Childhood exposures to environmental chemicals and neurodevelopmental outcomes in congenital heart disease

BACKGROUND

Children with congenital heart defects have an increased risk of neurodevelopmental disability. The impact of environmental chemical exposures during daily life on neurodevelopmental outcomes in toddlers with congenital heart defects is unknown.

METHODS

This prospective study investigated the impacts of early childhood exposure to mixtures of environmental chemicals on neurodevelopmental outcomes after cardiac surgery. Outcomes were assessed at 18 months of age using The Bayley Scales of Infant and Toddler Development-III. Urinary concentrations of exposure biomarkers of pesticides, phenols, parabens, and phthalates, and blood levels of lead, mercury, and nicotine were measured at the same time point. Bayesian profile regression and weighted quantile sum regression were utilized to assess associations between mixtures of biomarkers and neurodevelopmental scores.

RESULTS

One-hundred and forty infants were enrolled, and 110 (79%) returned at 18 months of age. Six biomarker exposure clusters were identified from the Bayesian profile regression analysis; and the pattern was driven by 15 of the 30 biomarkers, most notably 13 phthalate biomarkers. Children in the highest exposure cluster had significantly lower adjusted language scores by -9.41 points (95%CI: -17.2, -1.7) and adjusted motor scores by -4.9 points (-9.5, -0.4) compared to the lowest exposure. Weighted quantile sum regression modeling for the overall exposure-response relationship showed a significantly lower adjusted motor score (β = -2.8 points [2.5th and 97.5th percentile: -6.0, -0.6]). The weighted quantile sum regression index weights for several phthalates, one paraben, and one phenol suggest their relevance for poorer neurodevelopmental outcomes.

CONCLUSIONS

Like other children, infants with congenital heart defects are exposed to complex mixtures of environmental chemicals in daily life. Higher exposure biomarker concentrations were associated with significantly worse performance for language and motor skills in this population.

iMOVE: Intensive Mobility training with Variability and Error compared to conventional rehabilitation for young children with cerebral palsy: the protocol for a single blind randomized controlled trial

BACKGROUND

Cerebral palsy (CP) is the most common cause of physical disability in children. The best opportunity to maximize lifelong independence is early in motor development when there is the most potential for neuroplastic change, but how best to optimize motor ability during this narrow window remains unknown. We have systematically developed and pilot-tested a novel intervention that incorporates overlapping principles of neurorehabilitation and infant motor learning in a context that promotes upright mobility skill and postural control development. The treatment, called iMOVE therapy, was designed to allow young children with CP to self-initiate motor learning experiences similar to their typically developing peers. This manuscript describes the protocol for a subsequent clinical trial to test the efficacy of iMOVE therapy compared to conventional therapy on gross motor development and other secondary outcomes in young children with CP.

METHODS

The study is a single-blind randomized controlled trial. Forty-two participants with CP or suspected CP between the ages of 1-3 years will be randomized to receive either the iMOVE or conventional therapy group. Distinguishing characteristics of each group are detailed. Repeated measures of gross motor function will be collected throughout the 12-24 week intervention phase and at three follow-up points over one year post therapy. Secondary outcomes include measures of postural control, physical activity, participation and caregiver satisfaction.

DISCUSSION

This clinical trial will add to a small, but growing, body of literature on early interventions to optimize the development of motor control in young children with CP. The information learned will inform clinical practice of early treatment strategies and may contribute to improving the trajectory of motor development and reducing lifelong physical disability in individuals with CP.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02340026 . Registered January 16, 2015.

Short-Term Neurodevelopmental Outcome in Children Born With High-Risk Congenital Lung Lesions

BACKGROUND

This study sought to evaluate neurodevelopmental outcome in survivors of high-risk congenital lung lesions (CLLs) who underwent prenatal intervention or postnatal surgery within the first month of life.

METHODS

Forty-five high-risk CLL survivors underwent assessment using the Bayley Scales of Infant Development, 3rd Edition between July 2004 and December 2016. Scores were grouped as average, at-risk, and delayed based on SD intervals. Correlations between outcome and risk factors were analyzed by Fisher's exact test or two-sided t test as appropriate, with significant p values <0.05.

RESULTS

Open prenatal intervention was required in 13 (28.9%) children (fetal surgical resection, n = 4 , ex utero intrapartum treatment, n = 9), whereas 32 (71.1%) children had respiratory distress postnatally and required resection within the first month of life. Mean age at follow-up was 19.3 ± 10.3 months. Mean composite scores were within the expected average range. A total of 62.2% scored within the average range for all domains. At-risk scores were found in 26.7% of children in at least one domain, and 11.1% had delays in at least one domain. Neurodevelopmental outcome was similar between treatment groups. Prolonged ventilator support and neonatal intensive care unit stay, need for supplemental oxygen at day of life 30, gastroesophageal reflux disease, and delayed enteral feeding were associated with neurologic delays (all p < 0.05).

CONCLUSIONS

Neurodevelopmental scores for high-risk CLL survivors in infancy and toddlerhood are age appropriate. Neither fetal intervention nor the need for postnatal resection within the first month of life increases the risk of delays. Surrogate markers of a complicated neonatal course are predictive of adverse outcome.

Hearing Loss after Cardiac Surgery in Infancy: An Unintended Consequence of Life-Saving Care

OBJECTIVES

To investigate the prevalence of hearing loss after cardiac surgery in infancy, patient and operative factors associated with hearing loss, and the relationship of hearing loss to neurodevelopmental outcomes.

