Can stress biomarkers predict preterm birth in women with threatened preterm labor?

Computational Approaches for Connecting Maternal Stress to Preterm Birth

Multiple studies have hinted at a complex connection between maternal stress and preterm birth (PTB). This article describes the potential of computational methods to provide new insights into this relationship. For this, we outline existing approaches for stress assessments and various data modalities available for profiling stress responses, and review studies that sought either to establish a connection between stress and PTB or to predict PTB based on stress-related factors. Finally, we summarize the challenges of computational methods, highlighting potential future research directions within this field.

Advances in electrochemical biosensor design for the detection of the stress biomarker cortisol

The monitoring of stress levels in humans has become increasingly relevant, given the recent incline of stress-related mental health disorders, lifestyle impacts, and chronic physiological diseases. Long-term exposure to stress can induce anxiety and depression, heart disease, and risky behaviors, such as drug and alcohol abuse. Biomarker molecules can be quantified in biological fluids to study human stress. Cortisol, specifically, is a hormone biomarker produced in the adrenal glands with biofluid concentrations that directly correlate to stress levels in humans. The rapid, real-time detection of cortisol is necessary for stress management and predicting the onset of psychological and physical ailments. Current methods, including mass spectrometry and immunoassays, are effective for sensitive cortisol quantification. However, these techniques provide only single measurements which pose challenges in the continuous monitoring of stress levels. Additionally, these analytical methods often require trained personnel to operate expensive instrumentation. Alternatively, low-cost electrochemical biosensors enable the real-time detection and continuous monitoring of cortisol levels while also providing adequate analytical figures of merit (e.g., sensitivity, selectivity, sensor response times, detection limits, and reproducibility) in a simple design platform. This review discusses the recent developments in electrochemical biosensor design for the detection of cortisol in human biofluids. Special emphasis is given to biosensor recognition elements, including antibodies, molecularly imprinted polymers (MIPs), and aptamers, as critical components of electrochemical biosensors for cortisol detection. Furthermore, the advantages and limiting factors of various electrochemical techniques and sensing in complex biofluid matrices are overviewed. Remarks on the current challenges and future perspectives regarding electrochemical biosensors for stress monitoring are provided, including matrix effects (pH dependence and biological interferences), wearability, and large-scale production.

Trajectories of antepartum depressive symptoms and birthweight: a multicenter and prospective cohort study

BACKGROUND

Antepartum depression is a prevalent unhealthy mental health problem worldwide, particularly in low-income countries. It is a major contributor to adverse birth outcomes. Previous studies linking antepartum depression to birthweight have yielded conflicting results, which may be the reason that the depressive symptoms were only measured once during pregnancy. This study aimed to explore the associations between trajectories of antepartum depressive symptoms and birthweight.

METHODS

Depressive symptoms were assessed prospectively at each trimester in 3699 pregnant women from 24 hospitals across 15 provinces in China, using the Edinburgh Postpartum Depression Scale (EPDS). Higher scores of EPDS indicated higher levels of depressive symptoms. Associations between trajectories of depressive symptoms and birthweight were examined using group-based trajectory modeling (GBTM), propensity score-based inverse probability of treatment weighting (IPTW), and logistic regression.

RESULTS

GBTM identified five trajectories. Compared with the low-stable trajectory of depressive symptoms, only high-stable (OR = 1.35, 95% CI: 1.15-2.52) and moderate-rising (OR = 1.18, 95% CI: 1.12-1.85) had an increased risk of low birthweight (LBW) in the adjusted longitudinal analysis of IPTW. There was no significant increase in the risk of LBW in moderate-stable and high-falling trajectories. However, trajectories of depressive symptoms were not associated with the risk of macrosomia.

CONCLUSION

Antepartum depressive symptoms were not constant. Trajectories of depressive symptoms were associated with the risk of LBW. It is important to optimize and implement screening, tracking, and intervention protocols for antepartum depression, especially for high-risk pregnant women, to prevent LBW.

Virtual Reality Headset Simulating a Nature Environment to Improve Health Outcomes in Pregnant Women: A Randomized-Controlled Trial

The single-blind randomized-controlled experimental study aimed to determine the effects of watching nature images through virtual reality (VR) headset on stress, anxiety, and attachment levels of pregnant women with preterm birth threats (PBTs). The participants were 131 primiparous pregnant women admitted to the perinatology clinic due to PBT between April 5, 2022 and July 20, 2022. The intervention group watched videos containing nature images accompanied by nature sounds in six sessions through VR headset three times daily for 2 days. Each session lasted for 5 min. The data were accumulated with the Information Form, Stress Subscale of Depression Anxiety Stress Scale-21, State Anxiety Inventory, Prenatal Attachment Inventory, and Information Form of Satisfaction Level of VR Headset. State anxiety and stress levels of pregnant women in intervention group were statistically significantly lower than those in controls. There was no difference in prenatal attachment levels concerning intragroup comparisons of intervention group.

