Psychobiological effects of prenatal glucocorticoid exposure in 10-year-old-children

Patterns of respiratory sinus arrhythmia and trajectories of anxiety and depressive symptoms in early adolescence

In children and adults, individual differences in patterns of respiratory sinus arrhythmia (RSA; i.e., interactions between resting RSA and RSA reactivity to stress) have emerged as a central predictor of internalizing symptoms. However, it is unclear whether individual differences in patterns of RSA also contribute to internalizing symptoms during the key developmental period of early adolescence, when rates of internalizing symptoms sharply increase. In the present multi-wave longitudinal study, we assessed whether patterns of RSA predicted trajectories of the two most common types of internalizing symptoms among adolescents: anxiety and depression. In the baseline session, we assessed RSA at rest and in response to a psychosocial stressor (Trier Social Stress Test [TSST]) in a sample of 75 early adolescents (Mage = 12.85). Youth then completed measures of anxiety and depressive symptoms at baseline and four times over approximately two years. Findings indicate that RSA patterns predicted trajectories of anxiety, but not depression. Specifically, region of significance analyses indicated that individuals with high resting RSA who demonstrated RSA augmentation to the lab stressor evinced decreasing anxiety over the follow-up period. In direct contrast, adolescents with high resting RSA in combination with RSA withdrawal to the stressor exhibited a trajectory of increasing anxiety. Findings provide preliminary evidence for understanding RSA as a developmentally salient risk or protective factor.

Prenatal nicotine exposure during pregnancy results in adverse neurodevelopmental alterations and neurobehavioral deficits

Maternal tobacco use and nicotine exposure during pregnancy have been associated with adverse birth outcomes in infants and can lead to preventable pregnancy complications. Exposure to nicotine and other compounds in tobacco and electronic cigarettes (e-cigarettes) has been shown to increases the risk of miscarriage, prematurity, stillbirth, low birth weight, perinatal morbidity, and sudden infant death syndrome (SIDS). Additionally, recent data provided by clinical and pre-clinical research demonstrates that nicotine exposure during pregnancy may heighten the risk for adverse neurodevelopmental disorders such as Attention-Deficit Hyperactivity (ADHD), anxiety, and depression along with altering the infants underlying brain circuitry, response to neurotransmitters, and brain volume. In the United States, one in 14 women (7.2%) reported to have smoked cigarettes during their pregnancy with the global prevalence of smoking during pregnancy estimated to be 1.7%. Approximately 1.1% of women in the United States also reported to have used e-cigarettes during the last 3 months of pregnancy. Due to the large percentage of women utilizing nicotine products during pregnancy in the United States and globally, this review seeks to centralize pre-clinical and clinical studies focused on the neurobehavioral and neurodevelopmental complications associated with prenatal nicotine exposure (PNE) such as alterations to the hypothalamic-pituitary-adrenal (HPA) axis and brain regions such as the prefrontal cortex (PFC), ventral tegmental area (VTA), nucleus accumbens (NA), hippocampus, and caudate as well as changes to nAChR and cholinergic receptor signaling, long-term drug seeking behavior following PNE, and other related developmental disorders. Current literature analyzing the association between PNE and the risk for offspring developing schizophrenia, attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), anxiety, and obesity will also be discussed.

Glucocorticoids and Their Receptor Isoforms: Roles in Female Reproduction, Pregnancy, and Foetal Development

Alterations in the hypothalamic-pituitary-adrenal (HPA) axis and associated changes in circulating levels of glucocorticoids are integral to an organism's response to stressful stimuli. Glucocorticoids acting via glucocorticoid receptors (GRs) play a role in fertility, reproduction, placental function, and foetal development. GRs are ubiquitously expressed throughout the female reproductive system and regulate normal reproductive function. Stress-induced glucocorticoids have been shown to inhibit reproduction and affect female gonadal function by suppressing the hypothalamic-pituitary-gonadal (HPG) axis at each level. Furthermore, during pregnancy, a mother's exposure to prenatal stress or external glucocorticoids can result in long-lasting alterations to the foetal HPA and neuroendocrine function. Several GR isoforms generated via alternative splicing or translation initiation from the GR gene have been identified in the mammalian ovary and uterus. The GR isoforms identified include the splice variants, GRα and GRβ, and GRγ and GR-P. Glucocorticoids can exert both stimulatory and inhibitory effects and both pro- and anti-inflammatory functions in the ovary, in vitro. In the placenta, thirteen GR isoforms have been identified in humans, guinea pigs, sheep, rats, and mice, indicating they are conserved across species and may be important in mediating a differential response to stress. Distinctive responses to glucocorticoids, differential birth outcomes in pregnancy complications, and sex-based variations in the response to stress could all potentially be dependent on a particular GR expression pattern. This comprehensive review provides an overview of the structure and function of the GR in relation to female fertility and reproduction and discusses the changes in the GR and glucocorticoid signalling during pregnancy. To generate this overview, an extensive non-systematic literature search was conducted across multiple databases, including PubMed, Web of Science, and Google Scholar, with a focus on original research articles, meta-analyses, and previous review papers addressing the subject. This review integrates the current understanding of GR variants and their roles in glucocorticoid signalling, reproduction, placental function, and foetal growth.

