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

Influence of Preterm Birth and Environmental Context on Academic Performance and Neurodevelopmental Outcomes

BACKGROUND

Preterm birth affects 10% of all births annually in the United States. Outcomes of people born preterm are challenging to predict because of multiple influences, including gestational age, birth weight, and social and environmental contexts, that contribute to an individual's growth and developmental trajectory. The influence of toxic stress is underrepresented in the literature assessing preterm birth outcomes.

OBJECTIVES

The current analyses use the eco-bio-developmental model of poverty and preterm birth as a framework to model the pathways among toxic stress, preterm birth, and neurodevelopmental outcomes. Poverty and toxic stress were hypothesized to increase the risk for impaired neurodevelopmental and academic outcomes-both directly and indirectly.

METHODS

The analytic sample of 55,873 children aged 6-17 years was derived from the National Survey of Children's Health 2020-2021. Structural equation models with combined measurement and path models for each dependent variable were constructed using latent toxic stress variables. The structural path equations included direct paths from the latent measure of prenatal toxic stress, preterm birth status, and the latent measure of childhood toxic stress to the neurodevelopmental outcome, as well as an indirect, mediated path from prenatal toxic stress through preterm birth status to the outcome.

RESULTS

Across models, higher levels of prenatal toxic stress were significantly associated with preterm birth and lower birth weight ranges. Preterm low birth weight status was associated with a greater likelihood of neurodevelopmental impairment, repeating a grade, and special education plans. The predicted probabilities of neurodevelopmental impairment, repeating grades, and special education plans are significantly higher with above-average levels of exposure to prenatal and childhood toxic stress.

DISCUSSION

There is a need for prospective studies that assess predictors and outcomes of preterm birth that are stratified by gestational age and consider the timing, chronicity, and influence of toxic stress and environmental exposures. There is an imperative for public health programs and policies designed to support families, caregivers, and children to address the individual and structural social determinants of health that contribute to toxic stress, thereby increasing preterm birth rates and negatively affecting the outcomes of children born preterm.

Mental health, pain and tiredness in adults born very preterm or with very low birthweight

AIM

Adults born preterm have increased risk of mental health problems and other neurodevelopmental conditions. We aimed to investigate associations of mental health with pain and tiredness in adults born very preterm (VP; <32 weeks) or very low birthweight (VLBW; <1500 g) and at term, and whether these associations are influenced by physical activity.

METHODS

As part of an EU Horizon 2020 project, individual participant data from six prospective cohort studies were harmonised for 617 VP/VLBW and 1122 term-born participants. Mental health was assessed by the Achenbach System of Empirically Based Assessment Adult Self-Report. Pain and tiredness were harmonised based on specific items from self-reported questionnaires. Associations between mental health and pain or tiredness were explored by linear regression.

RESULTS

An increase in the mental health scales internalising, externalising and total problems was associated with increased pain and tiredness in the preterm and term group alike. Results were maintained when adjusting for physical activity.

CONCLUSION

The findings indicate that associations between mental health, pain and tiredness in adults are independent of gestation or birthweight. Future research should explore other potential mechanisms that may underlie the increased risk of mental health problems in the preterm population.

A test of differential susceptibility in behavior trajectories of preterm infants from preschool to adulthood

Preterm birth predisposes children to internalizing and externalizing behaviors that may persist into adolescence resulting in adult mental health conditions. Social and caregiving contexts, particularly for vulnerable infants born preterm, influence long-term outcomes, but mechanisms are not clearly understood. Healthcare teams caring for those born preterm face difficulty predicting who will be most affected by risk, who will most benefit, and the optimal timing of intervention. Differential susceptibility theory offers an alternative to the traditional risk-only assessments and theories by positing that individuals may be more, or less, susceptible to environmental influences. A sample of preterm- and term-born infants were followed from birth to 23 years of age. Mixed model repeated measures analyses of internalizing and externalizing behaviors were utilized for the comparison groups (N = 214; observations = 1070). Environmental contexts were indexed as proximal protection (low, moderate, high) and medical risk (low, moderate, high). Personal characteristic covariates of sex, race, socioeconomic status, and cognition were modeled. Internalizing behavior trajectories varied significantly over time. Early proximal protective environments conferred a sustained positive influence on behaviors. There is partial support for differential susceptibility theory suggesting that prematurity, as a malleability characteristic enables absorption of both the positive and negative influences of the environment, with greater intensity that those without malleability. The current analyses suggest lasting effects of the preschool age proximal environment on internalizing and externalizing behaviors in young adulthood for those born preterm. Understanding these nuances may aid healthcare professionals in the promotion and timing of interventions to support the child and family. The current manuscript reflects ongoing analyses of longitudinal data. No patient or public contribution to the analyses were required for testing the differential susceptibility theory. The authors would solicit patient or public contribution when implementing practice or policy changes based on the results.