STUDY DESIGN

Audiologic and neurodevelopmental evaluations were conducted on 348 children who underwent repair of congenital heart disease at the Children's Hospital of Philadelphia as part of a prospective study evaluating neurodevelopmental outcomes at 4 years of age. A prevalence estimate was calculated based on presence and type of hearing loss. Potential risk factors and the impact of hearing loss on neurodevelopmental outcomes were evaluated.

RESULTS

The prevalence of hearing loss was 21.6% (95% CI, 17.2-25.9). The prevalence of conductive hearing loss, sensorineural hearing loss, and indeterminate hearing loss were 12.4% (95% CI, 8.8-16.0), 6.9% (95% CI, 4.1-9.7), and 2.3% (95% CI, 0.6-4.0), respectively. Only 18 of 348 subjects (5.2%) had screened positive for hearing loss before this study and 10 used a hearing aid. After adjusting for patient and operative covariates, younger gestational age, longer postoperative duration of stay, and a confirmed genetic anomaly were associated with hearing loss (all P < .01). The presence of hearing loss was associated with worse language, cognition and attention (P <.01).

CONCLUSIONS

These findings suggest that the prevalence of hearing loss in preschool children after heart surgery in infancy may be 20-fold higher than in the 1% prevalence seen in the general population. Younger gestational age, presence of a genetic anomaly, and longer postoperative duration of stay were associated with hearing loss. Hearing loss was associated with worse neurodevelopmental outcomes.

Autosomal dominant mannose-binding lectin deficiency is associated with worse neurodevelopmental outcomes after cardiac surgery in infants

OBJECTIVES

The MBL2 gene is the major genetic determinant of mannose-binding lectin (MBL)-an acute phase reactant. Low MBL levels have been associated with adverse outcomes in preterm infants. The MBL2_Gly54Asp missense variant causes autosomal dominant MBL deficiency. We tested the hypothesis that MBL2_Gly54Asp is associated with worse neurodevelopmental outcomes after cardiac surgery in neonates.

METHODS

This is an analysis of a previously described cohort of patients with nonsyndromic congenital heart disease who underwent cardiac surgery with cardiopulmonary bypass before age 6 months (n = 295). Four-year neurodevelopment was assessed in 3 domains: Full-Scale Intellectual Quotient, the Visual Motor Integration development test, and the Child Behavior Checklist to assess behavior problems. The Child Behavior Checklist measured total behavior problems, pervasive developmental problems, and internalizing/externalizing problems. A multivariable linear regression model, adjusting for confounders, was fit.

RESULTS

MBL2_Gly54Asp was associated with a significantly increased covariate-adjusted pervasive developmental problem score (β = 3.98; P = .0025). Sensitivity analyses of the interaction between age at first surgery and MBL genotype suggested effect modification for the patients with MBL2_Gly54Asp (P_interaction = .039), with the poorest neurodevelopment outcomes occurring in children who had surgery earlier in life.

CONCLUSIONS

We report the novel finding that carriers of MBL2_Gly54Asp causing autosomal dominant MBL deficiency have increased childhood pervasive developmental problems after cardiac surgery, independent of other covariates. Sensitivity analyses suggest that this effect may be larger in children who underwent surgery at earlier ages. These data support the role of nonsyndromic genetic variation in determining postsurgical neurodevelopment-related outcomes in children with congenital heart disease.

Rates of autism and potential risk factors in children with congenital heart defects

OBJECTIVE

Atypical development, behavioral difficulties, and academic underachievement are common morbidities in children with a history of congenital heart defects and impact quality of life. Language and social-cognitive deficits have been described, which are associated with autism spectrum disorders. The current study aimed to assess the rates of autism spectrum disorders in a large sample of children with a history of congenital heart defects and to assess medical, behavioral, and individual factors that may be associated with the risk of autism spectrum disorders.

DESIGN

Participants included 195 children with a history of congenital heart defects, who are followed in a large-scale longitudinal study. Measures included behavioral data from 4-year-old neurodevelopmental evaluations and parent-report data from a later annual follow-up.

RESULTS

Using established cutoffs on an autism spectrum disorder screener, children with congenital heart defects showed higher rates of "possible" autism spectrum disorders than national rates, (Chi-square Test of Equal Proportions), all Ps < .05. A stepwise variable selection method was used to create a "best prediction model" and multivariable logistic regression was used to identify variables predicting diagnostic status. Factors associated with diagnostic risk included medical (delayed sternal closure, prematurity, positive genetic findings), behavioral (cognitive, language, attention issues), and individual (socioeconomic, cultural/racial) variables. ROC analyses identified a cutoff of 7 to maximize sensitivity/specificity based on parent-reported diagnosis.

CONCLUSIONS

Risk of autism spectrum disorder screening status in children with congenital heart defects was higher than expected from population rates. Findings highlight the need for referral to a specialist to assess the presence and severity of social-communication issues and congenital heart defects population-specific screening thresholds for children with concern for autism spectrum disorders.

