Preterm Fetal Growth Restriction and Developmental Care
The incidence of prematurity nationwide stands at 12.7 percent. Twenty-five to thirty percent of the preterm population is at risk for fetal growth restriction (FGR). FGR preterm infants show higher mortality rates, increased morbidity rates, and develop learning disabilities and school failure at a rate greater than fifty percent, compared to well-grown preterms of comparable gestational birth ages. The study will test the long term effectiveness into preschool and early school age of an in-Newborn Intensive Care Unit (NICU) developmental care method, the Newborn Individualized Developmental Care and Assessment Program (NIDCAP). The primary hypothesis to be tested is that the randomly assigned FGR preterm experimental group (E) children, who experienced NIDCAP in the NICU, will show better brain function and structure at 4 and 6 years corrected age (yCA), than the control group (C) children, who experienced standard NICU care. The study design is that of a prospective longitudinal randomized controlled trial with two parallel groups (C and E). Thirty infants born at postmenstrual ages (PMA) of 26-33 week (w) will be studied at 4yCA years and at 6yCA. The sample will be assessed in three domains, neuropsychological, neuroelectrophysiological (EEG) and neurostructural (MRI & fMRI). The primary independent variable will be treatment group (C and E). Additionally tested will be PMA, birth growth percentile (weight and head circumference), parent socioeconomic status, and parent cognitive function, all known to influence outcome. The sample will be described by existing medical and demographic measures at birth, and by behavior, brain function (EEG) and brain structure (MRI) at baseline in the NICU and at 2wCA. For the test of the primary dependent variable (executive function assessed using the NEPSY-II at age 4yCA and 6yCA) and the two secondary dependent variables (EEG: cortical coherence involving long distance frontal connectivity and MRI: frontal white matter fiber tracts), stepwise multiple linear regression analysis will be used. The five independent variables will be entered into the models. Main effects and two and three-way interaction terms will be evaluated for goodness-of-fit, assessed by use of adjusted R-squared. A sample size of 30 subjects will provide 80% statistical power (β=0.20; α=0.05, 2-tailed) to detect a mean difference of 3.2 points or greater in the executive function measure, assuming a pooled standard deviation of 3 points (standardized clinical effect size δ = 3.2 ÷ 3 = 1.1) based on a two-sample Student t-test. It is anticipated that the in-NICU intervention effect in terms of brain function and structure will set the stage for improvement in later performance, especially in terms of executive function, cognition, socio-emotional adaptation, and long-term school and life achievement.