Contact with caregivers is associated with composition of the infant gastrointestinal microbiome in the first 6 months of life.

OBJECTIVES: Little is known about how physical contact at birth and early caregiving environments influence the colonization of the infant gastrointestinal microbiome. We investigated how infant contact with caregivers at birth and within the first 2 weeks of life relates to the composition of the gastrointestinal microbiome in a sample of U.S. infants (n = 60). METHODS: Skin-to-skin and physical contact with caregivers at birth and early caregiving environments were surveyed at 2 weeks postpartum. Stool samples were collected from infants at 2 weeks, 2, 6, and 12 months of age and underwent 16S rRNA sequencing as a proxy for the gastrointestinal microbiome. Associations between early caregiving environments and alpha and beta diversity, and differential abundance of bacteria at the genus level were assessed using PERMANOVA, and negative binomial mixed models in DEseq2. RESULTS: Time in physical contact with caregivers explained 10% of variation in beta diversity at 2 weeks' age. The number of caregivers in the first few weeks of life explained 9% of variation in beta diversity at 2 weeks and the number of individuals in physical contact at birth explained 11% of variation in beta diversity at 6 months. Skin-to-skin contact on the day of birth was positively associated with the abundance of eight genera. Infants held for by more individuals had greater abundance of eight genera. DISCUSSION: Results reveal a potential mechanism (skin-to-skin and physical contact) by which caregivers influence the infant gastrointestinal microbiome. Our findings contribute to work exploring the social transmission of microbes.

Regulatory T-cell phenotypes in prenatal psychological distress.

BACKGROUND: Experiencing symptoms of psychological distress during pregnancy is common and has been linked to dysregulated immune functioning. In this context, immunoregulatory function is especially relevant because of its crucial role in establishment and maintenance of healthy pregnancy. However, little research has examined associations between women's prenatal psychological distress and immunoregulatory biomarkers. We investigated how symptoms of depression, anxiety, and stress relate to circulating levels of regulatory T-cells (Tregs). MATERIALS AND METHODS: Pregnant Latina women were assessed at around 12 weeks of pregnancy (N = 82). These assessments included blood draws and self-report questionnaires assessing symptoms of depression, state anxiety, pregnancy-related anxiety, and perceived stress. Flow cytometry on PBMCs was used to quantify circulating Tregs, defined as CD3+CD4+CD25hiCD127loFoxP3+, and subpopulations positive for one of the following intra- or extracellular markers, CD45RA, CTLA-4, Helios, PD-1, TIM-3, and TIGIT. We collected 82 samples at 12 weeks. Multivariable linear regressions tested for associations between symptoms of psychological distress and Treg concentrations, adjusted for gestational age. RESULTS: State anxiety symptoms at 12 weeks were negatively associated with parent Treg cell levels (b = -4.02, p = 0.023) and subpopulations Helios+ (b = -3.29, p = 0.019) and TIM3+ (b = -3.17, p = 0.008). Perceived stress was negatively associated with the PD-1+ subpopulation at 12 weeks (b = -4.02, p = 0.023). Depression was not related to Tregs or the subpopulations. CONCLUSION: Our observation that symptoms of anxiety and stress are related to tolerogenic immunology suggests a possible biomechanism explaining correlations of maternal mood disorders with adverse outcomes for mothers and offspring.

Association of pica with cortisol and inflammation among Latina pregnant women.