Rescue doses of antenatal corticosteroids, children's neurodevelopment, and salivary cortisol after a threatened preterm labor: a 30-month follow-up study

BACKGROUND

Antenatal corticosteroids reduce neonatal complications when administered to women at risk for preterm birth. Moreover, antenatal corticosteroid rescue doses are recommended for women who remain at risk after the initial course. However, there is controversy about the most appropriate frequency and the exact timing of administering additional antenatal corticosteroid doses because there are potential long-term negative effects on infants' neurodevelopment and physiological stress functioning.

OBJECTIVE

This study aimed to (1) to assess the long-term neurodevelopmental effects of receiving antenatal corticosteroid rescue doses in comparison with receiving only the initial course; (2) to measure the cortisol levels of infants of mothers who received antenatal corticosteroid rescue doses; (3) to examine a potential dose-response effect of the number of antenatal corticosteroid rescue doses on children's neurodevelopment and salivary cortisol.

STUDY DESIGN

This study followed 110 mother-infant pairs who underwent a spontaneous episode of threatened preterm labor until the children were 30 months old, regardless of their gestational age at birth. Among the participants, 61 received only the initial course of corticosteroids (no rescue dose group), and 49 participants required at least one rescue dose of corticosteroids (rescue doses group). The follow-up was carried out at 3 different times, namely at threatened preterm labor diagnosis (T1), when the children were 6 months of age (T2), and when the children were 30 months of corrected age for prematurity (T3). Neurodevelopment was assessed using the Ages & Stages Questionnaires, Third Edition. Saliva samples were collected for cortisol level determination.

RESULTS

First, the rescue doses group showed lower problem-solving skills at 30 months of age than the no rescue doses group. Second, the rescue doses group demonstrated higher salivary cortisol levels at 30 months of age. Third, a dose-response effect was found that indicated that the more rescue doses the rescue doses group received, the lower the problem-solving skills and the higher the salivary cortisol levels at 30 months of age.

CONCLUSION

Our findings reinforce the hypothesis that additional antenatal corticosteroid doses provided after the initial course may have long-term effects on the neurodevelopment and glucocorticoid metabolism of the offspring. In this regard, the results raise concerns about the negative effects of repeated doses of antenatal corticosteroids in addition to a full course. Further studies are necessary to confirm this hypothesis to help physicians reassess the standard antenatal corticosteroid treatment regimens.

Technical Update No. 439: Antenatal Corticosteroids at Late Preterm Gestation

OBJECTIVE

To update recommendations for administration of antenatal corticosteroids in the late preterm period.

TARGET POPULATION

Pregnant individuals at risk of preterm birth from 340 to 366 weeks gestation.

OPTIONS

Administration or non-administration of a single course of antenatal corticosteroids at 340 to 366 weeks gestation.

OUTCOMES

Neonatal morbidity (respiratory distress, hypoglycemia), long-term neurodevelopment, and other long-term outcomes (growth, cardiac/metabolic, respiratory).

BENEFITS, HARMS, AND COSTS

Administration of antenatal corticosteroids from 340 to 366 weeks gestation decreases the risk of neonatal respiratory distress but increases the risk of neonatal hypoglycemia. The long-term impacts of antenatal corticosteroid administration from 340 to 366 weeks gestation are uncertain.

EVIDENCE

For evidence on the neonatal effects of antenatal corticosteroid administration at late preterm gestation, we summarized evidence from the 2020 Cochrane review of antenatal corticosteroids and combined this with evidence from published randomized trials identified by searching Ovid MEDLINE from January 1, 2020, to May 11, 2022. Given the absence of direct evidence on the impact of late preterm antenatal corticosteroid administration on neurodevelopmental outcomes, we summarized evidence on the impact of antenatal corticosteroids across gestational ages on neurodevelopmental outcomes using the following sources: (1) the 2020 Cochrane review; and (2) evidence obtained by searching Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception to January 5, 2022. We did not apply date or language restrictions. Given the absence of direct evidence on the impact of late preterm antenatal corticosteroid administration on other long-term outcomes, we summarized evidence on the impact of antenatal corticosteroids across gestational ages on other long-term outcomes by combining findings from the 2020 Cochrane review with evidence obtained by searching Ovid MEDLINE for observational studies related to long-term cardiometabolic, respiratory, and growth effects of antenatal corticosteroids from inception to October 22, 2021. We reviewed reference lists of included studies and relevant systematic reviews for additional references. See Appendix A for search terms and summaries.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix B (Tables B1 for definitions and B2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

Maternity care providers, including midwives, family physicians, and obstetricians.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Exposure to antenatal corticosteroids and infant cortisol regulation