Temperamental and psychomotor predictors of ADHD symptoms in children born after a threatened preterm labour: a 6-year follow-up study

Children born after threatened preterm labour (TPL), regardless of whether it ends in preterm birth, may represent an undescribed "ADHD cluster". The aim of this cohort study is to identify early temperament and psychomotor manifestations and risk factors of TPL children who present ADHD symptoms. One hundred and seventeen mother-child pairs were followed from TPL diagnosis until the child's 6 years of life. TPL children were divided according to the prematurity status into three groups: full-term TPL (n = 26), late-preterm TPL (n = 53), and very-preterm TPL (n = 38). A non-TPL group (n = 50) served as control. Temperament and psychomotor development at age 6 months and ADHD symptoms at age 6 years were assessed. Perinatal and psychosocial factors were also recorded. All TPL groups showed higher severity of ADHD symptoms compared with non-TPL children (difference in means + 4.19 for the full-term group, + 3.64 for the late-preterm group, and  + 4.99 for the very-preterm group, all ps < 0.021). Concretely, very-preterm and late-preterm TPL children showed higher restless/impulsive behaviours, whereas full-term TPL children showed higher emotional lability behaviours. Higher surgency/extraversion and delayed fine motor skills at age 6 months predicted ADHD symptoms at 6 years in TPL children. Male sex, maternal state anxiety symptoms at TPL diagnosis, low parental education, and past maternal experience of traumatic events predicted higher ADHD symptoms in TPL children. Therefore, TPL children may have a higher risk for developing ADHD symptoms, presenting a phenotype that depends on the prematurity status. Moreover, the specific combination of early manifestations and risk factors suggests that TPL children may conform an undescribed group at-risk of ADHD symptoms.

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.

Trajectories of depressive symptoms during pregnancy and risk of premature birth: A multicenter and prospective cohort study

Previous studies only assessed the association between depressive symptoms and risk of preterm birth (PTB) at a time-point during pregnancy, resulting in inconsistent or contradictory results. Therefore, we aimed to explore the associations between the trajectories of depressive symptoms during pregnancy and risk of PTB. In total, 7732 pregnant women were included in 24 hospitals from 15 provinces of China. The Edinburgh Postpartum Depression Scale (EPDS) was used to evaluate depressive symptoms in the first, second, and third trimesters. Associations between depressive symptoms and risk of PTB were performed by group-based trajectory modeling (GBTM), propensity score-based inverse probability of treatment weighting (IPTW), and logistic regression. GBTM identified five trajectories: compared with persistently low-stable trajectory of depressive symptoms, women with moderate-stable (OR = 1.23, 95% CI: 1.02-1.76), high-falling (OR = 1.35, 95% CI: 1.11-2.21), moderate-rising (OR = 1.38, 95% CI: 1.06-2.04), and high-stable trajectory of depressive symptoms (OR = 1.40, 95% CI: 1.16-3.28) had an increased risk of PTB. In addition, the associations between trajectories of depressive symptoms and risk of PTB were most significant in multiparous women with a history of PTB. There was no difference in the risk of early-moderate PTB among different trajectories of depressive symptoms and only the risk of late PTB was different among different trajectories. In conclusion, the depressive symptoms of pregnant women were not constant during pregnancy, and different trajectories of depressive symptoms were associated with different risks of PTB.

Mental health, sleep quality, and hormonal circadian rhythms in pregnant women with threatened preterm labor: a prospective observational study

BACKGROUND

Threatened preterm labor (TPL) is an important obstetrical challenge. Pregnant women with TPL may develop psychological and physical problems such as mental health disorders, sleep disturbance, and hormonal circadian rhythm disruption. This study aimed to investigate the current state of mental health, sleep quality, and circadian rhythms of cortisol and melatonin secretion in pregnant women with TPL and normal pregnant women (NPW).

METHODS

A prospective observational clinical study was conducted at a maternal and child health hospital in Fuzhou, China, between June and July 2022. A total of 50 women between 32 and 36 weeks of gestation (TPL group, n = 20; NPW group, n = 30) were recruited. Data on anxiety symptom (Zung's Self-rating Anxiety Scale, SAS), depression symptom (Edinburgh Postnatal Depression Scale, EPDS), subjective sleep quality (Pittsburgh Sleep Quality Index, PSQI) and objective sleep outcomes (measured by actigraphy) of the pregnant women were collected at the time of enrolment. Salivary samples were collected once every 6 h (i.e., at 06:00, 12:00, 18:00, and 00:00) during 2 consecutive days to measure the circadian rhythm of hormone (cortisol and melatonin).

RESULTS

There were no differences found in the total scores of SAS, EPDS scores, subjective sleep quality between the TPL and NPW groups (P > 0.05). In contrast, significant differences were found in sleep efficiency, total sleep time, wake time after sleep onset, and average awakening time between the groups (P < 0.05). The circadian rhythm of melatonin secretion was disrupted in the TPL group (P = 0.350); however, it was maintained in the NPW group (P = 0.044). The circadian rhythm of cortisol secretion was disrupted in both groups (P > 0.05).