Increasing cumulative exposure to volatile anesthetic agents is associated with poorer neurodevelopmental outcomes in children with hypoplastic left heart syndrome

OBJECTIVES

Despite improved survival in children with hypoplastic left heart syndrome (HLHS), significant concern persists regarding their neurodevelopmental (ND) outcomes. Previous studies have identified patient factors, such as prematurity and genetic syndromes, to be associated with worse ND outcomes. However, no consistent relationships have been identified among modifiable management factors, including cardiopulmonary bypass strategies, and ND outcomes after cardiac surgery in infancy. Studies in immature animals, including primates, have demonstrated neurodegeneration and apoptosis in the brain after certain levels and extended durations of anesthetic exposure. Retrospective human studies have also suggested relationships between adverse ND effects and anesthetic exposure.

METHODS

Cumulative minimum alveolar concentration hours (MAC-hrs) of exposure to volatile anesthetic agents (VAA) (desflurane, halothane, isoflurane, and sevoflurane) were collected from an anesthetic database and medical record review for 96 patients with HLHS or variants. ND testing was performed between ages 4 and 5 years, including full-scale IQ, verbal IQ, performance IQ, and processing speed. Four generalized linear modes were hypothesized a priori and tested using a Gaussian (normal) distribution with an identity link.

RESULTS

Cumulative VAA exposure ranged from 0 to 35.3 MAC-hrs (median 7.5 hours). Using specified covariates identified previously as significant predictors of ND outcomes, statistically significant relationships were identified between total MAC-hrs exposure and worse full-scale IQ and verbal IQ scores (P's < .05) alone and after adjusting for relevant covariates.

CONCLUSIONS

Increased cumulative MAC-hrs exposure to VAA is associated with worse ND outcomes in certain domains in children with HLHS and variants.

Incidence and factors associated with sensorineural and conductive hearing loss among survivors of congenital diaphragmatic hernia

PURPOSE

The reported incidence of sensorineural hearing loss (SNHL) in long-term survivors of congenital diaphragmatic hernia varies widely in the literature. Conductive hearing loss (CHL) is also known to occur in CDH patients, but has been less widely studied. We sought to characterize the incidence and risk factors associated with SNHL and CHL in a large cohort of CDH patients who underwent standardized treatment and follow-up at a single institution.

METHODS

We retrospectively reviewed charts of all CDH patients in our pulmonary hypoplasia program from January 2004 through December 2012. Categorical variables were analyzed by Fisher's exact test and continuous variables by Mann-Whitney t-test (p≤0.05).

RESULTS

A total of 112 patients met study inclusion criteria, with 3 (2.7%) patients diagnosed with SNHL and 38 (34.0%) diagnosed with CHL. SNHL was significantly associated with requirement for ECMO (p=0.0130), prolonged course of hospitalization (p=0.0011), duration of mechanical ventilation (p=0.0046), requirement for tracheostomy (p=0.0013), and duration of loop diuretic (p=0.0005) and aminoglycoside therapy (p=0.0003).

CONCLUSIONS

We have identified hearing anomalies in over 30% of long-term CDH survivors. These findings illustrate the need for routine serial audiologic evaluations throughout childhood for all survivors of CDH and stress the importance of targeted interventions to optimize long-term developmental outcomes pertaining to speech and language.

Results of genome-wide analyses on neurodevelopmental phenotypes at four-year follow-up following cardiac surgery in infancy

BACKGROUND

Adverse neurodevelopmental sequelae are reported among children who undergo early cardiac surgery to repair congenital heart defects (CHD). APOE genotype has previously been determined to contribute to the prediction of these outcomes. Understanding further genetic causes for the development of poor neurobehavioral outcomes should enhance patient risk stratification and improve both prevention and treatment strategies.

METHODS

We performed a prospective observational study of children who underwent cardiac surgery before six months of age; this included a neurodevelopmental evaluation between their fourth and fifth birthdays. Attention and behavioral skills were assessed through parental report utilizing the Attention Deficit-Hyperactivity Disorder-IV scale preschool edition (ADHD-IV), and Child Behavior Checklist (CBCL/1.5-5), respectively. Of the seven investigated, three neurodevelopmental phenotypes met genomic quality control criteria. Linear regression was performed to determine the effect of genome-wide genetic variation on these three neurodevelopmental measures in 316 subjects.

RESULTS

This genome-wide association study identified single nucleotide polymorphisms (SNPs) associated with three neurobehavioral phenotypes in the postoperative children ADHD-IV Impulsivity/Hyperactivity, CBCL/1.5-5 PDPs, and CBCL/1.5-5 Total Problems. The most predictive SNPs for each phenotype were: a LGALS8 intronic SNP, rs4659682, associated with ADHD-IV Impulsivity (P=1.03 × 10(-6)); a PCSK5 intronic SNP, rs2261722, associated with CBCL/1.5-5 PDPs (P=1.11 × 10(-6)); and an intergenic SNP, rs11617488, 50 kb from FGF9, associated with CBCL/1.5-5 Total Problems (P=3.47 × 10(-7)). 10 SNPs (3 for ADHD-IV Impulsivity, 5 for CBCL/1.5-5 PDPs, and 2 for CBCL/1.5-5 Total Problems) had p<10(-5).

CONCLUSIONS

No SNPs met genome-wide significance for our three neurobehavioral phenotypes; however, 10 SNPs reached a threshold for suggestive significance (p<10(-5)). Given the unique nature of this cohort, larger studies and/or replication are not possible. Studies to further investigate the mechanisms through which these newly identified genes may influence neurodevelopment dysfunction are warranted.