Administration of antenatal corticosteroids (AC) is the standard of care during pregnancy for women who are at risk of early delivery. Evidence indicates that AC improve survival and reduce morbidity for preterm infants. However, research suggests that infants whose mothers receive AC have an altered hypothalamic-pituitary-axis (HPA) response to stressors in early life. Results are mixed regarding the nature of these effects, with studies showing both suppressed and augmented HPA activity. In addition, research is very limited beyond the 4th month of life. The purpose of this study was to determine if AC exposure was associated with infant cortisol levels in a resting state or in response to a stressor at 1, 6 and 12 months postnatal. We also evaluated the moderating role of preterm birth in this association. 181 women and their infants participated in the study. Women were recruited during the 3rd trimester of pregnancy; at this time, they completed the Perceived Stress Scale and provided 8 salivary samples over a 2-day period for cortisol assay. They provided these data again at 6 and 12 months postnatal. At 1, 6, and 12 months postnatal, salivary samples were collected from infants to examine their cortisol levels before and after participation in a 'stressor protocol'. Data were extracted from the medical record on AC exposure, gestational age, maternal obstetric risk, and neonatal morbidity. Mixed effects multilevel regression modeling was used to examine the aims. Infants whose mothers received AC had significantly lower resting state (B = -2.47, CI: -3.691, -0.0484) and post-stressor (B = -2.51, CI: -4.283, -0.4276) cortisol levels across the first year of life than infants whose mothers did not receive AC. There was no moderating effect of preterm birth on the relationship between AC exposure and cortisol. Results indicate a state of dampened HPA activation and cortisol hypo-arousal that persists across the first year of life among infants who were exposed to corticosteroids in utero. Further research is needed to examine mechanisms responsible for any alterations that occur during development of the fetal HPA axis, including epigenetic and biochemical factors that control hormonal secretion, negative feedback, and glucocorticoid receptor function throughout the HPA axis. Findings warrant careful consideration by obstetric clinicians of the benefits and risks of prescribing AC.

Neurological implications of antenatal corticosteroids on late preterm and term infants: a scoping review

The objective of this study was to synthesize the body of knowledge on the association between ACS exposure for risk of preterm birth and brain development in infants ultimately born late preterm and term. Three databases and eight conference proceedings were systematically searched (1972-2021). Selection criteria included ACS administration for risk of preterm delivery, cohort of late preterm and term infants, and assessment of brain development. Data on study characteristics, ACS administration, and neurological outcomes were extracted and qualitatively synthesized according to themes. Neurological outcomes of the included studies (n = 27) were grouped into four themes. The most common adverse outcomes were reduced neonatal head circumference, structural cortical differences on MRI, increased prevalence of psychiatric problems, and increased risk of neurodevelopmental delays in ACS-exposed late preterm and term infants. Our scoping review demonstrated that ACS exposure for risk of preterm delivery may have important neurological implications in infants ultimately born late preterm and term. Given that the existing research is at serious risk for bias, further research that accounts for confounders such as preterm labor, maternal stress, and the number of ACS courses is needed to better establish the long-term neurological effects of ACS on late preterm and term infants. IMPACT: Due to the difficulty in predicting preterm birth, approximately 40% of fetuses exposed to antenatal corticosteroids (ACS) are born at term (≥37 weeks' gestation). This scoping review summarizes the knowledge on the association between ACS exposure for risk of preterm birth and brain development in late preterm and term infants. The majority of studies reported that ACS exposure was associated with adverse brain development outcomes across various domains, such as reduced neonatal head circumference, cortical differences on MRI, and increased prevalence of psychiatric problems and neurodevelopmental delays in late preterm and term infants.

Developmental Programming by Perinatal Glucocorticoids

Early-life environmental factors can have persistent effects on physiological functions by altering developmental procedures in various organisms. Recent experimental and epidemiological studies now further support the idea that developmental programming is also present in mammals, including humans, influencing long-term health. Although the mechanism of programming is still largely under investigation, the role of endocrine glucocorticoids in developmental programming is gaining interest. Studies found that perinatal glucocorticoids have a persistent effect on multiple functions of the body, including metabolic, behavioral, and immune functions, in adulthood. Several mechanisms have been proposed to play a role in long-term programming. In this review, recent findings on this topic are summarized and the potential biological rationale behind this phenomenon is discussed.

Programming of a developmental imbalance in hypothalamic glutamatergic/GABAergic afferents mediates low basal activity of the hypothalamic-pituitary-adrenal axis induced by prenatal dexamethasone exposure in male offspring rats

