Congenital malformations among liveborn infants with trisomies 18 and 13

The American Association for Thoracic Surgery (AATS) 2023 Expert Consensus Document: Recommendation for the care of children with trisomy 13 or trisomy 18 and a congenital heart defect

OBJECTIVES

Recommendations for surgical repair of a congenital heart defect in children with trisomy 13 or trisomy 18 remain controversial, are subject to biases, and are largely unsupported with limited empirical data. This has created significant distrust and uncertainty among parents and could potentially lead to suboptimal care for patients. A working group, representing several clinical specialties involved with the care of these children, developed recommendations to assist in the decision-making process for congenital heart defect care in this population. The goal of these recommendations is to provide families and their health care teams with a framework for clinical decision making based on the literature and expert opinions.

METHODS

This project was performed under the auspices of the AATS Congenital Heart Surgery Evidence-Based Medicine Taskforce. A Patient/Population, Intervention, Comparison/Control, Outcome process was used to generate preliminary statements and recommendations to address various aspects related to cardiac surgery in children with trisomy 13 or trisomy 18. Delphi methodology was then used iteratively to generate consensus among the group using a structured communication process.

RESULTS

Nine recommendations were developed from a set of initial statements that arose from the Patient/Population, Intervention, Comparison/Control, Outcome process methodology following the groups' review of more than 500 articles. These recommendations were adjudicated by this group of experts using a modified Delphi process in a reproducible fashion and make up the current publication. The Class (strength) of recommendations was usually Class IIa (moderate benefit), and the overall level (quality) of evidence was level C-limited data.

CONCLUSIONS

This is the first set of recommendations collated by an expert multidisciplinary group to address specific issues around indications for surgical intervention in children with trisomy 13 or trisomy 18 with congenital heart defect. Based on our analysis of recent data, we recommend that decisions should not be based solely on the presence of trisomy but, instead, should be made on a case-by-case basis, considering both the severity of the baby's heart disease as well as the presence of other anomalies. These recommendations offer a framework to assist parents and clinicians in surgical decision making for children who have trisomy 13 or trisomy 18 with congenital heart defect.

Treatment courses and outcomes of oesophageal atresia in patients with trisomy 18: a case series of 271 patients from a nationwide database in Japan

OBJECTIVE

To describe characteristics, treatments and clinical outcomes of patients with trisomy 18 and oesophageal atresia, using a nationwide database in Japan.

DESIGN

Descriptive study using a retrospective cohort.

SETTING

A nationwide inpatient database including 90% of hospitals with neonatal intensive care units in Japan.

PATIENTS

Patients hospitalised within a day after birth for both oesophageal atresia and trisomy 18 between July 2010 and March 2020.

INTERVENTIONS

Radical surgery for oesophageal atresia.

MAIN OUTCOME MEASURES

Characteristics, treatment course and outcomes.

RESULTS

Among 271 patients with both oesophageal atresia and trisomy 18, 70 patients underwent radical surgery for oesophageal atresia. Patients who underwent radical surgery were less likely to have severe cardiac anomalies (17% vs 32%; p=0.020), but more likely to undergo cardiac surgery (21% vs 9.5%; p=0.012) than those who did not. The overall in-hospital mortality was lower (54% vs 79%; p<0.001) and the median age at death was higher (210 days vs 39 days; p<0.001) in patients who underwent radical surgery than the others. Postoperative mortality within 30 days after radical surgery was 5.7%. Patients who underwent radical surgery were likely to be discharged to home (50% vs 18%; p<0.001), whereas the age at home discharge (median 314 days vs 216 days; p=0.19) and the requirement for each home treatment did not differ significantly by radical surgery.

CONCLUSION

This study provides information that will aid the clinical decision-making process for patients with oesophageal atresia and trisomy 18. Radical surgery may be a safe and feasible treatment option.

Contemporary Trends in Cardiac Surgical Care for Trisomy 13 and 18 Patients Admitted to Hospitals in the United States

OBJECTIVE

To assess rates of cardiac surgery and the clinical and demographic features that influence surgical vs nonsurgical treatment of congenital heart disease (CHD) in patients with trisomy 13 (T13) and trisomy 18 (T18) in the United States.

STUDY DESIGN

A retrospective study was performed using the Pediatric Health Information System. All hospital admissions of children (<18 years of age) with T13 and T18 in the United States were identified from 2003 through 2022. International Classifications of Disease (ICD) codes were used to identify presence of CHD, extracardiac comorbidities/malformations, and performance of cardiac surgery.

RESULTS

Seven thousand one hundred thirteen patients were identified. CHD was present in 62% (1625/2610) of patients with T13 and 73% (3288/4503) of patients with T18. The most common CHD morphologies were isolated atrial/ventricular septal defects (T13 40%, T18 42%) and aortic hypoplasia/coarctation (T13 21%, T18 23%). Single-ventricle morphologies comprised 6% (100/1625) of the T13 and 5% (167/3288) of the T18 CHD cohorts. Surgery was performed in 12% of patients with T13 plus CHD and 17% of patients with T18 plus CHD. For all cardiac diagnoses, <50% of patients received surgery. Nonsurgical patients were more likely to be born prematurely (P < .05 for T13 and T18). The number of extracardiac comorbidities was similar between surgical/nonsurgical patients with T13 (median 2 vs 2, P = .215) and greater in surgical vs nonsurgical patients with T18 (median 3 vs 2, P < .001). Hospital mortality was <10% for both surgical cohorts.

CONCLUSIONS

Patients with T13 or T18 and CHD receive surgical palliation, but at a low prevalence (≤17%) nationally. Given operative mortality <10%, opportunity exists perhaps for quality improvement in the performance of cardiac surgery for these vulnerable patient populations.

Airway findings in trisomy 13 and trisomy 18: A 10-year retrospective review

BACKGROUND AND OBJECTIVES

Trisomy 18 and trisomy 13 are the most common autosomal trisomies following trisomy 21, with overall incidence rising. Both diagnoses are characterized by multisystem involvement and were previously thought to be incompatible with life. New data suggest that prolonged survival is possible, and thus many families are opting for more aggressive medical interventions. This study aims to describe airway findings in trisomy 18 and trisomy 13, as these have not been comprehensively studied and can impact medical decision-making. We hypothesize that most children with trisomy 18 and trisomy 13 will have abnormal findings on airway endoscopy.

METHODS

This a 10-year retrospective analysis of children with trisomy 13 or trisomy 18 who underwent endoscopic airway evaluation at a single center between 2011 and 2021. A total of 31 patients were evaluated.

RESULTS

Thirty-one patients were included and underwent flexible bronchoscopy by a pediatric pulmonologist, often in conjunction with rigid bronchoscopy performed by pediatric otolaryngology. Findings were typically complimentary. All patients had at least one clinically significant finding on evaluation, and most patients had both upper and lower airway, as well as static and dynamic airway findings. The most common airway findings in children with trisomy 13 and 18 include tracheomalacia, bronchomalacia, laryngomalacia, hypopharyngeal collapse, glossoptosis, and bronchial compression.