Science of interdisciplinary salivary bioscience: history and future directions

Salivary bioscience is noteworthy in its history, as well as in the breadth and scope of its impact. The minimally invasive nature of sampling oral fluid allows for evaluation of individual and intra-individual change in biological processes in ways and settings not possible with traditional biospecimens. The range of measurements is expansive (e.g., DNA, hormones, cytokines, antibodies) and modern technologies enable simultaneous multisystem assessment from a singlet specimen. Used in combination with modern multivariate analytical models, the capacity to repeatedly assess multisystem and level measurements collected from the same individual over time enable operationalization, testing and refinement of complex biobehavioral models. This review describes the emerging narrative of salivary bioscience, and aims to inform and reveal opportunity for innovation and discovery.

Differential Susceptibility: An Explanation for Variability in Life Course Health and Developmental Outcomes

Differential susceptibility theory posits that some individuals, with specific characteristics, are more, or less susceptible than others, to both adverse and beneficial environmental influences. It offers a perspective for understanding the directional trajectories across the life course affected by daily context and individual characteristics, in order to identify influential components. The aim of this article is to describe differential susceptibility theory, critically evaluate research findings in which the theory is tested, and consider implications of differential susceptibility theory as a theoretical framework for nursing science. Preterm birth trajectories and outcomes research are used as a lens for this examination.

A systematic review and meta-analysis of randomized controlled trials comparing 17-alpha-hydroxyprogesterone caproate versus placebo for the prevention of recurrent preterm birth

BACKGROUND

Preterm birth causes an increased risk for perinatal morbidity and mortality.

OBJECTIVE

To determine whether mid-trimester 17-alpha-hydroxyprogesterone caproate (17-OHPC) reduces the risk of recurrent preterm birth and adverse perinatal outcomes.

SEARCH STRATEGY

Systematic search to identify relevant studies published in different languages, registered after 2000, using appropriate MeSH terms.

SELECTION CRITERIA

Inclusion criteria were women between 16 and 26⁺⁶  weeks of pregnancy with history of preterm delivery in any pregnancy randomized to either 17-OHPC or placebo/no treatment.

DATA COLLECTION AND ANALYSIS

The number of preterm births and adverse outcomes in the 17-OHPC and placebo arms over the total number of patients in each randomized group were used to calculate the risk ratio (RR) by random-effects models using the Mantel-Haenszel method. Between-study heterogeneity was assessed using tau² , χ² (Cochrane Q), and I² statistics.

MAIN RESULTS

Four studies were included. There was a 29% (RR 0.71; 95% CI, 0.53-0.96; P=0.001), 26% (RR 0.74; 95% CI, 0.58-0.96; P=0.021), and 40% (RR 0.60; 95% CI, 0.42-0.85; P=0.004) reduction in recurrent preterm birth at <37, <35, and <32 weeks, respectively, in the 17-OHPC group compared with placebo. The reduction in neonatal death was 68% (RR 0.32; 95% CI, 0.15-0.66; P=0.002).

CONCLUSIONS

17-OHPC could reduce the risk of recurrent preterm birth at <37, <35, and <28 weeks and neonatal death.

PROSPERO

CDR42017082190.

Prematurity and cardiovascular risk at early adulthood

BACKGROUND

Theories of early stress exposure and allostatic load offer a lifespan perspective to adult health after prematurity based on these early stressors affecting endocrine and metabolic systems. In this study, we examine cardiovascular and metabolic risk by comparing two groups of preterm infants who experienced a full spectrum of neonatal illness and a term-born group at age 23.

METHODS

Of the 215 infants recruited at birth, 84% participated at age 23. The cohort included 45 full-term (FT), 24 healthy preterm (HPT), and 111 sick preterm (SPT) infants. Socio-economic status was equivalent across groups. Cardiovascular and metabolic outcomes were as follows: blood pressure (BP), fasting glucose and lipid profiles, weight, waist-hip ratio (WHR), and body mass index (BMI). Clinical and subclinical ranges were compared across neonatal groups and gender.

RESULTS

At age 23, the HPT and SPT groups had higher systolic BP compared with the FT group. The SPT group had lower weight compared with the FT and HPT groups. No group differences were found on diastolic BP, glucose, total cholesterol, high-density lipids, low-density lipids, triglycerides, BMI, or WHR. Preterm males had more systolic hypertension and low high-density lipids than FT males. Former preterm males and females had high WHR ratios and BMI at 23 years. Subclinical prehypertensive rates were highest for the HPT female group, followed by the SPT females. Only one (4.2%) HPT adult male was clinically diabetic.

CONCLUSIONS

As young adults, HPT and SPT infants had early indicators of cardiovascular risk but no indicators of metabolic risk. There is utility in using clinical and subclinical ranges to identify early cardiovascular risk in early adulthood.

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.