Comparison of Hair Cortisol Levels and Perceived Stress in Mothers Who Deliver at Preterm and Term

The association between maternal prenatal hair cortisol concentration and preterm birth: A systematic review and meta-analysis

BACKGROUND

The risk of preterm birth (PTB) increases when experiencing stress during pregnancy. Chronic stress has been associated with a dysregulation of the hypothalamic-pituitary-adrenal axis, for which hair cortisol concentration (HCC) is a promising biomarker. However, previous studies on the association between HCC and PTB yielded inconsistent results. This systematic review and meta-analysis synthesized previous studies on the association between maternal HCC before and during pregnancy and spontaneous PTB.

METHODS

Data was extracted from N = 11 studies with k = 19 effect sizes retrieved from PubMed, Embase, Web of Science, CINAHL and citation searching by hand in June 2023 and updated in October 2023. Standardized mean differences were calculated, and a random-effects three-level meta-analysis was conducted. Effect heterogeneity was assessed using Q and I2.

RESULTS

HCC during pregnancy was higher among PTB than term groups, but effects were not statistically significant (z = 0.11, 95% CI: - 0.28, 0.51, p = .54) and total heterogeneity was high (Q16 = 60.01, p < .001, I2Total = 92.30%). After leaving out two possible outlier studies in sensitivity analyses, HCC was lower among preterm compared to term delivering groups, although not statistically significant (z = - 0.06, 95% CI: - 0.20, 0.08, p = .39) but with a substantially reduced total heterogeneity (Q12 = 16.45, p = .17, I2Total = 42.15%). No moderators affected the estimates significantly, but an effect of trimester and gestational age at delivery is likely.

CONCLUSION

There is currently no evidence of prenatal HCC differences between PTB and term groups as effects were small, imprecise, and not significant. Low statistical power and methodological weaknesses of the small-scale studies challenge possible biological inferences from the small effects, but further research on HCC during pregnancy is highly encouraged.

Trajectories of brain and behaviour development in the womb, at birth and through infancy

Birth is often seen as the starting point for studying effects of the environment on human development, with much research focused on the capacities of young infants. However, recent imaging advances have revealed that the complex behaviours of the fetus and the uterine environment exert influence. Birth is now viewed as a punctuate event along a developmental pathway of increasing autonomy of the child from their mother. Here we highlight (1) increasing physiological autonomy and perceptual sensitivity in the fetus, (2) physiological and neurochemical processes associated with birth that influence future behaviour, (3) the recalibration of motor and sensory systems in the newborn to adapt to the world outside the womb and (4) the effect of the prenatal environment on later infant behaviours and brain function. Taken together, these lines of evidence move us beyond nature-nurture issues to a developmental human lifespan view beginning within the womb.

The Association Between Pre-Pregnancy and First-Trimester Hair Cortisol and Preterm Birth: A Causal Inference Model

Background Adverse life events and chronic psychological distress before and during pregnancy have frequently been associated with preterm birth (PTB) but the biological underpinnings remain unclear. We investigated the association between corticosteroid levels in pre-pregnancy and first-trimester hair and the risk of PTB. Methods We followed 1,808 pregnant women from a prospective pre-birth cohort study in Lima, Perú. Hair samples were taken at the end of the first pregnancy trimester. The two most proximal 3cm segments to the scalp (representing pre-pregnancy and first-trimester) were analyzed to obtain hair cortisol and cortisone concentrations (HCC and HCNC). PTB was defined as birth < 37 completed gestational weeks. We constructed four generalized propensity scores for pre-pregnancy and first-trimester HCC and HCNC to create corresponding inverse probability weights before fitting marginal structural models for estimating the effect of HCC and HCNC on PTB risk. Results Pre-pregnancy Log HCC was not independently associated with PTB risk (RR = 0.97; 95%CI: 0.79, 1.19). In contrast, one SD increase from the mean first-trimester Log HCC was independently associated with a 37% (95%CI: 1.11, 1.69) increased risk of PTB. Although imprecise, pre-pregnancy Log HCNC was negatively associated with PTB risk (RR = 0.84; 95%CI: 0.58, 1.20), whereas the association between first-trimester Log HCNC and PTB risk was positive (RR = 1.20; 95%CI: 0.87, 1.65). Conclusions Our findings show that chronic corticosteroid levels in early pregnancy are causally linked to PTB risk in pregnant Peruvian women. This finding contributes to understanding the biological underpinnings of PTB better to enhance PTB prevention.

