Association between umbilical cord glucocorticoids and blood pressure at age 3 years

Prenatal glucocorticoids exposure and adverse cardiovascular effects in offspring

Glucocorticoids (GCs) are steroid hormones fundamental to the body's normal physiological functions and are pivotal in fetal growth and development. During gestation, the mother's cortisol concentration (active GCs) escalates to accommodate the requirements of fetal organ development and maturation. A natural placental GCs barrier, primarily facilitated by 11β hydroxysteroid dehydrogenase 2, exists between the mother and fetus. This enzyme transforms biologically active cortisol into biologically inactive corticosterone, thereby mitigating fetal GCs exposure. However, during pregnancy, the mother may be vulnerable to adverse factor exposures such as stress, hypoxia, caffeine, and synthetic GCs use. In these instances, maternal serum GCs levels may surge beyond the protective capacity of the placental GCs barrier. Moreover, these adverse factors could directly compromise the placental GCs barrier, resulting in excessive fetal exposure to GCs. It is well-documented that prenatal GCs exposure can detrimentally impact the offspring's cardiovascular system, particularly in relation to blood pressure, vascular function, and heart function. In this review, we succinctly delineate the alterations in GCs levels during pregnancy and the potential mechanisms driving these changes, and also analyze the possible causes of prenatal GCs exposure. Furthermore, we summarize the current advancements in understanding the adverse effects and mechanisms of prenatal GCs exposure on the offspring's cardiovascular system.

Associations of prenatal maternal depressive symptoms with cord blood glucocorticoids and child hair cortisol levels in the project viva and the generation R cohorts: a prospective cohort study

BACKGROUND

Prior studies have reported conflicting results regarding the association of prenatal maternal depression with offspring cortisol levels. We examined associations of high levels of prenatal depressive symptoms with child cortisol biomarkers.

METHODS

In Project Viva (n = 925, Massachusetts USA), mothers reported their depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy, cord blood glucocorticoids were measured at delivery, and child hair cortisol levels were measured in mid-childhood (mean (SD) age: 7.8 (0.8) years) and early adolescence (mean (SD) age: 13.2 (0.9) years). In the Generation R Study (n = 1644, Rotterdam, The Netherlands), mothers reported depressive symptoms using the Brief Symptom Inventory (BSI) during pregnancy, and child hair cortisol was measured at a mean (SD) age of 6.0 (0.5) years. We used cutoffs of ≥ 13 for the EPDS and > 0.75 for the BSI to indicate high levels of prenatal depressive symptoms. We used multivariable linear regression models adjusted for child sex and age (at outcome), and maternal pre-pregnancy BMI, education, social support from friends/family, pregnancy smoking status, marital status, and household income to assess associations separately in each cohort. We also meta-analyzed childhood hair cortisol results from both cohorts.

RESULTS

8.0% and 5.1% of women respectively experienced high levels of prenatal depressive symptoms in Project Viva and the Generation R Study. We found no associations between high levels of maternal depressive symptoms during pregnancy and child cortisol biomarkers in either cohort.

CONCLUSIONS

The present study does not find support for the direct link between high levels of maternal depressive symptoms and offspring cortisol levels.

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.

Associations of maternal glucose markers in pregnancy with cord blood glucocorticoids and child hair cortisol levels

Exposure to maternal hyperglycemia in utero has been associated with adverse metabolic outcomes in offspring. However, few studies have investigated the relationship between maternal hyperglycemia and offspring cortisol levels. We assessed associations of gestational diabetes mellitus (GDM) with cortisol biomarkers in two longitudinal prebirth cohorts: Project Viva included 928 mother-child pairs and Gen3G included 313 mother-child pairs. In Project Viva, GDM was diagnosed in N = 48 (5.2%) women using a two-step procedure (50 g glucose challenge test, if abnormal followed by 100 g oral glucose tolerance test [OGTT]), and in N = 29 (9.3%) women participating in Gen3G using one-step 75 g OGTT. In Project Viva, we measured cord blood glucocorticoids and child hair cortisol levels during mid-childhood (mean (SD) age: 7.8 (0.8) years) and early adolescence (mean (SD) age: 13.2 (0.9) years). In Gen3G, we measured hair cortisol at 5.4 (0.3) years. We used multivariable linear regression to examine associations of GDM with offspring cortisol, adjusting for child age and sex, maternal prepregnancy body mass index, education, and socioeconomic status. We additionally adjusted for child race/ethnicity in the cord blood analyses. In both Project Viva and Gen3G, we observed null associations of GDM and maternal glucose markers in pregnancy with cortisol biomarkers in cord blood at birth (β = 16.6 nmol/L, 95% CI -60.7, 94.0 in Project Viva) and in hair samples during childhood (β = -0.56 pg/mg, 95% CI -1.16, 0.04 in Project Viva; β = 0.09 pg/mg, 95% CI -0.38, 0.57 in Gen3G). Our findings do not support the hypothesis that maternal hyperglycemia is related to hypothalamic-pituitary-adrenal axis activity.