This study was intended to demonstrate that prenatal dexamethasone exposure (PDE) can induce low basal activity of the hypothalamic-pituitary-adrenal axis (HPAA) in male offspring rats and explore the underlying mechanism. Pregnant rats were subcutaneously administered 0.2 mg/kg/d dexamethasone from gestational day (GD) 9 to GD20. Male GD20 fetuses and postnatal day 85 adult male offspring rats were sacrificed under anesthesia. Hypothalamic cells were from GD20∼postnatal day (PD) 7 fetal male rats, treated with different concentrations of dexamethasone and the glucocorticoid receptor (GR) antagonist mifepristone for 5 days. The results suggested that dexamethasone enhanced the expression of hypothalamic L-glutamic acid decarboxylase (GAD) 67 by activating GR, further stimulating the conversion of glutamate to gamma-aminobutyric acid (GABA) and inducing an imbalance in glutamatergic/GABAergic afferents in the hypothalamic paraventricular nucleus (PVN). This imbalance change was maintained postnatally, leading to the inhibition of parvocellular neurons, and mediating the low basal activity of the HPAA in PDE offspring rats, which was manifested by decreased levels of blood adrenocorticotropic hormone and corticosterone as well as reduced expression levels of corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) in the hypothalamus. Programming of a developmental imbalance in glutamatergic/GABAergic afferents in the PVN is a potential mechanism responsible for low basal activity of the HPAA in male PDE rats.

Prenatal ethanol exposure-induced hypothalamic an imbalance of glutamatergic/GABAergic projections and low functional expression in male offspring rats

This study was designed to demonstrate that prenatal ethanol exposure (PEE) can induce low functional expression of the hypothalamus in male offspring rats and explore the underlying mechanism. Pregnant rats were administered 4 g/kg ethanol or normal saline by oral gavage each day from gestational day (GD) 9 to GD20. Male GD20 foetuses and postnatal day 120 adult offspring rats were sacrificed under anaesthesia. Hypothalamic cells from male GD20~postnatal day (PD) 7 rats were treated with different doses of corticosterone and the glucocorticoid receptor (GR) antagonist mifepristone for 5 days. In this study, we found that PEE-induced overexposure of maternal glucocorticoids enhanced the expression of L-glutamic acid decarboxylase (GAD) 67 in the hypothalamic paraventricular nucleus (PVN) by activating the glucocorticoid metabolic activation system, further inducing the conversion of glutamate to L-gamma-aminobutyric acid (GABA) and developmental imbalance of glutamatergic/GABAergic projections to the PVN. The imbalance change was maintained until after birth, resulting in the inhibition of parvocellular neurons and low functional expression of the hypothalamus in PEE offspring rats. Our study indicated that low functional expression of the hypothalamus in male PEE offspring rats was associated with developmental programming of an imbalance of glutamatergic/GABAergic projections to the PVN.

No Association of Antenatal Synthetic Glucocorticoid Exposure and Hair Steroid Levels in Children and Adolescents

CONTEXT

Antenatal synthetic glucocorticoid (sGC) treatment constitutes a potent programming factor of the hypothalamic-pituitary-adrenal (HPA) axis. Previous findings from our group revealed long-term changes in cortisol stress reactivity following antenatal sGC therapy. However, the few prior studies exclusively relied on spot measurements of phasic HPA axis activity, which may not adequately capture cortisol output over prolonged periods of time.

OBJECTIVE

To address this gap, the current study utilized hair steroid concentrations, a valid marker of integrated long-term HPA-axis activity, to investigate endocrine changes in individuals treated with antenatal sGC.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study comprised 76 term-born children (7-12 years) and 58 adolescents (14-18 years). Cumulated hormonal secretion in scalp hair over a 3-month period was determined for different biomarkers of tonic HPA axis activity by liquid chromatography coupled with tandem mass spectrometry. Hair steroid levels were compared between participants with antenatal sGC therapy (dexamethasone or betamethasone) and different control groups.

RESULTS

Findings from this study provide no evidence for a significant effect of antenatal sGCs on long-term hair steroid concentrations. Participants treated with antenatal sGC exhibited comparable levels of hair cortisol, cortisone, dehydroepiandrosterone, and cortisol/dehydroepiandrosterone ratios compared to those of mothers who had been admitted to hospital for pregnancy complications but had never received sGC therapy and controls from physiological pregnancies.

CONCLUSION

In conjunction with data from previous studies, it is thus tempting to speculate that sGC may affect the capacity of dynamic changes and flexible adaption of an individual's HPA axis rather than changes in tonic steroid output.

Antenatal corticosteroid administration is associated with decreased growth of the fetal thymus: a prospective cohort study

OBJECTIVE

To examine the effect of antenatal corticosteroid administration (ACS) on fetal thymus growth in women who received ACS compared with gestational-age-matched controls.

STUDY DESIGN

Fetal thymus size and growth were measured in women at risk for preterm delivery who received ACS and compared with a matched cohort of women who were at low risk for preterm delivery and did not receive ACS. Fetal thymus perimeter and diameter were measured by 2-D ultrasound at baseline and every 2 weeks until delivery.

RESULTS

After adjusting for confounders, ACS exposure was associated with a significant reduction in thymus perimeter size (-0.70; 95% CI: -1.33, -0.07; P = 0.03). For every additional week of exposure, thymus growth trajectory was significantly decreased in ACS-exposed fetuses (P = 0.04).

CONCLUSION

The association between ACS and reduced fetal thymus growth should be further examined to establish the impact of ACS on childhood thymus development and immune programming.

