Major chromosomal anomalies among very low birth weight infants in the Vermont Oxford Network

Prevalence and Clinical Significance of Commonly Diagnosed Genetic Disorders in Preterm Infants

Background and Objectives

Preterm infants (<34 weeks' gestation) experience high rates of morbidity and mortality before hospital discharge. Genetic disorders substantially contribute to morbidity and mortality in related populations. The prevalence and clinical impact of genetic disorders is unknown in this population. We sought to determine the prevalence of commonly diagnosed genetic disorders in preterm infants, and to determine the association of disorders with morbidity and mortality.

Methods

This was a retrospective multicenter cohort study of infants born from 23 to 33 weeks' gestation between 2000 and 2020. Genetic disorders were abstracted from diagnoses present in electronic health records. We excluded infants transferred from or to other health care facilities prior to discharge or death when analyzing clinical outcomes. We determined the adjusted odds of pre-discharge morbidity or mortality after adjusting for known risk factors.

Results

Of 320,582 infants, 4196 (1.3%) had genetic disorders. Infants with trisomy 13, 18, 21, or cystic fibrosis had greater adjusted odds of severe morbidity or mortality. Of the 17,427 infants who died, 566 (3.2%) had genetic disorders. Of the 65,968 infants with a severe morbidity, 1319 (2.0%) had genetic disorders.ConclusionsGenetic disorders are prevalent in preterm infants, especially those with life-threatening morbidities. Clinicians should consider genetic testing for preterm infants with severe morbidity and maintain a higher index of suspicion for life-threatening morbidities in preterm infants with genetic disorders. Prospective genomic research is needed to clarify the prevalence of genetic disorders in this population, and the contribution of genetic disorders to preterm birth and subsequent morbidity and mortality.

Article Summary

Genetic disorders were found in 1.3% of preterm infants and at a higher rate (2.0%) in infants who died or developed severe morbidity.

What’s Known on This Subject

Previous research described the prevalence and associated short-term morbidity and mortality of trisomy 13, 18, and 21 in preterm infants. The prevalence of other commonly diagnosed genetic disorders and associated short-term morbidity and mortality in preterm infants is unknown.

What This Study Adds

In a multicenter, retrospective cohort of 320,582 preterm (<34 weeks' gestation) infants, we found that 1.3% had genetic disorders diagnosed through standard care. Multiple disorders were associated with increased adjusted odds of morbidities or mortality prior to hospital discharge.

Contributors Statement Page

Selin S. Everett conceptualized and designed the study, conducted analyses, drafted the initial manuscript, and critically reviewed and revised the manuscript.Dr. Thomas Hays conceptualized and designed the study, drafted the initial manuscript, and critically reviewed and revised the manuscript.Miles Bomback conceptualized and designed the study and critically reviewed and revised the manuscript.Drs. Veeral N. Tolia and Reese H. Clark coordinated and supervised data collection and critically reviewed and revised the manuscript.Dr. Rakesh Sahni conceptualized and designed the study and critically reviewed and revised the manuscript.Dr. Alex Lyford conducted analyses and critically reviewed and revised the manuscript. Dr. Ronald J. Wapner reviewed and critically revised the manuscript.All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

Very low birth weight infants with congenital heart disease: A multicenter cohort study in Japan

BACKGROUND

The frequency, mortality, and morbidity of very low birth weight (VLBW) infants with congenital heart disease (CHD) in Asian countries are limited. In addition, little is known about the risk factors of death in these infants.

METHODS

A retrospective, multicenter cohort study was conducted. VLBW infants with CHD born between 2006 and 2010, and followed to 5 years of age, were included in the analysis. Multiple logistic regression analysis was performed to identify the risk factors of death.