CONCLUSIONS

In the third trimester of pregnancy, women with TPL suffer from poorer sleep quality and disruption of circadian rhythm of melatonin secretion compared with NPW. Nevertheless, there were no differences found in mental health (i.e., anxiety and depression) and circadian rhythm of cortisol secretion. Large-scale studies should be conducted to evaluate these changes in women with TPL.

TRIAL REGISTRATION

The study was registered from Chinese Clinical Trial Registry (Number: ChiCTR2200060674) on 07/06/2022.

Increased risk of preterm delivery with high cortisol during pregnancy is modified by fetal sex: a cohort study

Background

Previous studies show an association between maternal plasma and salivary cortisol and preterm birth but have been primarily conducted in high-income countries. It is unknown whether salivary cortisol is a risk factor for preterm birth in Ghana. Our objective was to determine whether maternal salivary cortisol during pregnancy was associated with pregnancy duration and preterm delivery in Ghana.

Methods

We conducted a cohort study of 783 pregnant women in Ghana. We measured salivary cortisol at baseline (mean 16 wk), 28 wk., and 36 wk. gestation. Pregnancy duration was determined primarily by ultrasound. We used adjusted linear regression models to examine the association between cortisol and pregnancy duration and Poisson regression models to determine the risk of preterm delivery among women with high cortisol at baseline or 28 wk. gestation.

Results

Mean pregnancy duration was 39.4 ± 1.8 wk. and 6.6% had a preterm delivery. Mean maternal cortisol increased throughout pregnancy, from 4.9 ± 2.7 nmol/L at baseline (16 wk) to 6.4 ± 3.2 nmol/L at 28 wk. and 7.9 ± 3.0 nmol/L at 36 wk. gestation. In adjusted analyses, higher cortisol concentrations at baseline (β = − 0.39, p = .002) and 28 wk. (β = − 0.49, p = .001), but not 36 wk. (β = − 0.23, p = .084) were associated with a shorter pregnancy duration. Women with high cortisol at baseline (> 6.3 nmol/L) had an increased relative risk of preterm delivery (RR (95% CI): 1.96 (1.13, 3.40)), but the association between high cortisol at 28 wk. and preterm delivery was not significant. There was a significant interaction with fetal sex (p-for-interaction = 0.037): among women carrying male fetuses, high cortisol at baseline increased the risk of preterm delivery threefold (3.18 (1.51, 6.71)) while there was no association (1.17 (0.50, 2.74)) among women carrying female fetuses.

Conclusion

Higher maternal cortisol is associated with a shorter pregnancy duration and an increased risk of preterm delivery. Subgroup analysis by fetal sex revealed that this association is evident primarily among women carrying male fetuses. Future studies of cortisol and preterm delivery should include consideration of fetal sex as a potential effect modifier.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-05061-8.

The type of previous abortion modifies the association between air pollution and the risk of preterm birth

BACKGROUND

Air pollution and previous abortion have been reported to be related to preterm birth (PTB). But rare study examined the effect of air pollution on PTB risk among mothers with previous abortion.

OBJECTIVE

To estimate the effect of air pollution on PTB and the potential effect modification of previous abortion on such an association in rural part of Henan province (China).

METHOD

Based on National Free Preconception Health Examination Project (NFPHEP), information from the medical records of 57,337 mothers with previous abortion were obtained. An inverse distance-weighted model was used to estimate exposure levels of air pollutants. The effect of air pollution on the risk of PTB was estimated with a multiple logistic regression model. Stratified and interaction analyses were undertaken to explore the potential effect modification of previous abortion on this association.

RESULTS

The risk of PTB was positively associated with exposure to levels of nitrogen dioxide (NO₂; OR: 1.03; 95%CI: 1.02-1.04)], and sulfur dioxide (SO₂; 1.04; 1.02-1.07), and negatively associated with ozone (O₃) exposure (0.97; 0.97-0.98) during the entire pregnancy. Besides, we observed a positive effect of carbon monoxide (CO) exposure during the third trimester of pregnancy on PTB (1.14; 1.01-1.29). The type of previous abortion could modify the effect of air pollution on the PTB risk (P-_interaction < 0.05). Compared with mothers with previous induced abortion, mothers with previous spontaneous abortion carried a higher risk of PTB induced by NO₂, CO, and O₃.

CONCLUSIONS

The risk of PTB was positively associated with levels of NO₂, SO₂ and CO, and negatively associated with the O₃ level. The types of previous abortion could modify the effect of air pollution on PTB. Mothers who had an abortion previously, especially spontaneous abortion, should avoid exposure to air pollution to improve their pregnancy outcome.