Developmental programming of shyness: A longitudinal, prospective study across four decades

Although shyness is a ubiquitous phenomenon with early developmental origins, little research has examined the influence of prenatal exposures on the developmental trajectory of shyness. Here, we examined trajectories of shyness from childhood to adulthood in three groups (N = 254), with varying degrees of prenatal adversity as indicated by the number of stressful exposures: extremely low birth weight (ELBW; <1000 g) survivors prenatally exposed to exogenous corticosteroids (ELBW+S, n = 56); ELBW survivors not prenatally exposed to exogenous corticosteroids (ELBW+NS, n = 56); and normal birth weight (NBW, n = 142) controls. Multilevel modeling revealed that the ELBW+S individuals exhibited the highest levels of childhood shyness, which remained stable into adulthood. The ELBW+NS and NBW controls had comparably low levels of childhood shyness; however, the ELBW+NS individuals experienced patterns of increasing shyness, while NBW controls displayed decreases in shyness into adulthood. We speculate that individuals exposed to multiple prenatal stressors (i.e., ELBW+S) may be developmentally programmed to be more sensitive to detecting social threat, with one manifestation being early developing, stable shyness, while increasing shyness among ELBW+NS individuals may reflect a later developing shyness influenced by postnatal context. We discuss the implications of these findings for understanding the developmental origins and developmental course of human shyness from childhood through adulthood.

Persistent Effects of Antenatal Synthetic Glucocorticoids on Endocrine Stress Reactivity From Childhood to Adolescence

CONTEXT

Antenatal synthetic glucocorticoid (sGC) therapy has been identified as a potent programming factor of the hypothalamic-pituitary-adrenal (HPA) axis. We previously observed significantly increased cortisol stress responses in 6- to 11-year-old, term-born children exposed to antenatal sGCs compared with controls. These findings call for longitudinal follow-up studies to evaluate long-term effects of antenatal sGCs, given that adolescence is marked by a substantial shift of HPA axis functioning.

OBJECTIVE

This study aimed to longitudinally investigate the stability of antenatal sGC-related effects on cortisol stress reactivity from childhood to adolescence.

DESIGN, SETTING, AND PARTICIPANTS

To evaluate long-term trajectories of antenatal sGCs, we longitudinally followed a subsample (n = 44) of our children's cohort into adolescence (14 to 18 years old) for a second assessment. To this end, 22 adolescents with antenatal sGC exposure and 22 untreated controls underwent a standardized laboratory stressor [Trier Social Stress Test (TSST)].

RESULTS

Besides a general increase in HPA axis reactivity from childhood to adolescence (P < 0.05), participants treated with antenatal sGCs showed significantly higher cortisol levels in response to the TSST compared with controls during both developmental stages (P < 0.05). Furthermore, we observed a moderating effect of sGCs on rank-order stability of cortisol stress reactivity from childhood to adolescence (P < 0.05) with a trend (P = 0.07) for higher rank-order stability in sGC-exposed individuals (r = 0.37) compared with controls (r = -0.20).

CONCLUSION

These findings suggest that antenatal sGCs yield long-term changes of HPA axis reactivity that persist into adolescence and may confer increased vulnerability for developing stress-related disorders.

Programming for increased expression of hippocampal GAD67 mediated the hypersensitivity of the hypothalamic-pituitary-adrenal axis in male offspring rats with prenatal ethanol exposure

An imbalance of excitatory and inhibitory signals in the brain has been proposed to be one of the main pathological features of various diseases related to hypothalamic-pituitary-adrenal axis (HPAA) dysfunction. Excessive glutamate release induces neuronal excitotoxicity, while glutamic acid decarboxylase (GAD) 67 promotes the transformation of excessive glutamate to γ-aminobutyric acid (GABA). Our previous studies demonstrated that prenatal ethanol exposure (PEE) causes foetal over-exposure to maternal corticosterone and hypersensitivity of the HPAA after birth, but its intrauterine programming mechanism is unknown. In this study, PEE was shown to lead to an enhanced potential excitatory ability of the hypothalamus and hypersensitivity of the HPAA, as well as mild abnormal hippocampal morphology, demethylation of the -1019 to -691-bp region in the hippocampal GAD67 promoter and upregulation of GAD67 expression accompanied by a reduction in glutamatergic neurons and increase in GABAergic neurons in PEE male offspring. Similar changes were also found in PEE male foetal rats. Furthermore, corticosterone increased the expression of the glucocorticoid receptor (GR) and GAD67 in foetal hippocampal H19-7 cells in a concentration-dependent manner, accompanied by demethylation of the GAD67 promoter, a decrease in glutamatergic neurons and increase in GABAergic neurons. The GR inhibitor, mifepristone, reversed the effects of corticosterone on H19-7 cells. These results suggested that PEE-induced excessive corticosterone can lead to upregulation of GAD67 through epigenetic modification mediated by the GR in the male foetal hippocampus, thereby weakening the negative regulation of the HPAA by the hippocampus and increasing the potential excitatory ability of the hypothalamus. These changes persisted until after birth, resulting in hypersensitivity of the HPAA. However, gender differences were observed in the hippocampal development, morphology and GAD67 expression associated with PEE. Programming for the increased expression of hippocampal GAD67 is a potential mechanism responsible for the hypersensitivity of the HPAA in PEE male rats.