Perchlorate exposure and dose estimates in infants

Perchlorate is a naturally occurring inorganic anion used as a component of solid rocket fuel, explosives, and pyrotechnics. Sufficiently high perchlorate intakes can modify thyroid function by competitively inhibiting iodide uptake in adults; however, little is known about perchlorate exposure and health effects in infants. Food intake models predict that infants have higher perchlorate exposure doses than adults. For this reason, we measured perchlorate and related anions (nitrate, thiocyanate, and iodide) in 206 urine samples from 92 infants ages 1-377 days and calculated perchlorate intake dose for this sample of infants. The median estimated exposure dose for this sample of infants was 0.160 μg/kg/day. Of the 205 individual dose estimates, 9% exceeded the reference dose of 0.7 μg/kg/day; 6% of infants providing multiple samples had multiple perchlorate dose estimates above the reference dose. Estimated exposure dose differed by feeding method: breast-fed infants had a higher perchlorate exposure dose (geometric mean 0.220 μg/kg/day) than infants consuming cow milk-based formula (geometric mean 0.103 μg/kg/day, p < 0.0001) or soy-based formula (geometric mean 0.027 μg/kg/day, p < 0.0001), consistent with dose estimates based on dietary intake data. The ability of perchlorate to block adequate iodide uptake by the thyroid may have been reduced by the iodine-sufficient status of the infants studied (median urinary iodide 125 μg/L). Further research is needed to see whether these perchlorate intake doses lead to any health effects.

Goitrogenic anions, thyroid-stimulating hormone, and thyroid hormone in infants

BACKGROUND

Environmental exposure of infants to perchlorate, thiocyanate, nitrate, might interfere with thyroid function. U.S. women with higher background perchlorate exposure have higher thyroid-stimulating hormone (TSH) and lower thyroxine (T4). There are no studies with individual measures of thyroid function and these goitrogens available in infants.

OBJECTIVE

We examined the association of urinary perchlorate, nitrate, iodide, and thiocyanate with urinary T4 and TSH in infants and whether that association differed by sex or iodide status.

METHODS

We used data and samples from the Study of Estrogen Activity and Development, which assessed hormone levels of full-term infants over the first 12 months of life. The study included 92 full-term infants between birth and 1 year of age seen up to four times. Perchlorate, thiocyanate, nitrate, and iodide were measured in 206 urine samples; TSH and T4 and were measured in urines and in 50 blood samples.

RESULTS

In separate mixed models, adjusting for creatinine, age, sex, and body mass index, infants with higher urinary perchlorate, nitrate or thiocyanate had higher urinary TSH. With all three modeled, children with higher nitrate and thiocyanate had higher TSH, but higher perchlorate was associated with TSH only in children with low iodide. Unexpectedly, exposure to the three chemicals was generally associated with higher T4.

CONCLUSIONS

The association of perchlorate exposure with increased urinary TSH in infants with low urinary iodide is consistent with previous findings. Higher thiocyanate and nitrate exposure were also associated with higher TSH in infants.

Are breast-fed infants more resilient? Feeding method and cortisol in infants

The effect of feeding method on stress hormone levels in infants is unknown. We studied infants from birth to 1 year and found salivary cortisol 40% higher in breast-fed infants compared with formula-fed infants. The higher cortisol levels among breast-fed children may be involved in the analgesic effect of breastfeeding.

Isoflavones in urine, saliva, and blood of infants: data from a pilot study on the estrogenic activity of soy formula

In the United States, about 25% of infant formula sold is based on soy protein, which is an important source of estrogenic isoflavones in the human food supply. Nevertheless, few studies report isoflavone levels in infants. We did a partly cross-sectional and partly longitudinal pilot study to examine children's exposure to isoflavones from different feeding methods. A total of 166 full-term infants between birth and 1 year of age were recruited into soy formula, cow milk formula, or breast milk regimens according to their feeding histories. A total of 381 urine, 361 saliva, and 88 blood samples were collected at 382 visits. We used automated online solid-phase extraction coupled to high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for measuring three isoflavones (daidzein, genistein, and equol) in urine, and used similar LC/MS/MS techniques for saliva and blood spots. Concentrations of daidzein and genistein were undetectable in most blood or saliva samples from children fed breast milk or cow milk formula. The proportion of non-detectable values was somewhat lower in urine than in the other matrices. Concentrations of equol were detectable only in a few urine samples. For both daidzein and genistein, urine contained the highest median concentrations, followed by blood and then saliva. Urinary concentrations of genistein and daidzein were about 500 times higher in the soy formula-fed infants than in the cow milk formula-fed infants. The correlations between matrices for either analyte were strikingly lower than the correlation between the two analytes in any single matrix. We did not find significant correlations between isoflavone concentrations and the levels of certain hormones in children fed soy formula. Our results, based on much larger numbers of infants, strongly confirm previous reports, but whether phytoestrogens in soy formula are biologically active in infants is still an open question. We plan further longitudinal studies focusing on physical and developmental findings reflecting the effects of estrogen exposure.

Pilot studies of estrogen-related physical findings in infants

BACKGROUND

Soy formula containing estrogenic isoflavones is widely used in the United States. Infants consuming soy formula exclusively have high isoflavone exposures. We wanted to study whether soy formula prolonged the physiologic estrogenization of newborns, but available quantitative descriptions of the natural history of breast and genital development are inadequate for study design.

OBJECTIVE

We piloted techniques for assessing infants' responses to the withdrawal from maternal estrogen and gathered data on breast and genital development in infants at different ages.