CONCLUSION

These findings can have significant implications for clinical care, and thus knowledge of trends has the potential to improve counseling on expected clinical course, presurgical planning, and informed consent before interventions.

The common trisomy syndromes, their cardiac implications, and ethical considerations in care

PURPOSE OF REVIEW

To review the incidence of congenital heart disease in the trisomies, highlight the history of cardiac surgery in trisomy 21 comparing it to the increase in cardiac surgery in trisomies 13 and 18, discuss ethical issues specific to trisomies 13 and 18, and suggest a pathway of shared decision-making in the management of congenital heart disease in trisomy 13 and 18, specifically congenital heart surgery.

RECENT FINDINGS

Congenital heart disease is prevalent in the trisomies and the management of these defects, especially surgical intervention, has changed. In the late 20th century, survival after cardiac surgery in trisomy 21 vastly improved, significantly decreasing morbidity and mortality secondary to pulmonary hypertension. Similarly, procedures and surgeries have been performed with increasing frequency in trisomy 13 and 18 patients and concomitantly, survival in this patient population is increasing. Yet across the United States, the willingness to perform cardiac surgery in trisomy 13 and 18 is variable, and there is ethical controversy about the correct action to take. To address this concern, a shared decision-making approach with an informed parent(s) is advised.

SUMMARY

As the care and management of congenital heart disease changed in trisomy 21, so too it has with trisomy 13 and 18. Physicians and parents should develop goal-directed treatment plans balancing the risk versus benefit and consider cardiac surgical repair if feasible and beneficial.

Recent Advances in Pediatric Pulmonary Hypertension: Implications for Diagnosis and Treatment

PURPOSE

Pediatric pulmonary hypertension (PH) is a condition characterized by elevated pulmonary arterial pressure, which has the potential to be life-limiting. The etiology of pediatric PH varies. When compared with adult cohorts, the etiology is often multifactorial, with contributions from prenatal, genetic, and developmental factors. This review aims to provide an up-to-date overview of the causes and classification of pediatric PH, describe current therapeutics in pediatric PH, and discuss upcoming and necessary research in pediatric PH.

METHODS

PubMed was searched for articles relating to pediatric pulmonary hypertension, with a particular focus on articles published within the past 10 years. Literature was reviewed for pertinent areas related to this topic.

FINDINGS

The evaluation and approach to pediatric PH are unique when compared with that of adults, in large part because of the different, often multifactorial, causes of the disease in children. Collaborative registry studies have found that the most common disease causes include developmental lung disease and subsets of pulmonary arterial hypertension, which includes genetic variants and PH associated with congenital heart disease. Treatment with PH-targeted therapies in pediatrics is often guided by extrapolation of adult data, small clinical studies in pediatrics, and/or expert consensus opinion. We review diagnostic considerations and treatment in some of the more common pediatric subpopulations of patients with PH, including developmental lung diseases, congenital heart disease, and trisomy 21.

IMPLICATIONS

The care of pediatric patients with PH requires consideration of unique pediatric-specific factors. With significant variability in disease etiology, ongoing efforts are needed to optimize treatment strategies based on disease phenotype and guide evidence-based practices.

Focus on the frontier issue: progress in noninvasive prenatal screening for fetal trisomy from clinical perspectives

The discovery of cell-free fetal DNA (cffDNA) in maternal blood and the rapid development of massively parallel sequencing have revolutionized prenatal testing from invasive to noninvasive. Noninvasive prenatal screening (NIPS) based on cffDNA enables the detection of fetal trisomy through sequencing, comparison, and bioassays. Its accuracy is better than that of traditional screening methods, and it is the most advanced clinical application of high-throughput sequencing technologies. However, the existing sequencing methods are limited by high costs and complex sequencing procedures. These limitations restrict the availability of NIPS for pregnant women. Many amplification methods have been developed to overcome the limitations of sequencing methods. The rapid development of non-sequencing methods has not been accompanied by reviews to summarize them. In this review, we initially describe the detection principles for sequencing-based NIPS. We summarize the rapidly evolving amplification technologies, focusing on the need to reduce costs and simplify the procedures. To ensure that the testing systems are feasible and that the testing processes are reliable, we expand our vision to the clinic. We evaluate the clinical validity of NIPS in terms of sensitivity, specificity, and positive predictive value. Finally, we summarize the application guidelines and discuss the corresponding quality control methods for NIPS. In addition to cffDNA, extracellular vesicle DNA, RNA, protein/peptide, and fetal cells can also be detected as biomarkers of NIPS. With the development of prenatal testing, NIPS has become increasingly important. Notably, NIPS is a screening test instead of a diagnostic test. The testing methods and procedures used in the NIPS process require standardization.

Survival rates and outcomes of pregnancies with prenatal diagnosis of trisomy 18: A 16-year experience from a public hospital in South Africa

OBJECTIVE

Many studies, largely from high-income countries (HIC), have reported outcomes in babies with trisomy 18 (T18), with a paucity of data from Africa. Knowledge of outcomes is important in counselling women prenatally diagnosed with T18. We aimed to review all prenatally diagnosed cases of T18 between January 2006 and December 2021.

METHOD

Demographic data, diagnosis, gestation and outcome data were obtained from the Astraia® database and patient files.

RESULTS

We included 88 pregnant women of whom 46 terminated their pregnancies (30 beyond 24 weeks' gestation). Three underwent foeticides, one had a caesarean section for maternal obstetric reasons and 26 underwent inductions of labour without foetal monitoring. Four neonates were live born but none lived >8 h. In those who continued their pregnancies, the mean gestation at delivery was 34.8 weeks, 14 (33%) were live births and only 5 survived for >24 h with none surviving to 1 year of life.

CONCLUSION

In our cohort, infants with T18 had lower live birth rates and shorter survival than in the current literature from HIC. This may be due to the implementation of non-aggressive intrapartum care and comfort care for the neonates. This has implications for counselling in our setting.

Young adolescent with trisomy 13

A young adolescent girl with trisomy 13 was admitted twice to the paediatric department: the first time because of haematocolpos due to uterus didelphys and unilateral transverse vaginal septum, and the second time because of heart failure due to ruptured sinus of Valsalva aneurysm. As a consequence of the historical early high mortality rate in trisomy 13, we are not aware of known complications in older patients. With better survival nowadays through childhood, we advise structural ultrasonographic cardiac and female genital screening in trisomy 13 patients reaching adolescent age.

Outcome after Prenatal Diagnosis of Trisomy 13, 18, and 21 in Fetuses with Congenital Heart Disease

Fetal congenital heart disease (CHD) is often associated with chromosomal abnormalities. Our primary aim was to assess stillbirth and neonatal mortality rates for pregnancies complicated by trisomies 13, 18, and 21 in the presence of CHD, from a single tertiary referral center during 2000-2020 in a retrospective cohort study. The secondary aims were to investigate maternal morbidity in these pregnancies, and to study the gestational or neonatal age when mortality occurred. Inclusion criteria were the prenatal diagnosis of at least one structural CHD, together with prenatally diagnosed fetal trisomy 13, 18, or 21. One-hundred and sixty patients with fetal trisomy 13 (14.4%), fetal trisomy 18 (28.8%), and fetal trisomy 21 (56.9%) were evaluated. In total, 98 (61.3%) families opted for the termination of pregnancy (TOP). Of the remaining 62 (38.8%) pregnancies, 16 (25.8%) resulted in intrauterine fetal death/death during delivery. Ten out of twenty-one (47.6%) infants with trisomy 13 or 18 were born alive. The livebirth rate was 87.8% (36/41) for infants with trisomy 21. Early neonatal death was observed in nine (19.6%) infants. Thirty-one (86.1%) infants with trisomy 21 survived the first year of life. These data may be helpful for counseling affected parents when the decision to terminate or continue the pregnancy should be considered.