RESULTS

Among 3247 VLBW infants, 126 various CHDs (3.9 %) were identified. The most common lesions were ventricular septal defect, tetralogy of Fallot (TOF), and coarctation of the aorta/interrupted aortic arch, in that order. The proportions of left-sided and right-sided outflow obstruction (TOF, pulmonary stenosis) were 15.1 % and 15.9 %, respectively. Trisomy 18 and trisomy 13 were present in 32 (25.4 %) of 126 VLBW infants with CHD. Nine patients were lost to follow-up. Overall, 45 patients (35.7 %) died up to 5 years of age. Serious CHD [odds ratio (OR), 19.2; 95 % confidential interval (CI), 3.94-93.11; p < 0.0001], sepsis (OR, 42.3; 95 % CI, 5.39-332.22; p < 0.0001), chromosomal /named anomalies (OR, 7.50; 95%CI, 2.09-26.94; p = 0.001), and no-invasive treatments (OR, 9.89; 95%CI, 2.28-42.91; p = 0.001) were associated with death. On excluding chromosomal anomalies, twelve of 71 patients (16.9 %) died, and only sepsis (OR, 35.5, 95%CI, 2.63-477.1; p = 0.0008) was an independent risk factor.

CONCLUSIONS

Trisomy 18 and trisomy 13 of chromosomal anomalies are frequently associated with VLBW infants with CHD. The mortality of VLBW infants with CHD is high, even when chromosomal anomalies are excluded. Sepsis has a significant impact on death in VLBW infants with CHD.

Household Air Pollution from Biomass Fuel for Cooking and Adverse Fetal Growth Outcomes in Rural Sri Lanka

The aim of this study was to investigate the impact of biomass fuel for cooking on adverse fetal growth outcomes in Sri Lanka. A cross-sectional study of mothers recruited at maternity clinics in rural communities in Sri Lanka’s Central Province was undertaken. Data pertaining to household air pollution and fetal growth parameters were collected using an interviewer-administered questionnaire. Logistic regression models, adjusted for potential confounders, were used to evaluate the impact of biomass fuel for cooking on low birth weight (LBW) and small for gestational age (SGA) parameters. Findings showed that exposure to biomass cooking fuels during pregnancy was associated with an increased risk of LBW adjusted odds ratio (aOR) 2.74 (95% CI 1.08–6.96) and SGA (aOR: 1.87, 95% CI 1.03–3.41) compared with the use of clean energy. The risk of LBW was highest for traditional biomass stoves compared to improved biomass stoves (aOR: 3.23, 95% 1.17–8.89) and biomass use in kitchens without a chimney compared to kitchens with a chimney (aOR: 4.63, 95% 1.54–13.93). Similar trends were observed for SGA.

Epidemiology of Birth Defects in Very Low Birth Weight Infants in Japan

OBJECTIVE

To evaluate the mortality and morbidity of very low birth weight (VLBW) preterm infants with birth defects in Japan.

STUDY DESIGN

Data were collected prospectively for infants weighing <1501 g and born at <37 weeks of gestation admitted to centers of the Neonatal Research Network of Japan during 2003-2016. We compared outcomes of infants with and without birth defects using Pearson χ² test, Wilcoxon rank-sum test, log-rank test, nominal logistic regression analysis, and stratified analysis by birth defect subgroups. This study was approved by the Ethics Committee of Kyoto University Graduate School and Faculty of Medicine.

RESULTS

Among 57 730 VLBW preterm infants, 3557 infants (6.2%) were born with birth defects. Chromosomal abnormalities, congenital heart defects, and congenital malformation of the digestive system were the most common categories. Among diseases, Trisomy 18, Down syndrome, and cleft palate were the most prevalent. There were significant differences between perinatal characteristics of infants with and without birth defects. Most categories of morbidity occurred more frequently in infants with birth defects compared with those without birth defects. The aOR for mortality during the neonatal intensive care unit admission was 10.6 (95% CI 9.5-11.7) for infants with birth defects. A stratified analysis identified birth defect categories with good, moderate, and poor prognoses.

CONCLUSIONS

This detailed information about mortality and morbidity of preterm VLBW infants with birth defects should be useful for genetic counseling as well as prenatal and neonatal care, with the limitation that we lacked information about the timing of diagnosis, abortion, or stillbirth.