Glucocorticoids in preterm human milk

Background

Glucocorticoids (GCs), cortisol and cortisone, are essential regulators of many physiological responses, including immunity, stress and mammary gland function. GCs are present in human milk (HM), but whether maternal and infant factors are associated with HM GC concentration following preterm birth is unclear.

Materials and methods

HM samples were collected on postnatal day 5 and 10 and at 4 months’ corrected age (4m CA) in a cohort of moderate- and late-preterm infants. GCs in HM were measured by liquid chromatography-tandem mass spectrometry. Relationships between GCs in HM and both maternal and infant characteristics were investigated using Spearman’s correlations and linear mixed models.

Results

170 mothers of 191 infants provided 354 HM samples. Cortisol concentrations in HM increased from postnatal day 5–4m CA (mean difference [MD] 0.6 ± 0.1 ng/ml, p < 0.001). Cortisone concentration did not change across lactation but was higher than cortisol throughout. Compared to no antenatal corticosteroid (ANS), a complete course of ANS was associated with lower GC concentrations in HM through to 4m CA (cortisol: MD –0.3 ± 0.1 ng/ml, p < 0.01; cortisone MD –1.8 ± 0.4 ng/ml, p < 0.001). At 4m CA, higher maternal perceived stress was negatively associated with GC concentrations in HM (cortisol adjusted beta-coefficient [aβ] –0.01 ± 0.01 ng/ml, p = 0.05; and cortisone aβ –0.1 ± 0.03 ng/ml, p = 0.01), whereas higher postpartum depression and maternal obesity were associated with lower cortisone concentrations (aβ –0.1 ± 0.04 ng/ml p < 0.05; MD [healthy versus obese] –0.1 ± 0.04 ng/ml p < 0.05, respectively). There was a weak positive correlation between GC concentrations in HM and gestational age at birth (r = 0.1, p < 0.05). Infant birth head circumference z-score was negatively associated with cortisol concentrations (aβ –0.01 ± 0.04 ng/ml, p < 0.05). At hospital discharge, fat-free mass showed a weak positive correlation with cortisol concentrations (r = 0.2, p = 0.03), while fat mass showed a weak negative correlation with cortisone concentrations (r = –0.25, p < 0.001).

Conclusion

The mammary gland appears to protect the infant from cortisol through inactivation into cortisone. Maternal and infant characteristics were associated with concentration of GCs in HM, including ANS, stress and depression scores, obesity, gestational age and infant size. The effects of HM glucocorticoids on long-term health outcomes requires further research.

Determination of hormones in human urine by ultra-high-performance liquid chromatography/triple-quadrupole mass spectrometry

Steroid hormones play a critical role in maintaining the homeostasis of human metabolism. Urine as a noninvasive sample has been extensively used in clinical diagnosis for hormones homeostasis. In this study, the simultaneous characterization of fourteen hormones in urine was performed based on ultra-high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPHLC/ESI(+)-MS/MS) with multiple reaction monitoring in the positive ionization mode. The target hormones were cortisone, cortisol, 11-deoxycortisol, aldosterone, corticosterone, 11-deoxycorticosterone, progesterone, 17-OH-progesterone, pregnenolone, estrone, estradiol, estriol, testosterone and dehydreopiandrosterone. β-Glucuronidase/sulfatase deconjugation and liquid-liquid extraction (LLE) were conducted for the determination of urinary hormones (free + conjugated forms). The limits of detection (LODs) ranged from 0.2 ng/mL (11-deoxycortisol and testosterone) to 1 ng/mL (cortisone). The extraction recovery of the targeted compounds ranged from 87% to 127%, indicating sufficient extraction efficiency for the LLE process. Intraday precision was below 10% and the accuracy ranged from 84% to 122%. The profiling analysis of hormones in urine samples helps to understand the metabolic state of biological systems and can be employed as a diagnostic tool in diseases developed by endocrine-disrupted systems.

Placental 11β-HSD2 and Cardiometabolic Health Indicators in Infancy

OBJECTIVE

Fetal excessive exposure to glucocorticoids may program cardiometabolic risk. Placental 11 β-hydroxysteroid dehydrogenase 2 (11β-HSD2) serves as a barrier to prevent fetal overexposure to maternal glucocorticoids. It has not been explored whether placental 11β-HSD2 levels are associated with cardiometabolic health in postnatal life.

RESEARCH DESIGN AND METHODS

In a prospective birth cohort study of 246 mother-infant pairs, we measured placental 11β-HSD2 expression and maternal (32-35 weeks of gestation) and cord plasma cortisol concentrations. The primary outcomes were HOMA of insulin resistance (IR) and blood pressure (BP) in infants at age 1 year. Other outcomes included fasting insulin, HOMA β-cell function, carotid intima-media thickness, weight z score, and skinfold thickness (triceps and subscapular) at age 1 year.

