Preterm Birth Is Associated With Depression From Childhood to Early Adulthood

Perinatal cumulative risk scores for depression symptoms in young people from the Growing Up in New Zealand longitudinal study

BACKGROUND

Adolescent depression has increased markedly over the last decade and often persists into adulthood with a range of adverse outcomes. Identifying the perinatal risk factors contributing to adolescent depression is crucial to advise early interventions.

METHODS

The study included 4563 young people from the Growing Up in New Zealand (GUiNZ) longitudinal study who completed a questionnaire on depression symptoms at age 12 years (Centre for Epidemiological Studies Depression Scale for Children (CESD-10). Cumulative Risk (CR) scores were created by combining the perinatal risk factors significantly associated with depression symptoms. Then, these CR scores were grouped into three levels and their association with depression symptoms was investigated in univariable and multivariable analyses.

RESULTS

We found a statistically significant association between the CR scores (from one to six perinatal risk factors) and depression score at age 12, compared to the no-risk factor group, suggesting a dose-response relationship. In the adjusted analysis, young people exposed to the lower CR score (1-3 risk factors) had a 0.85 unit increase in depression score (p- < .001), and those exposed to the higher CR (4 ≥ risk factors) had a 1.70 unit increase (p < .001) compared to no perinatal risk factors.

LIMITATIONS

Our model was focused on the perinatal CR score without including the effects of childhood risk factors.

CONCLUSIONS

The perinatal CR score is a valuable approach to identifying the subgroup of young people who are most at risk for depression symptoms. As such, early interventions that simultaneously address multiple perinatal risk factors for depression are recommended.

Associations of air pollutants and related metabolites with preterm birth during pregnancy

OBJECTIVE

This study aimed to investigate the influence of exposure to ambient fine particulate matter (PM2.5) and its components during pregnancy on the prevalence of preterm birth (PTB). Additionally, we sought to identify the susceptible exposure window. Furthermore, we explored the potential mediating role of blood analysis and a comprehensive metabolic panel in the association between pollutant exposure and PTB incidence.

METHODS

This birth cohort study recruited 139 participants with PTB outcomes and 1713 controls from Fujian Maternal and Child Health Hospital between January 2021 and June 2023. Sociodemographic characteristics and clinical treatment data during participants' first pregnancies were collected. The exposure levels to pollutants during pregnancy were estimated via a combined geographic-statistical model utilising satellite remote sensing data. The distributional lag nonlinear modelling was employed to assess associations between pollutant exposure during pregnancy and the prevalence of PTB. Weighted quantile regression was used to identify key components associated with PM2.5 and PTB during pregnancy. Additionally, a mediating effect analysis was conducted to evaluate the role of blood analysis. The metabolic profile was used to screen for differentially abundant metabolites associated with PTB and explore their relative expression in relation to air pollutants and PTB incidence.

RESULTS

Following the adjustment for potential confounding variables, the mean weekly susceptibility windows for PM2.5 were identified as 7-10, 16-19, and 22-28 weeks; 8-10, and 15-19 weeks for inorganic sulfate; 6-10, and 15-28 weeks for nitrate; 6-12, and 15-28 weeks for ammonium (NH4+); and 7-9, 18-20, and 22-36 weeks for organic matter. During mixed exposure to PM2.5 components, the key component is NH4+. In the mixed exposure to PM2.5 components, NH4+ emerged as a key contributor. The results of the mediation analysis revealed that haemoglobin played a mediating role, accounting for 21.53 % of the association between exposure to environmental pollutants and the prevalence of PTB. It is noteworthy that, no mediating effects were observed for the other variables. Furthermore, non-targeted metabolomics identified 17 metabolites associated with PTB. Among these factors, hydrogen phosphate may impact metabolic pathways such as oxidative phosphorylation, influencing the risk of PTB. The interplay between environmental pollutants and metabolites, particularly through oxidative phosphorylation pathways, may contribute to PTB incidence.

