Cortisol levels versus self-report stress measures during pregnancy as predictors of adverse infant outcomes: a systematic review

Prenatal stress and hair cortisol in a sample of Latina women

BACKGROUND

Stress during pregnancy adversely impacts maternal and infant health. Dysregulation of the hypothalamic pituitary axis is a mediator of the relationship between stress and health. Evidence supporting an association between prenatal chronic stress and cortisol is limited, and the majority of research published has been conducted amongst White participants, who experience less chronic stress than people of color.

AIM

This study investigated associations between various measures of prenatal stress and hair cortisol concentrations which is a biomarker of the integrated stress response in a sample of Latina participants during the third trimester of pregnancy.

METHOD

Pregnant women (n=45) were surveyed with scales measuring chronic stress, perceived stress, pregnancy-related and pregnancy-specific anxiety. Hair samples were collected as an objective neuroendocrine measure of chronic stress. Linear regression analyses were performed to assess associations between stress measures and hair cortisol. Pre-pregnancy BMI, smoking during pregnancy, and steroid use during pregnancy were used as covariates in adjusted models.

RESULTS

Chronic stress, operationalized as maternal reports of neighborhood/housing strain, daily activities and relationship strain, discrimination, and financial strain, was significantly associated with higher hair cortisol concentrations. No significant associations were found between hair cortisol and perceived stress, pregnancy-related anxiety, nor pregnancy-specific anxiety in adjusted models.

CONCLUSION

Chronic stress may be a more robust correlate of physiological stress, as measured by hair cortisol in pregnancy, than other common measures of prenatal stress and anxiety.

Negative associations between maternal prenatal hair cortisol and child socioemotional problems

Maternal prenatal distress can participate in the programming of offspring development, in which exposure to altered maternal long-term cortisol levels as measured by hair cortisol concentrations (HCC) may contribute. Yet, studies investigating whether and how maternal prenatal HCC associates with problems in child socioemotional development are scarce. Furthermore, questions remain regarding the timing and potential sex-specificity of fetal exposure to altered cortisol levels and whether there are interactions with maternal prenatal distress, such as depressive symptoms. The subjects were drawn from those FinnBrain Birth Cohort families that had maternal reports of child socioemotional problems (the Brief Infant-Toddler Social and Emotional Assessment [BITSEA] at 2 years and/or the Strengths and Difficulties Questionnaire [SDQ] at 5 years) as follows: HCC1 population: maternal mid-pregnancy HCC measured at gestational week 24 with 5 cm segments to depict cortisol levels from the previous five months (n = 321); and HCC2 population: end-of-pregnancy HCC measured 1-3 days after childbirth (5 cm segment; n = 121). Stepwise regression models were utilized in the main analyses and a sensitivity analysis was performed to detect potential biases. Negative associations were observed between maternal HCC2 and child BITSEA Total Problems at 2 years but not with SDQ Total difficulties at 5 years, and neither problem score was associated with HCC1. In descriptive analyses, HCC2 was negatively associated with Internalizing problems at 2 years and SDQ Emotional problems at 5 years. A negative association was observed among 5-year-old girls between maternal HCC1 and SDQ Total Difficulties and the subscales of Conduct and Hyperactivity/inattentive problems. When interactions were also considered, inverse associations between HCC2 and BITSEA Internalizing and Dysregulation Problems were observed in subjects with elevated prenatal depressive symptoms. It was somewhat surprising that only negative associations were observed between maternal HCC and child socioemotional problems. However, there are previous observations of elevated end-of-pregnancy cortisol levels associating with better developmental outcomes. The magnitudes of the observed associations were, as expected, mainly modest. Future studies with a focus on the individual changes of maternal cortisol levels throughout pregnancy as well as studies assessing both maternal and child HPA axis functioning together with child socioemotional development are indicated.

Feasibility of Stress Research in Premature Infant-Maternal Dyads During and After Neonatal Intensive Care Unit Hospitalization

BACKGROUND

Stress from preterm infant admission to the neonatal intensive care unit (NICU) is associated with infant and maternal physiologic changes, including endocrine and epigenetic alterations. Little is known about the mechanisms connecting NICU stress to biologic changes, and whether preterm infant and maternal stress are reciprocal. As a preliminary step, feasibility and acceptability of measuring indicators of stress are required.

PURPOSE

This study evaluated the feasibility and acceptability of research examining perceptions and biologic markers of stress in premature infant-maternal dyads during and after NICU hospitalization.

METHODS

We evaluated study feasibility using a longitudinal descriptive design. Acceptability was measured via a maternal questionnaire. Exploratory data regarding hospitalization, perceptions of stress, social support and social determinants of health, and biologic markers of stress were collected during the first week of life and again 3 months after NICU.

RESULTS

Forty-eight mothers were eligible for the study, 36 mothers were approached, 20 mothers consented to participate, and 14 mothers completed data collection. Mothers reported high levels of study acceptability despite also voicing concern about the sharing of genetic data. Exploration of DNA methylation of SLC6A4 in preterm infants was significant for a strong correlation with perception of total chronic stress.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Clinical practice at the bedside in the NICU should include standardized screening for and early interventions to minimize stress. Complex research of stress is feasible and acceptable. Future research should focus on linking early life stress with epigenetic alterations and evaluation of the dyad for reciprocity.