Pica, the urge to consume items generally not considered food, such as dirt, raw starch, and ice, are particularly common among pregnant women. However, the biology of pica in pregnancy is not well understood. Therefore, this study aimed to assess how pica relates to endocrine stress and immune biomarkers in a cohort of pregnant Latina women in Southern California. Thirty-four women completed a structured pica questionnaire. Maternal urinary cortisol and plasma cytokine levels were measured between 21 and 31 weeks' gestation. Associations between pica during pregnancy and biomarkers were assessed using linear regression models adjusting for gestational age. Twelve (35.3%) of the pregnant women reported pica (geophagy and amylophagy) during pregnancy. In multivariate models, those who engaged in pica had higher levels of cortisol (ß: 0.37, 95% CI: 0.01, 0.073) and lower levels of IL-1ß (ß: -0.06, 95% CI: -0.11, -0.02), IL-8 (ß: -0.30, 95% CI: -0.56, -0.05), IL-21 (ß: -0.35, 95% CI: -0.63, -0.08), and type-1 inflammation composite (ß: -0.29, 95% CI: -0.44, -0.14) than women who did not engage in pica. These results suggest that biological stress and immune response differ for women with pica compared to those without. This study suggests novel physiological covariates of pica during pregnancy. Further research is needed to better understand the mechanisms and temporality underlying the observed associations between pica and endocrine and immune biomarkers.

Sociopolitical stressors are associated with psychological distress in a cohort of Latina women during early pregnancy.

Research suggests that the 2016 US election was a potential stressor among Latinos residing in the United States. Sociopolitical stressors targeted toward ethnic minority communities and become embodied through psychosocial distress. The current study investigates if and how sociopolitical stressors related to the 45th President, Donald Trump, and his administration are associated with psychological distress in early pregnancy of Latina women living in Southern California during the second half of his term. This cross-sectional analysis uses data from the Mothers' Cultural Experiences study (n = 90) collected from December 2018 to March 2020. Psychological distress was assessed in three domains: depression, state anxiety, and pregnancy-related anxiety. Sociopolitical stressors were measured through questionnaires about sociopolitical feelings and concerns. Multiple linear regression models examined the relationship between sociopolitical stressors and mental health scores, adjusting for multiple testing. Negative feelings and a greater number of sociopolitical concerns were associated with elevated pregnancy-related anxiety and depressive symptoms. The most frequently endorsed concern was about issues of racism (72.3%) and women's rights (62.4%); women endorsing these particular concerns also had higher scores on depression and pregnancy-related anxiety. No significant associations were detected with state anxiety after correction for multiple testing. This analysis is cross-sectional and cannot assess causality in the associations between sociopolitical stressors and distress. These results are consistent with the hypothesis that the 2016 election, the subsequent political environment, and the anti-immigrant rhetoric and policies of former President Trump and his administration were sources of stress for Latinos residing in the United States.

A longitudinal study of how women's prenatal and postnatal concerns related to the COVID-19 pandemic predicts their infants' social-emotional development.

Infant social-emotional development may be impacted by the COVID-19 pandemic. This study investigated associations between maternal pre- and postnatal pandemic-related concerns and social-emotional developmental risk. Data, collected in 2020-2021, came from 220 mothers (87% white, 6% Hispanic, 1% Black, 3% Asian, 1% American Indian, Mage = 32.46 years), and infants (53.18% male, Mage = 12.98 months) in the United States. Maternal postnatal pandemic-related concerns were associated with total risk scores (B = 6.09, p-value <.001) and offspring risk of scoring positive for problems related to inflexibility (B = 4.07, p-value = .006). The total score association was moderated by self-reported social support. Infants may be detrimentally impacted by the pandemic via maternal pandemic-related concerns. Maternal social support may buffer infants.

How prenatal cortisol levels relate to grandmother-mother relationships among a cohort of Latina women.

INTRODUCTION: As part of the human reproductive strategy, mothers receive childcare assistance from others. For kin, allomothers are adaptively incentivized to provide assistance due to inclusive fitness benefits. Previous studies across a broad range of populations identify grandmothers as particularly consistent allomothers. Minimal attention has been paid to the possibility that allomothers may begin investing in offspring quality during the prenatal stage of life. Here, we innovate within the area of grandmother allocare research by examining the prenatal stage of life and biopsychosocial mechanisms by which prenatal grandmother effects may be enacted. METHODS: Data derive from the Mothers' Cultural Experiences study, a cohort of 107 pregnant Latina women in Southern California. At <16 weeks' gestation, we administered questionnaires, collected morning urine samples, and measured cortisol by enzyme-linked immunosorbent assay, correcting for specific gravity. We measured the soon-to-be maternal and paternal grandmothers' relationship quality, social support, frequency of seeing each other, communicating, and geographic proximity to pregnant mothers, that is, their daughters and daughters-in-law. These measures were self-reported by the pregnant mothers. We assessed how grandmother constructs related to the pregnant women's depression, stress, anxiety, and cortisol levels. RESULTS: We observed benefits conferred by maternal grandmothers for mothers' prenatal mental health and lower cortisol levels. Paternal grandmothers also conferred mental health benefits to pregnant daughters-in-law, but higher cortisol levels. CONCLUSION: Our results suggest that grandmothers, especially maternal grandmothers, are able to improve their inclusive fitness by caring for pregnant daughters, and allomother support may positively impact prenatal health. This work extends the traditional cooperative breeding model by identifying a prenatal grandmother effect, and, by examining a maternal biomarker.

