Cerebral Palsy and Motor Impairment After Extreme Prematurity: Prediction of Diagnoses at Ages 2 and 10 Years.

OBJECTIVE: To identify perinatal factors in children born extremely preterm (EP) that were associated with motor impairment (MI) at 2 and 10 years of age and develop a predictive algorithm to estimate the risk of MI during childhood. STUDY DESIGN: Participants of the Extremely Low Gestational Age Newborns Study (ELGANS) were classified as: no MI, MI only at 2 years, MI only at 10 years, and MI at both 2 and 10 years, based on a standardized neurological examination at 2 and the Gross Motor Function Classification System (GMFCS) at 10 years of age. Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to develop the final predictive model. RESULTS: Of the 849 study participants, 64 (7.5%) had a diagnosis of MI at both 2 and 10 years and 63 (7.4%) had a diagnosis of MI at 1 visit but not the other. Of 22 total risk factors queried, 4 variables most reliably and accurately predicted MI: gestational age, weight z-score growth trajectory during neonatal intensive care unit (NICU) stay, ventriculomegaly, and cerebral echolucency on head ultrasound. By selecting probability thresholds of 3.5% and 7.0% at ages 2 and 10, respectively, likelihood of developing MI can be predicted with a sensitivity and specificity of 71.2%/72.1% at age 2 and 70.7%/70.7% at age 10. CONCLUSION: In our cohort, the diagnosis of MI at 2 years did not always predict a diagnosis of MI at 10 years. Specific risk factors are predictive of MI and can estimate an individual infant's risk at NICU discharge of MI at age 10 years.

Role of Genetic Susceptibility in the Development of Bronchopulmonary Dysplasia.

OBJECTIVE: To assess heritable contributions to bronchopulmonary dysplasia (BPD) risk in a twin cohort restricted to gestational age at birth <29 weeks. STUDY DESIGN: A total of 250 twin pairs (192 dichorionic, 58 monochorionic) born <29 weeks gestational age with known BPD status were identified. Three statistical methods applicable to twin cohorts (χ2 test, intraclass correlations [ICCs], and ACE modeling [additive genetic or A, common environmental or C, and unique environmental or E components]) were applied. Heritability was estimated as percent variability from A. Identical methods were applied to a subcohort defined by zygosity and to an independent validation cohort. RESULTS: χ2 analyses comparing whether neither, 1, or both of monochorionic (23, 19, 16) and dichorionic (88, 56, 48) twin pairs developed BPD revealed no difference. Although there was similarity in BPD outcome within both monochorionic and dichorionic twin pairs by ICC (monochorionic ICC = 0.34, 95% CI [0.08, 0.55]; dichorionic ICC = 0.39, 95% CI [0.25, 0.51]), monochorionic twins were not more likely than dichorionic twins to have the same outcome (P = .70). ACE modeling revealed no contribution of heritability to BPD risk (% A = 0.0%, 95% CI [0.0%, 43.1%]). Validation and zygosity based cohort results were similar. CONCLUSIONS: Our analysis suggests that heritability is not a major contributor to BPD risk in preterm infants <29 weeks gestational age.

Assessing Positive Child Health among Individuals Born Extremely Preterm.

OBJECTIVE: To assess the development of a Positive Child Health Index (PCHI) based on 11 adverse outcomes and evaluate the association of PCHI with quality of life (QoL) scores in a preterm cohort. STUDY DESIGN: A total of 889 children enrolled in the Extremely Low Gestational Age Newborn (ELGAN) study in 2002-2004 were followed up at 10 years of age. A parent/caregiver completed questionnaires for child QoL, asthma, visual or hearing impairment, gross motor function impairment, epilepsy, attention deficit/hyperactivity disorder, anxiety, and depression. The child was assessed for cognitive impairment, autism, and obesity. PCHI scores were computed and linear regression models were used to evaluate the relationship between QoL categories (psychosocial, physical, emotional, social, school, and total) and the PCHI (dichotomized and coded as a multilevel categorical predictor) and to assess sex differences. RESULTS: Among ELGAN children, higher PCHI scores were associated with higher reported QoL scores for all QoL categories. Children with no disorders and a PCHI of 100% had Pediatric Quality of Life Inventory total scores that were 11 points higher than children with 1 or more adverse outcomes (PCHI of <100%). Boys had lower QoL scores for the total, psychosocial, social, and school categories. CONCLUSIONS: Positive child health assessed using a quantitative PCHI was associated with QoL across the ELGAN cohort at school age. In the current study, the PCHI encompassed 11 outcomes assessed in ELGANs. Future research could include an enhanced panel of child health outcomes to support the use of PCHI as an indicator of positive child health.

Girls and Boys Born before 28 Weeks Gestation: Risks of Cognitive, Behavioral, and Neurologic Outcomes at Age 10 Years.

OBJECTIVES: To compare the prevalence of cognitive, neurologic, and behavioral outcomes at 10 years of age in 428 girls and 446 boys who were born extremely preterm. STUDY DESIGN: A total of 889 of 966 eligible children previously enrolled in the multicenter Extremely Low Gestational Age Newborns Study from 2002-2004 were evaluated at 10 years of age. Children underwent a neuropsychological battery and testing for autism spectrum disorder (ASD), and parents reported on their child's behavior, development, and seizures. RESULTS: Of the children, 28% of boys and 21% of girls exhibited moderate to severe impairment on summary measures of cognitive abilities. Boys had a higher prevalence of impairment than girls in nearly all measures of cognition, were more than twice as likely to have microcephaly (15% in boys, 8% in girls), and require more often assistive devices to ambulate (6% in boys, 4% in girls). In contrast, boys and girls had comparable risk for a history of seizure (identified in 10% of the cohort) or epilepsy (identified in 7% of the cohort). The boy-to-girl ratio of ASD (9% in boys, 5% in girls) was lower than expected compared with the overall US autism population. CONCLUSIONS: In this contemporary cohort of children born extremely premature and evaluated at school age, boys had higher prevalence of cognitive, neurologic, and behavioral deficits than girls. The ratio of boys to girls among those with ASD deserves further study as does the perinatal environmental-genetic interactions that might contribute to male preponderance of deficits in this high-risk sample.

Comparison of frozen and unfrozen blood spots for gene expression studies.

We studied gene expression in 9 sets of paired newborn blood spots stored for 8-10 years in either the frozen state or the unfrozen state. Fewer genes were expressed in unfrozen spots, but the average correlation coefficient for overall gene expression comparing the frozen and unfrozen state was 0.771 (95% CI, 0.700-0.828).