Prenatal Stress, Glucocorticoids, and Developmental Programming of the Stress Response

The early environment has a major impact on the developing embryo, fetus, and infant. Parental adversity (maternal and paternal) and glucocorticoid exposure before conception and during pregnancy have profound effects on the development and subsequent function of the hypothalamic-pituitary-adrenal axis and related behaviors. These effects are species-, sex-, and age-specific and depend on the timing and duration of exposure. The impact of these early exposures can extend across multiple generations, via both the maternal and paternal lineage, and recent studies have begun to determine the mechanisms by which this occurs. Improved knowledge of the mechanisms by which adversity and glucocorticoids program stress systems will allow development of strategies to ameliorate and/or reverse these long-term effects.

Dark shadow of the long white cloud: Neighborhood safety is associated with self-rated health and cortisol during pregnancy in Auckland, Aotearoa/New Zealand

Auckland, Aotearoa/New Zealand is a culturally and ethnically diverse city. Despite popular global conceptions regarding its utopian nature, the lived experience for many individuals in Auckland attests to the substantial social, economic, and health inequalities that exist there. In particular, rapidly rising home prices constrain housing decisions and force individuals to live in less desirable neighborhoods, with potential impacts on individual health. One of the pathways through which adverse neighborhood conditions could impact health is through alterations in the functioning of the hypothalamic pituitary adrenal (HPA)-axis, which regulates the physiological stress response. This paper evaluates the relationship between perceived neighborhood safety, self-rated health, and cortisol, an end product of HPA-axis activation, among women in late pregnancy. Pregnant women living in neighborhoods where they were concerned about safety of their property had poorer self-rated health and elevated morning cortisol, even after adjusting for maternal age, material deprivation, and ethnicity. However, fear of personal safety was unrelated to self-rated health and cortisol. These results suggest that maternal health in pregnancy is sensitive to perceptions regarding neighborhood safety. Such findings are important since higher cortisol levels in pregnancy could not only influence maternal health, but also the health and development of women's children.

Antenatal glucocorticoid treatment is associated with diurnal cortisol regulation in term-born children

Due to the rapid developmental changes that occur during the fetal period, prenatal influences can affect the developing central nervous system with lifelong consequences for physical and mental health. Glucocorticoids are one of the proposed mechanisms by which fetal programing occurs. Glucocorticoids pass through the blood-brain barrier and target receptors throughout the central nervous system. Unlike endogenous glucocorticoids, synthetic glucocorticoids readily pass through the placental barrier to reach the developing fetus. The synthetic glucocorticoid, betamethasone, is routinely given prenatally to mothers at risk for preterm delivery. Over 25% of the fetuses exposed to betamethasone will be born at term. Few studies have examined the lasting consequences of antenatal treatment of betamethasone on the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. The purpose of this study is to examine whether antenatal exposure to betamethasone alters circadian cortisol regulation in children who were born full term. School-aged children prenatally treated with betamethasone and born at term (n=19, mean (SD)=8.1 (1.2) years old) were compared to children not treated with antenatal glucocorticoids (n=61, mean (SD)=8.2 (1.4) years old). To measure the circadian release of cortisol, saliva samples were collected at awakening; 30, 45, and 60min after awakening; and in the evening. Comparison children showed a typical diurnal cortisol pattern that peaked in the morning (the cortisol awakening response) and gradually decreased throughout the day. In contrast, children exposed to antenatal betamethasone lacked a cortisol awakening response and had a flatter diurnal slope (p's<0.01). These data suggest that antenatal glucocorticoid treatment may disrupt the circadian regulation of the HPA axis among children born at term. Because disrupted circadian regulation of cortisol has been linked to mental and somatic health problems, future research is needed to determine whether children exposed to antenatal synthetic glucocorticoids are at risk for poor mental and physical health.

The Swiss Preschoolers' health study (SPLASHY): objectives and design of a prospective multi-site cohort study assessing psychological and physiological health in young children

Background

Children’s psychological and physiological health can be summarized as the child’s thinking, feeling, behaving, eating, growing, and moving. Children’s psychological and physiological health conditions are influenced by today’s life challenges: Thus, stress exposure and lack of physical activity represent important health challenges in older children. However, corresponding evidence for young children is scarce. The aim of Swiss Preschoolers’ Health Study (SPLASHY) is to examine the role of stress and physical activity on children’s psychological and physiological health, particularly on cognitive functioning, psychological well-being, adiposity and motor skills in children at an early stage of childhood. We will also assess the role of child and environmental characteristics and aim to define sensitive time points.