RESULTS

Placental 11β-HSD2 expression was negatively correlated with HOMA-IR (r = -0.17, P = 0.021) and fasting insulin (r = -0.18, P = 0.017) and marginally negatively correlated with systolic BP (r = -0.16, P = 0.057) but was not correlated with HOMA of β-cell function, diastolic BP, carotid intima-media thickness, and skinfold thickness (all P > 0.1) in infants at age 1 year. Cord plasma cortisol was negatively correlated to skinfold thickness (r = -0.20, P = 0007) but was not correlated with other outcomes at age 1 year. Maternal plasma cortisol was positively correlated with maximal carotid intima-media thickness (r = 0.20, P = 0.03) but was not correlated with other outcomes. Adjusting for maternal and infant characteristics, the associations were similar.

CONCLUSIONS

The study is the first to show that higher placental 11β-HSD2 expression is associated with lower IR in infancy. Independent cohort studies are required to confirm this novel finding.

Mechanisms of in utero cortisol effects on the newborn heart revealed by transcriptomic modeling

We have identified effects of elevated maternal cortisol (induced by maternal infusion 1 mg·kg-1·day-1) on fetal cardiac maturation and function using an ovine model. Whereas short-term exposure (115-130-day gestation) increased myocyte proliferation and Purkinje fiber apoptosis, infusions until birth caused bradycardia with increased incidence of arrhythmias at birth and increased perinatal death, despite normal fetal cortisol concentrations from 130 days to birth. Statistical modeling of the transcriptomic changes in hearts at 130 and 140 days suggested that maternal cortisol excess disrupts cardiac metabolism. In the current study, we modeled pathways in the left ventricle (LV) and interventricular septum (IVS) of newborn lambs after maternal cortisol infusion from 115 days to birth. In both LV and IVS the transcriptomic model indicated over-representation of cell cycle genes and suggested disruption of cell cycle progression. Pathways in the LV involved in cardiac architecture, including SMAD and bone morphogenetic protein ( BMP) were altered, and collagen deposition was increased. Pathways in IVS related to metabolism, calcium signaling, and the actin cytoskeleton were altered. Comparison of the effects of maternal cortisol excess to the effects of normal maturation from day 140 to birth revealed that only 20% of the genes changed in the LV were consistent with normal maturation, indicating that chronic elevation of maternal cortisol alters normal maturation of the fetal myocardium. These effects of maternal cortisol on the cardiac transcriptome, which may be secondary to metabolic effects, are consistent with cardiac remodeling and likely contribute to the adverse impact of maternal stress on perinatal cardiac function.

Associations between repeated measures of maternal urinary phthalate metabolites during pregnancy and cord blood glucocorticoids

BACKGROUND

Previous studies have suggested that phthalates might disrupt fetal steroidogenesis. However, the evidence of the effects of prenatal phthalate exposure across pregnancy on fetal glucocorticoids was insufficient.

OBJECTIVE

We investigated the associations between urinary phthalate metabolites across pregnancy and cord blood glucocorticoids in a prospective birth cohort.

METHODS

Our study included 553 mother-infant pairs from a prospective birth cohort conducted in Wuhan, China. Maternal urine samples were collected at 14, 24 and 36 weeks of gestation (mean). Urinary phthalate metabolites and cord blood glucocorticoids (cortisol and cortisone) were measured. Generalized estimating equation models were conducted to explore the relationships of phthalate metabolite concentrations at each trimester and glucocorticoid levels.

RESULTS

Among the participants, mono‑benzyl phthalate (MBzP) in the first trimester was associated with higher cortisol/cortisone ratio concentrations, and mono‑(2‑ethyl‑5‑carboxypentyl) phthalate (MECPP) and mono‑(2‑ethyl‑5‑oxohexyl) phthalate (MEOHP) measured in the third trimester were associated with decreased cortisone. Moreover, the associations between phthalates and glucocorticoids varied by sex. Among the female infants, each 10-fold increase in several maternal urinary phthalate metabolite concentrations in 1st and 3rd trimester was associated with the increased glucocorticoid levels with percent changes ranged from 16.2%-55.9%. However, among male infants, each 10-fold increase in maternal urinary MECPP, mono‑(2‑ethyl‑5‑hydroxyhexyl) phthalate (MEHHP) and MEOHP in 3rd trimester was associated with 20.8%-36.3% decreased cortisol and cortisone levels, respectively.

CONCLUSION

We have shown that prenatal phthalate exposure during early and late trimester disrupted the infant steroidogenesis and these associations might be modified by infant sex. To the best of our knowledge, this is the first study to evaluate phthalate exposure at three trimesters during pregnancy in relation to infant glucocorticoids.