Perinatal hair cortisol concentrations linked to psychological distress and unpredicted birth complications

Maternal well-being and stress during the perinatal period have been hypothesized to influence birth outcomes and the postnatal development of offspring. In the present study, we explored whether hair cortisol concentration (HCC) was related to symptoms of psychological distress during the perinatal period and with unpredicted birth complications (UBCs). Surveys measuring symptoms of perceived stress, state/trait anxiety, and depression were collected from 53 participants (mean age = 31.1, SD = 4.04; 83% Caucasian, 17% other races) during the third trimester and again at two and six months after birth, 24.5% of which reported UBCs. In a subset of participants, we measured HCC in hair samples collected during the third trimester (27-39 weeks) and six months after birth. Compared to participants reporting normal births, those reporting UBCs had significantly elevated composite stress, anxiety, and depression (SAD) scores two months after birth, but scores decreased by six months postpartum. During the third trimester, HCC was positively associated with reported SAD scores, and HCC was elevated in participants reporting birth complications. Logistic regression showed HCC, but not SAD scores, predicted UBCs (p = 0.023, pseudo R2= 19.7%). Repeated measures MANOVA showed HCC varied over the perinatal period depending on both SAD scores reported at two months postpartum and the experience of UBCs; but when SAD scores reported at six months postpartum were included in the model, the association between HCC and SAD scores and the influence of UBCs was diminished. Although generalizability is limited by our relatively small, homogeneous sample, findings support a positive association between reported psychological distress and HCC during pregnancy and at two months postpartum. We also report a novel finding that chronically elevated cortisol concentrations during pregnancy were related to the risk of UBCs and remain elevated through the early postpartum period, suggesting the importance of monitoring both psychological distress and HCC during the perinatal period.

Maternal anxiety forecasts shorter prolongation of pregnancies complicated by early-onset preeclampsia

PURPOSE

In early-onset preeclampsia, each additional day of pregnancy prolongation reduces offspring infant mortality about 9%. We evaluated if maternal stress at admission to hospital for early-onset preeclampsia predicted admission-to-delivery intervals in days.

METHODS

This prospective, longitudinal cohort-study involved 15 singleton pregnancies with a diagnosis of preeclampsia before 34 weeks gestation with intended expectant management. Upon hospital admission, maternal psychological stress was assessed with questionnaires and physiological stress with hair cortisol. Hair samples were analyzed in three hair segments representing the preconception period, and the first and second trimester of pregnancy.

RESULTS

Mean pregnancy prolongation was 16.2 days. Higher maternal anxiety at hospital admission significantly correlated with shorter admission-to-delivery intervals (r = - 0.54, p = 0.04). Chronically increased hair cortisol concentrations (i.e. from preconception through the second trimester) of pregnancy tended to be related to shorter admission-to-delivery intervals (p <. 10).

CONCLUSION

Higher reported anxiety is, and chronically high hair cortisol tended to be, related with fewer days of prolongation from admission to delivery in women with early-onset preeclampsia. These findings suggest that maternal stress might be a potential determinant of disease progression. Future research into early innovative stress-reducing interventions for early-onset preeclampsia may shed more light on the etiology and treatment of this disease.

Stress before conception and during pregnancy and maternal cortisol during pregnancy: A scoping review

BACKGROUND

Stress before conception and during pregnancy is associated with less favorable maternal and child health. Alterations in prenatal cortisol levels may serve as a central biological pathway linking stress to adverse maternal and child health. Research examining associations between maternal stress from childhood through pregnancy and prenatal cortisol has not been comprehensively reviewed.

METHOD

The current scoping review of 48 papers synthesizes studies reporting on associations between stress before conception and during pregnancy with maternal cortisol in pregnancy. Eligible studies measured childhood, the proximal preconception period, pregnancy, or lifetime stress based on stress exposures or appraisals and measured cortisol in saliva or hair during pregnancy.