Methods/design

In a total of 84 child care centers, children at preschool age (2–6 years) are recruited and are assessed immediately and one year later. Assessments include direct measurements of the children in the child care centers and at home as well as assessments of children’s behavior and environmental factors through informants (parents and child care educators).

Discussion

SPLASHY is one of the first studies in early childhood aiming to investigate the influence of stress and physical activity on children’s psychological and physiological health in a community-based longitudinal design.

Trial registration

Current Controlled Trials ISRCTN41045021 (date of registration: 21.03.14)

Expression of eight glucocorticoid receptor isoforms in the human preterm placenta vary with fetal sex and birthweight

INTRODUCTION

Administration of betamethasone to women at risk of preterm delivery is known to be associated with reduced fetal growth via alterations in placental function and possibly direct effects on the fetus. The placental glucocorticoid receptor (GR) is central to this response and recent evidence suggests there are numerous isoforms for GR in term placentae. In this study we have questioned whether GR isoform expression varies in preterm placentae in relation to betamethasone exposure, fetal sex and birthweight.

METHODS

Preterm (24-36 completed weeks of gestation, n = 55) and term placentae (>37 completed weeks of gestation, n = 56) were collected at delivery. Placental GR expression was examined using Western Blot and analysed in relation to gestational age at delivery, fetal sex, birthweight and betamethasone exposure. Data was analysed using non-parametric tests.

RESULTS

Eight known isoforms of the GR were detected in the preterm placenta and include GRα (94 kDa), GRβ (91 kDa), GRα C (81 kDa) GR P (74 kDa) GR A (65 kDa), GRα D1-3 (50-55 kDa). Expression varied between preterm and term placentae with a greater expression of GRα C in preterm placentae relative to term placentae. The only sex differences in preterm placentae was that GRα D2 expression was higher in males than females. There were no alterations in preterm placental GR expression in association with betamethasone exposure.

DISCUSSION

GRα C is the isoform involved in glucocorticoid induced apoptosis and suggests that its predominance in preterm placentae may contribute to the pathophysiology of preterm birth.

Prenatal ethanol exposure induces an intrauterine programming of enhanced sensitivity of the hypothalamic–pituitary–adrenal axis in female offspring rats fed with post-weaning high-fat diet

“Intrauterine programming” involved in the intrauterine origin of prenatal ethanol exposure induced enhanced sensitivity of the HPA axis in female offspring rats fed with high-fat diet.

Antenatal glucocorticoids: where are we after forty years?

Since their introduction more than forty years ago, antenatal glucocorticoids have become a cornerstone in the management of preterm birth and have been responsible for substantial reductions in neonatal mortality and morbidity. Clinical trials conducted over the past decade have shown that these benefits may be increased further through administration of repeat doses of antenatal glucocorticoids in women at ongoing risk of preterm and in those undergoing elective cesarean at term. At the same time, a growing body of experimental animal evidence and observational data in humans has linked fetal overexposure to maternal glucocorticoids with increased risk of cardiovascular, metabolic and other disorders in later life. Despite these concerns, and somewhat surprisingly, there has been little evidence to date from randomized trials of longer-term harm from clinical doses of synthetic glucocorticoids. However, with wider clinical application of antenatal glucocorticoid therapy there has been greater need to consider the potential for later adverse effects. This paper reviews current evidence for the short- and long-term health effects of antenatal glucocorticoids and discusses the apparent discrepancy between data from randomized clinical trials and other studies.

The effect of perinatal anxiety on bronchiolitis is influenced by polymorphisms in ROS-related genes

Background

Exposure to perinatal anxiety affects disease susceptibility in offspring but studies on the association between perinatal anxiety and gene polymorphisms are lacking. This study aimed to elucidate the interaction between perinatal anxiety and polymorphisms in antioxidant defense and innate immunity genes on the development of respiratory tract infections (RTIs) during early infancy.

Methods

Trait anxiety levels in 440 women were assessed by the State-Trait Anxiety Inventory during late gestation. The occurrence of RTIs, including bronchiolitis, during the first year of life was assessed by parent-reported doctor diagnosis. Polymorphisms in glutathione S-transferase P-1 (GSTP1, rs1695) and CD14 (rs2569190) were genotyped using the TaqMan assay. Copy number variations of GSTT1 were measured by real-time polymerase chain reaction.

Results

Exposure to high levels of perinatal anxiety increased the risk of bronchiolitis in the first year of life (adjusted odds ratio [aOR], 1.30; 95% confidence interval [CI]: 1.00–1.80), in particular among children with the AG + GG genotype of GSTP1 or the GSTT1 null genotype (aOR 3.36 and 2.79). In infants with the TC + CC genotype of CD14, high levels of perinatal anxiety were associated with an increased risk of upper RTI, lower RTI, and bronchiolitis (aOR 2.51, 4.60, and 4.31, respectively).

Conclusions

Perinatal maternal anxiety levels affect the occurrence of bronchiolitis in offspring. The effect of perinatal anxiety on the occurrence of bronchiolitis during infancy was influenced by genetic polymorphisms in antioxidant defense and innate immunity genes.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2466-14-154) contains supplementary material, which is available to authorized users.