Developmental origins of health and disease: current knowledge and potential mechanisms

Epidemiologic and clinical research has provided a large body of evidence supporting the developmental origins of health and disease (DOHaD), but there has been a relative dearth of mechanistic studies in humans due to the complexity of working with large, longitudinal cohorts. Nonetheless, animal models of undernutrition have provided substantial evidence for the potential epigenetic, metabolic, and endocrine mechanisms behind DOHaD. Furthermore, recent research has explored the interaction between the environment and the gastrointestinal system by investigating how the gut microbial ecology may impact the capacity for nutrient processing and absorption in a manner that may limit growth. This review presents a summary of current research that supports the concept of DOHaD, as well as potential mechanisms and interactions that explain how nutrition in utero and during early childhood influences lifelong health.

Dysregulation of 11beta-hydroxysteroid dehydrogenases: implications during pregnancy and beyond

Glucococorticoids play a critical role in the developmental programing and fetal growth. Key molecules mediating and regulating tissue-specific glucocorticoid actions are 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1 and 2 isozymes, both of which are expressed in the placenta and the fetal membranes. 11beta-HSD1 is implicated in the pathogenesis of metabolic syndrome and its dysregulation has been observed in pregnancy-related complications (pre-eclampsia, intrauterine growth restriction). Interestingly, preliminary clinical data have associated certain 11beta-HSD1 gene polymorphisms with hypertensive disorders in pregnancy, suggesting, if confirmed by further targeted studies, it's potential as a putative prognostic marker. Animal studies and observations in humans have confirmed that 11beta-HSD2 insufficiency is related with pregnancy adversity (pre-eclampsia, intrauterine growth restriction, preterm birth). Importantly, down-regulation or deficiency of placental 11beta-HSD2 is associated with significant restriction in fetal growth and low-birth weight, and unfavorable cardio-metabolic profile in adulthood. The potential association of 11beta-HSD1 tissue-specific dysregulation with gestational diabetes, as well as the plausible utility of 11beta-HSD2, as a biomarker of pregnancy adversity and later life morbidity, are emerging areas of intense scientific interest and future investigation.

Glucocorticoid-induced fetal origins of adult hypertension: Association with epigenetic events

Hypertension is a predominant risk factor for cardiovascular diseases and a major health care burden. Accumulating epidemiological and experimental evidence suggest that adult-onset hypertension may have its origins during early development. Upon exposure to glucocorticoids, the fetus develops hypertension, and the offspring may be programmed to continue the hypertensive trajectory into adulthood. Elevated oxidative stress and deranged nitric oxide system are not only hallmarks of adult hypertension but are also observed earlier in life. Endothelial dysfunction and remodeling of the vasculature, which are robustly associated with increased incidence of hypertension, are likely to have been pre-programmed during fetal life. Apparently, genomic, non-genomic, and epigenomic factors play a significant role in the development of hypertension, including glucocorticoid-driven effects on blood pressure. In this review, we discuss the involvement of the aforementioned participants in the pathophysiology of hypertension and suggest therapeutic opportunities for targeting epigenome modifiers, potentially for personalized medicine.

High expression levels of macrophage migration inhibitory factor sustain the innate immune responses of neonates

The vulnerability to infection of newborns is associated with a limited ability to mount efficient immune responses. High concentrations of adenosine and prostaglandins in the fetal and neonatal circulation hamper the antimicrobial responses of newborn immune cells. However, the existence of mechanisms counterbalancing neonatal immunosuppression has not been investigated. Remarkably, circulating levels of macrophage migration inhibitory factor (MIF), a proinflammatory immunoregulatory cytokine expressed constitutively, were 10-fold higher in newborns than in children and adults. Newborn monocytes expressed high levels of MIF and released MIF upon stimulation with Escherichia coli and group B Streptococcus, the leading pathogens of early-onset neonatal sepsis. Inhibition of MIF activity or MIF expression reduced microbial product-induced phosphorylation of p38 and ERK1/2 mitogen-activated protein kinases and secretion of cytokines. Recombinant MIF used at newborn, but not adult, concentrations counterregulated adenosine and prostaglandin E2-mediated inhibition of ERK1/2 activation and TNF production in newborn monocytes exposed to E. coli. In agreement with the concept that once infection is established high levels of MIF are detrimental to the host, treatment with a small molecule inhibitor of MIF reduced systemic inflammatory response, bacterial proliferation, and mortality of septic newborn mice. Altogether, these data provide a mechanistic explanation for how newborns may cope with an immunosuppressive environment to maintain a certain threshold of innate defenses. However, the same defense mechanisms may be at the expense of the host in conditions of severe infection, suggesting that MIF could represent a potential attractive target for immune-modulating adjunctive therapies for neonatal sepsis.

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.