METHODS

We studied 37 boys and 35 girls, from term pregnancies with normal birth weights, who were < 48 hr to 6 months of age, and residents of Philadelphia, Pennsylvania, during 2004-2005. One-third of the children of each sex and age interval were exclusively fed breast milk, soy formula, or cow-milk formula. Our cross-sectional study measured breast adipose tissue, breast buds, and testicular volume; observed breast and genital development; and collected vaginal wall cells and information on vaginal discharge. We assessed reliability of the measures.

RESULTS

Breast tissue was maximal at birth and disappeared in older children, consistent with waning maternal estrogen. Genital development did not change by age. Breast-milk secretion and withdrawal bleeding were unusual. Vaginal wall cells showed maximal estrogen effect at birth and then reverted; girls on soy appeared to show reestrogenization at 6 months.

CONCLUSIONS

Examination of infants for plausible effects of estrogens is valid and repeatable. Measurement of breast tissue and characterization of vaginal wall cells could be used to evaluate exposures with estrogen-like effects.

Early intervention in low birth weight premature infants: results at 18 years of age for the Infant Health and Development Program

OBJECTIVE

To assess whether improvements in cognitive and behavioral development seen in preschool educational programs persist, we compared those in a multisite randomized trial of such a program over the first 3 years of life (INT) to those with follow-up only (FUO) at 18 months of age.

METHODS

This was a prospective follow-up of the Infant Health and Development Program at 8 sites heterogeneous for sociodemographic characteristics. Originally 985 children were randomized to the INT (n = 377) or FUO (n = 608) groups within 2 birth weight strata: heavier low birth weight (HLBW; 2001-2499 g) and lighter low birth weight (LLBW; < or = 2000 g). Primary outcome measures were the Peabody Picture Vocabulary Test (PPVT-III), reading and mathematics subscales of the Woodcock-Johnson Tests of Achievement, youth self-report on the Total Behavior Problem Index, and high-risk behaviors on the Youth Risk Behavior Surveillance System (YRBSS). Secondary outcomes included Weschler full-scale IQ, caregiver report on the Total Behavior Problem Index, and caregiver and youth self-reported physical health using the Medical Outcome Study measure. Assessors were masked as to study status.

RESULTS

We assessed 636 youths at 18 years (64.6% of the 985, 72% of whom had not died or refused at prior assessments). After adjusting for cohort attrition, differences favoring the INT group were seen on the Woodcock-Johnson Tests of Achievement in math (5.1 points), YRBSS (-0.7 points), and the PPVT-III (3.8 points) in the HLBW youth. In the LLBW youth, the Woodcock-Johnson Tests of Achievement in reading was higher in the FUO than INT group (4.2).

CONCLUSIONS

The findings in the HLBW INT group provide support for preschool education to make long-term changes in a diverse group of children who are at developmental risk. The lack of observable benefit in the LLBW group raises questions about the biological and educational factors that foster or inhibit sustained effects of early educational intervention.

Developmental follow-up of breastfed term and near-term infants with marked hyperbilirubinemia

OBJECTIVE

In recent years, the increased prevalence of breastfeeding in conjunction with early discharge practices has increased the risk for marked hyperbilirubinemia in neonates. This has resulted in the potential for bilirubin brain injury in affected infants. The purpose of this study was to identify all infants >/=36 weeks' gestational age with bilirubin levels >25 mg/dL and evaluate them for early and late evidence of bilirubin brain injury.

METHODS

We reviewed the charts of all infants (from 1993-1996) >/=36 weeks' gestational age who were readmitted to the hospital during the first week of life with bilirubin levels >25 mg/dL. Readmission records were reviewed for early signs of bilirubin encephalopathy. Magnetic resonance imaging (MRIs) and Brainstem auditory-evoked responses (BAERs) were reviewed for evidence of bilirubin toxicity. At follow-up, study infants had a complete neurodevelopmental examination, repeat MRIs, and behavioral hearing evaluations.

RESULTS

From 1993 to 1996, we identified 6 term and near-term infants readmitted to the hospital within the first week of life with peak bilirubin values ranging from 26.4 mg/dL (451 micromol/L) to 36.9 mg/dL (631 micromol/L). Five of 6 infants had bilirubin values >30 mg/dL (513 micromol/L). All were exclusively breastfed or fed a combination of breast and bottle feedings. Five of 6 infants presented with abnormal neurologic signs. Four infants had initial MRIs, 3 of whom had increased signal intensity in the basal ganglia consistent with kernicterus. Two infants had abnormal BAERs; both also had abnormal MRIs. Five of 6 infants received exchange transfusions and all were treated with phototherapy and intravenous fluids. Follow-up examinations between 3 months and 2 years showed resolution of clinical signs in all but 1 infant. Four infants had a subsequent normal MRI and 1 had residual hearing impairment. One infant demonstrated severely abnormal developmental evaluations, as well as both an abnormal initial MRI and BAERs. Follow-up MRI showed evidence of encephalomalacia with changes not characteristic of kernicterus.

CONCLUSIONS

We observed transient neurologic abnormalities in 5 of 6 infants readmitted to the hospital during the first week of life with marked hyperbilirubinemia. The abnormalities resolved following aggressive management using hydration, phototherapy, and exchange transfusion and may not correlate with long-term prognosis. Less aggressive therapy may be associated with residual neurologic abnormalities. We speculate that inadequate establishment of breastfeeding coupled with early discharge practices may play a role in the development of marked hyperbilirubinemia in these infants.