Early signs of autism in infants whose mothers suffered from a threatened preterm labour: a 30-month prospective follow-up study

Infants born after a threatened preterm labour (TPL infants) are at high risk of autism spectrum disorder (ASD). Studying this population may provide insight on the pathophysiological underpinnings of this condition. This study aimed to (i) ascertain the presence and autistic symptom load in TPL infants aged age 30 months relative to non-TPL infants, regardless of preterm birth; (ii) explore the association between early (at 6 months) psychomotor development and temperament features with the autistic symptom load of TPL infants at age 30 months and (iii) examine the association among perinatal risk factors for ASD development with the autistic symptom load of TPL infants at age 30 months. A group of 111 mother-infant pairs recruited at TPL diagnosis and a group of 47 healthy mother-infant controls completed the follow-up. Irrespective of preterm birth, TPL infants showed higher autistic symptom load at age 30 months than non-TPL infants. TPL infants presented poorer communication and problem-solving skills, reduced smiling and laughter, and greater vocal reactivity at age 6 months, predicting higher autistic symptom load at age 30 months. Higher levels of anxiety symptoms in TPL mothers after a TPL diagnosis also predicted higher autistic symptom load for the infants at age 30 months. These results suggest that TPL infants may be an undescribed cluster, with features that differentiate them from other "at-risk" populations. These findings support the need for routine assessment of TPL infants and screening of anxiety symptoms in mothers.

Emotional regulation and psychomotor development after threatening preterm labor: a prospective study

A threatened preterm labor (TPL) represents an adverse prenatal event that may affect fetal neurodevelopment, even in absence of prematurity. Indeed, late-preterm infants, without neurological complications, also exhibit neurodevelopment impairment with psychomotor delay as well as emotional regulation disturbances, considered early manifestations of neuropsychiatric disorders. The aim of this study is to examine the impact of TPL on infant's psychomotor development and temperament. This prospective cohort study recruited mothers who suffered from a TPL and a control group of mothers without TPL and full-term gestation (n = 61). TPL infants were classified into three groups depending on delivery time: Full-Term (n = 37), Late-Preterm (n = 66), and Very-Preterm (n = 38). Neurodevelopmental assessment was performed at 6 months using the Ages & Stages Questionnaires for psychomotor development and the Infant Behaviour Questionnaire-Revised for temperament. After controlling for potential cofounders (multiple pregnancy and in vitro fertilization), Full-Term TPL infants, relative to the control group, exhibited development delay in Communication (p = 0.044) and Personal-social domains (p = 0.005) as well as temperament disturbances with higher Negative Affect (p = 0.013), lower Positive Affect (p = 0.010), and worse Emotional Regulation (p < 0.001) compared to Control. No differences were found between Full-Term and Late-Preterm TPL infants. TPL may represent a risk factor for neurodevelopmental disturbances in the offspring, affecting both psychomotor and emotional infant competences, even when infants were born at term.

Maternal adverse childhood experiences and their association with preterm birth: secondary analysis of data from universal health visiting

Background

Being born before full gestation can have short-term and life-long health implications, yet it remains difficult to determine the risk of preterm birth among expectant mothers. Across different health settings, increasing attention is given to the health and behavioural consequences of adverse childhood experiences (ACEs) such as child abuse or neglect, or exposure to harmful household environments (e.g. in which caregivers abuse alcohol), and the potential value of understanding these hidden harms when supporting individuals and families. A large international evidence base describes the association between childhood adversity and early years outcomes for mothers and children. However, the relationship between maternal ACEs and preterm birth has received far less attention.

Methods

Secondary analysis was carried out on anonymised cross-sectional data from health visiting services in south and west Wales that had previously captured information on mothers’ ACEs during routine contacts. Demographic data and information on mothers’ health were extracted from the Healthy Child Wales Programme.

Results

Half of all mothers sampled had experienced at least one ACE, with a history of ACEs more common among younger, white British mothers and those residing in deprived areas. Preterm birth was significantly independently associated with retrospective reports of childhood sexual abuse (adjusted odds ratio [AOR] = 3.83, 95% confidence interval [CI] = 1.19–12.32, p = 0.025), neglect (AOR = 7.60, 95%CI = 1.81–31.97, p = 0.006) and overall ACE exposure (AOR = 2.67, 95%CI = 1.14–6.23, p = 0.024), with one in ten mothers (10.0%) who experienced ≥4 ACEs having preterm birth. Sub-analyses revealed a more pronounced relationship among mothers with no known chronic health conditions, with those with ≥4 ACEs and no known chronic condition four times more likely to give birth preterm (AOR = 3.89, 95%CI = 1.40–10.80, p = 0.009).

Conclusions

Findings highlight the importance of the entire maternal experience. The experience of childhood adversity can have a lasting impact into and beyond the prenatal period, potentially increasing the risk of preterm birth, even among otherwise healthy women. Increasing our understanding of the potential perinatal outcomes associated with ACEs can help to inform how maternity services and partners offer trauma-sensitive support to mitigate some of the risks of early parturition, as well as target intergenerational cycles of adversity and poor health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04454-z.

