Longitudinal analysis of cortisol changes during pubertal development in indigenous Qom girls.

Pubertal research has primarily focused on hypothalamic-pituitary-gonadal axis (HPG) regulation of puberty, though the hypothalamic-pituitary-adrenal axis (HPA) is increasingly considered critical. Heightened HPA function proxied by increasing cortisol levels may play a role in accelerated pubertal timing. However, the extent to which cortisol varies across ages and its relation to pubertal changes in linear growth are less well substantiated.

Variation in maternal lactation practices associated with changes in diurnal maternal inflammation.

While the importance of human milk in shaping infant immune function is well established, the impact of at-the-nipple (ATN) breastfeeding on maternal immune status has been understudied. Since lactation evolved to support infant survival and boost maternal fitness, we predict that ATN breastfeeding will confer benefits on maternal immune function. We measure the absolute and relative frequency of different infant feeding methods (ATN breastfeeding, pumping, donated milk, other supplementation) used by postpartum women in Seattle, WA (USA).

Social Determinant Pathways to Hypertensive Disorders of Pregnancy Among Nulliparous U.S. Women.

Background: Hypertensive disorders of pregnancy are a leading cause of maternal morbidity and mortality in the United States and impact Black mothers at disproportionately higher rates. Hypertensive disparities among racialized groups are rooted in systemic inequalities, and we hypothesize that clinical markers of allostatic load capture embodied disparities in stressors that can link upstream social determinants of health with downstream hypertensive outcomes.

Methods: We analyzed observational cohort data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (n = 6,501) and developed a structural equation model linking latent social determinants of health, longitudinal markers of allostatic load across gestation, and hypertensive pregnancy outcomes in a multigroup framework.

COVID-19 stay-at-home restrictions increase the alignment in sleep and light exposure between school days and weekends in university students.

Younger adults have a biological disposition to sleep and wake at later times that conflict with early morning obligations like work and school; this conflict leads to inadequate sleep duration and a difference in sleep timing between school days and weekends. The COVID-19 pandemic forced universities and workplaces to shut down in person attendance and implement remote learning and meetings that decreased/removed commute times and gave students more flexibility with their sleep timing. To determine the impact of remote learning on the daily sleep-wake cycle we conducted a natural experiment using wrist actimetry monitors to compare activity patterns and light exposure in three cohorts of students: pre-shutdown in-person learning (2019), during-shutdown remote learning (2020), and post-shutdown in-person learning (2021).

SARS-CoV-2 specific antibody trajectories in mothers and infants over two months following maternal infection.

Infants exposed to caregivers infected with SARS-CoV-2 may have heightened infection risks relative to older children due to their more intensive care and feeding needs. However, there has been limited research on COVID-19 outcomes in exposed infants beyond the neonatal period. Between June 2020 - March 2021, we conducted interviews and collected capillary dried blood spots from 46 SARS-CoV-2 infected mothers and their infants (aged 1-36 months) for up to two months following maternal infection onset (COVID+ group, 87% breastfeeding).

Psychosocial and energetic factors on human female pubertal timing: a systematized review.

Childhood psychosocial stressors have been proposed to favour fast life history strategies promoting earlier puberty in females. However, studies demonstrating this association often do not elucidate causal mechanisms, nor account for greater childhood energetic availability - also known to promote rapid growth and earlier puberty. To assess the extent to which such confounding has been considered, we conducted a systematized review to identify studies examining measures of both prepubertal growth (e.

Milk From Women Diagnosed With COVID-19 Does Not Contain SARS-CoV-2 RNA but Has Persistent Levels of SARS-CoV-2-Specific IgA Antibodies.

Background: Limited data are available regarding the balance of risks and benefits from human milk and/or breastfeeding during and following maternal infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Objective: To investigate whether SARS-CoV-2 can be detected in milk and on the breast after maternal coronavirus disease 2019 (COVID-19) diagnosis; and characterize concentrations of milk immunoglobulin (Ig) A specific to the SARS-CoV-2 spike glycoprotein receptor binding domain (RBD) during the 2 months after onset of symptoms or positive diagnostic test.