Pulmonary hypertension in children following extracorporeal membrane oxygenation therapy and repair of congenital diaphragmatic hernia

OBJECTIVE

Pulmonary hypertension (PHT) is present in all children at birth, but its degree and rate of resolution in infants diagnosed with congenital diaphragmatic hernia (CDH) requiring extracorporeal membrane oxygenation (ECMO) need to be established.

STUDY DESIGN

Twenty-one ECMO/CDH survivors (aged 3.2 +/- 1.4 years) were prospectively evaluated by Doppler echocardiography (ECHO) to determine the presence of PHT. Twenty children without structural heart disease were used as controls. Study patients received a physical examination and an electrocardiograph examination, and their charts were reviewed for neonatal course data. Patients found to have PHT by ECHO received a complete history and exercise treadmill/oxygen desaturation study.

RESULTS

Eight of the 21 patients (38%) met echocardiographic criteria for PHT. No neonatal course data were found to be predictive of eventual PHT status. There was no correlation between physical examination or electrocardiographic findings and PHT. Complete histories showed five of the eight patients with PHT had some degree of exercise intolerance and seven had wheezing. Two of the seven patients studied on the treadmill desaturated 5% or greater from baseline.

CONCLUSION

There is evidence that PHT either persists or recurs in a significant portion of the ECMO/CDH population and may remain symptomatic well beyond the neonatal period.

Results at age 8 years of early intervention for low-birth-weight premature infants. The Infant Health and Development Program

OBJECTIVE

To reevaluate at age 8 years children who had participated during the first 3 years of life in a randomized clinical trial of special services for low-birthweight (LBW) premature infants.

DESIGN

Follow-up of a randomized controlled trial of premature infants (< or = 37 weeks' gestation), stratified by 2 LBW groups (lighter [< or = 2000 g] and heavier [2001-2500 g]) and divided into intervention (n=377) and follow-up only (n=608) groups.

SETTING

Eight sites serving diverse populations.

PARTICIPANTS

At age 8 years, 874 children were assessed: 336 in the intervention group and 538 in the follow-up only group.

INTERVENTION

The 3-year intervention consisted of home visits (birth to 3 years), child development center services (ages 1 to 3 years), and parent group meetings (ages 1 to 3 years).

PRIMARY OUTCOME MEASURES

Cognitive functioning (Weschler Intelligence Scale for Children-III; Peabody Picture Vocabulary Test-Revised); academic achievement (Woodcock-Johnson Tests of Achievement-Revised); and parental reports of school performance, behavior (Child Behavior Checklist), and health (Child General Health Survey).

RESULTS

At age 8 years, in the entire cohort and in the lighter LBW stratum, the intervention and follow-up only groups were similar on all primary outcome measures. Differences favoring the intervention group were found within the heavier LBW group: full-scale IQ score (4.4 points higher, P=.007), verbal IQ score (4.2 points higher, P=.01), performance IQ score (3.9 points higher, P=.02), mathematics achievement score (4.8 points higher, P=.04), and receptive vocabulary score (6.7 points higher, P=.001). On a physical functioning subscale, the whole intervention group received less favorable ratings, while the lighter LBW intervention group had lower maternal ratings assessing social limitations caused by behavior.

CONCLUSION

Although at age 8 years there were modest intervention-related differences in the cognitive and academic skills of heavier LBW premature children, attenuation of the large favorable effects seen at 3 years was observed in both the heavier and lighter LBW groups. This indicates a need to develop additional intervention strategies for LBW premature children that can provide sustained benefits.

Outcome for infants with congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation: the first year

Congenital diaphragmatic hernia (CDH) has been associated with a high mortality rate. The purposes of this study were to determine the impact of extracorporeal membrane oxygenation (ECMO) on the survival of infants with CDH and to document the sequelae and 1-year neurodevelopmental outcome for CDH infants who required ECMO. Thirty neonates with CDH were admitted between May 7, 1990 and October 1, 1992. Twenty required ECMO and were enrolled in our neonatal follow-up program. Information about the infants' neonatal course was obtained from chart review, and the infants were seen at 3, 6, and 12 months of age for medical and neurodevelopmental follow-up. Primary diaphragmatic repair was performed in 13 infants. Five required Goretex graft reconstruction (GGR), and two did not have repair. Sixteen (80%) of the 20 infants who required ECMO survived. The overall survival rate increased from 31% (10 of 32) in the 5 years previous to the start of the ECMO program to 63% (19 of 30) since then (P = .01). The most common sequelae noted by the time of discharge included gastroesophageal reflux (GER; 81%), the need for tube feeding (69%), and chronic lung disease (CLD; 62%). At 1 year of age, mean cognitive skills were average (87 +/- 23) and motor skills were borderline (75 +/- 24) according to the Bayley Scales of Infant Development. Hypotonia was present in 10 of 13 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Early intervention in low-birth-weight premature infants. Results through age 5 years from the Infant Health and Development Program

OBJECTIVE

To evaluate the persistence of effects on health and development at age 5 years of the Infant Health and Development Program, an early childhood intervention that was provided to low-birth-weight (LBW) premature infants from neonatal discharge through age 3 years.

DESIGN

Randomized, controlled, multicenter trial, stratified by two LBW groups: lighter (< or = 2000 g) and heavier (2001 to 2500 g).