Hair cortisol concentration across the peripartum period: Documenting changes and associations with depressive symptoms and recent adversity

Women experience dramatic physiological changes during pregnancy, including changes in the production of the “stress hormone,” cortisol. Evidence has been mixed regarding whether hair cortisol concentration (HCC) can be used to accurately capture the trajectory of cortisol during this period and whether factors related to psychosocial stress are related to HCC in pregnant and postpartum women. In the current study, we collected hair samples from 85 individuals during the peripartum period (with collection occasions in pregnancy [12–37 weeks], at 3–8 weeks postpartum, and at 5–8 months postpartum) from which we derived 783 monthly observations of HCC. In addition, at each assessment individuals reported their current depressive symptoms and experiences of recent psychosocial adversity. Using piecewise mixed effects modeling, we identified significant increases in HCC across pregnancy (approximately a 2-fold rise) followed by significant decreases in HCC postpartum. Beyond these effects, however, there was substantial within-individual variability in HCC. Disaggregating between- from within-individual associations of depressive symptoms and adversity with HCC, we found that within-individual fluctuations in adversity were positively coupled with levels of HCC. Overall, the current findings suggest that measurement of cortisol in human hair captures its trajectory from conception through six months postpartum, including prenatal increases and gradual recovery of typical levels following childbirth. In addition to the overall severity of psychosocial adversity, change in women's experiences of adversity during the peripartum period merit attention.

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We analyzed monthly estimates of hair cortisol concentration (HCC) across the peripartum period.

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HCC increased across pregnancy and decreased through six months postpartum.

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There was substantial within-person variability in HCC.

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Within-person fluctuations in recent adversity were positively coupled with HCC.

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Depressive symptoms were not significantly associated with HCC.

Development and validation of a transcriptomic signature-based model as the predictive, preventive, and personalized medical strategy for preterm birth within 7 days in threatened preterm labor women

Preterm birth (PTB) is the leading cause of neonatal death. The essential strategy to prevent PTB is the accurate identification of threatened preterm labor (TPTL) women who will have PTB in a short time (< 7 days). Here, we aim to propose a clinical model to contribute to the effective prediction, precise prevention, and personalized medical treatment for PTB < 7 days in TPTL women through bioinformatics analysis and prospective cohort studies. In this study, the 1090 key genes involved in PTB < 7 days in the peripheral blood of TPTL women were ascertained using WGCNA. Based on this, the biological basis of immune-inflammatory activation (e.g., IFNγ and TNFα signaling) as well as immune cell disorders (e.g., monocytes and Th17 cells) in PTB < 7 days were revealed. Then, four core genes (JOSD1, IDNK, ZMYM3, and IL1B) that best represent their transcriptomic characteristics were screened by SVM and LASSO algorithm. Therefore, a prediction model with an AUC of 0.907 was constructed, which was validated in a larger population (AUC = 0.783). Moreover, the predictive value (AUC = 0.957) and clinical feasibility of this model were verified through the clinical prospective cohort we established. In conclusion, in the context of Predictive, Preventive, and Personalized Medicine (3PM), we have developed and validated a model to predict PTB < 7 days in TPTL women. This is promising to greatly improve the accuracy of clinical prediction, which would facilitate the personalized management of TPTL women to precisely prevent PTB < 7 days and improve maternal-fetal outcomes.

Cumulative life stressors and stress response to threatened preterm labour as birth date predictors

PURPOSE

Preterm birth represents one of the main causes of neonatal morbimortality and a risk factor for neurodevelopmental disorders. Appropriate predictive methods for preterm birth outcome, which consequently would facilitate prevention programs, are needed. We aim to predict birth date in women with a threatened preterm labour (TPL) based on stress response to TPL diagnosis, cumulative life stressors, and relevant obstetric variables.

METHODS

A prospective cohort of 157 pregnant women with TPL diagnosis between 24 and 31 weeks gestation formed the study sample. To estimate the stress response to TPL, maternal salivary cortisol, α-amylase levels, along with anxiety and depression symptoms were measured. To determine cumulative life stressors, previous traumas, social support, and family functioning were registered. Then, linear regression models were used to examine the effect of potential predictors of birth date.

RESULTS

Lower family adaptation, higher Body Mass Index (BMI), higher cortisol levels and TPL diagnosis week were the main predictors of birth date. Gestational week at TPL diagnosis showed a non-linear interaction with cortisol levels: TPL women with middle- and high-cortisol levels before 29 weeks of gestation went into imminent labour.

CONCLUSION

A combination of stress response to TPL diagnosis (salivary cortisol) and cumulative life stressors (family adaptation) together with obstetric factors (TPL gestational week and BMI) was the best birth date predictor. Therefore, a psychosocial therapeutic intervention program aimed to increase family adaptation and decrease cortisol levels at TPL diagnosis as well as losing weight, may prevent preterm birth in symptomatic women.

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.