Methods: Using a longitudinal study design, we collected milk and breast skin swabs one to seven times from 64 lactating women with COVID-19 over a 2-month period, beginning as early as the week of diagnosis.

Traditional and biomedical maternal and neonatal care practices in a rural Indigenous population of the Bolivian Amazon.

In recent decades, Bolivia has expanded maternal and child health insurance coverage to improve access to prenatal and early life health care. Nationally, however, maternal and child health disparities persist along a rural-urban divide. Research is needed among rural populations to better understand local barriers to health care access and usage.

Birth mode and infectious morbidity risks in Qom children of Argentina.

Objectives: Cesarean delivery may increase childhood infectious morbidity risks via altered birth exposures and subsequent immune, microbial, and epigenetic development. Many Latin American indigenous populations experience dual burdens of infectious and chronic diseases, and are particularly vulnerable to rising rates of cesarean delivery and associated adverse outcomes. The Qom/Toba are an indigenous population in Argentina experiencing rapid lifestyle transitions.

Variation among populations in the immune protein composition of mother's milk reflects subsistence pattern.

Lay Summary: Adaptive immune proteins in mothers' milk are more variable than innate immune proteins across populations and subsistence strategies. These results suggest that the immune defenses in milk are shaped by a mother's environment throughout her life.

Background And Objectives: Mother's milk contains immune proteins that play critical roles in protecting the infant from infection and priming the infant's developing immune system during early life.

Timing of pubertal growth and menarche in indigenous Qom girls of Argentina.

Background: Pubertal timing is in part mediated by environmental factors, with greater energy availability often associated with earlier or more rapid development. Many indigenous populations are undergoing socioeconomic change that may affect pubertal development and related health risks, necessitating fundamental longitudinal research on growth and development in these populations.

Aim: Growth velocity and time to menarche among peri-urban indigenous Qom (Toba) girls in Argentina are described.

Salivary microbiomes of indigenous Tsimane mothers and infants are distinct despite frequent premastication.

Background: Premastication, the transfer of pre-chewed food, is a common infant and young child feeding practice among the Tsimane, forager-horticulturalists living in the Bolivian Amazon. Research conducted primarily with Western populations has shown that infants harbor distinct oral microbiota from their mothers. Premastication, which is less common in these populations, may influence the colonization and maturation of infant oral microbiota, including via transmission of oral pathogens.

Conflict or congruence? Maternal and infant-centric factors associated with shorter exclusive breastfeeding durations among the Tsimane.

Six months of exclusive breastfeeding (EBF) is considered optimal for infant health, though globally most infants begin complementary feeding (CF) earlier-including among populations that practice prolonged breastfeeding. Two frameworks for understanding patterns of early CF emerge in the literature. In the first, maternal and infant needs trade-off, as "maternal-centric" factors-related to time and energy demands, reproductive investment, cultural influences, and structural barriers- favor supplanting breastfeeding with earlier and increased CF.

Fatty acid composition in the mature milk of Bolivian forager-horticulturalists: controlled comparisons with a US sample.

Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6-82 weeks).

Evidence for a peak shift in a humoral response to helminths: age profiles of IgE in the Shuar of Ecuador, the Tsimane of Bolivia, and the U.S. NHANES.

Background: The peak shift model predicts that the age-profile of a pathogen's prevalence depends upon its transmission rate, peaking earlier in populations with higher transmission and declining as partial immunity is acquired. Helminth infections are associated with increased immunoglobulin E (IgE), which may convey partial immunity and influence the peak shift. Although studies have noted peak shifts in helminths, corresponding peak shifts in total IgE have not been investigated, nor has the age-patterning been carefully examined across populations.