SETTING

Eight socioeconomically heterogeneous clinical sites.

PARTICIPANTS

Of 985 eligible infants weighing 2500 g or less and at 37 weeks' or less gestational age, 377 infants were randomly assigned to the intervention group and 608 to the follow-up only group. About two thirds of the infants in each group were in the lighter LBW stratum, and one third were in the heavier LBW stratum.

INTERVENTION

The intervention group received home visits (from neonatal discharge through age 3 years) as well as center-based schooling (from 1 to 3 years of age). Children in both groups received pediatric surveillance.

MAIN OUTCOME MEASURES

Cognitive development, behavioral competence, and health status.

RESULTS

At age 5 years, the intervention group had full-scale IQ scores similar to children in the follow-up only group. However, in the heavier LBW stratum, children in the intervention group had higher full-scale IQ scores (3.7 points higher; P = .03) and higher verbal IQ scores (4.2 points higher; P = .02). No significant differences between intervention and follow-up only groups in cognitive measures at age 5 years were noted in the lighter LBW infants. The intervention and follow-up groups were similar in behavior and health measures regardless of LBW stratum.

CONCLUSION

The early childhood intervention provided in the first 3 years of life had effects on heavier LBW premature infants' IQ and verbal performance at age 5 years that were not observed for lighter LBW premature infants. The intervention did not affect health or behavior at age 5 years in either LBW stratum.

Costs incurred by parents of very low birth weight infants after the initial neonatal hospitalization

To assess the economic impact of the posthospitalization care of very low birth weight (VLBW) infants, the costs incurred in the first year of life by 32 VLBW infants were compared with those incurred by 34 term, comparison infants. Diaries and quarterly interviews revealed that VLBW infants averaged $10,139 in direct medical charges compared with $1179 for the term infants; the differential in charges was greatest in the first two quarters and virtually disappeared by the fourth quarter. In addition, expenditures associated with transportation and child care presented an added substantial burden, although only the former were significantly higher for the VLBW infants. Clinicians may need to inquire specifically about the burden on family resources because, despite the economic burden and evidence of less social support, the parents of VLBW infants were less likely to perceive their child's care as having an impact on the family than were the parents of term children.

A new method for delivering a taste without fluids to preterm and term infants

A new method for administering a taste to preterm and term infants has been developed that does not necessitate the delivery of rapid solutions. Sucrose, a sugar that in solution was shown to potentiate sucking behavior, was embedded in gelatin-based nipples that continuously release sweet taste when mouthed or sucked. The gelatin nipples and comparable latex nipples were adapted to measure sucking behavior and were tested in a within-subject design. The gelatin nipples potentiated sucking in preterm and term infants by increasing the frequency and strength of the responses. Few sucking measures varied significantly for preterm and term infants. Those that did vary might be attributable to differences in physical stamina, rather than to orosensory or hedonic factors. It was concluded that the flavored gelatin nipple provides an effective method for studying taste in infants and offers the possibility of routine chemosensory stimulation for research and clinical applications.

Growth and metabolic response of premature infants fed whey- or casein-dominant formulas after hospital discharge

We conducted a double-blind, randomized study to test the hypothesis that a whey-dominant formula permits a growth and metabolic advantage over a casein-dominant formula in preterm infants after hospital discharge. Nineteen low birth weight infants were studied for 6 months from the time of discharge. Ten received a casein-dominant formula, and nine received a whey-dominant formula. Growth (weight, length, head circumference, mid-arm circumference, and skin-fold thickness), biochemical measurements (alkaline phosphatase activity, acid-base status, and hemoglobin, serum total protein, albumin, and urea nitrogen levels), and quantity of formula intake did not differ significantly between the groups over a 6-month study period. Serum transthyretin and urea nitrogen concentrations differed significantly between the two feeding groups at the day of entry into the study only. The results indicate that, after hospital discharge, premature infants fed a whey-dominant formula do not differ in growth or biochemical measurements from those fed a casein-dominant formula.

Preliminary observations on maternal rating of health of children: data from three subspecialty clinics

Although routinely used in health surveys, the factors affecting maternal perceptions of health in children, especially those with health problems, have received little examination. This question has been addressed using a telephone interview of families of 483 children followed in one of three clinics at Children's Hospital of Philadelphia: the Neonatal Follow-up Program, the Pediatric Rheumatology Center and the Spina Bifida Program. Limitations in activities of daily living due to the health of the child, medical care use and variables indicative of socio-economic disadvantage were associated with a maternal rating of child health as fair/poor in all groups. The relationship was strongest in the rheumatologic group and less strong in the other two, suggesting that mothers may distinguish between a chronic active disease in a previously healthy child and the disability following a neonatal event in conceptualizing health. The results add to our information about maternal perceptions in assessing child health and suggest ways in which such ratings may prove useful in assessing health and health services for children with health problems.

The very low birth weight transport goes home: impact on the family

Very low birth weight (VLBW) infants are known to experience more health problems after discharge from the hospital, but the effects of such problems in terms of the demand for medical care and of the effect of this on the family are only just beginning to be described. A survey of the families of 132 children who were born weighing less than 1750 g at mostly suburban hospitals and transported to a Children's Hospital, who were 1-4 years old at the time of the survey, has revealed that these children continue to experience health problems to the extent that 35% are limited in one or more activities of daily living. They also incur greater use of health care services (17% hospitalized in the prior year; 54% with a doctor's visit in the prior month). The most important predictors of high perceived impact of these problems on the family is related to the number of activities limited by health, the age of the child, and the financial resources the family could bring to coping with the child's care. These findings provide further characterization of the families which may be most vulnerable to the ongoing health problems of the VLBW infant.

