and developmental outcomes between groups with or without a prenatal diagnosis and with or without presymptomatic preventive intervention.

RESULTS

The epilepsy occurrence rate was significantly lower in individuals diagnosed prenatally than in individuals diagnosed postnatally (p = 0.027). In individuals diagnosed prenatally, the epilepsy rate in the preventive intervention subgroup was significantly lower than that in the subgroup without preventive intervention (p = 0.008). Significant improvements in cognitive, language, and motor development were observed in individuals diagnosed prenatally compared to individuals diagnosed postnatally and in the preventive intervention subgroup compared to the subgroup without preventive intervention (p < 0.05).

INTERPRETATION

Based on this study, we cautiously speculate that early postpartum intervention may reduce the incidence of epilepsy and intractable epilepsy and improve developmental outcomes. Prophylactic intervention with sirolimus and vigabatrin may reduce the incidence of epilepsy. Larger prospective randomized controlled studies are required to support these findings.

WHAT THIS PAPER ADDS

Prenatal diagnosis and early intervention may improve developmental outcomes in children with tuberous sclerosis complex (TSC). Prophylactic intervention with sirolimus and vigabatrin may reduce the incidence of epilepsy. Cardiac and/or intracranial lesions combined with genetic testing can be used to diagnose TSC prenatally.

Advances in the Prenatal Management of Fetal Cardiac Disease

Advances in the field have improved the prenatal management of cardiovascular diseases over the past few decades; however, there remains considerable challenges in the approach towards patient selection as well as the applicability of available therapies. This review aims to discuss the current knowledge, outcomes and challenges for prenatal intervention for congenital heart disease.

Prenatal Sirolimus Treatment for Rhabdomyomas in Tuberous Sclerosis

BACKGROUND

In tuberous sclerosis, most cardiac rhabdomyomas regress spontaneously. In some cases, the tumors can cause life-threatening hemodynamic compromise requiring subsequent surgical resection. The mechanistic target of rapamycin inhibitors everolimus and sirolimus have shown to be effective treatments for multiple conditions. There are four reports of off-label treatment with transplacental sirolimus for fetal rhabdomyomas due to tuberous sclerosis complex. The optimal dosing regimen is unknown.

METHODS

We reviewed the medical records of all patients treated prenatally with sirolimus for rhabdomyomas. All fetuses had a clinical and molecular diagnosis of tuberous sclerosis complex (2012 Consensus Diagnostic Criteria, including a positive genetic test). Clinical history, mechanistic target of rapamycin inhibitor dosing and levels, outcome, and adverse events were reviewed after initiation of sirolimus treatment.

RESULTS

Three fetuses were treated with maternal sirolimus. Dosing regimens and subsequent trough levels differed from 1 mg/day to 6 mg/day and <1.0 ng/mL to 12.2 ng/mL. Cardiac rhabdomyomas gradually shrank in all patients. Growth restriction was noted in one patient. No severe adverse events occurred during the treatment period.

CONCLUSIONS

Maternal sirolimus appears to be a safe treatment option in prenatally detected rhabdomyomas with possible need for intervention. Follow-up visits with fetal ultrasound, echocardiography, and laboratory work should be performed weekly during the treatment period. The optimal dosing and trough level timepoints remain unclear. Based on our results, we recommend a sirolimus starting dose of at least 2 mg/m²/day, preferably 3-3.5 mg/m²/day to achieve a target trough level of 10-12 ng/mL.

Everolimus as a possible prenatal treatment of in utero diagnosed subependymal lesions in tuberous sclerosis complex: a case report

INTRODUCTION

The association between cardiac rhabdomyoma and intraventricular tumors and/or subcortical nodules is characteristic of tuberous sclerosis complex (TSC). Patients with TSC may have refractory seizures, autistic behavior, and cognitive decline.

CASE REPORT

The patient received the fetal diagnosis of TSC at the age of 19 weeks of gestations, where presented at prenatal ultrasound cardiac and brain tumors. Fetal MRI showed a lesion in the right and left lateral ventricles near the foramen of Monro associated with subependymal lesions along the entire ependyma of the lateral ventricles and several subcortical tubercles, and the fetal Doppler echocardiogram revealed three cardiac lesions. The fetus underwent intrauterine treatment with everolimus and presented regression and subsequent stabilization of the cardiac and brain lesions; additionally, the patient did not develop seizures or autism and presented good neuropsychomotor development.