Future Perspectives in Oxidative Stress in Trisomy 13 and 18 Evaluation

Autosomal aneuploidies are the most frequently occurring congenital abnormalities and are related to many metabolic disorders, hormonal dysfunctions, neurotransmitter abnormalities, and intellectual disabilities. Trisomies are generated by an error of chromosomal segregation during cell division. Accumulating evidence has shown that deregulated gene expression resulting from the triplication of chromosomes 13 and 18 is associated with many disturbed cellular processes. Moreover, a disturbed oxidative stress status may be implicated in the occurrence of fetal malformations. Therefore, a literature review was undertaken to provide novel insights into the evaluation of trisomy 13 (T13) and 18 (T18) pathogeneses, with a particular concern on the oxidative stress. Corresponding to the limited literature data focused on factors leading to T13 and T18 phenotype occurrence, the importance of oxidative stress evaluation in T13 and T18 could enable the determination of subsequent disturbed metabolic pathways, highlighting the related role of mitochondrial dysfunction or epigenetics. This review illustrates up-to-date T13 and T18 research and discusses the strengths, limitations, and possible directions for future studies. The progressive unification of trisomy-related research protocols might provide potential medical targets in the future along with the implementation of the foundation of modern prenatal medicine.

Consanguinity and Congenital Heart Disease Susceptibility: Insights into Rare Genetic Variations in Saudi Arabia

Congenital heart disease (CHD) encompasses a wide range of structural defects of the heart and, in many cases, the factors that predispose an individual to disease are not well understood, highlighting the remarkable complexity of CHD etiology. Evidence of familial aggregation of CHD has been demonstrated in different communities and for different cardiac lesions. Consanguinity, particularly among first cousins, is an added risk factor for these families, particularly in societies where it is considered a common cultural practice, as confirmed in previous studies conducted in Saudi Arabia and other countries. Through comprehensive genetic testing of affected families, we have been able to better understand the genetic basis of the various cardiac lesions and to delineate the molecular mechanisms involved in cardiac morphogenesis. In this review, we discuss the epidemiology and genetics of CHD in consanguineous populations focusing on Saudi Arabia as an extensive study model to address current advances and challenges in the clinical genetic diagnosis and prevention of CHD.

Trisomy 18 Trends over the Last 20 Years

OBJECTIVE

To evaluate the trends in hospitalizations for children with trisomy 18 over time and to determine the rate of invasive procedures on these children, using a large inpatient database.

STUDY DESIGN

A retrospective analysis using the Kids' Inpatient Database from 1997 to 2016 was performed for trisomy 18. We evaluated survival to discharge as well as the presence of pulmonary, skeletal, neurologic, gastrointestinal, renal, and hematologic/bleeding problems. We also searched for the following interventions, if performed: gastrostomy tube placement, tracheostomy, or cardiac procedure.

RESULTS

Over this period 10 151 admissions occurred in children with a diagnosis of trisomy 18. Between 1997 and 2016, the number of children admitted annually with trisomy 18 increased 74% from 1036 to 1798. The proportion of patients born prematurely remained stable at 14%-16% throughout the study. Gastrostomy tube placement increased 12-fold during the study period, tracheostomy increased 11-fold, and cardiac intervention increased 5-fold. The overall mortality rate decreased in those with trisomy 18 from 32% in 1997 to 21% in 2016.

CONCLUSIONS

We highlight a decreased inpatient mortality rate during the study period. The number of children undergoing interventions such as gastrostomy tube and tracheostomy increased, as did the number of children undergoing cardiac intervention. Although the number of procedures has increased with the mortality rate decreasing, it is unclear at present whether the 2 are related.

Genetic and epigenetic mechanisms in the development of congenital heart diseases

Congenital heart disease (CHD) is the most common of congenital cardiovascular malformations associated with birth defects, and it results in significant morbidity and mortality worldwide. The classification of CHD is still elusive owing to the complex pathogenesis of CHD. Advances in molecular medicine have revealed the genetic basis of some heart anomalies. Genes associated with CHD might be modulated by various epigenetic factors. Thus, the genetic and epigenetic factors are gradually accepted as important triggers in the pathogenesis of CHD. However, few literatures have comprehensively elaborated the genetic and epigenetic mechanisms of CHD. This review focuses on the etiology of CHD from genetics and epigenetics to discuss the role of these factors in the development of CHD. The interactions between genetic and epigenetic in the pathogenesis of CHD are also elaborated. Chromosome abnormalities and gene mutations in genetics, and DNA methylations, histone modifications and on-coding RNAs in epigenetics are summarized in detail. We hope the summative knowledge of these etiologies may be useful for improved diagnosis and further elucidation of CHD so that morbidity and mortality of children with CHD can be reduced in the near future.

Patterns of congenital anomalies among individuals with trisomy 13 in Texas

Few population-based studies have analyzed patterns of co-occurring birth defects among those with trisomy 13. We evaluated the frequency of all possible combinations of any one, two, three, or four additional co-occurring birth defects among 736 individuals with trisomy 13 using data from the Texas Birth Defects Registry for deliveries during 1999-2014. We calculated the observed-to-expected ratio for each combination, adjusting for the known tendency for birth defects to cluster non-specifically. To address potential ascertainment differences among live births and non-live births, we repeated analyses specifically among live births. The combination of defects with the largest observed-to-expected ratio was microcephalus, reduction deformities of brain (e.g., holoprosencephaly), anomalies of nose, and polydactyly. As expected, most of the highest 30 observed-to-expected ratios involved combinations with documented features of trisomy 13, including defects of the scalp (e.g., aplasia cutis) and heart. Results were similar among sensitivity analyses restricted to live births. Our findings may help further delineate the phenotypic spectrum for trisomy 13 and may inform future research related to improving screening and counseling for the condition.

Surveillance guidelines for children with trisomy 13

Trisomy 13 is one of the three most common aneuploidy syndromes in live-born infants. It is associated with mortality rates as high as 90% within the first year of life, in large part, due to the high prevalence of severe congenital abnormalities that increase mortality and morbidity. However, life-saving and life-prolonging medical interventions are being performed at a higher rate for these infants, resulting in increased rates of survival. Although cardiac complications have been well described in infants with trisomy 13, these patients also experience other complications such as respiratory, neurological, genitourinary, abdominal, otolaryngologic, and orthopedic complications that can impact their quality of life. The goal of this review is to present a comprehensive description of complications in children with trisomy 13 to aid in the development of monitoring and treatment guidelines for the increasing number of providers who will be caring for these patients throughout their lives. Where the evidence is available, this review presents screening recommendations to allow for more rapid detection and documentation of these complications.