Maternal distress, DNA methylation, and fetal programing of stress physiology in Brazilian mother-infant pairs.

Maternal prenatal psychosocial stress is associated with adverse hypothalamic-pituitary-adrenal axis (HPAA) function among infants. Although the biological mechanisms influencing this process remain unknown, altered DNA methylation is considered to be one potential mechanism. We investigated associations between maternal prenatal psychological distress, infant salivary DNA methylation, and stress physiology at 12 months. Mother's distress was measured via depression and anxiety in early and late pregnancy in a cohort of 80 pregnant adolescents. Maternal hair cortisol was collected during pregnancy. Saliva samples were collected from infants at 12 months to quantify DNA methylation of three stress-related genes (FKBP5, NR3C1, OXTR) (n = 62) and diurnal cortisol (n = 29). Multivariable linear regression was used to test for associations between prenatal psychological distress, and infant DNA methylation and cortisol. Hair cortisol concentrations in late pregnancy were negatively associated with two sites of FKBP5 (site 1: B = -22.33, p = .003; site 2: B = -15.60, p = .012). Infants of mothers with elevated anxiety symptoms in late pregnancy had lower levels of OXTR2 CpG2 methylation (B = -2.17, p = .03) and higher evening salivary cortisol (B = 0.41, p = .03). Furthermore, OXTR2 methylation was inversely associated with evening cortisol (B = -0.14, p-value ≤ .001). Our results are, to our knowledge, the first evidence that the methylation of the oxytocin receptor may contribute to the regulation of HPAA during infancy.

How a pregnant woman's relationships with her siblings relate to her mental health: a prenatal allocare perspective.

BACKGROUND: In cooperatively breeding species, individuals may promote their inclusive fitness through allomothering. Humans exhibit some features of cooperative breeding, and previous studies have focused on allomothering by grandparents and juvenile siblings in the postnatal period. We hypothesize that a pregnant woman's relationships with her siblings (offspring's maternal aunts and uncles) are beneficial for maternal affect in ways that can enhance the siblings' inclusive fitness. Maternal affect during pregnancy is a salient target of allocare given the detrimental effects of antepartum mood disorders on birth and infant outcomes. METHODOLOGY: We test our hypotheses in a cohort of pregnant Latina women in Southern California (N = 201). Predictor variables of interest include number of siblings a participant has, if she has sisters, frequency of seeing siblings, and frequency of communication with siblings. Outcome variables measuring maternal affect include depression, state anxiety, pregnancy-related anxiety and perceived stress. RESULTS: Having at least one sister and greater frequency of communication with siblings were associated with fewer depressive symptoms during pregnancy. No significant associations were found between sibling variables and other measures of affect. CONCLUSION AND IMPLICATIONS: Results suggest that how frequently you communicate with, and not how often you see, siblings could be protective against risk of antepartum depression. Sibling allomothering could impart effects through social-emotional support rather than instrumental support, as a strategy to benefit the prenatal environment in which future nieces and nephews develop. Allomothering may be particularly important in cultural contexts that value family relationships. Future studies should investigate other communities.

Development of the infant gut microbiome predicts temperament across the first year of life.