RESULTS

Higher maternal childhood stress was associated with higher cortisol awakening responses and alterations in typical pregnancy-specific changes in diurnal cortisol patterns across studies. In contrast, most studies of preconception and prenatal stress reported null associations with cortisol and those reporting significant effects were inconsistent in direction. A few studies found that the associations between stress and cortisol during pregnancy varied as a function of several moderators including social support and environmental pollution.

CONCLUSIONS

Although many studies have evaluated effects of maternal stress on prenatal cortisol, this scoping review is the first to synthesize existing literature on this topic. The association between stress before conception and during pregnancy and prenatal cortisol may depend on the developmental timing of stress and several moderators. Maternal childhood stress was more consistently associated with prenatal cortisol than proximal preconception or pregnancy stress. We discuss methodological and analytic factors that may contribute to mixed findings.

Efficacy of video-based relaxation technique to minimize stress in young adults during the COVID-19 pandemic

The uncertainty of the pandemic and rapid changes brought forth stressors for young adults as learning shifted to the online mode and most recreational activities required screen time. The objective was to evaluate the effectiveness of video-based diaphragmatic breathing relaxation technique in reduction of stress levels amongst young adults during COVID-19 pandemic. A quasi-experimental design with a sample size of 30 young adults undertook pre- and post-tests of subscale of Depression, Anxiety, and Stress Scale 21-items (DASS-21), negative emotion questionnaire, and hair cortisol concentration through enzyme-linked-immunosorbent assay technique. The findings indicate that there was a reduction in stress levels as majority of the items on the stress subscale of DASS-21 revealed lower stress at significant level. In addition, post-intervention participants reported a reduction in experience of negative emotions. Therefore, indicating that the diaphragmatic focused video-based intervention was effective in lowering stress and negative emotions.

Maternal hair cortisol concentrations and its association with increased insulin resistance in midpregnancy

PURPOSE

Stress and elevated maternal glycemia have negative effects on pregnancy. We evaluated the association of hair cortisol concentrations (HCC), a marker of chronic stress, with insulin resistance and gestational diabetes (GDM).

METHODS

In total, 527 women from Lima, Peru, provided a hair sample in the second trimester of their pregnancy to measure HCC using liquid chromatography-tandem mass spectrometry. Each 6 cm of hair captured HCC in early (T1=1-12 weeks) and midpregnancy (T2 = 13-24 weeks). GDM diagnosis was conducted in midpregnancy. Multivariable regression models adjusted for putative risk factorsincluding maternal sociodemographic factors, diabetes history, and hair characteristics, were used to estimate the association of HCC with GDM and various glycemic traits.

RESULTS

GDM was diagnosed in 122 (23%) women. Mean HCC across pregnancy was T1 = 3.7 (±3.4) pg/mg and T2 = 4.8 (±3.4) pg/mg. HCC was associated with increased log-transformed units of fasting insulin (T1 = 0.15 [0.03, 0.27], T2 = 0.17 [0.04, 0.30]), homeostasis model assessment for insulin resistance (T1 = 0.14 [0.01, 0.26], T2 = 0.17 [0.03, 0.30]), and homeostasis model assessment for β-cell function (T1 = 0.20 [0.05, 0.34], T2 = 0.20 [0.04, 0.36]), but not with GDM (T1 = 0.95 [0.63, 1.40], T2 = 1.11 [0.74, 1.67]).

CONCLUSIONS

Elevated maternal HCC was associated with abnormal insulin homeostasis in pregnancy. Dysregulation of the hypothalamic-pituitary-adrenal axis, as reflected by high HCC, may also contribute to insulin resistance syndrome in pregnancy.

Stressors and Impact of the COVID-19 Pandemic on Vulnerable Hispanic Caregivers and Children