Surveillance guidelines for children with trisomy 18

Trisomy 18 is the second most common aneuploidy syndromes in live born infants. It is associated with high mortality rates, estimated to be 75%-95% in the first year of life, as well as significant morbidity in survivors. The low survival is largely due to the high prevalence of severe congenital anomalies in infants with this diagnosis. However, interventions to repair or palliate those life-threatening anomalies are being performed at a higher rate for these infants, resulting in increased rates of survival beyond the first year of life. While it is well documented that trisomy 18 is associated with several cardiac malformations, these patients also have respiratory, neurological, neoplastic, genitourinary, abdominal, otolaryngologic, and orthopedic complications that can impact their quality of life. The goal of this review is to present a comprehensive description of complications in children with trisomy 18 to aid in the development of monitoring and treatment guidelines for the increasing number of providers who will be caring for these patients throughout their lives. Where the evidence is available, this review presents screening recommendations to allow for more rapid detection and documentation of these complications.

Cardiac Surgery in Trisomy 13 and 18: A Guide to Clinical Decision-Making

There has been substantial controversy regarding treatment of congenital heart defects in infants with trisomies 13 and 18. Most reports have focused on surgical outcomes versus expectant treatment, and rarely there has been an effort to consolidate existing evidence into a more coherent way to help clinicians with decision-making and counseling families. An extensive review of the existing literature on cardiac surgery in patients with these trisomies was conducted from 2004 to 2020. The effects of preoperative and perioperative factors on in-hospital and long-term mortality were analyzed, as well as possible predictors for postoperative chronic care needs such as tracheostomy and gastrostomy. Patients with minimal or no preoperative pulmonary hypertension and mechanical ventilation undergoing corrective surgery at a weight greater than 2.5 kg suffer from lower postoperative mortality. Infants with lower-complexity cardiac defects are likely to benefit the most from surgery, although their expected mortality is higher than that of infants without trisomy. Omphalocele confers an increased mortality risk regardless of cardiac surgery. Gastrointestinal comorbidities increased the risk of gastrostomy tube placement, while those with prolonged mechanical ventilation and respiratory comorbidities are more likely to require tracheostomy. Cardiac surgery is feasible in children with trisomies 13 and 18 and can provide improved long-term results. However, this is a clinically complex population, and both physicians and caretakers should be aware of the long-term challenges these patients face following surgery when discussing treatment options.

Congenital heart diseases: genetics, non-inherited risk factors, and signaling pathways

Background

Congenital heart diseases (CHDs) are the most common congenital anomalies with an estimated prevalence of 8 in 1000 live births. CHDs occur as a result of abnormal embryogenesis of the heart. Congenital heart diseases are associated with significant mortality and morbidity. The damage of the heart is irreversible due to a lack of regeneration potential, and usually, the patients may require surgical intervention. Studying the developmental biology of the heart is essential not only in understanding the mechanisms and pathogenesis of congenital heart diseases but also in providing us with insight towards developing new preventive and treatment methods.

Main body

The etiology of congenital heart diseases is still elusive. Both genetic and environmental factors have been implicated to play a role in the pathogenesis of the diseases. Recently, cardiac transcription factors, cardiac-specific genes, and signaling pathways, which are responsible for early cardiac morphogenesis have been extensively studied in both human and animal experiments but leave much to be desired. The discovery of novel genetic methods such as next generation sequencing and chromosomal microarrays have led to further study the genes, non-coding RNAs and subtle chromosomal changes, elucidating their implications to the etiology of congenital heart diseases. Studies have also implicated non-hereditary risk factors such as rubella infection, teratogens, maternal age, diabetes mellitus, and abnormal hemodynamics in causing CHDs.

These etiological factors raise questions on multifactorial etiology of CHDs. It is therefore important to endeavor in research based on finding the causes of CHDs. Finding causative factors will enable us to plan intervention strategies and mitigate the consequences associated with CHDs. This review, therefore, puts forward the genetic and non-genetic causes of congenital heart diseases. Besides, it discusses crucial signaling pathways which are involved in early cardiac morphogenesis. Consequently, we aim to consolidate our knowledge on multifactorial causes of CHDs so as to pave a way for further research regarding CHDs.

Conclusion

The multifactorial etiology of congenital heart diseases gives us a challenge to explicitly establishing specific causative factors and therefore plan intervention strategies. More well-designed studies and the use of novel genetic technologies could be the way through the discovery of etiological factors implicated in the pathogenesis of congenital heart diseases.

Genetic Contribution to Congenital Heart Disease (CHD)

Congenital heart defects (CHD) are the most common congenital problems in neonates. The basis for CHD is multifactorial, involving genetic and environmental components. The elucidation of genetic components remains difficult because it is a genetically heterogeneous disease. Currently, the major identified genetic causes include chromosomal abnormalities, large subchromosomal deletions/duplications, and point mutations. However, much more remains to be unraveled. An important insight from the research on the genetics of CHD is that any change at the genetic level that alters the dosage of genes required in any process during heart development results in a developmental defect. The use of conventional gene identification (linkage analysis and direct targeted sequencing) methods followed by the rapid advancements in high-throughput technologies (copy number variant platforms, SNP arrays, and next-generation sequencing) has identified an extensive list of genetic causes. However, the most common presentation of CHD is in the form of sporadic cases. Therefore, it is important to identify their underlying genetic cause. In this review, we revisit the causal genetic factors of CHD and discuss the clinical implications of research in the field.

The association of Trisomy 13 and 18 and hospital discharge outcomes among neonates in California: A retrospective cohort study

BACKGROUND

Despite Trisomy 13 and 18 being among the most fatal congenital anomalies, limited information exists about resource utilization and factors associated with length of stay (LOS) and total hospital charges (THC) for these anomalies.

METHODS

We studied data sets of the patient discharge data set from the California Office of Statewide Health Planning and Development from 2006 to 2010, to determine differences in resource utilization for survivors and non-survivors and identify the predictors of LOS and total hospital charges. Descriptive statistics were assessed for demographic and clinical characteristics. General linear regression models were used to identify predictors of LOS and THC.

RESULTS

Seventy-six Trisomy 13 and 115 Trisomy 18 patients were identified, for whom inpatient mortality was 27.6% and 20.9%, respectively. In patients with Trisomy 13, after adjusting for gender, ethnicity, advanced directive (DNR), insurance and co-morbidities on multivariate analysis, the provision of more than 96 h of mechanical ventilation was associated with significantly increased LOS (standard error, SE) by 18.0 ± 5.3 days and THC (SE) by $399,000 ± $85,000. In terms of insurance type, patients with private coverage had 10.8 ± 4.9 days more than patients with Medicaid. In patients with Trisomy 18, on multivariate analysis, after adjusting for gender, ethnicity, DNR, insurance and co-morbidities, more than 96 h of mechanical ventilation was associated with increased LOS (SE) by 36.8 ± 6.8 days and THC (SE) by $365,000 ± $59,000.