Triploidy in a Live-Born Extremely Low Birth Weight Twin: Clinical Aspects

Triploidy is a rare chromosomal aberration characterized by a karyotype with 69 chromosomes. Triploid fetuses usually are miscarried in early pregnancy. We present a case of a triploid twin and a genetically unaffected co-twin, conceived through in vitro fertilization. A discordant growth was registered at 20 weeks of gestation. Cesarean section was performed at 355/7 gestational week. The second twin was extremely growth restricted female (780 g) with oligohydramnios and severe respiratory distress, and died at 20 hours of age. The autopsy revealed unilobar left lung, bilobar right lung, and cysts of the terminal bronchioles. Quantitative fluorescent polymerase chain reaction detected triploidy compatible pattern. So, early intrauterine growth restriction may be a sign of triploidy, which must be proven by pre or postnatal genetic testing.

Congenital Anomalies in Very-Low-Birth-Weight Infants: A Nationwide Cohort Study

BACKGROUND

Management of newborn infants with congenital anomalies is challenging and requires a multidisciplinary approach. The prevalence of congenital anomalies in very-low-birth-weight infants (VLBWIs; birth weight <1,500 g) has been rarely reported.

OBJECTIVES

The aim of this study was to investigate the epidemiology of congenital anomalies in VLBWIs and the association with early mortality and major morbidities.

STUDY DESIGN

A prospective cohort study was performed using data collected from 70 centers registered in the Korean Neonatal Network. Data from the VLBWIs with major congenital anomalies (n = 289) and the controls (n = 867), selected by 1:3 frequency matching for gestational age, were compared.

RESULTS

The overall prevalence of major congenital anomalies in VLBWIs was 34.9 per 1,000 live births (289/8,156). The top 2 ranked subgroups of congenital anomalies were the digestive system (31.7%) and congenital heart defects (27.7%), followed by chromosomal anomalies, genitourinary tract defect, central nervous system, other anomalies, undefined, and respiratory system. The group with congenital anomalies had a higher mortality (40.7%) than the control group (11.1%). Each subgroup of congenital anomalies, except for chromosomal anomalies, increased the risk of mortality, with the highest odds ratio associated with "other" anomalies, which includes hydrops fetalis and congenital diaphragmatic hernia. In the multivariate analysis, congenital anomaly was a risk factor for mortality, bronchopulmonary dysplasia, and severe-grade intraventricular hemorrhage. VLBWIs with congenital anomaly demonstrated impaired in-hospital growth as compared with the control group.

CONCLUSION

Congenital anomaly increased the risk of in-hospital mortality and was associated with short-term neonatal morbidities in the VLBWIs.

The importance of anthropological methods in the diagnosis of rare diseases

Most of inborn errors of metabolism (IEMs) and rare endocrine-metabolic diseases (REMD) are rare diseases. According to the European Commission on Public Health, a rare disease is defined, based on its prevalence, as one affecting one in 2000 people. Many IEMs affect body stature, cause craniofacial abnormalities, and disturb the developmental process. Therefore, body proportion, dysmorphic characteristics, and morphological parameters must be assessed and closely monitored. This can be achieved only with the help of an anthropologist who has adequate tools. This is why the role of an anthropologist in collaboration with the physician in the diagnostic process is not to be underestimated. Clinical anthropologists contribute to assessing physical development and improve our understanding of the natural history of rare metabolic diseases. This paper presents anthropometric techniques and methods, such as analysis of demographic data, anthropometric parameters at birth, percentile charts, growth patterns, bioimpedance, somatometric profiles, craniofacial profiles, body proportion indices, and mathematical models of growth curves used in certain rare diseases. Contemporary anthropological methods play an important role in the diagnostic process of rare genetic diseases.

NICU management and outcomes of infants with trisomy 21 without major anomalies

OBJECTIVE

To describe how trisomy 21 affects neonatal intensive care management and outcomes of full-term infants without congenital anomalies.

STUDY DESIGN

Retrospective cohort of full-term infants without anomalies with and without trisomy 21 admitted to Pediatrix NICUs from 2005 to 2012. We compared diagnoses, management, length of stay, and discharge outcomes.

RESULTS

In all, 4623 infants with trisomy 21 and 606 770 infants without trisomy 21 were identified. One-third of infants in the NICU with and without trisomy 21 were full term without major anomalies. Trisomy 21 infants had more respiratory distress, thrombocytopenia, feeding problems, and pulmonary hypertension. They received respiratory support for a longer period of time and had a longer length of stay.