Psychological sequelae are important elements of the burden of disease among caregivers. Recognition of the impact of adversity and stress biomarkers is important to prevent mental health problems that affect rearing practices and child well-being. This cross-sectional study explored social determinants of health (SDoH)-mediated stressors during COVID-19 and risks for mental health problems among caregivers of children with prenatal Zika virus exposure. Twenty-five Hispanic caregivers completed surveys assessing SDoH vulnerabilities, COVID-exposures and impact, post-traumatic stress disorder (PTSD) symptomatology, and provided a hair sample for cortisol concentration (HCC). Most caregivers had low education, household income < $15,000/year, and were unemployed. Stressors included disrupted child education and specialized services, and food insecurity. While most reported PTSD symptomatology, multivariate linear regression models adjusted for the caregiver's age, education, and the child's sex, revealed that caregivers with high symptomatology had significantly lower HCC than those with low symptomatology and those with food insecurity had significantly higher HCC than participants without food insecurity. The impact of COVID-19 on daily life was characterized on average between worse and better, suggesting variability in susceptibility and coping mechanisms, with the most resilient identifying community support and spirituality resources. SDoH-mediators provide opportunities to prevent adverse mental health outcomes for caregivers and their children.

Maternal hair cortisol concentrations across pregnancy and the early postpartum period in a Puerto Rican sample

OBJECTIVE

Hair cortisol is a noninvasive, long-term biomarker of human stress. Strengths and weaknesses of this biomarker as a proxy measure of perinatal stress are not yet well understood. Hair cortisol data were collected from pregnant women in Puerto Rico to investigate maternal cortisol level variance across pregnancy.

METHODS

In 2017, we recruited 86 pregnant women planning to birth at a large urban hospital. We aimed to collect four hair samples from each participant, one in each trimester and one in the postpartum period.

RESULTS

Median cortisol in the first trimester (n = 82) was 5.7 picograms/milligram (pg/mg) (range: 1.0-62.4). In the second, third, and postpartum periods, the medians were 6.8 pg/mg (1.0-69.5), (n = 46), 20.1 pg/mg (5.6-89.0), (n = 30), and 14.1 pg/mg (1.7-39.8), (n = 9), respectively. These medians disguise a 10-fold and 50-fold variability for two participants. Our sample sizes declined sharply when Hurricane Maria caused major disruptions in services and participants' lives.

CONCLUSION

Maternal hair cortisol concentrations were lower in the first and second trimester than the third trimester and early postpartum period. We also observed a wide range of variation in cortisol levels throughout pregnancy and in the postpartum period.

Sociodemographic and Biological Factors of Health Disparities of Mothers and Their Very Low Birth-Weight Infants

BACKGROUND

Black mothers and their very low birth-weight infants in the United States have increased risk of adverse neonatal and maternal health outcomes compared with White mothers and infants. Disparities in adverse birth outcomes associated with sociodemographic factors are difficult to quantify and modify, limiting their usefulness in assessing intervention effects.

PURPOSE

To test hypotheses that (1) the biological factors of maternal testosterone and cortisol are associated with sociodemographic factors and (2) both factors are associated with neonatal health and maternal mental health and healthy behaviors between birth and 40 weeks' gestational age.

METHODS

We used a descriptive, longitudinal design. Eighty-eight mothers and very low birth-weight neonates were recruited from a tertiary medical center in the United States. Data on sociodemographic factors and neonatal health were collected from medical records. Maternal mental health and healthy behaviors were collected with questionnaires. Maternal salivary testosterone and cortisol levels were measured using enzyme immunoassays. Data were analyzed primarily using general linear and mixed models.

RESULTS

High testosterone and/or low cortisol levels were associated with younger age, less education, enrollment in a federal assistance program, being unmarried, being Black, poorer neonatal health, and delayed physical growth. Low cortisol level was related to higher levels of depressive symptoms. Black mothers had fewer healthy behaviors than White mothers.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Findings confirm that biological factors are associated with sociodemographic factors, and both are associated with neonatal health and maternal mental health and healthy behaviors. We propose using sociodemographic and biological factors concurrently to identify risk and develop and evaluate ante- and postpartum interventions.Video abstract available athttps://journals.na.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=59.

Measures of anxiety, depression and stress in the antenatal and perinatal period following a stillbirth or neonatal death: a multicentre cohort study

BACKGROUND

The grief associated with the death of a baby is enduring, however most women embark on another pregnancy, many in less than a year following their loss. Symptoms of anxiety and depression are reported to be increased in pregnancies after perinatal death, although effect on maternal stress is less clear. Variation between individual studies may result from differences in gestation at sampling, the questionnaire used and the type of antecedent perinatal death. We aimed to describe quantitative measures of anxiety, depression, stress and quality of life at different timepoints in pregnancies after perinatal death and in the early postnatal period.