CONCLUSION

It is the first evidence that mTOR inhibitors may help to prevent neurological complications associated with TSC.

Maternal sirolimus therapy and fetal growth restriction

Fetal growth restriction associated with continued maternal sirolimus therapy in pregnancy has not been reported. We hereby present a case of maternal sirolimus therapy resulting in fetal growth restriction and propose a multi-hit model. This hypothetic model is based on inhibition of mTOR signaling pathway and epigenetic modulation. This case report adds to the paucity of literature on continued monotherapeutic maternal sirolimus in pregnancy and its adverse fetal effects.

Sirolimus Can Increase the Disappearance Rate of Cardiac Rhabdomyomas Associated with Tuberous Sclerosis: A Prospective Cohort and Self-Controlled Case Series Study

OBJECTIVES

To investigate the efficacy and safety of sirolimus in the treatment of cardiac rhabdomyomas associated with tuberous sclerosis complex and the specific benefits in different subgroups.

STUDY DESIGN

The study was a prospective cohort and self-controlled case series study. Based on the prevalence of cardiac rhabdomyoma at different ages, we estimated the natural tumor disappearance rate. The subgroup analysis was done by Cox regression. Self-controlled case series method was used to assess the magnitude and duration of the drug effect. Adverse events were described.

RESULTS

A total of 217 patients were included in the cohort study. Tumor disappearance rate was higher in younger age groups (hazard ratio = 0.99, P = .027) and female patients (hazard ratio = 2.08, P = .015). The age-adjusted incidence ratio showed that the disappearance of rhabdomyomas between 3 and 6 months was more related to sirolimus. Adverse events were observed 60 times in 42 of 217 children, mainly stomatitis.

CONCLUSIONS

Sirolimus can increase the disappearance rate of cardiac rhabdomyoma in the tuberous sclerosis complex population. Efficacy varies by sex and age: female and younger patients have higher tumor disappearance rate. Sirolimus is well-tolerated.

Cardiac rhabdomyoma with hydrops fetalis: Prenatal management by abdominal drainage

OBJECTIVE

We described a case of fetal cardiac rhabdomyoma complicated by hydrops. And we discussed our approach during pregnancy.

CASE REPORT

A 23-year-old woman primigravida was referred at 29 weeks of gestation (WG) to prenatal unit for a large hyperechogenic intracardiac mass associated with fetal hydrops. An intrauterine peritoneo-amniotic shunt was placed. Complete regression of ascites and pericardial effusions were observed after 34 WG with drain in good position.

CONCLUSION

Cardiac rhabdomyoma is the most common prenatal cardiac tumor. These tumors are benign, asymptomatic and spontaneously regress after birth. However, in some cases, these tumors may cause severe obstructions on the fetal heart and need specific treatment.

Fetal therapy using rapamycin for a rapidly enlarging, obstructive, cervical lymphatic malformation: a case report

WHAT'S ALREADY KNOWN ABOUT THIS TOPIC?: Fetal lymphatic malformations (LMs) can be detected on prenatal ultrasound and until recently, therapeutic options were limited. Recently the mammalian target of rapamycin inhibitor rapamycin has emerged as a safe, effective therapy for children with LMs and multiple studies have demonstrated improved efficacy if started early. WHAT DOES THIS STUDY ADD?: We report the first in-utero therapy with rapamycin for a rapidly enlarging, obstructive, fetal cervical LM. Fetal therapy with rapamycin was safe and effective in managing this severe malformation, despite rapamycin being started only in the last 6.5 weeks of pregnancy. We speculate that had rapamycin been commenced earlier, the reduction in mass size might have been even greater.

Everolimus for severe arrhythmias in tuberous sclerosis complex related cardiac rhabdomyomas

Intracardiac rhabdomyoma is the most common primary cardiac tumor in children. Most cases are associated with tuberous sclerosis complex (TSC). Most of them are asymptomatic in the neonate and do not require treatment. However, some develop cardiovascular symptoms such as arrhythmias, heart failure, and ventricular inflow/outflow tract obstruction in the neonatal period with early death. Many of these tumors are not candidates for surgical resection and medical management is limited. Treatment with mammalian target of rapamycin (mTOR) inhibitor is currently approved for the management of central nervous tumors and angiomyolipoma in TSC. Two patients with malignant arrhythmias related to nonsurgical multiple rhabdomyomas associated with TSC who were successfully treated with an mTOR inhibitor were described. Everolimus therapy showed significant regression of rhabdomyomas with rapid improvement of arrhythmias and heart failure prior to tumor shrinkage.