CONCLUSION

One-third of infants with trisomy 21 admitted to the NICU are full term without major anomalies. Common diagnoses and greater respiratory needs place infants with trisomy 21 at risk for longer length of stay.

Birth weight, length and head circumference: Progression and impact over the outcome of patients with congenital heart disease

BACKGROUND

There are few studies assessing the birth measures of patients with congenital heart disease (CHD). Our aim to evaluate their progression and impact over the outcome.

METHODS

The cases consisted of patients with CHD during their first hospitalization in a reference cardiac and pediatric intensive care unit (ICU) from Southern Brazil. Controls were composed of patients with no clinical evidence of CHD hospitalized soon after cases. The cases underwent high-resolution karyotype and fluorescence in situ hybridization (FISH) for 22q11 microdeletion. We analyzed birth weight, length and head circumference of patients of both groups. For CHD patients, we evaluated their progression and impact until hospitalization at ICU.

RESULTS

Our sample was composed of 198 cases and controls. We observe a difference in birth weight of CHD patients only in relation to general population. There was a significant increase in children with CHD and weight below the lower limit from birth until the hospitalization at ICU, and this occurred more in those without complex CHD. Syndromic patients and with an extracardiac malformation also presented a greater difficulty to maintain not only the weight but also the length/height until the hospitalization. Individuals with weight below the lower limit at hospitalization who died had a tendency to present longer stay at ICU.

CONCLUSIONS

Some CHD patients, especially without complex defects, and with syndromic aspect and a major extracardiac malformation, present a higher difficult to maintain their weight and growth, and, therefore, may be at risk and should be more closely monitored.

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.

[Congenital anomalies of poor prognosis. Genetics Consensus Committee]

INTRODUCTION

The Genetic Branch of the Chilean Society of Paediatrics, given the draft Law governing the decriminalisation of abortion on three grounds, focusing on the second ground, which considers the "embryo or foetus suffering from a congenital structural anomaly or a genetic disorder incompatible with life outside the womb", met to discuss the scientific evidence according to which congenital anomalies (CA) may be included in this draft law.

METHODOLOGY

Experts in clinical genetics focused on 10 CA, reviewed the literature evidence, and met to discuss it.

RESULTS

It was agreed not to use the term "incompatible with life outside the womb", as there are exceptions and longer survivals, and change to "congenital anomaly of poor prognosis (CAPP)". Ten CA were evaluated: serious defects of neural tube closure: anencephaly, iniencephaly and craniorachischisis, pulmonary hypoplasia, acardiac foetus, ectopia cordis, non-mosaic triploidy, "limb body wall" complex, "body stalk" anomaly, trisomy 13, trisomy 18, and bilateral renal agenesis. Findings on the prevalence, natural history, prenatal diagnostic methods, survival, and reported cases of prolonged survival were analysed. Post-natal survival, existence of treatments, and outcomes, as well as natural history without intervention, were taken into account in classifying a CA as a CAPP.

CONCLUSION

A CAPP would be: anencephaly, severe pulmonary hypoplasia, acardiac foetus, cervical ectopia cordis, non-mosaic triploidy, limb body wall complex, body stalk anomaly, non-mosaic trisomy 13, non-mosaic trisomy 18, and bilateral renal agenesis. For their diagnosis, it is required that all pregnant women have access to assessments by foetal anatomy ultrasound and occasionally MRI, and cytogenetic and molecular testing.

Rare copy number variants implicated in posterior urethral valves

The cause of posterior urethral valves (PUV) is unknown, but genetic factors are suspected given their familial occurrence. We examined cases of isolated PUV to identify novel copy number variants (CNVs). We identified 56 cases of isolated PUV from all live-births in New York State (1998-2005). Samples were genotyped using Illumina HumanOmni2.5 microarrays. Autosomal and sex-linked CNVs were identified using PennCNV and cnvPartition software. CNVs were prioritized for follow-up if they were absent from in-house controls, contained ≥ 10 consecutive probes, were ≥ 20 Kb in size, had ≤ 20% overlap with variants detected in other birth defect phenotypes screened in our lab, and were rare in population reference controls. We identified 47 rare candidate PUV-associated CNVs in 32 cases; one case had a 3.9 Mb deletion encompassing BMP7. Mutations in BMP7 have been associated with severe anomalies in the mouse urethra. Other interesting CNVs, each detected in a single PUV case included: a deletion of PIK3R3 and TSPAN1, duplication/triplication in FGF12, duplication of FAT1--a gene essential for normal growth and development, a large deletion (>2 Mb) on chromosome 17q that involves TBX2 and TBX4, and large duplications (>1 Mb) on chromosomes 3q and 6q. Our finding of previously unreported novel CNVs in PUV suggests that genetic factors may play a larger role than previously understood. Our data show a potential role of CNVs in up to 57% of cases examined. Investigation of genes in these CNVs may provide further insights into genetic variants that contribute to PUV.

