Lower infant mortality, higher household size, and more access to contraception reduce fertility in low- and middle-income nations

The Combined Contributions of Newborn Stress and Parenting Stress on Toddler Language Development

OBJECTIVE

To examine the longitudinal associations between newborn neurobehavioral stress signs, maternal parenting stress, and several indices of toddler language development.

STUDY DESIGN

Participants include 202 mother-infant dyads (104 girls). We measured stress signs in neonates in the hospital at least 24 hours after birth using the Neonatal Intensive Care Unit Network Neurobehavioral Scale. At 7 months, parenting stress (competence, attachment, and role restriction) was assessed using the Parenting Stress Index. At 18 months, mothers completed the Communicative Development Inventories, which measured toddler gesturing, expressive vocabulary, and receptive vocabulary. Longitudinal path modeling was used to estimate associations between neonatal stress signs, parenting stress, and toddler language, and a model was generated for each language outcome. Child sex, birth weight, and family income were included as covariates.

RESULTS

Infants who exhibited greater neurobehavioral stress signs at birth produced significantly fewer social-communicative gestures at 18 months of age. Among infants whose mothers reported low (but not high) levels of parenting stress during the first postnatal year, newborn stress signs were negatively associated with 18-month-olds' receptive vocabulary size. Neither newborn stress signs nor parenting stress were significantly related to toddler expressive vocabulary size.

CONCLUSIONS

Our findings uncover a negative association between newborn stress signs and toddler gesturing. Furthermore, our results suggest that caregiver stress and neonatal stress signs interact to predict toddler receptive vocabulary. Taken together, these results demonstrate that some neonates who exhibit increased neurobehavioral stress signs may be at heightened risk for experiencing language difficulties. These children may benefit from additional support in infancy.

Net benefit of smaller human populations to environmental integrity and individual health and wellbeing

Introduction

The global human population is still growing such that our collective enterprise is driving environmental catastrophe. Despite a decline in average population growth rate, we are still experiencing the highest annual increase of global human population size in the history of our species-averaging an additional 84 million people per year since 1990. No review to date has accumulated the available evidence describing the associations between increasing population and environmental decline, nor solutions for mitigating the problems arising.

Methods

We summarize the available evidence of the relationships between human population size and growth and environmental integrity, human prosperity and wellbeing, and climate change. We used PubMed, Google Scholar, and Web of Science to identify all relevant peer-reviewed and gray-literature sources examining the consequences of human population size and growth on the biosphere. We reviewed papers describing and quantifying the risks associated with population growth, especially relating to climate change.

Results

These risks are global in scale, such as greenhouse-gas emissions, climate disruption, pollution, loss of biodiversity, and spread of disease-all potentially catastrophic for human standards of living, health, and general wellbeing. The trends increasing the risks of global population growth are country development, demographics, maternal education, access to family planning, and child and maternal health.

Conclusion

Support for nations still going through a demographic transition is required to ensure progress occurs within planetary boundaries and promotes equity and human rights. Ensuring the wellbeing for all under this aim itself will lower population growth and further promote environmental sustainability.

Knowledge and practice of family planning among pregnant tribal women in Southern India: an observational study

BACKGROUND

There are over 700 Scheduled Tribes (ST) living in 30 Indian states. As with other indigenous groups across the world, Indian ST have some of the poorest infant and child health outcomes of any communities in India. A child born to an ST family is 19% more likely to die in the first month of life and has a 45 percent risk of dying in their first year compared with other Indian populations. Research suggests that early conception, high fertility, and low use of family planning methods are large contributors to these disparities.

METHODS

A cross sectional survey in Kannada was conducted among 303 pregnant tribal women in Mysore, India after obtaining informed consent. Univariate and multivariable analyses were carried out to determine the demographic and psychosocial factors associated with knowledge of contraceptive methods using Stata 14.0.

RESULTS

There was widespread knowledge about female sterilization, while only 39.3% of women reported hearing about one or more forms of temporary contraception, and 36.3% knew where to get them. The largest proportion of women had heard about copper-T (33.0%), followed by oral contraceptive pills (23.8%), condoms (11.9%), and injectables (4.6%). Only 2.7% of women reported ever using any form of temporary contraception. Results from the multivariable logistic regression indicated that knowledge of at least one form of temporary contraception was linked to higher age (adjusted odds ratio[AOR]: 1.09; 95% CI: 1.02, 1.17), greater number of years of marriage (AOR: 0.90; 95% CI: 0.85, 0.96), and last birth in a government facility (AOR: 3.67; 95% CI: 1.99, 6.82).

CONCLUSIONS

The study revealed poor knowledge and utilization of temporary contraceptive methods among a tribal population in rural Mysore, India. Interventions aiming to increase knowledge of contraceptive options are important for birth spacing in this population and should target younger women and those without contact with government health facilities.

An evolutionary perspective on social inequality and health disparities: Insights from the producer-scrounger game

There is growing concern with social disparities in health, whether relating to gender, ethnicity, caste, socio-economic position or other axes of inequality. Despite addressing inequality, evolutionary biologists have had surprisingly little to say on why human societies are prone to demonstrating exploitation. This article builds on a recent book, 'The Metabolic Ghetto', describing an overarching evolutionary framework for studying all forms of social inequality involving exploitation. The dynamic 'producer-scrounger' game, developed to model social foraging, assumes that some members of a social group produce food, and that others scrounge from them. An evolutionary stable strategy emerges when neither producers nor scroungers can increase their Darwinian fitness by changing strategy. This approach puts food systems central to all forms of human inequality, and provides a valuable lens through which to consider different forms of gender inequality, socio-economic inequality and racial/caste discrimination. Individuals that routinely adopt producer or scrounger tactics may develop divergent phenotypes. This approach can be linked with life history theory to understand how social dynamics drive health disparities. The framework differs from previous evolutionary perspectives on inequality, by focussing on the exploitation of foraging effort rather than inequality in ecological resources themselves. Health inequalities emerge where scroungers acquire different forms of power over producers, driving increasing exploitation. In racialized societies, symbolic categorization is used to systematically assign some individuals to low-rank producer roles, embedding exploitation in society. Efforts to reduce health inequalities must address the whole of society, altering producer-scrounger dynamics rather than simply targeting resources at exploited groups.