Prospective evaluation of associations between prenatal cortisol and adulthood coronary heart disease risk: the New England family study

OBJECTIVE

Increasing evidence suggests that early life factors may influence coronary heart disease (CHD) risk; however, little is known about the contributions of prenatal cortisol. Objectives were to prospectively assess the associations of maternal cortisol levels during pregnancy with offspring's 10-year CHD risk during middle age.

METHODS

Participants were 262 mother-offspring dyads from the New England Family Study. Maternal free cortisol was assessed in third-trimester maternal serum samples. Ten-year CHD risk was calculated in offspring at a mean age of 42 years, using the validated Framingham risk algorithm incorporating diabetes, systolic and diastolic blood pressure, total and high-density lipoprotein cholesterol, smoking, age, and sex.

RESULTS

In multivariable-adjusted linear regression analyses adjusted for age and race/ethnicity, high versus low maternal cortisol tertile was associated with 36.7% (95% confidence interval [CI] = 8.4% to 72.5%) greater mean 10-year CHD risk score in women. There was no association in men (-2.8%, 95% CI = -23.8% to 24.0%). Further adjustment for in utero socioeconomic position showed 26.1% (95% CI = -0.5% to 59.9%) greater CHD risk in women. Adjustment for maternal age and size for gestational age had little effect on findings.

CONCLUSIONS

Maternal prenatal cortisol levels were positively associated with 10-year CHD risk among female, and not male, offspring. Adjusting for socioeconomic position during pregnancy reduced effect size in women, suggesting that it may be a common prior factor in both maternal cortisol and CHD risk. These findings provide evidence that targeting mothers who have elevated prenatal cortisol levels, including elevated cortisol in the setting of low socioeconomic position, may potentially reduce long-term CHD risk in their offspring.

Fetal Neurology: The Role of Fetal Stress

Fetal development and growth, as well as the timing of birth is influenced by the intrauterine environment. Many environmental factors causing the fetal stress can interfere with fetal development and leave long-term and profound consequences on health. Fetal glucocorticoid overexposure has primarily significant consequences for the development of the central nervous system. In response to an adverse intrauterine conditions, the fetus is able to adapt its physiology to promote survival. However, these adaptations can result in permanent changes in tissue and organ structure and function that directly ‘program’ predisposition to disease. Cardiometabolic disorders, behavioral alterations and neuropsychiatric impairments in adulthood and/ or childhood may have their roots in the fetal period of life. Fetal response to stress and its prenatal and lifelong consequences are discussed in this review.

How to cite this article

Kadić AS. Fetal Neurology: The Role of Fetal Stress. Donald School J Ultrasound Obstet Gynecol 2015;9(1):30-39.

The acute autonomic stress response and amniotic fluid glucocorticoids in second-trimester pregnant women

OBJECTIVE

The maternal autonomic nervous system (ANS) has received little attention in the investigation of biological mechanisms linking prenatal stress to fetal cortisol (F) excess. In vitro, norepinephrine and epinephrine inhibit placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which protects the fetus from F overexposure by inactivating it to cortisone (E). Here, we investigated the acute ANS stress response to an amniocentesis and its association with amniotic fluid F, E, and E/(E + F) as a marker of fetoplacental 11β-HSD2 activity.

METHODS

An aliquot of amniotic fluid was obtained from 34 healthy, second-trimester pregnant women undergoing amniocentesis. Repeated assessment of mood states served to examine the psychological stress response to amniocentesis. Saliva samples were collected to measure stress-induced changes in salivary α-amylase concentrations in response to amniocentesis. Cardiac parameters were measured continuously.

RESULTS

Undergoing amniocentesis induced significant psychological and autonomic alterations. Low-frequency (LF)/high-frequency (HF) baseline, suggested to reflect sympathovagal balance, was negatively correlated with amniotic E/(E + F) (r=-0.53, p = .002) and positively with F (r = 0.62, p < .001). In contrast, a stronger acute LF/HF response was positively associated with E/(E + F) (r = 0.44, p = .012) and negatively with F (r=-0.40, p = .025).

CONCLUSIONS

These findings suggest that the maternal ANS is involved in the regulation of the fetoplacental barrier to stress. Allostatic processes may have been initiated to counterbalance acute stress effects. In contrast, higher LF/HF baseline values, possibly indicative of chronic stress exposure, may have inhibited 11β-HSD2 activity in the fetoplacental unit. These results parallel animal findings of up-regulated placental 11β-HSD2 in response to acute stress but impairment under chronic stress.

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 association between perceived emotional support, maternal mood, salivary cortisol, salivary cortisone, and the ratio between the two compounds in response to acute stress in second trimester pregnant women

OBJECTIVE

Little is known about the effect of social support on the reactivity of the hypothalamic-pituitary-adrenal (HPA) axis during pregnancy. Moreover, when investigating the HPA axis most studies do not consider the activity of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), an enzyme within the salivary glands that inactivates cortisol to cortisone. This study explores the association between perceived emotional support and the maternal psychobiological stress response to a standardized naturalistic stressor by assessing maternal mood and the reactivity of salivary cortisol (SalF), salivary cortisone (SalE), and the SalE/(E+F) ratio as a marker of 11β-HSD2 activity.