CONCLUSION

Understanding predictors that are associated with longer LOS and higher THC may be associated in hospital resource allocation for this vulnerable population of infants.

Outcome of isolated fetal talipes: A systematic review and meta-analysis

INTRODUCTION

The aim of this systematic review was to explore the outcome of fetuses with a prenatal diagnosis of isolated talipes.

MATERIAL AND METHODS

Medline, Embase, Cinahl, and Clinicaltrials.gov databases were searched. The outcomes explored were: associated anomalies detected at follow-up ultrasound examination; fetal magnetic resonance imaging (MRI) and birth; chromosomal abnormalities detected with standard and chromosomal microarray analysis, intrauterine, neonatal, and perinatal death, and termination of pregnancy; rate of surgical and nonsurgical treatment; neurodevelopmental outcome; and false-positive rate of prenatal diagnosis. Meta-analyses of proportions were used to combine data.

RESULTS

Twenty-five studies (1567 fetuses) were included. Associated anomalies were detected in 7.8% (95% CI 0.1%-29.3%) of cases at follow-up ultrasound, and in 4.0% (95% CI 0.1%-13.2%) of cases, fetal MRI identified anomalies not detected at ultrasound assessment. Similarly, 7.0% (95% CI 3.4%-11.7%) of cases labeled as isolated talipes on prenatal imaging were found to have associated anomalies at birth. Abnormal karyotype was present in 3.6% (95% CI 1.7%-6.2%) of fetuses, whereas no anomaly was found at chromosomal microarray analysis, although this outcome was reported by only 1 study. Intrauterine death occurred in 0.99% (95% CI 0.4%-1.9%) of fetuses, whereas the corresponding figures for neonatal death and termination of pregnancy were 1.5% (95% CI 0.6%-2.6%) and 2.2% (95% CI 1.2%-3.4%), respectively. Surgical management of anomalies after birth was found in 41.7% (95% CI 27.0%-57.2%) of fetuses with isolated talipes, and 54.8% (95% CI 31.5%-77.0%) had nonsurgical management of the anomalies after birth. Abnormal neurodevelopmental outcome was reported in 7.6% (95% CI 1.0%-19.4%) of children, although this analysis was affected by the small number of included cases and short time of follow up.

CONCLUSIONS

Isolated talipes detected on prenatal ultrasound carries a generally good prognosis. The incidence of additional abnormalities detected on fetal MRI, aneuploidy, or neurodevelopmental disability is relatively low. However, longitudinal ultrasound assessment during pregnancy and a thorough postnatal evaluation are recommended to rule out associated anomalies that may significantly impact short- and long-term prognosis.

Trisomy 13 and 18-Prevalence and mortality-A multi-registry population based analysis

The aim of the study is to determine the prevalence, outcomes, and survival (among live births [LB]), in pregnancies diagnosed with trisomy 13 (T13) and 18 (T18), by congenital anomaly register and region. Twenty-four population- and hospital-based birth defects surveillance registers from 18 countries, contributed data on T13 and T18 between 1974 and 2014 using a common data-reporting protocol. The mean total birth prevalence (i.e., LB, stillbirths, and elective termination of pregnancy for fetal anomalies [ETOPFA]) in the registers with ETOPFA (n = 15) for T13 was 1.68 (95% CI 1.3-2.06), and for T18 was 4.08 (95% CI 3.01-5.15), per 10,000 births. The prevalence varied among the various registers. The mean prevalence among LB in all registers for T13 was 0.55 (95%CI 0.38-0.72), and for T18 was 1.07 (95% CI 0.77-1.38), per 10,000 births. The median mortality in the first week of life was 48% for T13 and 42% for T18, across all registers, half of which occurred on the first day of life. Across 16 registers with complete 1-year follow-up, mortality in first year of life was 87% for T13 and 88% for T18. This study provides an international perspective on prevalence and mortality of T13 and T18. Overall outcomes and survival among LB were poor with about half of live born infants not surviving first week of life; nevertheless about 10% survived the first year of life. Prevalence and outcomes varied by country and termination policies. The study highlights the variation in screening, data collection, and reporting practices for these conditions.

Importance of Follow-Up and Early Detailed Evaluation in Early Onset Growth Restricted Fetuses

Early onset fetal growth restriction (EO-FGR) is associated with significant feto-maternal complications, therefore efforts should be made to identify the causes and the potential outcome of the pregnancy. Some of the pitfalls in first-trimester imaging of the fetal anomalies are related to the inadequacy of the examination, because of the fetal position and limited clarity in relation to the size of the structures being examined. In this paper we present a case where careful ultrasound scan follow-up and the use of both approaches transabdominal and transvaginal were useful to complete a detailed structural evaluation as part of the diagnosis, management and prognosis of a fetuses diagnosed with EO-FGR in the first trimester and a triploidy with atypical ultrasound features.

Epidemiologic Assessment of Microtia in Over 23 Million Consecutive United States Births

PURPOSE

Conflicting data exist regarding the incidence, demographics, and abnormalities associated with microtia. Using a large national cohort database, a comprehensive evaluation of microtia in the United States was performed.

METHODS

The Kids' Inpatient Database was reviewed over a 15-year consecutive period. Information regarding patient demographics, comorbidities, postoperative complications, and hospital setting was collected. Statistical tests were analyzed using independent t tests and χ analysis.

RESULTS

A total of 23,479,792 births over 15 consecutive years from 1997 to 2012 were included in the study. Microtia was identified in 1563 births. Incidence of microtia was higher in males (P<0.01) and patients of Asian or Hispanic race (P<0.01). Patients with microtia had significantly more congenital anomalies relative to the rest of the population (P<0.01). Specifically, cardiac and genitourinary anomalies were 51 and 19 times, respectively, more likely in microtia patients. Risk of associated congenital anomalies with microtia was highest in female and Black patients. 12.6% of all microtia patients had an associated craniofacial syndrome with a comparable postsurgical course to the nonsyndromic population.

CONCLUSION

This study represents the largest national, longitudinal study of microtia allowing for demographic, socioeconomic, and comorbidity commentary. By quantifying relative risk of associated congenital anomalies, it can help inform the type and utility of screening modalities when evaluating microtia patients.

Altered Resistin Concentrations in Mid-trimester Amniotic Fluid of Fetuses With Trisomies 18 and 13: A Window onto the Pathophysiology of Trisomies 18 and 13

BACKGROUND/AIM

The study aimed to examine whether resistin is present in second trimester amniotic fluid from pregnancies with trisomy 18 and 13 and evaluate its concentration in comparison with euploid pregnancies.

PATIENTS AND METHODS

The study included 37 women who underwent amniocentesis. Eleven fetuses had trisomy 18, 3 had trisomy 13, while 23 had a normal karyotype.

RESULTS

Resistin was detected in all cases. The mean level of resistin in trisomy 18 was statistically significantly lower compared to euploid controls. Resistin levels in all abnormal cases were below its median concentration in euploid controls. ROC analysis showed very good prognostic value for both trisomies.