Combination percutaneous and medical management of cardiac rhabdomyomas obstructing tricuspid valve inflow: Case report

BACKGROUND

Cardiac rhabdomyomas can be prenatally diagnosed in patients with tuberous sclerosis complex. Many neonates require no intervention in early life other than close monitoring for regression of tumor over the period of months to years. In rare instances, cardiac rhabdomyomas can result in obstruction to blood flow or decreased ventricular function.

CASE REPORT

We describe the case of a neonate who was prenatally diagnosed with multiple large cardiac rhabdomyomas, one of which caused clinically significant obstruction to prograde blood flow across the tricuspid valve in the newborn period. To address the disturbance to prograde pulmonary blood flow, the patient underwent successful ductal stent placement in the neonatal period. A troponin elevation was noted shortly after birth, but no evidence of coronary compression or involvement was demonstrated by coronary angiography. The patient has subsequently been treated with sirolimus over a period of three months, with noted regression in tumors and improvement in tricuspid valve inflow.

CONCLUSIONS

A brief review of the literature regarding the diagnosis, treatment, and management of neonatal patients with cardiac rhabdomyomas is presented. A combined percutaneous and medical management approach may be of benefit in future cases of rhabdomyomas causing obstruction to pulmonary blood flow.

A Multidisciplinary Approach in Prenatal Diagnosis of TSC With Cardiac Rhabdomyoma as the Initial Symptom

The long-term prognosis of a fetus with cardiac rhabdomyoma (CR) depends on the correlation with tuberous sclerosis complex (TSC). In recent years, the numerous variations of uncertain significance (VUS) of TSC genes produced by high-throughput sequencing have made counseling challenging, studies until now have tended to side-step the tricky topics. Here, we integrated detailed parental phenotype, echocardiography, neuro MRI, and genetic information to conduct a comprehensive evaluation of 61 CR fetuses. As a result, multiple CRs and cerebral lesions appeared in 90 and 80%, respectively of fetuses with pathogenic (P)/likely pathogenic (LP) TSC1/TSC2 variations. Overall, 85.7% of the live-born infants with P/LP presented with TSC-associated signs. While, 85.7% of VUS without nervous findings had good prognoses. Genetic evidence and cerebral MRI findings are the most sensitive index to assess long-term prognosis, which complement and confirm each other for a TSC diagnosis. In total, 68.9% of fetuses with CR could benefit from this multidisciplinary approach, which turned out to be potentially clinically actionable with precise clinical/genetic diagnosis or had a foreseeable outcome. Our practice provides a practical and feasible solution for perinatal management and prognostic guidance for fetuses with CR.

"The First Thousand Days" Define a Fetal/Neonatal Neurology Program

Gene-environment interactions begin at conception to influence maternal/placental/fetal triads, neonates, and children with short- and long-term effects on brain development. Life-long developmental neuroplasticity more likely results during critical/sensitive periods of brain maturation over these first 1,000 days. A fetal/neonatal program (FNNP) applying this perspective better identifies trimester-specific mechanisms affecting the maternal/placental/fetal (MPF) triad, expressed as brain malformations and destructive lesions. Maladaptive MPF triad interactions impair progenitor neuronal/glial populations within transient embryonic/fetal brain structures by processes such as maternal immune activation. Destructive fetal brain lesions later in pregnancy result from ischemic placental syndromes associated with the great obstetrical syndromes. Trimester-specific MPF triad diseases may negatively impact labor and delivery outcomes. Neonatal neurocritical care addresses the symptomatic minority who express the great neonatal neurological syndromes: encephalopathy, seizures, stroke, and encephalopathy of prematurity. The asymptomatic majority present with neurologic disorders before 2 years of age without prior detection. The developmental principle of ontogenetic adaptation helps guide the diagnostic process during the first 1,000 days to identify more phenotypes using systems-biology analyses. This strategy will foster innovative interdisciplinary diagnostic/therapeutic pathways, educational curricula, and research agenda among multiple FNNP. Effective early-life diagnostic/therapeutic programs will help reduce neurologic disease burden across the lifespan and successive generations.