METHODS

Women recruited from three sites in the North-West of England. Women were asked to participate if a previous pregnancy had ended in a perinatal death. Participants completed validated measures of psychological state (Cambridge Worry Score, Edinburgh Postnatal Depression Score (EPDS), Generalized Anxiety Disorder 7-item score) and health status (EQ-5D-5L™ and EQ5D-Visual Analogue Scale) at three time points, approximately 15 weeks' and 32 weeks' gestation and 6 weeks postnatally. A sample of hair was taken at approximately 36 weeks' gestation for measurement of hair cortisol in a subgroup of women. The hair sample was divided into samples from each trimester and cortisol measured by ELISA.

RESULTS

In total 112 women participated in the study. Measures of anxiety and depressive symptoms decreased from the highest levels at 15 weeks' gestation to 6-weeks postnatal (for example mean GAD-7: 15 weeks 8.2 ± 5.5, 6 weeks postnatal 4.4 ± 5.0, p<0.001). Hair cortisol levels fell in a similar profile to anxiety and depression symptoms (p<0.05). In contrast, the median EQ-5D index, measuring health status was 0.768 at 15 weeks' gestation (Interquartile range (IQR) 0.684-0.879), 0.696 at 32 weeks' (IQR 0.637-0.768) and 0.89 (0.760-1.00) at 6 weeks postnatal. There was a negative relationship between EPDS and perceived health status.

CONCLUSIONS

This study demonstrated heightened anxiety and depressive symptoms and elevated cortisol levels in women in pregnancies after a stillbirth or neonatal death which decrease as pregnancy progresses. Further studies are needed to determine optimal care for women to address these negative psychological consequences.

Hair Cortisol Concentrations Are Associated with Dental Anxiety during Pregnancy

Dental anxiety (DA) and hair cortisol concentrations (HCC) are associated with psychological symptoms and vary during pregnancy. We aimed to examine the association between HCC and DA at two points of pregnancy. Participants were pregnant mothers (n = 533) drawn from the FinnBrain Birth Cohort Study donating a hair sample at gestational week (gwk) 24 (n = 442) and/or at delivery (n = 176) and completed questionnaires on DA. Two groups, HCC1 and HCC2, treated as separate in the analyses, were formed according to the hair sample donation time i.e., gwk24 and delivery. 85 subjects were included in both groups. MDAS, EPDS, and SCL-90 were used to measure DA, depressive and anxiety symptoms, respectively, at gwk14 for the HCC1 group and gwk34 for the HCC2 group. The association between DA and HCC was studied with a binary logistic regression model, adjusted for anxiety and depressive symptoms, age, BMI, and smoking status. Individuals with high DA had lower HCC levels at gwk24 (OR = 0.548; 95% CI = 0.35–0.86; p = 0.009), but the association was not statistically significant at the delivery (OR = 0.611; 95% CI = 0.28–1.33; p = 0.216). The independent association between HCC and DA in pregnant women suggests that long-term cortisol levels could play a role in the endogenous etiology of DA. Further studies are however, needed.

Antepartum Depression and Preterm Birth: Pathophysiology, Epidemiology, and Disparities due to structural racism

PURPOSE OF REVIEW

Informed by the evidence of links between physiology of stress and parturition, we review recent epidemiologic evidence (2015-2020) of antenatal depression as a risk factor for preterm birth (PTB). We also explain racial/ethnic disparities in depression and preterm birth as a consequence of structural racism.

RECENT FINDINGS

Epidemiologic evidence is consistent in linking antepartum depression with an elevated risk of PTB. Antidepressant usage has been linked with an elevated risk of PTB. However, recent evidence suggests that severity of depression is the underlying driver of the elevated risk attributed to antidepressant usage. The number of depressive symptoms, as a proxy for severity of maternal stress, may be a more informative predictor of PTB than criterion based predictors. Across various study designs, measurement modalities, and populations, antenatal depression predicts an elevated risk of delivering preterm. The physiology of stress provides a plausible explanation for this observation. Excessive stress-induced elevations in maternal and then fetal HPA hormones can alter maternal and fetal homeostasis and hasten the timing of parturition. Antenatal depression and exposure to structural racism are two stressors that can trigger the maternal stress response. Chronically elevated levels of stress hormones among women of color in the USA provide a likely physiologic explanation for Black-White disparities in the risk of PTB. Focusing on the number of depressive symptoms as the more informative predictor of PTB raises several questions. We consider these questions as well as directions for future research in the context of recent advances in the field.