CONCLUSION

Resistin is a constituent of mid-trimester amniotic fluid of pregnancies with trisomies 13 and 18, exhibiting lower levels than those in euploid fetuses. The reduced levels of resistin in amniotic fluid may be associated with early changes in metabolic pathways and immunoinflammatory responses.

Role of Overexpressed Transcription Factor FOXO1 in Fatal Cardiovascular Septal Defects in Patau Syndrome: Molecular and Therapeutic Strategies

Patau Syndrome (PS), characterized as a lethal disease, allows less than 15% survival over the first year of life. Most deaths owe to brain and heart disorders, more so due to septal defects because of altered gene regulations. We ascertained the cytogenetic basis of PS first, followed by molecular analysis and docking studies. Thirty-seven PS cases were referred from the Department of Pediatrics, King Abdulaziz University Hospital to the Center of Excellence in Genomic Medicine Research, Jeddah during 2008 to 2018. Cytogenetic analyses were performed by standard G-band method and trisomy13 were found in all the PS cases. Studies have suggested that genes of chromosome 13 and other chromosomes are associated with PS. We, therefore, did molecular pathway analysis, gene interaction, and ontology studies to identify their associations. Genomic analysis revealed important chr13 genes such as FOXO1, Col4A1, HMGBB1, FLT1, EFNB2, EDNRB, GAS6, TNFSF1, STARD13, TRPC4, TUBA3C, and TUBA3D, and their regulatory partners on other chromosomes associated with cardiovascular disorders, atrial and ventricular septal defects. There is strong indication of involving FOXO1 (Forkhead Box O1) gene-a strong transcription factor present on chr13, interacting with many septal defects link genes. The study was extended using molecular docking to find a potential drug lead for overexpressed FOXO1 inhibition. The phenothiazine and trifluoperazine showed efficiency to inhibit overexpressed FOXO1 protein, and could be potential drugs for PS/trisomy13 after validation.

Investigating the characteristics of echocardiogram, surgical treatment, chromosome and prognosis for fetal right heart enlargement: A STROBE-compliant article

The prognosis of right heart enlargement varies according to different etiologies. The purpose of this study was to investigate the characteristics of echocardiogram, surgical treatment, chromosome and prognosis for fetal right heart enlargement.The foetal echocardiogram was performed on 3987 pregnant women, and then 88 fetuses with right heart enlargement were identified. The data about prenatal and postnatal echocardiograms, postnatal cardiac surgical treatment, karyotype analysis and autopsy after induced labor were analyzed in the 88 fetuses.Except the 1111 cases that had loss of follow-up, 2876 cases had complete data. Among the 2876 cases, right heart enlargement was identified in 88 fetuses. Of the 88 fetuses, 15 had total atrioventricular septal defect (unbalanced type: right ventricular dominance), 15 Ebstein's anomaly, 18 fallot tetrad, 14 double outlet right ventricle, 13 total anomalous pulmonary venous drainage, and 13 premature closure of ductus arteriosus. Chromosomal abnormality was found in 12 cases.There are many etiological factors causing right heart enlargement. The prognosis is better in the fetuses with single heart malformation than in the fetuses who have extracardiac malformation or/and chromosomal abnormality besides heart malformation. Fetal echocardiography combined with karyotype analysis can provide important bases for evaluating the prognosis of fetuses with right heart enlargement.

Interference with the C-terminal structure of MARF1 causes defective oocyte meiotic division and female infertility in mice

Meiosis-arrest female 1 (MARF1) is a recently identified key oogenic regulator essential for the maintenance of female fertility and genome integrity in mice. However, the detailed functions and the underlying mechanisms of MARF1 remain elusive. Here, in an attempt to create a mouse model expressing fluorescent protein-tagged MARF1 to facilitate further exploration of the roles of MARF1 in oocytes, we produced a Marf1-eGFP knockin (KI) mouse line in which the C-terminal structure and function of MARF1 were interfered by its fusing eGFP peptide. Using these Marf1-eGFP-KI mice, we revealed, unexpectedly, the functions of MARF1 in the control of oocyte meiotic division. We found that the Marf1-eGFP-KI females ovulated mature oocytes with severe meiotic and developmental defects, and thus were infertile. Moreover, meiotic reinitiation was delayed while meiotic completion was accelerated in the KI-oocytes, which was coincident with the increased incidence of oocyte aneuploidy. Therefore, MARF1 is indispensable for maintaining the fidelity of homolog segregation during oocyte maturation, and this function relies on its C-terminal domains.

Coexistence of Trisomy 13 and SRY (-) XX Ovotesticular Disorder of Sex Development

INTRODUCTION

Ovotesticular disorder of sex development (OT-DSD) is a rare disorder of sexual differentiation characterized by the presence of both testicular and ovarian tissue in an individual and the majority of cases have been reported with 46,XX karyotype. In 46,XX cases, testicular differentiation may occur due to the translocation of SRY to the X chromosome or to an autosome.

CASE REPORT

Herein, we present a female newborn with a combination of trisomy 13 and SRY (-) XX OT-DSD.

CONCLUSION

Trisomy 13 is a relatively common and well-known chromosomal disorder in which disorders of sexual differentiation are not frequent. In the absence of SRY, overexpression of pro-testis genes, or decreased expression of pro-ovarian/anti-testis genes have been suggested as underlying mechanisms of testicular formation. The findings in this patient were suggestive of an underlying genomic disorder associated with FGF9 and/or SPRY2.

Hypoxia due to positive pressure ventilation in Edwards' syndrome: A case report

Edwards’ syndrome also known as trisomy 18 is a congenital disorder associated with cardiovascular issues including ventricular septal defect (VSD), atrial septal defect (ASD) and patent duct arteriosus (PDA). An emergency colostomy was performed on a neonate born with an imperforate anus. Pre-operative transthoracic echocardiography showed presence of VSD, a patent foramen ovale (PFO) or ASD. Even though the baby had a good general condition and optimal peripheral oxygen saturation (SpO₂), during positive pressure ventilation, she suffered severe hypoxia (50% SpO₂). The cause of the hypoxia was thought to be the right-left shunt and so during a second attempt at anaesthesia a vasopressor (noradrenaline 0.03 µg/kg/min) was infused to increase systemic vascular resistance. Thereafter, SpO₂ increased to 80–90% and the surgery was completed. The baby recovered without any neurological complications. Genetic testing post-partum showed she had Edwards’ syndrome.

The genetics of congenital heart disease… understanding and improving long-term outcomes in congenital heart disease: a review for the general cardiologist and primary care physician

PURPOSE OF REVIEW

This review has two purposes: to provide an updated review of the genetic causes of congenital heart disease (CHD) and the clinical implications of these genetic mutations, and to provide a clinical algorithm for clinicians considering a genetics evaluation of a CHD patient.

RECENT FINDINGS

A large portion of congenital heart disease is thought to have a significant genetic contribution, and at this time a genetic cause can be identified in approximately 35% of patients. Through the advances made possible by next generation sequencing, many of the comorbidities that are frequently seen in patients with genetic congenital heart disease patients can be attributed to the genetic mutation that caused the congenital heart disease. These comorbidities are both cardiac and noncardiac and include: neurodevelopmental disability, pulmonary disease, heart failure, renal dysfunction, arrhythmia and an increased risk of malignancy. Identification of the genetic cause of congenital heart disease helps reduce patient morbidity and mortality by improving preventive and early intervention therapies to address these comorbidities.