Progression of Fetal Brain Lesions in Tuberous Sclerosis Complex

Tuberous sclerosis (TSC) is a multisystem autosomal dominant genetic disorder due to loss of function of TSC1/TSC2 resulting in increased mTOR (mammalian target of rapamycin) signaling. In the brain, TSC is characterized by the formation of specific lesions that include subependymal and white matter nodules and cortical tubers. Cells that constitute TSC lesions are mainly Giant cells and dysmorphic neurons and astrocytes, but normal cells also populate the tubers. Although considered as a developmental disorder, the histopathological features of brain lesions have been described in only a limited number of fetal cases, providing little information on how these lesions develop. In this report we characterized the development of TSC lesions in 14 fetal brains ranging from 19 gestational weeks (GW) to term and 2 postnatal cases. The study focused on the telencephalon at the level of the caudothalamic notch. Our data indicate that subcortical lesions, forming within and at the vicinity of germinative zones, are the first alterations (already detected in 19GW brains), characterized by the presence of numerous dysmorphic astrocytes and Giant, balloon-like, cells. Our data show that cortical tuber formation is a long process that initiates with the presence of dysmorphic astrocytes (by 19–21GW), progress with the apparition of Giant cells (by 24GW) and mature with the appearance of dysmorphic neurons by the end of gestation (by 36GW). Furthermore, the typical tuberal aspect of cortical lesions is only reached when bundles of neurofilament positive extensions delineate the bottom of the cortical lesion (by 36GW). In addition, our study reveals the presence of Giant cells and dysmorphic neurons immunopositive for interneuron markers such as calbindin and parvalbumin, suggesting that TSC lesions would be mosaic lesions generated from different classes of progenitors.

Phosphoproteomic Analysis of Neonatal Regenerative Myocardium Revealed Important Roles of Checkpoint Kinase 1 via Activating Mammalian Target of Rapamycin C1/Ribosomal Protein S6 Kinase b-1 Pathway

BACKGROUND

In mammals, regenerative therapy after myocardial infarction is hampered by the limited regenerative capacity of adult heart, whereas a transient regenerative capacity is maintained in the neonatal heart. Systemic phosphorylation signaling analysis on ischemic neonatal myocardium might be helpful to identify key pathways involved in heart regeneration. Our aim was to define the kinase-substrate network in ischemic neonatal myocardium and to identify key pathways involved in heart regeneration after ischemic insult.

METHODS

Quantitative phosphoproteomics profiling was performed on infarct border zone of neonatal myocardium, and kinase-substrate network analysis revealed 11 kinases with enriched substrates and upregulated phosphorylation levels, including checkpoint kinase 1 (CHK1) kinase. The effect of CHK1 on cardiac regeneration was tested on Institute of Cancer Research CD1 neonatal and adult mice that underwent apical resection or myocardial infarction.

RESULTS

In vitro, CHK1 overexpression promoted whereas CHK1 knockdown blunted cardiomyocyte proliferation. In vivo, inhibition of CHK1 hindered myocardial regeneration on resection border zone in neonatal mice. In adult myocardial infarction mice, CHK1 overexpression on infarct border zone upregulated mammalian target of rapamycin C1/ribosomal protein S6 kinase b-1 pathway, promoted cardiomyocyte proliferation, and improved cardiac function. Inhibiting mammalian target of rapamycin activity by rapamycin blunted the neonatal cardiomyocyte proliferation induced by CHK1 overexpression in vitro.

CONCLUSIONS

Our study indicates that phosphoproteome of neonatal regenerative myocardium could help identify important signaling pathways involved in myocardial regeneration. CHK1 is found to be a key signaling responsible for neonatal regeneration. Myocardial overexpression of CHK1 could improve cardiac regeneration in adult hearts by activating the mammalian target of rapamycin C1/ribosomal protein S6 kinase b-1 pathway. Thus, CHK1 might serve as a potential novel target in myocardial repair after myocardial infarction.

Fetal cardiac rhabdomyomas treated with maternal sirolimus

OBJECTIVE

To review the pathophysiology of rhabdomyomas and the emerging option of prenatal treatment of fetal cardiac rhabdomyomas.

METHODS

We present a case of fetal rhabdomyomas causing significant hemodynamic compromise that received in utero treatment of maternal sirolimus. Genetic amniocentesis confirmed a TSC2 mutation. A treatment program was initiated with a 10-mg loading dose titrated to a goal maternal trough of 10 to 15 ng/dL. In order to follow fetal cardiac function, a sophisticated method of speckle tracking echocardiography was used before and after treatment. Obstetric ultrasound was used to monitor fetal growth, and clinical surveillance, echocardiography, and brain MRI were used to monitor postnatal growth and development through 6 months of neonatal life.

