Suzy Barcelos Winchester

Developmental origins theory from prematurity to adult disease.

Developmental Origins Theory has received little coverage in the nursing literature, even though it has received much attention in other sciences. The theory proposes that prenatal stress provokes adaptive changes in endocrine and metabolic processes that become permanently programmed and impact later adult health. This paper reviews the theory and describes the primary neuroendocrine mechanism of hypothalamic-pituitary-adrenal axis function. Supporting research evidence in preterm infant and adult samples is presented. Through knowledge of the theory and the long-term sequelae for preterm infants, nurses will have a different theoretical perspective and growing evidence to consider in their care for pregnant women and infants.

Characteristic Processes in Close Peer Friendships of Preterm Infants at Age 12.

Close friendships become important at middle-school age and are unexplored in adolescents born prematurely. The study aimed to characterize friendship behaviors of formerly preterm infants at age 12 and explore similarities and differences between preterm and full-term peers on dyadic friendship types. From the full sample of N = 186, one hundred sixty-six 12-year-old adolescents (40 born full term, 126 born preterm) invited a close friend to a 1.5 hour videotaped laboratory play session. Twenty adolescents were unable to participate due to scheduling conflicts or developmental disability. Characteristic friendship behaviors were identified by Q-sort followed by Q-factoring analysis. Friendship duration, age, and contact differed between the full-term and preterm groups but friendship activities, behaviors, and quality were similar despite school service use. Three Q-factors, leadership, distancing, and mutual playfulness, were most characteristic of all dyads, regardless of prematurity. These prospective, longitudinal findings demonstrate diminished prematurity effects at adolescence in peer friendship behavior and reveal interpersonal dyadic processes that are important to peer group affiliation and other areas of competence.

Academic, social, and behavioral outcomes at age 12 of infants born preterm.

The effects of gradient levels of perinatal morbidity on school outcomes have been investigated at age 12 in four preterm groups, classified as healthy (no medical or neurological illness), medical morbidity, neurological morbidity, and small-for-gestational-age (SGA), and a full-term comparison group. Teachers report on academic competence, social skills, and problem behaviors. Data on school type, classroom setting, and school service use are gathered from school records. Preterm groups are found to be equivalent to full-term peers in social skills and problem behavior. Preterm groups with neurological and SGA morbidity have the lowest academic competence scores. Unexpectedly, preterm infants with medical morbidity have higher academic competence scores compared with the other preterm groups. School service use increases with greater perinatal morbidity and is contingent on multiple rather than single indicators of perinatal morbidity. Continued monitoring of preterm infants through early adolescence will ensure that appropriate school services and resources are available to maximize their school success.

Prematurity, Birth Weight, and Socioeconomic Status Are Linked to Atypical Diurnal Hypothalamic–Pituitary–Adrenal Axis Activity in Young Adults

In a prospective, case-controlled longitudinal design, 180 preterm and fullterm infants who had been enrolled at birth participated in a comprehensive assessment battery at age 23. Of these, 149 young adults, 34 formerly full-term and 115 formerly preterm (22 healthy preterm, 48 with medical complications, 21 with neurological complications, and 24 small for gestational age) donated five saliva samples from a single day that were assayed for cortisol to assess diurnal variation of the hypothalamic-pituitary-adrenal (HPA) axis. Analyses were conducted to determine whether prematurity category, birth weight, and socioeconomic status were associated with differences in HPA axis function. Pre- and perinatal circumstances associated with prematurity influenced the activity of this environmentally sensitive physiological system. Results are consistent with the theory of Developmental Origins of Health and Disease and highlight a possible mechanism for the link between prematurity and health disparities later in life.

Trajectories of problem behaviors from 4 to 23 years in former preterm infants

Premature infants have significant risk for later behavior problems. This study examined growth trajectories of three problem behaviors across five developmental age points from preschool to early adulthood in a well-characterized sample of premature infants. The effects of neonatal risk, gender, and socioeconomic context were modeled on these trajectories. The longitudinal sample was comprised of preterm infants (N = 160) with full variation of neonatal morbidity and birth weight (640–1,950 g). Trajectories of externalizing, internalizing and attention problem behaviors from 4 to 23 years, measured by the Child Behavior Checklist, were tested using latent growth curve modeling. The results indicate individual variation in the number of externalizing and internalizing problems over time. Externalizing problems were not significantly different for males and females, but male scores were consistently higher. Neonatal risk was significantly associated with higher internalizing problems at age 4, but was not predictive at school age and beyond. Attention-problem scores increased from early preschool through adolescence for males, but females had little change over the same ages. SES was not predictive of any problem behavior trajectories and no significant two-way interactions were found. The results advance understanding of stability and change of three important problem behaviors through preschool, childhood, and adolescence to young adulthood in prematurely born infants in order to inform clinicians about timely assessment and the refinement of effective interventions.