SUMMARY

Through an understanding of the clinical implications of the genetic underpinning of congenital heart disease, clinicians can provide care tailored to an individual patient and continue to improve the outcomes of congenital heart disease patients.

Congenital talipes equinovarus and congenital vertical talus secondary to sacral agenesis

Sacral agenesis is a rare congenital defect which is associated with foot deformities such as congenital talipes equinovarus (CTEV) and less commonly congenital vertical talus (CVT). We report a 3-year-old Caucasian girl who was born with right CTEV and left CVT secondary to sacral agenesis. Her right foot was managed with a Ponseti casting method at 2 weeks, followed by an Achilles tenotomy at 4 months. The left foot was initially managed with a nocturnal dorsi-flexion splint. Both feet remained resistant and received open foot surgery at 10 months producing plantigrade feet with neutral hindfeet. At 19 months, she failed to achieve developmental milestones and examinations revealed abnormal lower limb reflexes. A full body MRI was performed which identified the sacral agenesis. We advocate early MRI of the spine to screen for spinal defects when presented with resistant foot deformities, especially when bilateral.

Major anomalies and birth-weight influence NICU interventions and mortality in infants with trisomy 13 or 18

OBJECTIVE

To describe neonatal intensive care unit (NICU) medical interventions and NICU mortality by birth weight and major anomaly types for infants with trisomy 13 (T13) or 18 (T18).

STUDY DESIGN

Retrospective cohort analysis of infants with T13 or T18 from 2005 to 2012 in the Pediatrix Medical Group. We classified infants into three groups by associated anomaly type: neonatal surgical, non-neonatal surgical and minor. Outcomes were NICU medical interventions and mortality.

RESULTS

841 infants were included from 186 NICUs. NICU mortality varied widely by anomaly type and birth weight, from 70% of infants <1500 g with neonatal surgical anomalies to 31% of infants ⩾2500 g with minor anomalies. Infants ⩾1500 g without a neonatal surgical anomaly comprised 66% of infants admitted to the NICU; they had the lowest rates of NICU medical interventions and NICU mortality.

CONCLUSIONS

Risk stratification by anomaly type and birth weight may help provide more accurate family counseling for infants with T13 and T18.

Sinus of Valsalva Aneurysm in a Patient With Mosaic Trisomy 13: Case Report and Brief Review of the Literature

This report describes a unique case involving an obese 16-year-old boy with a mosaic form of trisomy 13 and no previous cardiac history who presented with a new murmur, hypertension, pleural effusions, and congestive heart failure in the context of sore throat and fever. Evaluation revealed a diagnosis of ruptured noncoronary sinus of Valsalva (SOV) aneurysm. The diagnosis and surgical management of a ruptured noncoronary SOV aneurysm in a pediatric patient are briefly outlined. An SOV aneurysm is an anatomic dilation of one of the sinuses of the aortic root. Aneurysmal dilation occurs more commonly in the right aortic sinus (70%-80%), compared to the noncoronary sinus (23%-25%), and more rarely the left coronary sinus (5%). Rupture of these aneurysms has been reported to be both spontaneous and secondary to physical exertion, hypertension, or trauma. Signs of rupture include a continuous murmur, patients may present with chest pain or with symptoms of acute congestive heart failure. Diagnosis, in this case, was made by transthoracic echocardiography with careful interpretation of color Doppler images.

A tumor profile in Edwards syndrome (trisomy 18)

Constitutional trisomy 18 causes Edwards syndrome, which is characterized by intellectual disability and a particular set of malformations. Although this condition carries high mortality during prenatal and early postnatal life, some of the rare infants who survive the first months develop benign and malignant tumors. To determine the tumor profile associated with Edwards syndrome, we performed a systematic review of the literature. This review reveals a tumor profile differing from those of Down (trisomy 21) and Patau (trisomy 13) syndromes. The literature covers 45 malignancies: 29 were liver cancers, mainly hepatoblastomas found in Japanese females; 13 were kidney tumors, predominantly nephroblastomas; 1 was neuroblastoma; 1 was a Hodgkin disease; and 1 was acute myeloid leukemia in an infant with both trisomy 18 and type 1 neurofibromatosis. No instances of the most frequent malignancies of early life-cerebral tumors, germ cell tumors, or leukemia--are reported in children with pure trisomy 18. Tumor occurrence does not appear to correlate with body weight, tissue growth, or cancer genes mapping to chromosome 18. Importantly, the most recent clinical histories report successful treatment; this raises ethical concerns about cancer treatment in infants with Edwards syndrome. In conclusion, knowledge of the Edwards' syndrome tumor profile will enable better clinical surveillance in at-risk organs (i.e., liver, kidney). This knowledge also provides clues to understanding oncogenesis, including the probably reduced frequency of some neoplasms in infants and children with this genetic condition. © 2016 Wiley Periodicals, Inc.

Sacrococcygeal Teratoma associated with Trisomy 13

Sacrococcygeal teratoma (SCT) is rarely associated with syndromes. We report a female newborn with a prenatal diagnosis of small sacrococcygeal teratoma and postnatally diagnosed as having trisomy 13. The sacrococcygeal teratoma was excised. It was reported as mature teratoma. The child succumbed to sepsis postoperatively.

Genetics of Congenital Heart Defects: The NKX2-5 Gene, a Key Player

Congenital heart defects (CHDs) represent the biggest fraction of morbid congenital anomalies worldwide. Owing to their complex inheritance patterns and multifactorial etiologies, these defects are difficult to identify before complete manifestation. Research over the past two decades has established firmly the role of genetics in the development of these congenital defects. While syndromic CHDs are more straightforward, non-syndromic CHDs are usually characterized by multiple mutations that affect intricate inter-connected developmental pathways. Knock-out and gene expression studies in mice and other genetic models have been performed to elucidate the roles of these implicated genes. Functional analysis has not been able to resolve the complete picture, as increasingly more downstream effects are continuously being assigned to CHD mutant factors. NKX2-5, a cardiac transcription factor, has received much attention for its role in cardiac dysmorphogenesis. Approximately 50 different mutations in this gene have been identified to date, and only a few have been functionally characterized. The mutant NKX2-5 factor can regulate a number of off-targets downstream to facilitate CHD development. This review summarizes the genetic etiology of congenital heart defects and emphasizes the need for NKX2-5 mutation screening.

A female newborn having mosaicism with near-tetraploidy and trisomy 18

Tetraploidy is characterized by the presence of four complete sets of chromosomes in an individual. Full tetraploidy is usually considered lethal. To date, only ten live-births with the condition have been reported. Trisomy 18 without neonatal intensive treatment is also known to be fatal. We report a female newborn who had mosaicism with near-tetraploidy and trisomy 18 (94,XXXX,+18,+18/47,XX,+18). She had features of conditions. The most plausible mechanism of the formation was a failure of cytoplasmic cleavage at the first division of the zygote. The longer survival of the patient compared with the 10 previously reported live-births with non-mosaic tetraploidy may be due to the dominance of the trisomy cells. We suggest that non-tetraploid cells, even when trisomic for chromosome 18, might contribute to longer survival in comparison to non-mosaic tetrapolid patients.