CONCLUSIONS

The evidence indicates that exposure to PM2.5 and its components during pregnancy were a significant risk factor for PTB. Notably, specific weekly exposure windows were identified for pollutants during pregnancy. Among the PM2.5 components, NH4+ exhibited the most substantial weight in the association analysis between exposure to the mixture of components and PTB. Furthermore, our mediation analysis revealed that haemoglobin serves as a partial mediator in the relationship between exposure to pollutants during pregnancy and the prevalence of PTB. Additionally, maternal serum metabolic profiles differed between the preterm and control groups. Notably, a combined effect involving hydrogen phosphate and mixed exposure to PM2.5 fractions further contributed to the development of PTB. Oxidative phosphorylation pathways may play pivotal roles in this intricate association.

Mortality from external causes in late adolescence and early adulthood by gestational age and sex: a population-based cohort study in four Nordic countries

BACKGROUND

External causes of death, such as accidents, substance use, and suicide, contribute substantially to mortality during adolescence and early adulthood and show marked sex differences. Individuals born preterm are at increased risk of mental disorders, and impaired cognitive and executive functions, potentially increasing their vulnerability to death from external causes. We investigated sex-specific associations between gestational age at birth and mortality from external causes during late adolescence and early adulthood.

METHODS

Individual level data from national health registries in Denmark (1978-2001), Finland (1987-2003), Norway (1967-2002), and Sweden (1974-2001) were linked to form nationwide cohorts. In total, 6,924,697 participants were followed from age 15 years to a maximum of 50 years in 2016-2018. Gestational age was categorized as "very/moderately preterm" (23-33 weeks), "late preterm" (34-36 weeks), "early term" (37-38 weeks), "full term" (39-41 weeks), and "post term" (42-44 weeks). Outcomes were mortality from external causes overall and from the largest subgroups transport accidents, suicide, and drugs or alcohol. We estimated sex-specific hazard ratios (HRs), with full term as the reference, and pooled each country's estimates in meta-analyses.

RESULTS

Across gestational ages mortality was higher for males than females. Individuals born very/moderately preterm had higher mortality from external causes, with HRs 1.11 (95% confidence interval [CI] 0.99-1.24) for males and 1.55 (95% CI 1.28-1.88) for females. Corresponding estimates for late preterm born were 1.11 (95% CI 1.04-1.18) and 1.15 (95% CI 1.02-1.29), respectively. Those born very/moderately preterm had higher mortality from transport accidents, but precision was low. For females, suicide mortality was higher following very/moderately preterm birth (HR 1.76, 95% CI 1.34-2.32), but not for males. Mortality from drugs or alcohol was higher in very/moderately and late preterm born males (HRs 1.23 [95% CI 0.99-1.53] and 1.29 [95% CI 1.16-1.45], respectively) and females (HRs 1.53 [95% CI 0.97-2.41] and 1.35 [95% CI 1.07-1.71], respectively, with some heterogeneity across countries).

CONCLUSIONS

Mortality from external causes overall was higher in preterm than full term born among both males and females. A clear sex difference was seen for suicide, where preterm birth was a risk factor in females, but not in males.

Physical activity and cognitive function in adults born very preterm or with very low birth weight-an individual participant data meta-analysis

OBJECTIVE

Individuals born very preterm (<32 weeks of gestation) or with very low birthweight (<1500g) have lower cognitive function compared with term-born peers. Furthermore, some studies suggest that they are less physically active as young adults than controls, but the relationship between physical activity and cognitive function remains unclear. We performed an individual participant data meta-analysis to examine whether being born preterm/with very low birth weight is associated with physical activity in adulthood and examined if cognitive function mediates this association.

STUDY DESIGN

Cohorts with data on physical activity and cognitive function in adults born very preterm/very low birth weight and term-born controls were recruited from the Research on European Children and Adults Born Preterm, and the Adults Born Preterm International Collaboration Consortia. A systematic literature search was performed in PubMed and Embase.

RESULTS

Five cohorts with 1644 participants aged 22-28 years (595 very preterm/very low birth weight and 1049 controls) were included. Adults born very preterm/very low birth weight reported 1.11 (95% CI: 0.68 to 1.54) hours less moderate to vigorous physical activity per week than controls, adjusted for cohort, age and sex. The difference between individuals born very preterm/very low birth weight and controls was larger among women than among men. Neither intelligence quotient nor self-reported executive function mediated the association between very preterm/very low birth weight and moderate to vigorous physical activity. Results were essentially the same when we excluded individuals with neurosensory impairments.