METHODS

Repeated saliva samples and measures of maternal mood were obtained from 34 healthy second trimester pregnant women undergoing amniocentesis which served as a psychological stressor. The pregnant women additionally responded to a questionnaire of perceived emotional support and provided sociodemographic (e.g., maternal educational degree) and pregnancy-specific data (e.g., planned versus unplanned pregnancy).

RESULTS

Perceived emotional support neither showed a significant effect on mood nor on the SalF or SalE response to stress. However, a moderately strong positive association was found between perceived emotional support and SalE/(E+F) (r=.49). Additionally, the final regression analysis revealed a significant negative relationship between educational degree, planned/unplanned pregnancy and SalE/(E+F).

CONCLUSION

Findings suggest a higher metabolization of cortisol to cortisone in pregnant women with higher emotional support. In contrast, higher maternal education and unplanned pregnancy appear to be associated with decreased salivary 11β-HSD2 activity. The current study emphasizes the importance of taking the activity of 11β-HSD2 into account when examining SalF.

Changes in the maternal hypothalamic-pituitary-adrenal axis in pregnancy and postpartum: influences on maternal and fetal outcomes

Overexposure of the developing fetus to glucocorticoids is hypothesised to be one of the key mechanisms linking early life development with later life disease. The maternal hypothalamic-pituitary-adrenal (HPA) axis undergoes dramatic changes during pregnancy and postpartum. Although cortisol levels rise threefold by the third trimester, the fetus is partially protected from high cortisol by activity of the enzyme 11β-hydroxysteroid dehydrogenase type 2 (HSD11B2). Maternal HPA axis activity and activity of HSD11B2 may be modified by maternal stress and disease allowing greater transfer of glucocorticoids from mother to fetus. Here we review emerging data from human studies linking dysregulation of the maternal HPA axis to outcomes in both the mother and her offspring. For the offspring, greater glucocorticoid exposure is associated with lower birth weight and shorter gestation at delivery. In addition, evidence supports longer term consequences for the offspring including re-setting of the HPA axis and susceptibility to neurodevelopmental problems and cardiometabolic disease. For the mother, the changes in the HPA axis, particularly in the postpartum period, may increase vulnerability to mood disturbances. Further understanding of the changes in the HPA axis during pregnancy and the impact of these changes may ultimately allow early identification of those most at risk of future disease.

Combined quantification of corticotropin-releasing hormone, cortisol-to-cortisone ratio and progesterone by liquid chromatography-Tandem mass spectrometry in placental tissue

With mid-gestation the production of placental corticotropin-releasing hormone (CRH) starts to steadily increase. The fetal peptide CRH excerts direct functions at the feto-maternal interface (vasodilatation, timing of birth) via its interaction with progesterone and indirectly ensures maturation and growth of fetal organ systems for delivery by driving fetal cortisol production via its induction of adrenocorticotropic hormone release. This feedback loop is tightly controlled by the amount of enzymatic cortisol/cortisone turnover in the placental syncytiotrophoblast by 11β-hydroxy-steroid dehydrogenase type 2 (11β-HSD2). Traditionally, placental tissue hormones have been quantified by immunological methods (e.g. RIA or ELISA), which have the drawback of possible cross-reactivity and tissue perturbations. Most importantly, it is not possible to quantify CRH and steroid hormones, such as cortisol, cortisone and progesterone together in the same sample with these methods. Hence, we aimed to develop and validate a quantitative mass spectrometry (MS) method for multi-modal quantification of these placental hormones: While CRH was readily detectable throughout the placenta, the placental levels of progesterone and especially cortisol and cortisone were higher at the placental base facing the maternal side. The HPLC-MS/MS procedure showed excellent selectivity and sufficient limit of quantification in placental tissue homogenates to allow for simultaneous detection of CRH, cortisol and cortisone, and progesterone.

11β Hydroxysteroid dehydrogenase type 2 and dietary acid load are independently associated with blood pressure in healthy children and adolescents

BACKGROUND

The reduced activity of 11β hydroxysteroid dehydrogenase type 2 (11βHSD2) contributes to elevated blood pressure (BP) in clinical syndromes, but its effect on BP in the physiologic range is unclear.

OBJECTIVES

We examined the association of 11βHSD2 activity with BP in healthy children independent of known BP-related dietary and other factors and determined whether the diet-dependent acid load may constitute a dietary factor related to BP.