Global Birth Prevalence of Spina Bifida by Folic Acid Fortification Status: A Systematic Review and Meta-Analysis

BACKGROUND

Birth defects remain a significant source of worldwide morbidity and mortality. Strong scientific evidence shows that folic acid fortification of a region's food supply leads to a decrease in spina bifida (a birth defect of the spine). Still, many countries around the world have yet to approve mandatory fortification through government legislation.

OBJECTIVES

We sought to perform a systematic review and meta-analysis of period prevalence of spina bifida by folic acid fortification status, geographic region, and study population.

SEARCH METHODS

An expert research librarian used terms related to neural tube defects and epidemiology from primary research from 1985 to 2010 to search in EMBASE and MEDLINE. We searched the reference lists of included articles and key review articles identified by experts.

SELECTION CRITERIA

Inclusion criteria included studies in English or French reporting on prevalence published between January 1985 and December 2010 that (1) were primary research, (2) were population-based, and (3) reported a point or period prevalence estimate of spina bifida (i.e., prevalence estimate with confidence intervals or case numerator and population denominator). Two independent reviewers screened titles and abstracts for eligible articles, then 2 authors screened full texts in duplicate for final inclusion. Disagreements were resolved through consensus or a third party.

DATA COLLECTION AND ANALYSIS

We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses, or PRISMA, abstracting data related to case ascertainment, study population, folic acid fortification status, geographic region, and prevalence estimate independently and in duplicate. We extracted overall data and any subgroups reported by age, gender, time period, or type of spina bifida. We classified each period prevalence estimate as "mandatory" or "voluntary" folic acid fortification according to each country's folic acid fortification status at the time data were collected (as determined by a well-recognized fortification monitoring body, Food Fortification Initiative). We determined study quality on the basis of sample representativeness, standardization of data collection and birth defect assessment, and statistical analyses. We analyzed study-level period prevalence estimates by using a random effects model (α level of < 0.05) for all meta-analyses. We stratified pooled period prevalence estimates by birth population, fortification status, and continent.

RESULTS

Of 4078 studies identified, we included 179 studies in the systematic review and 123 in a meta-analysis. In studies of live births (LBs) alone, period prevalences of spina bifida were (1) lower in geographical regions with mandatory (33.86 per 100,000 LBs) versus voluntary (48.35 per 100,000 LBs) folic acid fortification, and (2) lower in studies of LBs, stillbirths, and terminations of pregnancy in regions with mandatory (35.22 per 100,000 LBs) versus voluntary (52.29 per 100,000 LBs) fortification. In LBs, stillbirths, and terminations of pregnancy studies, the lowest pooled prevalence estimate was in North America (38.70 per 100,000). Case ascertainment, surveillance methods, and reporting varied across these population-based studies.

CONCLUSIONS

Mandatory legislation enforcing folic acid fortification of the food supply lags behind the evidence, particularly in Asian and European countries. This extensive literature review shows that spina bifida is significantly more common in world regions without government legislation regulating full-coverage folic acid fortification of the food supply (i.e., Asia, Europe) and that mandatory folic acid fortification resulted in a lower prevalence of spina bifida regardless of the type of birth cohort. African data were scarce, but needed, as many African nations are beginning to adopt folic acid legislation.

Survival of children with trisomy 13 and trisomy 18: A multi-state population-based study

Trisomy 13 (T13) and trisomy 18 (T18) are among the most prevalent autosomal trisomies. Both are associated with a very high risk of mortality. Numerous instances, however, of long-term survival of children with T13 or T18 have prompted some clinicians to pursue aggressive treatment instead of the traditional approach of palliative care. The purpose of this study is to assess current mortality data for these conditions. This multi-state, population-based study examined data obtained from birth defect surveillance programs in nine states on live-born infants delivered during 1999-2007 with T13 or T18. Information on children's vital status and selected maternal and infant risk factors were obtained using matched birth and death certificates and other data sources. The Kaplan-Meier method and Cox proportional hazards models were used to estimate age-specific survival probabilities and predictors of survival up to age five. There were 693 children with T13 and 1,113 children with T18 identified from the participating states. Among children with T13, 5-year survival was 9.7%; among children with T18, it was 12.3%. For both trisomies, gestational age was the strongest predictor of mortality. Females and children of non-Hispanic black mothers had the lowest mortality. Omphalocele and congenital heart defects were associated with an increased risk of death for children with T18 but not T13. This study found survival among children with T13 and T18 to be somewhat higher than those previously reported in the literature, consistent with recent studies reporting improved survival following more aggressive medical intervention for these children. © 2015 Wiley Periodicals, Inc.

Sirt6 depletion causes spindle defects and chromosome misalignment during meiosis of mouse oocyte

Sirt6, a member of the sirtuin family of NAD-dependent protein deacetylases, has been implicated in multiple biological processes. However, the roles of Sirt6 in meiosis have not been addressed. In the present study, by employing knockdown analysis in mouse oocytes, we evaluated the effects of Sirt6 on meiotic apparatus. We found that specific depletion of Sirt6 results in disruption of spindle morphology and chromosome alignment in oocytes. Consistent with this observation, incidence of aneuploidy is also markedly increased in Sirt6-depleted oocytes. Furthermore, confocal scanning showed that kinetochore-microtubule interaction, an important mechanism controlling chromosome segregation, is severely impaired in metaphase oocytes following Sirt6 knockdown. Unexpectedly, we discovered that Sirt6 modulates the acetylation status of histone H4K16 as their knockdown specifically induces the hyperacetylation of H4K16 in oocytes, which may be associated with the defective phenotypes described above via altering kinetochore function. Altogether, our data reveal a novel function of Sirt6 during oocyte meiosis and indicate a pathway regulating meiotic apparatus.

Parental counseling in trisomy 18: Novel insights in prenatal features and postnatal survival

Data on the outcome of trisomy T18 (T18) when diagnosed during pregnancy are lacking. We performed a retrospective study of pregnancies complicated by T18 diagnosed at our center and a literature search for publications on the topic, with pooled estimates of survival rates at different gestational and post-natal ages. In our series, all the 60 patients included in the analysis had prenatally detected ultrasound anomalies, which were evidenced in the first trimester or at the second trimester scan in 73% of cases. In the continued pregnancies, ultrasound findings did not correlate with prenatal or post-natal outcome. A meta-analysis of available literature and our data showed that 48% [37-60%] of fetuses were live born, and among these 39% [11-72%] survived beyond 48 hr and 11% [3-21%] beyond 1 month. Our results confirm that prenatal ultrasound has high sensitivity in detection of T18 but is not predictive of the outcome of the continued pregnancies. The data on survival support that T18, even when antenatally diagnosed, cannot be considered as a uniformly lethal syndrome.

Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy

How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures.