Early childhood nutrition, education and fertility milestones in Guatemala

Age at childbirth and change in BMI across the life-course: evidence from the INCAP Longitudinal Study

Background

Parity has been associated with both short- and long-term weight gain in women. However, it is not clear if timing of parity across the reproductive age has different associations with BMI.

Methods

To prospectively assess the association between age at childbirth and maternal change in BMI, we analyzed data from the ongoing INCAP Longitudinal Study, which started in 1969 in four villages in Guatemala. Cohort women (n=778) provided information on reproductive history and anthropometric measures were measured in 1988-89 (adolescence, 15 to 25y), 2002-04 (early adulthood, 26 to 36y) and 2015-17 (mid adulthood, 37 to 55y). We evaluated the associations of number of live births in the period preceding each study wave (1969-77 to 1988-89, 1988-89 to 2002-04 and 2002-04 to 2015-17) with BMI change in the same period using multivariable linear regression models.

Results

Number of live births between 1988 and 89 and 2002-04 was positively associated with increased BMI, while there was not an association between number of live births and BMI in the other intervals. Women who had one, two, or three or more children between 1988 and 89 and 2002-04 had 0.90 (kg/m², 95% CI: -0.55, 2.35), 2.39 (kg/m², 95% CI: 1.09, 3.70) and 2.54 (kg/m², 95% CI: 1.26, 3.82) higher BMI, respectively, than women who did not give birth in the same period.

Conclusions

Our findings suggest that women who had three or more children during early adulthood gained more weight compared to women who had no children in the same period. In contrast, women who had children earlier or later in their reproductive lives did not gain additional weight compared to those who did not have children during that period. Childbirth may have different associations with BMI based on the mother’s age.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04485-6.

Twenty-three-year demographic history of the Affenberg Japanese macaques (Macaca fuscata), a translocated semi-free-ranging group in southern Austria

Demographic studies on translocated primate groups provide a unique opportunity to study population dynamics, social strategies, and reproductive parameters of a species adapting to new environments. In 1996, 38 Japanese macaques (Macaca fuscata) of the Minoo-H group (Osaka Prefecture, Japan) were translocated to Affenberg Landskron, a four-hectare naturally forested park in southern Austria. By January 2020, the population had increased to 160 individuals, and a total of 223 births were recorded. Births peaked in late April to late May, and the timing was influenced by neither offspring sex nor parity status of the mother. Infant mortality was low (8.97%), mostly involving primiparous females, and the average interbirth intervals were shorter following the death of an infant (1.10 years) than a surviving infant (1.77 years). Females rarely had offspring with the same males repeatedly, and the reproductive success among males declined with increasing years of presence in the group. The main aspects of reproduction, mortality, and mate choice are consistent with published data on natural and provisioned populations in Japan and those translocated to other countries. The life expectancy for females, however, was relatively high (11.72% chance of reaching the age of 20), whereas birth control prevented them from using their lifetime reproductive potential. By January 2020, the number of old individuals (> 18 years; 17.5%) was close to that of juveniles (< 4 years; 22.5%). The specific group composition, along with the inability of males to emigrate out of their natal group, may affect the social dynamics of the population, which merits further attention in future studies.

Socio-Ecological Challenges as Modulators of Women's Reproductive Trajectories

Amenorrhea, anovulatory cycles, miscarriages, and other reproductive outcomes are often seen as pathological. Life history theory, in contrast, treats those outcomes as adaptations that helped women optimize the timing of reproductive ventures across our evolutionary history. Women's bodies adjust their reproductive strategies in response to socio-ecological conditions, a process mediated by the hypothalamic-pituitary-adrenal axis (HPAA). Here, we review the links between socio-ecological conditions, HPAA activity, and the pace of women's reproductive transitions such as puberty, age at first birth, interbirth interval, and perimenopause. We also discuss the HPAA's role as a modulator of reproductive function: It not only suppresses it but may also prime women's bodies for future reproductive ventures. We conclude by reviewing challenges and opportunities within our subfield, including the need for transdisciplinary teams to develop longitudinal studies to improve our understanding of women's reproductive trajectories and outcomes from the moment they are conceived.

Human reproduction and health: an evolutionary perspective

According to life history theory, increased investment in reproductive function (physiology and behaviour) at different times throughout the life course affects the risk of many diseases and, ultimately, longevity. Although genetic factors contribute to interindividual and interpopulation variation in reproductive traits, the dominant source of variability is phenotypic plasticity during development and adult life. Reproductive traits in both sexes evolved sensitivity to ecological conditions, as reflected in contemporary associations of hormone concentrations with geographical setting, nutritional status, and physical activity level. Lifetime exposure to increased concentrations of sex hormones is associated with the risk of some cancers, hence decreasing fertility patterns contribute to secular increases in their incidence. Conversely, increased investment in reproductive function might compromise somatic investment in health, such that faster sexual maturation and higher parity increases risk of diabetes and cardiovascular disease. An evolutionary perspective on reproductive biology could improve the efficacy of public health efforts to reduce the risk of hormone-sensitive cancers and other non-communicable diseases.

Developmental influences on fertility decisions by women: an evolutionary perspective

Developmental environments are crucial for shaping our life course. Elements of the early social and biological environments have been consistently associated with reproduction in humans. To date, a strong focus has been on the relationship between early stress, earlier menarche and first child birth in women. These associations, found predominately in high-income countries, have been usefully interpreted within life-history theory frameworks. Fertility, on the other hand--a missing link between an individual's early environment, reproductive strategy and fitness--has received little attention. Here, we synthesize this literature by examining the associations between early adversity, age at menarche and fertility and fecundity in women. We examine the evidence that potential mechanisms such as birth weight, childhood body composition, risky health behaviours and developmental influences on attractiveness link the early environment and fecundity and fertility. The evidence that menarche is associated with fertility and fecundity is good. Currently, owing to the small number of correlational studies and mixed methodologies, the evidence that early adversity predicts fecundity and fertility is not conclusive. This area of research is in its infancy; studies examining early adversity and adult fertility decisions that can also examine likely biological, social and psychological pathways present opportunities for future fertility research.

Female Literacy Rate is a Better Predictor of Birth Rate and Infant Mortality Rate in India

BACKGROUND

Educated women are known to take informed reproductive and healthcare decisions. These result in population stabilization and better infant care reflected by lower birth rates and infant mortality rates (IMRs), respectively.

MATERIALS AND METHODS

Our objective was to study the relationship of male and female literacy rates with crude birth rates (CBRs) and IMRs of the states and union territories (UTs) of India. The data were analyzed using linear regression. CBR and IMR were taken as the dependent variables; while the overall literacy rates, male, and female literacy rates were the independent variables.

RESULTS

CBRs were inversely related to literacy rates (slope parameter = -0.402, P < 0.001). On multiple linear regression with male and female literacy rates, a significant inverse relationship emerged between female literacy rate and CBR (slope = -0.363, P < 0.001), while male literacy rate was not significantly related to CBR (P = 0.674). IMR of the states were also inversely related to their literacy rates (slope = -1.254, P < 0.001). Multiple linear regression revealed a significant inverse relationship between IMR and female literacy (slope = -0.816, P = 0.031), whereas male literacy rate was not significantly related (P = 0.630).

CONCLUSION

Female literacy is relatively highly important for both population stabilization and better infant health.

Food insecurity and age at menarche among adolescent girls in Jimma Zone Southwest Ethiopia: a longitudinal study

BACKGROUND

Age at menarche is the reflection of cumulative pre-adolescent exposure of girls to either adverse environment such as food insecurity or affluent living conditions. Food insecurity could result in inadequate nutrient intake and stress, both of which are hypothesized to have opposing effects on the timing of menarche through divergent pathways. It is not known whether food insecure girls have delayed menarche or early menarche compared with their food secure peers. In this study we test the competing hypothesis of the relationship between food insecurity and age at menarche among adolescent girls in the Southwest Ethiopia.

METHODS

We report on 900 girls who were investigated in the first two rounds of the five year longitudinal survey. The semi-parametric frailty model was fitted to determine the effect of adolescent food insecurity on time to menarche after adjusting for socio-demographic and economic variables.

RESULTS

Food insecure girls have menarche one year later than their food secure peer (median age of 15 years vs 14 years). The hazard of menarche showed a significant decline (P = 0.019) as severity of food insecurity level increased, the hazard ratio (HR) for mild food insecurity and moderate/severe food insecurity were 0.936 and 0.496, respectively compared to food secure girls. Stunted girls had menarche nearly one year later than their non-stunted peers (HR = 0.551, P < 0.001).

CONCLUSION

Food insecurity is associated with delay of age at menarche by one year among girls in the study area. Stunted girls had menarche one year later than their non-stunted peers. Age at menarche reflects the development of girls including the timing of sexual maturation, nutritional status and trajectory of growth during the pre-pubertal periods. The findings reflect the consequence of chronic food insecurity on the development and well-being of girls in the study area.

Childhood nutrition and later fertility: pathways through education and pre-pregnant nutritional status

Better childhood nutrition is associated with earlier physical maturation during adolescence and increased schooling attainment. However, as earlier onset of puberty and increased schooling can have opposing effects on fertility, the net effect of improvements in childhood nutrition on a woman's fertility are uncertain. Using path analysis, we estimate the strength of the pathways between childhood growth and subsequent fertility outcomes in Guatemalan women studied prospectively since birth. Height for age z score at 24 months was positively related to body mass index (BMI kg/m2) and height (cm) in adolescence and to schooling attainment. BMI was negatively associated (-0.23 +/- 0.09 years per kg/m2; p < .05) and schooling was positively associated (0.38 +/- 0.06 years per grade; p < .001) with age at first birth. Total associations with the number of children born were positive from BMI (0.07 +/- 0.02 per kg/m2; p < .05) and negative from schooling (-0.18 +/- 0.02 per grade; p < .01). Height was not related to age at first birth or the number of children born. Taken together, childhood nutrition, as reflected by height at 2 years, was positively associated with delayed age at first birth and fewer children born. If schooling is available for girls, increased growth during childhood will most likely result in a net decrease infertility.

Diet, nutrition, and the life-course approach to cancer prevention

Cancer results from the interaction of genetic susceptibility and environmental exposures. The diagnosis of cancer is age related; there is a marked increase in cancer incidence after the reproductive years. Nutrient and toxicant exposures are important contributors to the risk of some cancers. Nutrition, as a determinant of growth and body composition, also influences cancer risk, directly due to carcinogens in foods or indirectly by the hormonal and metabolic response to growth and obesity. There is strong evidence that obesity and rapid growth enhance the risk of cancer. The prevention of cancer should start before conception; mothers should start pregnancy with a healthy weight and avoid excessive or low weight gain during pregnancy. Key micronutrients are important for normal embryonic development and fetal growth. Infant growth should be assessed based on optimal health across all stages of the life course, rather than following the present approach of "bigger is better. " This model may increase cancer risk in later life, because bigger is closely linked to fatter. Recent studies of energy expenditure in children indicate that excess energy intakes may have been recommended over the past decades, contributing to the surge in global obesity. Food preferences and habits regarding physical activity and play become set relatively early in life; parents and teachers provide key guidance leading to the adoption of a healthy or an unhealthy lifestyle. Thus, cancer prevention efforts should begin with childhood and continue through all stages of the life course.

Rationale for a follow-up study focusing on economic productivity

Past studies of nutrition, human capital formation, and economic productivity have been limited by the fact that biomedical researchers and economists work largely in isolation, with loss of complementarity. Biomedical researchers are faulted for not adequately addressing bias and measurement issues and for naive analyses and interpretation of results, whereas economists are criticized for using simplistic nutrition and physiological measures and for relying on statistical methods rather than experimental designs. To avoid these problems, a multidisciplinary team of biomedical investigators and economists undertook a follow-up study in 2002-04 of a cohort of young men and women, who participated as young children in a randomized community trial of nutrition supplementation carried out from 1969-77 Previous studies, particularly the original trial and a 1988-89 follow- up, are described to provide an overview of the data available for linkage with the 2002-04 follow-up. Key results from these earlier studies are reviewed but judged inconclusive because the data used were collected when many subjects were still growing and developing physically, in school, unmarried, and/or not yet settled into occupations. The subjects were 26 to 41 years of age in 2003, permitting a more complete assessment of human capital and economic productivity. The experimental design of the 1969-77 original study, 35 years of follow-up, use of robust methods of data collection, and the participation of a multidisciplinary team will likely lead to the most comprehensive assessment to date of the importance of nutrition for economic productivity.