Abnormal truncal muscle tone as a useful early marker for developmental delay in low birth weight infants

Thirty-four outborn premature infants of appropriate gestational ages with birth weights less than 1,750 g were seen in follow-up at 3, 6, 12, and 18 months, corrected age to assess the incidence of abnormalities of muscle tone and the relationship of the site of early abnormalities to 18-month developmental status. The incidence of abnormal tone was most common at 3 months and declined with increasing age. The percentages of infants with abnormal tone at 3, 6, 12, and 18 months, respectively, were: increased lower extremity tone--62%, 71%, 38%, 9%; decreased lower extremity tone--3%, 3%, 6%, 9%; increased truncal tone--41%, 15%, 6%, 0%; decreased truncal tone--21%, 18%, 15%, 6%. Infants with truncal hypertonicity at 3 months had significantly lower Bayley motor and mental scores at 18 months when compared with infants with normal truncal tone (P less than .05). However, infants with lower extremity hypertonicity at 3 months were no different developmentally at 18 months from infants with normal tone. Infants with truncal or lower extremity hypotonicity fared the worst developmentally (P less than .05). We conclude that there is a high incidence of abnormal muscle tone in premature infants up to 18 months of age and that early truncal tone abnormalities are associated with a worse developmental outcome.

Abnormal shoulder girdle muscle tone in premature infants during their first 18 months of life

To document the incidence of and neonatal factors associated with abnormal shoulder girdle muscle tone in premature infants at follow-up, we studied 125 consecutively admitted infants weighing less than 1,750 g treated in The Children's Hospital of Philadelphia intensive care nursery and subsequently seen in the Neonatal Follow-up Program up to 18 months of age. Fifty-seven infants (46%) displayed abnormal shoulder girdle muscle tone which presented clinically as scapular retractions. These infants had significantly lower birth weights (P less than .001) and gestational age (P less than .001) as well as a higher incidence of acute and chronic pulmonary disease (P less than 0.01) and CNS insults (P less than .05) when compared with infants without scapular retractions. The 57 infants with scapular retractions were further divided into two groups: 42 infants (74%) in whom scapular retractions were associated with generalized mild hypertonicity and 15 infants (26%) in whom scapular retractions compensated for trunk and neck hypotonicity. The infants with scapular retractions and hypotonicity had a significantly higher incidence of neonatal neurologic morbidity including seizures, major resuscitations, and birth asphyxia (P less than .01) when compared with the infants with scapular retractions and hypertonicity. Shoulder girdle tone abnormalities in the first year of life inhibit crawling, sitting, and object manipulation and, therefore, may manifest as delays in motor development. Identification of infants with significant neonatal risk factors for tone abnormalities is important to allow for earlier therapeutic intervention.

Response of preterm infants to diphtheria-tetanus-pertussis immunizations

To establish guidelines for the routine use of diphtheria, tetanus, and pertussis (DTP) vaccine in preterm infants, we quantitated antibody responses of preterm infants to DTP and determined the nature and extent of side effects. Twenty-five preterm infants were immunized with 0.5 ml DTP vaccine at routine intervals. Term infants served as controls. Immediately before each immunization and 2 months after the third, DTP-specific antibodies were quantitated. Clinical side effects were determined by parental report. After the second immunization, 100% of preterm infants had evidence of specific antibody production against diphtheria, tetanus, and pertussis. The incidence of side effects was low, but irritability was significantly more common in preterm infants after the second immunization. These observations suggest that the initiation of primary immunization with DTP in preterm infants need not be delayed beyond 2 months of age.

Long-term follow-up of newborns with persistent pulmonary hypertension

Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome associated with high morbidity and mortality. Mechanical ventilation attempts to maintain a PaCO2 less than 30 torr and a pH greater than 7.5 until pulmonary hypertension resolves. To assess whether the disease or its therapy adversely affects neurodevelopmental or cardiorespiratory outcome, 11 infants diagnosed and treated for PPHN were evaluated at a mean age of 31 months. Nine had normal developmental quotients (DQs) and 2 had mildly delayed DQs. Eight children were entirely normal neurologically, 2 had slightly increased lower-extremity tone, and 1 had unilateral hypertonia. All cardiac exams, echocardiograms, and ECGs were normal. Four children had chronic lung disease requiring either daily or intermittent bronchodilator therapy; however, their activity levels were unaffected. These results suggest that subsequent normal development with little significant medical compromise may be expected in this group of critically ill infants.

Nonnutritive sucking during gavage feeding enhances growth and maturation in premature infants

The effects of nonnutritive sucking (NNS) by means of a pacifier during gavage feeding were studied in 30 premature infants whose birth weight was less than 1,500 g. The addition of NNS accelerated the maturation of the sucking reflex, facilitating a more rapid transition from gavage to oral feedings. Additionally, NNS decreased intestinal transit time and caused a more rapid weight gain despite comparable caloric intake resulting in a shortened hospital stay. Although the physiologic mechanisms resulting from this form of oral stimulation remain to be investigated, our data suggest that NNS may be an important factor to consider in the feeding of premature infants.