Perturbations to the gut microbiome are implicated in altered neurodevelopmental trajectories that may shape life span risk for emotion dysregulation and affective disorders. However, the sensitive periods during which the microbiome may influence neurodevelopment remain understudied. We investigated relationships between gut microbiome composition across infancy and temperament at 12 months of age. In 67 infants, we examined if gut microbiome composition assessed at 1-3 weeks, 2, 6, and 12 months of age was associated with temperament at age 12 months. Stool samples were sequenced using the 16S Illumina MiSeq platform. Temperament was assessed using the Infant Behavior Questionnaire-Revised (IBQ-R). Beta diversity at age 1-3 weeks was associated with surgency/extraversion at age 12 months. Bifidobacterium and Lachnospiraceae abundance at 1-3 weeks of age was positively associated with surgency/extraversion at age 12 months. Klebsiella abundance at 1-3 weeks was negatively associated with surgency/extraversion at 12 months. Concurrent composition was associated with negative affectivity at 12 months, including a positive association with Ruminococcus-1 and a negative association with Lactobacillus. Our findings support a relationship between gut microbiome composition and infant temperament. While exploratory due to the small sample size, these results point to early and late infancy as sensitive periods during which the gut microbiome may exert effects on neurodevelopment.

How do grandparents influence child health and development? A systematic review.

Grandparents are often a key source of care provision for their grandchildren, yet they are sidelined in caregiving research and policy decisions. We conducted a global, systematic review of the literature to examine the scope and quality of studies to date (PROSPERO database CRD42019133894). We screened 12,699 abstracts across 7 databases, and identified 206 studies that examined how grandparents influence child health and development. Indicators of grandparent involvement were contact, caregiving behaviors, and financial support. Our review focused on two research questions: how do grandparents influence child health and development outcomes, and what range of child outcomes is reported globally? We examined study design, sample characteristics, key findings, and outcomes pertaining to grandchildren's physical health, socio-emotional and behavioral health, and cognitive and educational development.  Our search captured studies featuring grandparent custodial care (n = 35), multigenerational care (n = 154), and both types of care (n = 17). We found substantial heterogeneity in the data provided on co-residence, caregiving roles, resources invested, outcomes, and mechanisms through which "grandparent effects" are manifested. We identified two important issues, related to operationalizing indicators of grandparent involvement and conceptualizing potential mechanisms, leading to gaps in the evidence base. Currently, our understanding of the pathways through which grandparents exert their influence is constrained by limited data on what grandparents actually do and insufficient attention given to interpersonal and structural contexts. We present a conceptual framework to explicitly measure and theorize pathways of care, with a view to inform research design and policy implementation. We underscore the need for more robust data on three indicators of caregiver involvement-contact, behavior, and support-and for careful description of structural and interpersonal contexts in caregiving research.

Systematic Review of Chronic Discrimination and Changes in Biology During Pregnancy Among African American Women.

Profound racial health disparities in maternal and infant health exist in the USA. Discrimination based on race may contribute to these disparities, but the biological pathways through which racial discrimination acts on health are not fully known. Even less is known about these pathways during development. Examining how racial discrimination becomes biology is paramount because it may shed light on how and when such social forces result in lasting biological consequences for health and wellbeing. To begin exploring this issue, we performed a systematic review of the relationships between experiences of chronic racial discrimination and relevant biomarkers measured during pregnancy among African American women. The literature search included studies published prior to August 2018 in the MEDLINE, Embase, and PsycINFO databases, and 11 studies met our inclusion criteria. We evaluated the articles based on the biological system that the authors investigated, which included the immune, neuroendocrine, and cardiovascular systems. We found that the current literature provides preliminary evidence that experiences of chronic racial discrimination are associated with changes in maternal biology during pregnancy. However, the literature was limited in both quantity and quality. We found only 11 studies that addressed this subject, four of which only provided indirect evidence, and many studies had small sample sizes. Future work in this area should develop more informative methods that consider the interaction between interpersonal and structural racial discrimination, individual variation, and sociocultural factors. We conclude researchers should continue to work in this area and focus on developing more effective study designs and larger sample sizes.