Examining solutions to missing data in longitudinal nursing research

PURPOSE Longitudinal studies are highly valuable in pediatrics because they provide useful data about developmental patterns of child health and behavior over time. When data are missing, the value of the research is impacted. The studys purpose was to (1) introduce a three-step approach to assess and address missing data and (2) illustrate this approach using categorical and continuous-level variables from a longitudinal study of premature infants. METHODS A three-step approach with simulations was followed to assess the amount and pattern of missing data and to determine the most appropriate imputation method for the missing data. Patterns of missingness were Missing Completely at Random, Missing at Random, and Not Missing at Random. Missing continuous-level data were imputed using mean replacement, stochastic regression, multiple imputation, and fully conditional specification (FCS). Missing categorical-level data were imputed using last value carried forward, hot-decking, stochastic regression, and FCS. Simulations were used to evaluate these imputation methods under different patterns of missingness at different levels of missing data. RESULTS The rate of missingness was 16-23% for continuous variables and 1-28% for categorical variables. FCS imputation provided the least difference in mean and standard deviation estimates for continuous measures. FCS imputation was acceptable for categorical measures. Results obtained through simulation reinforced and confirmed these findings. PRACTICE IMPLICATIONS Significant investments are made in the collection of longitudinal data. The prudent handling of missing data can protect these investments and potentially improve the scientific information contained in pediatric longitudinal studies.

Long-Term Effects of Prematurity, Cumulative Medical Risk, and Proximal and Distal Social Forces on Individual Differences in Diurnal Cortisol at Young Adulthood:

This study examined the effects of prematurity, cumulative medical risk, and proximal and distal social forces on individual differences in the activity of the hypothalamic–pituitary–adrenal (HPA) axis in young adulthood. A prospective sample of 149 infants born healthy preterm (PT; n = 22), sick PT (n = 93, medical illness, neurological illness, small for gestational age), and full term (n = 34) was recruited from a Level III neonatal intensive care unit in southern New England between 1985 and 1989 and followed to age 23 years. Cumulative medical risk was indexed across seven assessment waves (spanning 17 years) using medical and neurological health status at birth, toddlerhood (ages 18 and 30 months), childhood (ages 4 and 8 years), and adolescence (ages 12 and 17 years). Distal risk included socioeconomic status (SES) at birth. Proximal social factors were indexed from assessments of the home environment and measures of child vulnerability and maternal self-esteem, involvement, and control style from birth, 4 years, 8 years, and 12 years. At age 23 years, five saliva samples were collected upon awakening, 45 min after waking, 4 hr after waking, 8 hr after waking, and bedtime (later assayed for cortisol). Results reveal effects of cumulative medical risk on the diurnal pattern of HPA axis activity, with moderating effects of SES and proximal social factors. Findings are discussed in terms of implications for contemporary theories related to developmental sensitivity and susceptibility to context and the developmental origins of health and disease theory.

Prematurity and perinatal adversity effects hypothalamic-pituitary-adrenal axis reactivity to social evaluative threat in adulthood

This study examined the long-term effects of prematurity and perinatal adversity on individual differences in stress-related reactivity and regulation of the HPA axis. A prospective sample of 155 infants born preterm and healthy (n = 20), medical illness (n = 48), neurological illness (n = 26), and small for gestational age (n = 24) and full-term (n = 37) were recruited between 1985 and 1989. At age 23 years, multiple saliva samples were collected before and after participation in the Trier Social Stress Test and later assayed for cortisol. Results reveal that at age 23 years, infants born premature with neurological complications showed higher cortisol reactivity to social evaluative threat compared to either their full-term, small for gestation age, medically ill, or healthy preterm peers. Findings are discussed in terms of implications for contemporary theories that propose effects of early adversity on biological sensitivities and susceptibilities, which translate experience into developmental outcomes related to poor health and risk for disease.

Cumulative risk and protection on diurnal cortisol patterns in preterm infants at young adulthood

immune response, general homeostasis, is a primary neuroendocrine marker for stress and hypothalamic-pituitary-adrenal axis function. The purpose of this study was to examine diurnal patterns of cortisol in preterm and full term infants at young adulthood. This prospective, longitudinal study of 215 preterm infants (healthy, medical, neurological, small for gestational age) and a fullterm cohort were recruited at birth and followed to age 23. Five diurnal salivary samples were collected in timed intervals during a typical day. Enzyme immunoassay analyses were conducted in duplicate. Analysis of Variance and hierarchical linear regression analyses were used. At 23 years, those born full-term displayed a normal diurnal cortisol pattern. In contrast, those born preterm with acute neonatal illness had the most distinct diurnal patterns. Birth weight affected the cortisol awakening response contingent upon preterm group status. Socioeconomic status further predicted diurnal cortisol patterns. Dysregulation of this stress biomarker may be an early indicator of adult stress-related disease. The DOHaD framework offers a lifespan perspective on prematurity and adult outcomes, with potential for early identification of those at risk for later stress-related disease.