CONCLUSION

Adults born very preterm/very low birth weight, especially women, reported less moderate to vigorous physical activity than their term-born peers. Cognitive function did not mediate this association. Considering the risk of adverse health outcomes among individuals born preterm, physical activity could be a target for intervention.

Hofbauer cell function in the term placenta associates with adult cardiovascular and depressive outcomes

Pathological placental inflammation increases the risk for several adult disorders, but these mediators are also expressed under homeostatic conditions, where their contribution to adult health outcomes is unknown. Here we define an inflammation-related expression signature, primarily expressed in Hofbauer cells of the term placenta and use expression quantitative trait loci to create a polygenic score (PGS) predictive of its expression. Using this PGS in the UK Biobank we conduct a phenome-wide association study, followed by Mendelian randomization and identify protective, sex-dependent effects of the placental module on cardiovascular and depressive outcomes. Genes differentially regulated by intra-amniotic infection and preterm birth are over-represented within the module. We also identify aspirin as a putative modulator of this inflammation-related signature. Our data support a model where disruption of placental Hofbauer cell function, due to preterm birth or prenatal infection, contributes to the increased risk of depression and cardiovascular disease observed in these individuals.

Neurodevelopmental, Mental Health, and Parenting Issues in Preterm Infants

The World Health Organization in its recommendations for the care of preterm infants has drawn attention to the need to address issues related to family involvement and support, including education, counseling, discharge preparation, and peer support. A failure to address these issues may translate into poor outcomes that extend across the lifespan. In this paper, we review the often far-reaching impact of preterm birth on the health and wellbeing of the parents and highlight the ways in which psychological stress may have a negative long-term impact on the parent-child interaction, attachment, and the styles of parenting. This paper addresses the following topics: (1) neurodevelopmental outcomes in preterm infants, including cognitive, sensory, and motor difficulties, (2) long-term mental health issues in premature infants that include elevated rates of anxiety and depressive disorders, autism, and somatization, which may affect social relationships and quality of life, (3) adverse mental health outcomes for parents that include elevated rates of depression, anxiety, and symptoms of post-traumatic stress, as well as increased rates of substance abuse, and relationship strain, (4) negative impacts on the parent-infant relationship, potentially mediated by maternal sensitivity, parent child-interactions, and attachment, and (5) impact on the parenting behaviors, including patterns of overprotective parenting, and development of Vulnerable Child Syndrome. Greater awareness of these issues has led to the development of programs in neonatal mental health and developmental care with some data suggesting benefits in terms of shorter lengths of stay and decreased health care costs.

Preterm birth and the risk of multimorbidity in adolescence: a multiregister-based cohort study

BACKGROUND

Multimorbidity affects people of all ages, but the risk factors of multimorbidity in adolescence are unclear. The aim of this study was to examine preterm birth (<37 weeks) as a shared risk factor for multiple health outcomes and the role of gestational age (degree of prematurity) in the development of increasingly complex multimorbidity (two, three, or four health outcomes) in adolescence (age 10-18 years).

METHODS

We used population-wide data from Finland (1 187 610 adolescents born 1987-2006) and Norway (555 431 adolescents born 1998-2007). Gestational age at birth was ascertained from medical birth registers and categorised as 23-27 weeks (extremely preterm), 28-31 weeks (very preterm), 32-33 weeks (moderately preterm), 34-36 weeks (late preterm), 37-38 weeks (early term), 39-41 weeks (term, reference category) and 42-44 weeks (post-term). Children who died or emigrated before their 10th birthday, and those with missing or implausible data on gestational age, birthweight, or covariates, were excluded. Health outcomes at age 10-18 years were ascertained from specialised health care and mortality registers. We calculated hazard ratios (HRs) and population attributable fractions (PAFs) with 95% CIs for multiple health outcomes during adolescence.