RESULTS

Sirolimus was initiated from 28 to 36 weeks of gestation with improvement of cardiac status. During this period, intrauterine growth restriction developed. Postnatally, the infant has had stable rhabdomyomas and cardiac function without reinitiating sirolimus. Brain MRI demonstrated scattered cortical tubers and subependymal nodules, and the infant has not had seizure-like activity. At 6 months of age, the infant has achieved appropriate developmental milestones.

CONCLUSION

In counseling cases of prenatal onset large obstructing rhabdomyomas and cardiac compromise, in utero sirolimus treatment can be considered.

A Dramatic Response to Sirolimus Therapy in a Premature Infant With Massive Cardiac Rhabdomyoma

Cardiac rhabdomyomas in neonates may cause significant cardiac risk. Recently, sirolimus has been used to treat these lesions. The dose, duration, and monitoring for therapy are unknown. A case of sirolimus use in a premature neonate is presented. No significant adverse effects were seen. Review of published cases is included. (Level of Difficulty: Advanced.)

Fetal cardiac abnormalities: Genetic etiologies to be considered

Congenital heart diseases are a common prenatal finding. The prenatal identification of an associated genetic syndrome or a major extracardiac anomaly helps to understand the etiopathogenic diagnosis. Besides, it also assesses the prognosis, management, and familial recurrence risk while strongly influences parental decision to choose termination of pregnancy or postnatal care. This review article describes the most common genetic diagnoses associated with a prenatal finding of a congenital heart disease and a suggested diagnostic process.

Clinical and genetic description of patients with prenatally identified cardiac tumors

OBJECTIVE

Rhabdomyomas are the most common type of prenatal cardiac tumors. When isolated, 50% to 70% are related to the tuberous sclerosis complex (TSC). The aim of this study was to reinforce the importance of additional clinical data in patients with prenatal heart tumors.

METHODS

From 2010 to 2017, 10 prenatally detected cardiac tumors were referred to the Genetics Department, and a complete family history was taken. Postnatal echocardiographic and full clinical evaluation were completed. Next generation sequencing (NGS) of the TSC1 and TSC2 genes was performed.

RESULTS

The 10 cases were postnatally confirmed as rhabdomyomas. Four de novo and four family cases were detected, and only one patient was previously aware of the TSC diagnosis. Molecular analysis by NGS was performed in four patients with three TSC2 mutations, two of which were previously reported and one not.

DISCUSSION

Prenatal cardiac tumors are associated with TSC in 60% of cases. Prenatal diagnosis of cardiac tumors permits a further analysis of family members using the fetus as a clue for familial disease diagnosis.

Sirolimus therapy for fetal cardiac rhabdomyoma in a pregnant woman with tuberous sclerosis

Rhabdomyoma is the most common fetal cardiac tumor, and its development is related to tuberous sclerosis. Fetal cardiac rhabdomyomas often spontaneously regress in utero or after birth, but large tumors can cause hemodynamic obstruction. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, has been used as an immunosuppressant after organ transplantation. The mTOR inhibitors are well-known to have anti-tumor activity, and they have been used for the treatment of patients with tuberous sclerosis. In the current case, fetal cardiac rhabdomyoma was completely resolved in utero during oral sirolimus treatment in the mother with tuberous sclerosis. This case shows that oral sirolimus therapy in pregnancy may be a treatment for multiple or large fetal cardiac rhabdomyomas.

Management of fetal tumors

In this review article, we discuss the most common fetal tumors, their prenatal management, and outcomes. Overall, the most important outcome predictors are tumor histology, size, vascularity, and location. Very large lesions, lesions causing cardiac failure, and hydrops and lesions obstructing the fetal airway have the poorest outcome, as they may cause fetal death or complications at the time of delivery. Fetal therapy has been developed to improve outcomes for the most severe cases and can consist of transplacental therapy (sirolimus for rhabdomyomas or steroids for hemangiomas and microcystic lung lesions) or surgical intervention (shunting of cystic masses, tumor ablation, occlusion of blood flow or airway exploration, and protection). Given the rarity of fetal tumors, patients should be referred to expert centers where care can be optimized and individualized to allow the best possible outcomes.