A systematic review of hair cortisol during pregnancy: Reference ranges and methodological considerations

The present study systematically reviewed 56 articles that assessed hair cortisol concentrations during pregnancy collected from PubMed, Scopus, and Web of Science on 8/9/19 and updated on 6/29/20. Our goals were to establish reference ranges by trimester based on published studies. The majority of any given sample (e.g., 70 %, the range of -1SD to +1SD) is expected to fall between 0 and 34.15 pg/mg in trimester 1 and 2, and between 8.59 and 44 pg/mg in trimester 3, with very wide ranges (e.g., values of >250 pg/mg) and substantially higher values (e.g., averages of 200's-300's reaching as high as 768 pg/mg) coming out of one specific lab. Delineating a reference range for hair cortisol concentrations across pregnancy is challenging because of known factors like differences in values returned by different laboratories and assay types. We observed inconsistency in descriptions of the data and data preparation steps post-assay. Key findings include that only half of the studies examining all three trimesters showed a constant increase in mean levels (most retrospectively assessed via segmenting), with considerable variability in patterns of change. None of the studies reported individual patterns of change. Examining within-person changes are an important next step for the field. We conclude that researchers should more clearly report decisions around outliers, units, and specifics of data transformations in the future in order to improve our ability to compare findings across studies, to understand differences in HCC values reported, and potentially to understand differences in reported associations of HCC with other phenotypes in the literature.

Assessment of prenatal stress-related cortisol exposure: focus on cortisol accumulation in hair and nails

Prenatal stress adversely affects offspring development. Although cortisol is hypothesized to be a key mediator of stress-induced developmental deficits, determining the amount of fetal cortisol exposure produced by maternal stress has proved challenging. Current approaches, such as measuring cortisol concentrations in maternal plasma, saliva, or urine, amniotic fluid, fetal plasma, or cord blood, all have significant limitations for assessing cumulative fetal cortisol exposure over time. A recently emerging approach is to measure cortisol concentrations in maternal hair and/or newborn hair or nail samples. Maternal hair cortisol potentially shows long-term production across each trimester of pregnancy, whereas neonatal hair or nail cortisol is thought to reflect mainly third trimester hormone accumulation. This review first describes fetal adrenocortical development, placental cortisol metabolism, and the various sources of fetal cortisol exposure across pregnancy. We then summarize the results obtained from "classical" methods of assessing prenatal cortisol exposure prior to the advent of hair and nail cortisol measurement. Lastly, we discuss the initial development and validation of the hair cortisol methodology, its subsequent application to studies of chronic stress, and recent findings regarding maternal and neonatal hair or nail cortisol concentrations in relation to prenatal stress and other variables of interest.

Hair Cortisol Concentrations as a Biological Marker of Maternal Prenatal Stress: A Systematic Review

Recently, biological markers of maternal prenatal stress, hair cortisol, along with saliva, blood, and urine cortisol, have received attention. However, it is necessary to validate measuring hair cortisol concentrations (HCC) as a biomarker of perceived stress among healthy and high-risk pregnant women. This study aimed to confirm the correlation between HCC and the perceived stress of pregnant women over 18 years of age. In this systematic review, we used various search engines to extract relevant articles using specific keywords related to pregnancy, hair cortisol, and psychological stress. Four out of 3639 studies met the inclusion criteria. We conducted a quality assessment with the help of three independent reviewers using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. The correlation between HCC and perceived stress was confirmed in one study. There was only one study on hair washing, shampoo, conditioner, and hair structure that could affect hair samples. In four studies, hair samples differed in length, methods of storage, and laboratory analysis. The review was limited to confirming the relationship between HCC and perceived stress in pregnant women based on the current evidence. Studies on hair cortisol need regulated and standardized methods for collection, storage, and analysis of hair samples.