Stress and Metabolomics for Prediction of Spontaneous Preterm Birth: A Prospective Nested Case-Control Study in a Tertiary Hospital

Spontaneous preterm birth (sPTB) is the leading cause of infant morbidity and mortality worldwide. Deficiency of effective predict methods is an urgent problem that needs to be solved. Numbers of researchers spare no efforts to investigate differential indicators. To evaluate the value of the differential indicators, a prospective nested case-control study was carried out. Among an overall cohort of 1,050 pregnancies, 20 sPTB pregnancies, and 20 full-term pregnancies were enrolled in this study. Participants were followed-up until labor. The psychological profile was evaluated utilizing the Zung Self-Rating Depression Scale at 11-14 weeks. Stress-related biomarker-cortisol and metabolites were detected by Electrochemiluminescence Immunoassay (ECLIA) and Gas Chromatography-Mass Spectrometry (GC-MS) in serum samples during pregnancy, respectively. The expression level of cortisol was up-regulated in serum and the score of the Zung Self-Rating Depression Scale was significantly higher in the sPTB group when compared to the control group. Note that, 29 metabolomics were differentially expressed between the sPTB group and the control group. The scores of the Zung Self-Rating Depression Scale, the level of cortisol, Eicosane, methyltetradecanoate, and stearic acid in serum were selected to establish the model with lasso logistic regression. Validation of the model yielded an optimum corrected AUC value of 89.5%, 95% CI: 0.8006-0.9889 with a sensitivity of 100.0%, and specificity of 78.9%. In conclusion, this study establishes a prediction model of sPTB with five variables, which may predict sPTB more accurately and sensitively in the second trimester.

Overly optimistic prediction results on imbalanced data: a case study of flaws and benefits when applying over-sampling

Information extracted from electrohysterography recordings could potentially prove to be an interesting additional source of information to estimate the risk on preterm birth. Recently, a large number of studies have reported near-perfect results to distinguish between recordings of patients that will deliver term or preterm using a public resource, called the Term/Preterm Electrohysterogram database. However, we argue that these results are overly optimistic due to a methodological flaw being made. In this work, we focus on one specific type of methodological flaw: applying over-sampling before partitioning the data into mutually exclusive training and testing sets. We show how this causes the results to be biased using two artificial datasets and reproduce results of studies in which this flaw was identified. Moreover, we evaluate the actual impact of over-sampling on predictive performance, when applied prior to data partitioning, using the same methodologies of related studies, to provide a realistic view of these methodologies' generalization capabilities. We make our research reproducible by providing all the code under an open license.

Associations Between Placental Corticotropin-Releasing Hormone, Maternal Cortisol, and Birth Outcomes, Based on Placental Histopathology

Preterm birth remains the leading cause of neonatal morbidity and mortality, with complex biochemical pathways requiring continued understanding and assessment. The objective of this study is to assess the associations between maternal cortisol and placental corticotropin-releasing hormone (placental CRH) concentrations with birth outcomes when stratified by placental histopathology. We conducted an analysis of 112 singleton pregnancies who received betamethasone between 23 and 34 weeks' gestation. Maternal blood and saliva were collected prior to betamethasone administration and samples assayed for plasma cortisol (pCort), salivary cortisol (sCort), and placental CRH levels. Placental findings were characterized as inflammatory, maternal vascular underperfusion (MVU), or no pathology, and compared for the outcomes of placental CRH, pCort, and sCort levels, gestational age at birth (GAB), and birthweight percentiles (BWP). Thirty-six subjects were characterized as inflammatory, 38 as MVU, and 38 without placental abnormalities. Histopathology groups differed significantly on placental CRH levels, GAB, and BWP. Post hoc tests suggested that the MVU group had higher placental CRH than the inflammatory or no pathology groups, and despite delivering earlier than the other two groups, the inflammatory group had infants with significantly higher BWP. No differences existed between groups in terms of mean plasma or sCort levels. Higher placental CRH and pCort levels were associated with earlier GAB in the overall sample, but when split by group, these associations remained significant only among the MVU group. Higher placental CRH was also associated with lower BWP in the overall sample but did not remain significant when split by group. Higher sCort was associated with lower BWP only in the MVU group. There is differentiation of placental CRH, cortisol, and birth outcomes when evaluated by placental histopathology. This highlights the importance of evaluating birth outcomes within the context of placental histopathology.

Clinical information extraction for preterm birth risk prediction

This paper contributes to the pursuit of leveraging unstructured medical notes to structured clinical decision making. In particular, we present a pipeline for clinical information extraction from medical notes related to preterm birth, and discuss the main challenges as well as its potential for clinical practice. A large collection of medical notes, created by staff during hospitalizations of patients who were at risk of delivering preterm, was gathered and analyzed. Based on an annotated collection of notes, we trained and evaluated information extraction components to discover clinical entities such as symptoms, events, anatomical sites and procedures, as well as attributes linked to these clinical entities. In a retrospective study, we show that these are highly informative for clinical decision support models that are trained to predict whether delivery is likely to occur within specific time windows, in combination with structured information from electronic health records.