Fertility behavior and reproductive outcomes among young Guatemalan adults

Fertility rates have declined in many developing countries and this has implications for health and development of subsequent generations. Guatemala has the highest fertility rates in Central America. Reproductive histories were obtained by interview in 2002-04, in a cohort of 779 women and 647 men who had participated as young children in a nutrition supplementation trial in Guatemala conducted between 1969 and 1977. Most women (77%) and men (79%) are currently married. Among the 700 women and 524 men reporting at least one birth, mean age at first birth was 20.7 +/- 3.8 years and 23.1 +/- 3.9 years respectively. Knowledge (> 80%) and use (approximately 70%) of modern contraceptive methods is fairly high; knowledge increases with parental socioeconomic status (SES) as measured in 1975. Younger respondents have experienced fewer pregnancies and live births compared with older respondents; age-specific fertility rates between 20 and 24 years were 294, 249, 236, and 261 births per 1,000 women, respectively, for women born from 1962-65, 1966-69, 1969-73, and 1974-77. Women in the top tertile of parental SES have had significantly fewer pregnancies (3.3) compared with those in the middle (3.7) and lower (3.8) tertiles. Migrants to Guatemala City reported greater knowledge of contraceptive methods, fewer pregnancies and living children, higher age at first birth, and more pregnancy and newborn complications as compared with cohort members who remained in the original villages (p < .05 for each comparison). Fertility rates, especially between 20 and 24 years, have declined over time. Differences in reproductive behaviors by parental SES and current residence suggest the role of social transitions in determining family formation in Guatemala.

Childhood exposure to the 1944–1945 Dutch famine and subsequent female reproductive function

BACKGROUND

Childhood caloric restriction may lead to permanent changes in the hypothalamo-pituitary-gonadal axis, which could lead to impaired female reproductive ability. We assessed the effect of childhood exposure to the 1944-1945 Dutch famine on subsequent female reproductive function.

METHODS

This was a population-based cohort study in Utrecht, The Netherlands. Between 1983 and 1985, 6030 women born between 1932-1941 were classified by questionnaire according to their famine exposure experiences. Dates of marriage, first and second childbirth, and information on a medical reason for having no children or fewer children than wanted were available from questionnaires, as well as ages and type of menopause.

RESULTS

Severe famine exposure during childhood significantly decreased chances of first and second childbirth at any given time after marriage or first childbirth [adjusted hazard ratios (HR) 0.86, 95% confidence interval (CI) 0.76-0.96; and HR 0.87, 95% CI 0.78-0.97, respectively). Risk of a medical reason for having no or fewer children than wanted was increased in the severely exposed (odds ratio 1.88; 95% CI 1.29-2.74), as was the risk of a surgical menopause (HR 1.53; 95% CI 1.27-1.84).

CONCLUSIONS

Our findings support the presence of longstanding modest effects of childhood famine exposure on reproductive function in women.

Correlates and determinants of child anthropometrics in Latin America: background and overview of the symposium

In Latin America and the Caribbean (LAC) about one in six children under 5 years of age--or about 9 million children--suffer from longer-run undernourishment reflected in stunting. This paper introduces, places in perspective and presents a common micro analytical framework for the seven papers in this symposium that investigate the household and community determinants of child malnourishment in eight countries in LAC. These papers are the outcomes of a research project supported by the Inter-American Development Bank (IDB) Research Department Latin American and Caribbean Research Network Project on "Child Health, Poverty and the Role of Social Policies" in 2003-2004.

Effects of early childhood supplementation on the educational achievement of women

OBJECTIVE

Malnutrition during early childhood has been suggested to cause functional disadvantages in adults, including reduced intelligence and lower educational achievement (EA). We assessed the effects of improved nutrition in early life on the EA of women in 4 rural Guatemalan villages.

METHODS

The study sample comprised 130 female singletons exposed to either Atole (53%, 91 kcal and 6.4 g protein/100 mL) or Fresco (47%, 33 kcal/100 mL, no protein) during the prenatal period and the first 2 years of life. EA was assessed at the ages of 22 to 29 years by knowledge, numeracy, and several reading tests. A summary measure of EA was computed based on 5 tests, and outcome variables were categorized into quintiles. Analysis was based on a proportional odds model. Generalized estimating equations were used to account for sibling clustering.

RESULTS

Overall, 36.2% of women completed primary school. Women exposed to Atole had better EA than those exposed to Fresco (odds ratio [OR]: 2.8; 95% confidence interval [CI], 1.4, 5.4), with a significant treatment-by-schooling interaction. Atole was not associated with EA (OR: 1.5; 95% CI: 0.7, 3.2) among women who did not complete primary school, whereas among those who completed primary school, Atole was associated with improved EA (OR: 13.7; 95% CI: 3.7, 50.8).

CONCLUSIONS

We conclude that better nutrition during early childhood improved adult EA, but only among children who completed primary school.