Minimally-invasive methods for examining biological changes in response to chronic stress: A scoping review

BACKGROUND

Nurse researchers are increasingly interested in incorporating biological indicators related to chronic stress, or repeated or constant exposure to psychological stressors. Minimally invasive collection methods may improve access to vulnerable populations.

OBJECTIVE

To map biological indicators measured through minimally invasive methods investigating biological changes in response to chronic stress.

DESIGN, DATA SOURCES, AND METHODS

The paper seeks to answer two questions: What are the characteristics of the minimally-invasive methods used to measure the biological correlates of chronic stress? What are the limitations regarding the use of the minimally-invasive methods and/or biological indicators identified above? Authors completed a scoping review following guidelines from the Joanna Briggs Institute Manual and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews. A literature search was completed in PubMed, PsycINFO, and Scopus. 2518 articles were screened and 145 studies were included. Data were extracted using a standardized extraction tool, compiled, and coded.

RESULTS

Studies included minimally-invasive methods to measure the hypothalamic-adrenal-pituitary axis (N = 173), immune and inflammatory markers (N = 118), and adult neurogenesis (N = 6). Cortisol was most frequently measured (N = 136), usually in saliva (N = 86). Studies included a variety of limitations for the methods and indicators, including concerns about timing and accuracy of collection, frequency of sampling, and controlling for acute stressors.

CONCLUSIONS

Nurse researchers have access to many minimally-invasive methods to measure altered biological processes related to chronic stress. A gap identified by this review is the paucity of minimally-invasive methods for investigating neurogenesis; the measurement of brain derived neurotrophic factor in plasma is a distal proxy and further research is needed to test the response of peripheral levels to psychosocial stress interventions. Additionally, while this scoping review allows nurse researchers to consider possible biological indicators to include in their research, future research is still needed on some of the basic premises of stress research, including agreement on the conceptualization of chronic stress.

Chronic HPA activity in mothers with preterm delivery: A pilot nested case-control study

BACKGROUND

Chronic hypothalamic-pituitary-adrenal (HPA) axis activity role in the pathogenesis of preterm birth (PTB) remains unclear due to inconsistent measures with limited ability to monitor long-term cortisol concentrations. We explored this relationship using the novel method of assessing cortisol in hair, which is a valid and reliable measure of chronic HPA axis activity.

METHODS

137 participants (40 PTB cases and 97 controls from a birth cohort of pregnant women in Peru) were interviewed and invited to provide a 9-cm hair sample from the posterior vertex position of the scalp (mean = 13 weeks gestation). Hair cortisol concentration (HCC) was determined using luminescence immunoassay and values were natural-log transformed. PTB cases were defined as women who delivered before 37 gestational weeks. Case-control differences were assessed using multivariable linear and logistic regressions.

RESULTS

Overall, combined pre-conception and first-trimester HCC was 13% lower among cases as compared with controls (p-value = 0.01). Compared with controls, maternal HCC among PTB cases were 14% (p = 0.11), 10% (p = 0.22) and 14% (p = 0.08) lower for 3-6 months pre-conception, 0-3 months pre-conception, and first trimester, respectively. After adjusting for putative confounders, a 1-unit increase in HCC was associated with 55% reduced odds of PTB (aOR = 0.45; 95% CI: 0.17-1.17). For a 1-unit increase in HCC in the scalp-intermediate and scalp-distal segments (representing HCC concentrations in 0-3 months pre-conception and first trimester), the corresponding odds for PTB were 0.53 (95% CI: 0.19-1.48) and 0.39 (95% CI: 0.13-1.13), respectively.

CONCLUSIONS

Women who deliver preterm, as compared with those who deliver at term, have lower preconception and first trimester HCC. Our findings suggest that HPA axis activation, integral to the adaptive stress-response system, may be chronically dysregulated in women at increased risk of PTB.

Maternal prenatal hair cortisol is associated with prenatal depressive symptom trajectories

Maternal prenatal cortisol levels have been inconsistently associated with self-reports of prenatal psychological distress (PD). Previous research has linked hair cortisol concentration (HCC) evaluating cumulatively the previous months with cross-sectional PD measures that usually cover the past week(s), which may lead to misleading conclusions on their relations. We aimed to investigate how maternal HCC relates to cumulative PD measures across pregnancy.