DESIGN

We conducted a cross-sectional analysis in 267 healthy children (age range: 4-14 y) who provided a 24-h urine sample, a parallel 3-d weighed dietary record, and 1-3 BP measurements ±1.5 y around the urine collection. The ratio of urinary free cortisone to cortisol measured by using a radioimmunoassay was used as an index for 11βHSD2. Urinary net acid excretion and the urinary and dietary potential renal acid load (PRAL) were used to predict the diet-dependent acid load. The PRAL was calculated as the sum of major mineral nonbicarbonate anions minus the sum of mineral cations. Sex-, age- and height-independent SD scores (SDSs) of systolic and diastolic BP were used as outcomes in linear regression analyses.

RESULTS

11βHSD2 was inversely associated with systolic BP SDSs in basic models and in analyses adjusted for body size, maternal BP, breastfeeding, and dietary intakes of total energy, salt, and fruit and vegetables (P = 0.03). In models that included indexes of dietary acid load instead of fruit and vegetables, all 3 acid-load biomarkers were significantly (P = 0.006-0.02) directly related to systolic BP.

CONCLUSION

A lower 11βHSD2 activity and higher dietary acid load may independently contribute to higher systolic BP in healthy children.

Glucocorticoid excess and the developmental origins of disease: two decades of testing the hypothesis--2012 Curt Richter Award Winner

Low birthweight, a marker of an adverse in utero environment, is associated with cardiometabolic disease and brain disorders in adulthood. The adaptive changes made by the fetus in response to the intra-uterine environment result in permanent changes in physiology, structure and metabolism, a phenomenon termed early life programming. One of the key hypotheses to explain programming, namely over exposure of the developing fetus to glucocorticoids, was proposed nearly two decades ago, following the observation that the fetus was protected from high glucocorticoid levels in the mother by the actions of the placental barrier enzyme, 11β-hydroxysteroid dehydrogenase, which converts active glucocorticoids into inactive products. Numerous mechanistic studies in animal models have been carried out to test this hypothesis using manipulations to increase maternal glucocorticoids. Overall, these have resulted in offspring of lower birthweight, with an activated hypothalamic-pituitary-adrenal (HPA) axis and an adverse metabolic profile and behavioural phenotype in adulthood. Altered glucocorticoid activity or action is a good candidate mechanism in humans to link low birthweight with cardiometabolic and brain disorders. We have carried out detailed studies in men and women showing that high levels of endogenous glucocorticoids, or treatment with exogenous glucocorticoids, is associated with an adverse metabolic profile, increased cardiovascular disease and altered mood and cognitive decline. Our laboratory carried out the first translational studies in humans to test the glucocorticoid hypothesis, firstly demonstrating in studies of adult men and women, that low birthweight was associated with high fasting cortisol levels. We went on to dissect the mechanisms underlying the high fasting cortisol, demonstrating activation of the HPA axis, with increased cortisol responses to stimulation with exogenous adrenocorticotrophin hormone, lack of habituation to the stress of venepuncture, and increased cortisol responses to psychosocial stress. We have developed new dynamic tests to dissect the mechanisms regulating HPA axis central negative feedback sensitivity in humans, and demonstrated that this may be altered in obesity, one component of the metabolic syndrome. There are now studies in humans demonstrating that high circulating levels of maternal cortisol during pregnancy correlate negatively with birthweight, suggesting that excess glucocorticoids can by-pass the placental barrier. Deficiencies in the barrier enzyme, potentially increasing fetal glucocorticoid exposure, can also arise in association with maternal stress, malnutrition and disease, and can be inhibited by consumption of liquorice, which contains glycyrrhizin, an HSD inhibitor. Importantly, studies in humans have now demonstrated that high maternal cortisol in pregnancy and/or inhibition of HSD2 are associated with programmed outcomes in childhood including higher blood pressure, behavioural disorders as well as altered brain structure. We are investigating this further, using novel magnetic resonance imaging techniques to study the developing fetal brain in utero. The translational studies in support of the glucocorticoid hypothesis, and demonstrating that glucocorticoids are both mediators and targets of programming, are exciting and raise the question of whether this information can be used to identify those individuals most at risk of later life disease. In a recent study we showed that alterations in DNA methylation at genes important in regulating cortisol levels, tissue glucocorticoid action, blood pressure and fetal growth, are present in adulthood in association with both early life parameters and cardiometabolic risk factors. These preliminary data add to the limited literature in humans indicating a persisting epigenetic link between early life events and subsequent disease risk. Such findings open novel avenues for further exploration of the contribution of glucocorticoids to later life disease.