FINDINGS

Individuals were followed up from age 10 to 18 years (mean follow-up: 6 years, SD: 3 years). Preterm birth was associated with increased risks of 20 hospital-treated malignant, cardiovascular, endocrinological, neuropsychiatric, respiratory, genitourinary, and congenital health outcomes, after correcting for multiple testing and ignoring small effects (HR <1·2). Confounder-adjusted HRs comparing preterm with term-born adolescents were 2·29 (95% CI 2·19-2·39) for two health outcomes (PAF 9·0%; 8·3-9·6), and 4·22 (3·66-4·87) for four health outcomes (PAF 22·7%; 19·4-25·8) in the Finnish data. Results in the Norwegian data showed a similar pattern. We observed a consistent dose-response relationship between an earlier gestational age and elevated risks of increasingly complex multimorbidity in both datasets.

INTERPRETATION

Preterm birth is associated with increased risks of diverse multimorbidity patterns at age 10-18 years. Adolescents with a preterm-born background could benefit from diagnostic vigilance directed at multimorbidity and a multidisciplinary approach to health care.

FUNDING

European Union Horizon 2020, Academy of Finland, Foundation for Pediatric Research, Sigrid Jusélius Foundation, Signe and Ane Gyllenberg Foundation.

The early life course-related traits with three psychiatric disorders: A two-sample Mendelian randomization study

Objectives

Several studies have indicated a potential association between early life course-related traits and neurological and psychiatric disorders in adulthood, but the causal link remains unclear.

Methods

Instrumental variables (IVs) that have been shown to be strongly associated with exposure were obtained from summary data of genome-wide association studies (GWASs). Four early life course-related traits [i.e., birthweight (BW), childhood body mass index (BMI), early body size, and age at first birth (AFB)] were used as exposure IVs to estimate their causal associations with three neurological and psychiatric diseases [i.e., Alzheimer's disease (AD), major depressive disorder (MDD), and attention-deficit hyperactivity disorder (ADHD)]. Four different statistical methods, i.e., inverse-variance weighting (IVW), MR-Egger (MRE), weighted median (WM), and weighted mode (Wm), were performed in our MR analysis. Sensitivity analysis was performed by using the leave-one-out method, and horizontal pleiotropy was assessed using the MR-PRESSO package.

Results

There was evidence suggesting that BW has a causal effect on AD (OR_MR-PRESSO = 1.05, p = 1.14E-03), but this association was not confirmed via multivariable Mendelian randomization (MVMR) (OR_MVMR = 0.97, 95% CI 0.92-1.02, p = 3.00E-01). A strong relationship was observed between childhood BMI and ADHD among both sexes; a 1-SD increase in BMI significantly predicted a 1.46-fold increase in the OR for ADHD (p = 9.13E-06). In addition, a similar relationship was found between early life body size and ADHD (OR_MR-PRESSO = 1.47, p = 9.62E-05), and this effect was mainly driven by male participants (OR_MR-PRESSO = 1.50, p = 1.28E-3). Earlier AFB could significantly predict a higher risk of MDD (OR_MR-PRESSO = 1.19, p = 1.96E-10) and ADHD (OR_MR-PRESSO = 1.45, p = 1.47E-15). No significant causal associations were observed between the remaining exposures and outcomes.

Conclusion

Our results reveal the adverse effects of childhood obesity and preterm birth on the risk of ADHD later in life. The results of MVMR also show that lower BW may have no direct relationship with AD after adjusting for BMI. Furthermore, AFB may predict a higher risk of MDD.

Dry Eye Parameters and Lid Geometry in Adults Born Extremely, Very, and Moderately Preterm with and without ROP: Results from the Gutenberg Prematurity Eye Study