Women's experiences of antenatal transfer for threatened premature labour in NSW: A qualitative study

BACKGROUND

Each year thousands of pregnant women experiencing threatened premature labour are transferred considerable distances across Australia to access higher level facilities but only a small proportion of these women go on to actually give birth to a premature baby. Women from regional areas are required to move away from their home, children and support networks because of a perceived risk of birthing in a centre without neonatal intensive care facilities.

AIM

This study examines the experience of women undergoing antenatal transfer for threatened premature labour in New South Wales and the Australian Capital Territory who do not give birth during their transfer admission.

METHODS

Thirteen semi-structured in-depth interviews were held with women across five tertiary referral sites across New South Wales and the Australian Capital Territory, and analysed until saturation for themes.

FINDINGS

Seven urban and six rural women were interviewed. Women and their families were all negatively affected by antenatal transfer. Factors that helped enable a positive experience were; enhanced sense of safety in the tertiary unit, and individual qualities of staff. Factors that contributed to negative experiences were; inadequate and conflicting information, and no involvement or choice in the clinical decision-making process to move to another facility.

CONCLUSIONS

Antenatal transfer is an extremely stressful experience for women and their families. The provision of high quality written and verbal information, and the inclusion of women's perception of risk in the clinical decision making process will improve the experience for women and their families in NSW and the ACT.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Non-invasive monitoring of stress biomarkers in the newborn period

The neonatal period is a highly sensitive time span during which stressful experiences may have an influence on later health outcomes. Medical procedures applied to newborn babies during hospitalization are stressors that trigger a physiological and psychological stress response. Stress response has been traditionally evaluated using scores based on behavioural signs such as facial expressions, limb movements, crying, etc., which are subjectively interpreted. Only few studies have employed measurable physiological signs to objectively evaluate the stress response to specific interventions. The aim of this review is to inform of recently developed biochemical methods that allow clinicians to evaluate the stress response to medical procedures performed in the neonatal period in biological samples non-invasively obtained. Stress biomarkers are based on the physiological stress response mediated by the hypophysis-pituitary-adrenal axis and the sympathetic-adreno-medullary systems. Cortisol is at present the most widely employed laboratory determination to measure stress levels. In recent years, sequentially determined salivary cortisol levels have allowed non-invasive monitoring of newborn infants under stressful conditions in the NICU.

Anxiety and depressive symptoms, and stress biomarkers in pregnant women after in vitro fertilization: a prospective cohort study

STUDY QUESTION

Does in vitro fertilization (IVF) affect the course of anxiety and depressive symptoms as well as physiological stress from pregnancy to postpartum period?

SUMMARY ANSWER

IVF mothers have more anxiety symptoms and higher stress biomarker levels but fewer depression symptoms than natural conception mothers at the third trimester of pregnancy, but these differences are negligible during postpartum period.

WHAT IS KNOWN ALREADY

Cross-sectional studies have found an association between IVF and high stress levels during the prenatal period. There is, however, no follow-up study about the IVF effect on the mental health status from pregnancy to postpartum, adopting simultaneous measurement of self-reported symptoms and stress biomarkers.

STUDY DESIGN, SIZE, DURATION

This is a prospective cohort study. A total of 243 eligible women were recruited during the third trimester of pregnancy (60 women after successful IVF and 183 who conceived naturally). The recruitment was performed during a 12-month period, and the follow-up was carried out until 3 months after delivery.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study was performed in the Division of Obstetrics in a regional referral center. The State scale of the State-Trait Anxiety Inventory (STAI-S) and the Beck Depression Inventory-Sort Form (BDI/SF) were used as anxiety and depression indicators, respectively; salivary cortisol and α-amylase levels as stress biomarkers. Anxiety, depression and stress biomarkers were measured at the third trimester of pregnancy (T1), at 48 h after birth (T2) and at 3 months after birth (T3). Associations with IVF were assessed using ordinal mixed models for anxiety and depressive symptoms and linear quantile models for stress biomarkers.

MAIN RESULTS AND THE ROLE OF CHANCE

Relative to natural conception mothers, IVF mothers had higher STAI-S scores at T1 (P = 0.016, odds ratio (OR) = 2.46), and this difference remained steady from T1 to T2 (P = 0.37, OR = 0.70) and from T2 to T3 (P = 0.36, OR = 0.69). In the case of depressive symptoms, the IVF group obtained lower BDI/SF scores at T1 (P < 0.001, OR = 0.192). This difference was apparently reduced from T1 to T2 (P = 0.072, OR = 2.21) and remained constant from T2 to T3 (P = 0.107, OR = 2.09). It is important to note that whereas the mean BDI/SF score was not clinically significant for any group (it was lower than the cut-off 4), the mean STAI-S score of the IVF group at T1 was so (it was higher than the cut-off 19). As for stress biomarkers, IVF mothers had higher cortisol levels at T1 (P = 0.043, Δlog(cortisol) = 0.88) compared to natural conceptions. From T1 to T2 cortisol levels of both groups increased at the relatively same rate (P = 0.81, Δlog(cortisol) = -0.16). However, the progressions tended to be different from T2 to T3, with IVF mothers exhibiting a sharp decrease in cortisol levels (P = 0.059, Δlog(cortisol) = -0.94), while natural conceptions value remained steady. In the case of α-amylase, there were no statistically significant differences between both groups at T1 (P = 0.7, Δlog(α-amylase) = -0.095). On the contrary, while IVF mothers showed sustained α-amylase levels across the time, the progression was different in the natural conception group, who showed a decrease in α-amylase levels from T1 to T2 (P = 0.049, Δlog(α-amylase) = 0.596) and a non-significant increase from T2 to T3 (P = 0.53, Δlog(α-amylase) = -0.283).