Mortality and morbidity of VLBW infants with trisomy 13 or trisomy 18

OBJECTIVE

Little is known about how very low birth weight (VLBW) affects survival and morbidities among infants with trisomy 13 (T13) or trisomy 18 (T18). We examined the care plans for VLBW infants with T13 or T18 and compared their risks of mortality and neonatal morbidities with VLBW infants with trisomy 21 and VLBW infants without birth defects.

METHODS

Infants with birth weight 401 to 1500 g born or cared for at a participating center of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network during the period 1994-2009 were studied. Poisson regression models were used to examine risk of death and neonatal morbidities among infants with T13 or T18.

RESULTS

Of 52,262 VLBW infants, 38 (0.07%) had T13 and 128 (0.24%) had T18. Intensity of care in the delivery room varied depending on whether the trisomy was diagnosed before or after birth. The plan for subsequent care for the majority of the infants was to withdraw care or to provide comfort care. Eleven percent of infants with T13 and 9% of infants with T18 survived to hospital discharge. Survivors with T13 or T18 had significantly increased risk of patent ductus arteriosus and respiratory distress syndrome compared with infants without birth defects. No infant with T13 or T18 developed necrotizing enterocolitis.

CONCLUSIONS

In this cohort of liveborn VLBW infants with T13 or T18, the timing of trisomy diagnosis affected the plan for care, survival was poor, and death usually occurred early.

Early births and congenital birth defects: a complex interaction

Congenital birth defects and early/premature birth are common complex conditions affecting populations throughout the world, the interaction of which accounts for a significant proportion of neonatal morbidity and mortality. The relationship between these two conditions is not well understood. Several congenital birth defects can directly lead to early delivery. In addition, certain fetal conditions may necessitate early or premature delivery, several of which are also associated with maternal conditions necessitating early birth. Further understanding of both the incidences and causes of congenital birth defects and of early and premature birth will facilitate establishment of strategies to improve neonatal mortality and morbidity.

Ten-year review of major birth defects in VLBW infants

OBJECTIVE

Birth defects (BDs) are an important cause of infant mortality and disproportionately occur among low birth weight infants. We determined the prevalence of BDs in a cohort of very low birth weight (VLBW) infants cared for at the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) centers over a 10-year period and examined the relationship between anomalies, neonatal outcomes, and surgical care.

METHODS

Infant and maternal data were collected prospectively for infants weighing 401 to 1500 g at NRN sites between January 1, 1998, and December 31, 2007. Poisson regression models were used to compare risk of outcomes for infants with versus without BDs while adjusting for gestational age and other characteristics.

RESULTS

A BD was present in 1776 (4.8%) of the 37 262 infants in our VLBW cohort. Yearly prevalence of BDs increased from 4.0% of infants born in 1998 to 5.6% in 2007, P < .001. Mean gestational age overall was 28 weeks, and mean birth weight was 1007 g. Infants with BDs were more mature but more likely to be small for gestational age compared with infants without BDs. Chromosomal and cardiovascular anomalies were most frequent with each occurring in 20% of affected infants. Mortality was higher among infants with BDs (49% vs 18%; adjusted relative risk: 3.66 [95% confidence interval: 3.41-3.92]; P < .001) and varied by diagnosis. Among those surviving >3 days, more infants with BDs underwent major surgery (48% vs 13%, P < .001).

CONCLUSIONS

Prevalence of BDs increased during the 10 years studied. BDs remain an important cause of neonatal morbidity and mortality among VLBW infants.