Prenatal xenobiotic exposure and intrauterine hypothalamus-pituitary-adrenal axis programming alteration

The hypothalamic-pituitary-adrenal (HPA) axis is one of the most important neuroendocrine axes and plays an important role in stress defense responses before and after birth. Prenatal exposure to xenobiotics, including environmental toxins (such as smoke, sulfur dioxide and carbon monoxide), drugs (such as synthetic glucocorticoids), and foods and beverage categories (such as ethanol and caffeine), affects fetal development indirectly by changing the maternal status or damaging the placenta. Certain xenobiotics (such as caffeine, ethanol and dexamethasone) may also affect the fetus directly by crossing the placenta into the fetus due to their lipophilic properties and lower molecular weights. All of these factors probably result in intrauterine programming alteration of the HPA axis, which showed a low basal activity but hypersensitivity to chronic stress. These alterations will, therefore, increase the susceptibility to adult neuropsychiatric (such as depression and schizophrenia) and metabolic diseases (such as hypertension, diabetes and non-alcoholic fatty liver disease). The "over-exposure of fetuses to maternal glucocorticoids" may be the main initiation factor by which the fetal HPA axis programming is altered. Meantime, xenobiotics can directly induce abnormal epigenetic modifications and expression on the important fetal genes (such as hippocampal glucocorticoid receptor, adrenal steroidogenic acute regulatory protein, et al) or damage by in situ oxidative metabolism of fetal adrenals, which may also be contributed to the programming alteration of fetal HPA axis.

Glucocorticoids and fetal programming part 1: Outcomes

Fetal development is a critical period for shaping the lifelong health of an individual. However, the fetus is susceptible to internal and external stimuli that can lead to adverse long-term health consequences. Glucocorticoids are an important developmental switch, driving changes in gene regulation that are necessary for normal growth and maturation. The fetal hypothalamic-pituitary-adrenal (HPA) axis is particularly susceptible to long-term programming by glucocorticoids; these effects can persist throughout the life of an organism. Dysfunction of the HPA axis as a result of fetal programming has been associated with impaired brain growth, altered behaviour and increased susceptibility to chronic disease (such as metabolic and cardiovascular disease). Moreover, the effects of glucocorticoid-mediated programming are evident in subsequent generations, and transmission of these changes can occur through both maternal and paternal lineages.

Early stress and human behavioral development: emerging evolutionary perspectives

Stress experienced early in life exerts a powerful, lasting influence on development. Converging empirical findings show that stressful experiences become deeply embedded in the child’s neurobiology, with an astonishing range of long-term effects on cognition, emotion, and behavior. In contrast with the prevailing view that such effects are the maladaptive outcomes of ‘toxic’ stress, adaptive models regard them as manifestations of evolved developmental plasticity. In this paper, I offer a brief introduction to adaptive models of early stress and human behavioral development, with emphasis on recent theoretical contributions and emerging concepts in the field. I begin by contrasting dysregulation models of early stress with their adaptive counterparts; I then introduce life history theory as a unifying framework, and review recent work on predictive adaptive responses (PARs) in human life history development. In particular, I discuss the distinction between forecasting the future state of the environment (external prediction) and forecasting the future state of the organism (internal prediction). Next, I present the adaptive calibration model, an integrative model of individual differences in stress responsivity based on life history concepts. I conclude by examining how maternal–fetal conflict may shape the physiology of prenatal stress and its adaptive and maladaptive effects on postnatal development. In total, I aim to show how theoretical work from evolutionary biology is reshaping the way we think about the role of stress in human development, and provide researchers with an up-to-date conceptual map of this fascinating and rapidly evolving field.

Antenatal steroids: can we optimize the dose?

PURPOSE OF REVIEW

The beneficial effects of antenatal steroids in women at risk of preterm birth are evident. A dose of 24 mg appears sufficient, but there are insufficient data to recommend betamethasone or dexamethasone, a single steroid dose, the optimal interval between doses and repeated courses, the gestational age at which treatment is beneficial and the long-term effects of steroid treatment. This review addresses these aspects of antenatal steroid treatment.

RECENT FINDINGS

Although the 12-h and 24-h dosing intervals are equivalent with respect to prevention of respiratory distress syndrome, the former enables the completion of treatment in 50% more neonates delivered prematurely. Reducing the single steroid dose in patients at risk for premature birth reduces the associated maternal side effects. An inverse relationship has been demonstrated between the number of corticosteroid courses and foetal growth. The reduced size of exposed foetuses has been attributed to birth at earlier gestational ages and decreased foetal growth. Evidence suggests that antenatal exposure to synthetic glucocorticoids in term-born children has long-lasting effects, which may have important implications in the recommendation of steroids before elective caesarean at term.

SUMMARY

The short-term and long-term effects of the dosage regimen on the pregnant mother and foetus remain unclear.