LIMITATIONS REASON FOR CAUTION

Since this follow-up study has been carried out from the third trimester of pregnancy, the findings cannot be generalized to extremely preterm births.

WIDER IMPLICATIONS OF THE FINDINGS

IVF women may have lower depressive symptoms for being pregnant. However, due to the potential pregnancy complications associated with IVF, they may have higher physiological stress and clinically significant anxiety at the third trimester of pregnancy but not during postpartum. Taking into account that both prenatal high maternal cortisol levels and prenatal clinically significant anxiety increase the risk of disturbance in the fetal neurodevelopment, psychological therapy should be extended during pregnancy in IVF women.

STUDY FUNDING/COMPETING INTEREST(S)

MV funded by FIS PI17/0131 grant from the Instituto de Salud Carlos III (ISCIII) and RETICS funded by the PN 2018-2011, and the European Regional Development Fund, reference RD16/0022/0001; AG-B funded by a 'Juan Rodés' Grant (JR17/00003) from the ISCIII. CC-P funded by a 'Miguel Servet I' Grant (CP16/00082) from the ISCIII. Authors declare no competing interests.

Weight stigma and acculturation in relation to hair cortisol among Asian Americans with overweight and obesity: A cross-sectional study

Weight stigma is a pervasive problem for Americans, but little is known about its impact on the health of Asian Americans. Authors examined the relationship between weight stigma and cortisol and whether acculturation moderated this relationship. Asian Americans (n = 166) with overweight or obesity completed questionnaires and provided a 50-mg hair sample to assay cortisol. Results revealed a negative correlation between weight stigma and cortisol. However, this was no longer significant after controlling of relevant covariates. The level of acculturation did not significantly moderate this relationship. The non-significant relationships among weight stigma, cortisol, and acculturation are discussed along with future directions.

The Effect of Prenatal Stress, Proxied by Marital and Paternity Status, on the Risk of Preterm Birth

Uncertainty and insecurity in the relationship between the mother and father of a child are responsible for heightened maternal stress, which can lead to preterm birth (PTB). Different intensities of prenatal stress (proxied by four levels of marital status linked with the presence or absence of paternal data on birth records) were defined as the Marital-Father Data index. We assessed the impact of those varying intensities of prenatal stress on PTB with respect to parity among a group of Polish mothers residing in Krakow (N = 87,916). We found a pattern across the adjusted risk ratios (RR) of preterm birth that ordered these estimates in an increasing trend towards higher risk, beginning with the group of married mothers with father data present (baseline), through the groups of legitimizing marriages—married after conception with father data present (RR = 1.1; 95% Confidence Intervals (CI) 1.0–1.2) and unmarried mothers with father data present (RR = 1.3; 95% CI 1.2–1.5) to the group of unmarried mothers with father data absent (RR = 1.9; 95% CI 1.7–2.2). The adjusted p for the linear trend between Marital-Father Data index and PTB was less than 0.001. The adjusted effect of perceived prenatal stress differed with respect to parity (confirmed by statistically significant interactions between Marital-Father Data index levels and parity), with a higher magnitude of this effect noted among multiparous versus primiparous women. Low paternal involvement and support during pregnancy may negatively affect PTB risk and this effect may differ in relation to parity status. More attention should be paid to maternal pregnancy stress, especially of multiparous mothers, to decrease the risk of unfavorable birth outcomes.

Stress and the HPA Axis: Balancing Homeostasis and Fertility

An organism’s reproductive fitness is sensitive to the environment, integrating cues of resource availability, ecological factors, and hazards within its habitat. Events that challenge the environment of an organism activate the central stress response system, which is primarily mediated by the hypothalamic–pituitary–adrenal (HPA) axis. The regulatory functions of the HPA axis govern the cardiovascular and metabolic system, immune functions, behavior, and reproduction. Activation of the HPA axis by various stressors primarily inhibits reproductive function and is able to alter fetal development, imparting a biological record of stress experienced in utero. Clinical studies and experimental data indicate that stress signaling can mediate these effects through direct actions in the brain, gonads, and embryonic tissues. This review focuses on the mechanisms by which stress activation of the HPA axis impacts fertility and fetal development.