Obesity in pregnancy-Long-term effects on offspring hypothalamic-pituitary-adrenal axis and associations with placental cortisol metabolism: A systematic review

Obesity, affecting one in three pregnant women worldwide, is not only a major obstetric risk factor. The resulting low-grade inflammation may have a long-term impact on the offspring's HPA axis through dysregulation of maternal, placental and fetal corticosteroid metabolism, and children born of obese mothers have increased risk of diabetes and cardiovascular disease. The long-term effects of maternal obesity on offspring neurodevelopment are, however, undetermined and could depend on the specific effects on placental and fetal cortisol metabolism. This systematic review evaluates how maternal obesity affects placental cortisol metabolism and the offspring's HPA axis. Pubmed, Embase and Scopus were searched for original studies on maternal BMI, obesity, and cortisol metabolism and transfer. Fifteen studies were included after the screening of 4556 identified records. Studies were small with heterogeneous exposures and outcomes. Two studies found that maternal obesity reduced placental HSD11β2 activity. In one study, umbilical cord blood cortisol levels were affected by maternal BMI. In three studies, an altered cortisol response was consistently seen among offspring in childhood (n = 2) or adulthood (n = 1). Maternal BMI was not associated with placental HSD11β1 or HSD11β2 mRNA expression, or placental HSD11β2 methylation. In conclusion, high maternal BMI is associated with reduced placental HSD11β2 activity and a dampened cortisol level among offspring, but the data is sparse. Further investigations are needed to clarify whether the HPA axis is affected by prenatal factors including maternal obesity and investigate if adverse effects can be ameliorated by optimising the intrauterine environment.

Long-Term Effects of Child Early Surgical Ventricular Septal Defect Repair on Maternal Stress

The ventricular septal defect (VSD) represents the most common congenital heart defect (CHD). The diagnosis of and cardiac surgery for their child's VSD are highly stressful experiences for parents; especially mothers, who are at risk of developing long-lasting stress-related symptoms. This study examined long-term alterations in maternal stress including self-reported psychological and biophysiological stress levels in a case-control design. We investigated 24 mothers of children with an isolated, surgically corrected VSD compared to non-affected controls. Maternal self-reports on psychopathology, everyday stress, parenting stress and hair cortisol concentrations (HCC) were measured during children's primary school age (6-9 years, t1) and early adolescence (10-14 years, t2). In maternal self-reports, psychopathology and stress symptoms in the VSD-group and controls were comparable at t1, whereas at t2, mothers in the VSD-group even showed a decrease in psychopathology. Maternal HCC levels in the VSD-group were significantly lower (hypocortisolism) than HCC levels of controls at t1. This effect was no longer observed at t2 reflecting an approximation of HCC levels in the VSD-group to controls' levels. This study highlights the potential for improved stress hormone balance and psychological well-being in mothers following their child's surgical VSD repair. However, the need for parent-centered interventions is discussed, particularly during peri-operative phases and in early child developmental stages.

Current Understanding of the Roles of Gut-Brain Axis in the Cognitive Deficits Caused by Perinatal Stress Exposure

The term 'perinatal environment' refers to the period surrounding birth, which plays a crucial role in brain development. It has been suggested that dynamic communication between the neuro-immune system and gut microbiota is essential in maintaining adequate brain function. This interaction depends on the mother's status during pregnancy and/or the newborn environment. Here, we show experimental and clinical evidence that indicates that the perinatal period is a critical window in which stress-induced immune activation and altered microbiota compositions produce lasting behavioral consequences, although a clear causative relationship has not yet been established. In addition, we discuss potential early treatments for preventing the deleterious effect of perinatal stress exposure. In this sense, early environmental enrichment exposure (including exercise) and melatonin use in the perinatal period could be valuable in improving the negative consequences of early adversities. The evidence presented in this review encourages the realization of studies investigating the beneficial role of melatonin administration and environmental enrichment exposure in mitigating cognitive alteration in offspring under perinatal stress exposure. On the other hand, direct evidence of microbiota restoration as the main mechanism behind the beneficial effects of this treatment has not been fully demonstrated and should be explored in future studies.

The COVID-19 Pandemic: Implications for Maternal Mental Health and Early Childhood Development

Women are particularly susceptible to mental health challenges during the perinatal period. With the onset of the COVID-19 pandemic in 2020, much concern was raised about the impact that the associated isolation, uncertainty, grief, loss and economic upheaval would have on mental health. Women experienced a disproportionate amount of environmental strain during this time, including economic stress and challenges associated with being essential workers; stressors were perhaps most prevalent in communities of color and immigrant groups. For women who were pregnant during the height of the pandemic, it is clear that stress, anxiety, and depression were increased due to changes in medical care and decreases in social support. Increased mental health challenges in the perinatal period have been shown to impact social-emotional, cognitive and behavioral health in infants and children, so the potential consequences of the COVID-19 era are great. This paper discusses these potential impacts and describes important pathways for future research.