Background/Aims: This study aimed to analyze the effects of perinatal history on tear film properties and lid geometry in adults born preterm. Methods: The Gutenberg Prematurity Eye Study (GPES) is a German prospective examination of adults born preterm and term aged 18 to 52 years with Keratograph® 5M and Schirmer test I. Main outcome measures were first non-invasive tear film break-up time (F-NITBUT), bulbar redness (BR), Schirmer test, and nasal palpebral angle measurement. The associations with gestational age (GA), birth weight (BW), and BW percentile, retinopathy of prematurity (ROP), ROP treatment, and other perinatal factors were evaluated using regression analyses. Results: 489 eyes of 255 preterm and 277 eyes of 139 full-term individuals (aged 28.6 +/− 8.8 years, 220 females) were included. Of these, 33 participants (56 eyes) had a history of spontaneously regressed ROP and 9 participants (16 eyes) had a history of ROP treatment. After adjustment for age and sex, lower F-NITBUT (<20 s) was associated with ROP treatment (OR = 4.42; p = 0.025). Lower GA correlated with increased bulbar redness (B = −0.02; p = 0.011) and increased length of wetting in the Schirmer test (B = −0.69; p = 0.003). Furthermore, low GA was associated with narrowing of the nasal palpebral angle (B = 0.22; p = 0.011) adjusted for age and sex, but not when considering ROP in the multivariable model. Conclusion: Our analyses indicate that perinatal history affects ocular surface properties, tear production and lid geometry in adults born term and preterm. This might indicate that affected persons have a predisposition to diseases of the corneal surface such as the dry eye disease.

Preterm birth, poor foetal growth and anxiety disorders in a Finnish nationwide register sample

Aim

We examined the associations between preterm birth, poor foetal growth and anxiety disorders among children and adolescents. Additionally, we examined the impact of common comorbidities and specific anxiety disorders separately.

Methods

Three Finnish registers provided data on a nationwide birth cohort of 22,181 cases with anxiety disorders and 74,726 controls. Conditional logistic regression was used to examine the associations.

Results

Extremely very preterm birth and moderate‐late preterm birth were associated with increased adjusted odds ratios (aOR) for anxiety disorders (aOR 1.39, 95% CI 1.11–1.75 and aOR 1.13, 95% CI 1.03–1.23, respectively). Weight for gestational age of less than −2SD (aOR 1.29, 95% CI 1.17–1.42) and −2SD to −1SD (aOR 1.08, 95% CI 1.03–1.14) were associated with increased odds ratios for anxiety disorders. When comorbidities were considered, the associations became statistically insignificant for pure anxiety disorders, but remained significant in the groups with comorbid depressive or neurodevelopmental disorders.

Conclusion

Preterm birth and poor foetal growth increased the odds for anxiety disorders. However, the associations seem to be explained by the conditions of comorbid depressive and neurodevelopmental disorders. Comorbidities should be considered when examining and treating child and adolescent anxiety disorders.

Long-Term Neurodevelopmental Outcomes after Moderate and Late Preterm Birth: A Systematic Review

OBJECTIVE

To systematically review and perform meta-analyses on the long-term neurodevelopmental outcomes of adults born moderate and late preterm (MLPT) in relation to cognitive functioning and psychiatric disorders.

STUDY DESIGN

A search was conducted to identify any studies that involved prematurity in adulthood. From these studies, reports that included a group of MLPT adults and included description of cognitive and/or mental health domains (including specific long-term outcomes) were selected.

RESULTS

In total, 155 publications were identified, but only 16 papers met the inclusion criteria. A small effect size (g = 0.38) was found in MLPT to demonstrate poorer intellectual performance compared with those born at term. Moreover, MLPT adults exhibited greater odds for any psychiatric (OR 1.14), substance use (OR 1.16), mood (OR 1.06), and psychotic disorders (OR 1.40).

CONCLUSIONS

Despite inconsistency due to the methodologic differences between the selected studies, MLPT showed minor long-term effects into adulthood. However, more studies are needed, because prematurity seems to confer some vulnerability to biological and environmental factors that enhance susceptibility to adverse neurodevelopment outcomes.

Editorial: Is Preterm Birth Overlooked in Child and Adolescent Psychiatry?

Obstetric factors have long been recognized as risk factors for the later development of poor mental health. One of the most consistently reported of these associations is for preterm birth (birth before 37 weeks' gestation), a form of early adversity that impacts health and development across the life course. Preterm birth is not uncommon: in 2014, 10.6% of live births globally (nearly 15 million babies) were preterm.¹ Advances in neonatal care since the early 1990s have dramatically increased the numbers of babies who survive extreme preterm birth (birth at <28 weeks' gestation) in high-income countries. This has led to growing interest in how extreme preterm birth impacts longer term outcomes including psychosocial development across the life span.