METHODS

Subjects (N = 595) were drawn from the FinnBrain Birth Cohort Study. Maternal HCC was measured from hair samples collected at gestational week (gwk) 24 (HCC1, n = 467) and at delivery (HCC2, n = 222). As HCC1 and HCC2 comprised mostly of different subjects, they were considered as independent populations. Maternal PD assessments at gwks 14, 24, and 34 were the Edinburgh Postnatal Depression Scale (EPDS), the anxiety subscale of the Symptom Checklist (SCL-90), the Pregnancy-Related Anxiety Questionnaire -Revised2 (PRAQ-R2), and a daily hassles scale. Cumulative PD comprised of the mean scores of two consecutive assessments (mean1 = gwks 14 and 24; mean2 = gwks 24 and 34). In addition, EPDS and SCL scores were modelled by using growth mixture modelling to identify symptom trajectory categories. Regression models were adjusted for age, body mass index, education and use of selective serotonin/serotonin-norepinephrine reuptake inhibitor medication.

RESULTS

In the adjusted regression model, higher HCC2 was related to the "consistently elevated" prenatal depressive symptoms trajectory in comparison to "consistently low" (β =.71, p =.021) and "low and increasing" (β =.82, p = .011) symptom trajectories. Additionally, the cumulative mean (mean 1) of daily hassles in relationships was associated with HCC1 (β = 0.25, p = .004). General or pregnancy-related anxiety symptoms were unrelated to HCC after adjustment for the covariates.

CONCLUSIONS

The assessment of cumulative or trajectory measures of PD can reveal important associations with maternal prenatal HCC, even though the associations are generally weak. Of the different dimensions of PD, prenatal trajectories of depressive symptoms were most consistently linked with end-pregnancy HCC levels.

Hair cortisol, perceived stress, and social support in mother-child dyads living in an urban neighborhood

Women and children belonging to a racial/ethnic minority bear a disproportionate burden of psychosocial stress that increases their vulnerability to adverse health outcomes. Hair cortisol has been rapidly advanced as a biomarker of the intensity and course of the stress response over time and may provide an opportunity to increase our understanding of the role of psychological stress in health. However, research on the link between hair cortisol levels and subjective measures of maternal and child stress among low-income and minority individuals is limited. The goal of this study was to examine the association between stress and hair cortisol in low income, minority women and children who experience disproportionate exposure to chronic stress. A convenience sample of 54 minority mother/child dyads from a busy primary care clinic in the second poorest medium-sized city in the US participated in the study. Mothers self-reported perceived stress, social support, household characteristics and other demographic factors, and their children (ages 7-14 years) reported on the perceived level of safety in their neighborhood and exposure to violence as markers of child stress. Three-centimeter hair samples were collected from both mothers and children during the clinic visit, and hair cortisol levels were assessed via enzyme-linked immunosorbent assays. Linear regression models examined associations between maternal and child hair cortisol, and between hair cortisol and perceived stress level in women, and moderation by social support. Maternal hair cortisol was not significantly associated with mother's perceived stress. Maternal and child hair cortisol levels were positively associated (p = .007) but this association was not moderated by maternal perceived social support. These findings suggest that hair cortisol is strongly associated among this sample of minority mother-child dyads and is not moderated by social support.

Autonomic nervous system development and its impact on neuropsychiatric outcome

The central autonomic nervous system (ANS) is essential for maintaining cardiovascular and respiratory homeostasis in the newborn and has a critical role in supporting higher cortical functions. At birth, the central ANS is maturing and is vulnerable to adverse environmental and physiologic influences. Critical connections are formed early in development between the ANS and limbic system to integrate psychological and body responses. The Polyvagal Theory, developed by Stephen Porges, describes how modulation of the autonomic vagal impulse controls social responses and that a broad range of neuropsychiatric disorders may be due to impaired vagal balance, with either deficient vagal tone or excessive vagal reactivity. Under additional circumstances of prematurity, growth restriction, and environmental stress in the fetus and newborn, the immature ANS may undergo "dysmaturation". Maternal stress and health as well as the intrauterine environment are also quite important and have been implicated in causing ANS changes in the infant and neuropsychiatric diseases in children. This review will cover the aspects of ANS development and maturation that have been associated with neuropsychiatric disorders in children.