Developmental perturbation induced by maternal asthma during pregnancy: the short- and long-term impacts on offspring

Maternal asthma is a common disease to complicate human pregnancy. Epidemiological studies have identified that asthma during pregnancy increases the risk of a number of poor outcomes for the neonate including growth restriction, lower birthweight, preterm delivery, neonatal resuscitation, and stillbirth. Asthma therefore represents a significant health burden to society and could have an impact on the lifelong health of the children of women with asthma. Our research has identified that maternal asthma in pregnancy induces placental dysfunction and developmental perturbation in the fetus in a sex specific manner. These alterations in development could increase the risk of metabolic disease in adulthood of children of asthmatic mothers, especially females. In this paper, we will discuss the evidence currently available that supports the hypothesis that children of mothers with asthma may be at risk of lifelong health complications which include diabetes and hypertension.

Lack of renal 11 beta-hydroxysteroid dehydrogenase type 2 at birth, a targeted temporal window for neonatal glucocorticoid action in human and mice

Background

Glucocorticoid hormones play a major role in fetal organ maturation. Yet, excessive glucocorticoid exposure in utero can result in a variety of detrimental effects, such as growth retardation and increased susceptibility to the development of hypertension. To protect the fetus, maternal glucocorticoids are metabolized into inactive compounds by placental 11beta-hydroxysteroid dehydrogenase type2 (11βHSD2). This enzyme is also expressed in the kidney, where it prevents illicit occupation of the mineralocorticoid receptor by glucocorticoids. We investigated the role of renal 11βHSD2 in the control of neonatal glucocorticoid metabolism in the human and mouse.

Methods

Cortisol (F) and cortisone (E) concentrations were measured in maternal plasma, umbilical cord blood and human newborn urine using HPLC. 11βHSD2 activity was indirectly assessed by comparing the F/E ratio between maternal and neonatal plasma (placental activity) and between plasma and urine in newborns (renal activity). Direct measurement of renal 11βHSD2 activity was subsequently evaluated in mice at various developmental stages. Renal 11βHSD2 mRNA and protein expression were analyzed by quantitative RT-PCR and immunohistochemistry during the perinatal period in both species.

Results

We demonstrate that, at variance with placental 11βHSD2 activity, renal 11βHSD2 activity is weak in newborn human and mouse and correlates with low renal mRNA levels and absence of detectable 11βHSD2 protein.

Conclusions

We provide evidence for a weak or absent expression of neonatal renal 11βHSD2 that is conserved among species. This temporal and tissue-specific 11βHSD2 expression could represent a physiological window for glucocorticoid action yet may constitute an important predictive factor for adverse outcomes of glucocorticoid excess through fetal programming.

The impact of maternal cortisol concentrations on child arterial elasticity

Epidemiological studies suggest that glucocorticoid excess in the fetus may contribute to the pathophysiology of cardiovascular diseases in adulthood. However, the impact of maternal glucocorticoid on the cardiovascular system of the offspring has not been much explored in studies involving humans, especially in childhood. The objective of this study was to assess the influence of maternal cortisol concentrations on child arterial elasticity. One hundred and thirty pregnant women followed from 1997 to 2000, and respective children 5–7 years of age followed from 2004 to 2006 were included in the study. Maternal cortisol was determined in saliva by an enzyme immunoassay utilizing the mean concentration of nine samples of saliva. Arterial elasticity was assessed by the large artery elasticity index (LAEI; the capacitive elasticity of large arteries) by recording radial artery pulse wave, utilizing the equipment HDI/PulseWave CR-2000 Cardiovascular Profiling System®. The nutritional status of the children was determined by the body mass index (BMI). Insulin concentration was assessed by chemiluminescence, and insulin resistance by the homeostasis model assessment. Blood glucose, total cholesterol and fractions (LDL-c and HDL-c) and triglyceride concentrations were determined by automated enzymatic methods. The association between maternal cortisol and child arterial elasticity was assessed by multivariate linear regression analysis. There was a statistically significant association between maternal cortisol and LAEI (P= 0.02), controlling for birth weight, age, BMI and HDL-c of the children. This study suggests that exposure to higher glucocorticoid concentrations in the prenatal period is associated to lower arterial elasticity in childhood, an earlier cardiovascular risk marker.

Physiological concentrations of serum cortisol are related to vascular risk markers in prepubertal children

There is increasing evidence that cortisol contributes to cardiovascular risk. It is unclear whether physiological concentrations of serum cortisol are related to vascular risk markers in children. The cross-sectional associations between morning serum cortisol and cardiovascular risk markers: blood pressure (BP) and carotid intima-media thickness (IMT), were examined in a sample of healthy prepubertal children (age, 6.8 ± 0.1 y) attending primary care clinics. Serum cortisol was associated with increased systolic BP (SBP; n = 223; p < 0.001) and carotid IMT (n = 91; p < 0.0001). These associations were independent from age, BMI, body fat, waist, insulin resistance, serum lipids, and heart rate (HR). No gender interactions were apparent in these associations. In summary, a higher morning serum cortisol within the physiological range is in prepubertal children associated with vascular risk markers. Because childhood risk factors predict adult risk for cardiovascular disease, these observations may have implications in the prevention of cardiovascular disease early in life.