Teen motherhood in cross-cultural perspective

Mean age at menarche and climate variables on a global scale

OBJECTIVES

Cross-population variation in age at menarche is related to many factors. The purpose of this study was to examine climate variables in relation to mean age at menarche among 87 modern human populations. We hypothesized a later age at menarche among populations living in areas with high precipitation variability, heavy seasonal rainfall, and high temperatures year-round due to water-borne diseases and periods of resource scarcity.

METHODS

Using a comparative dataset, we examined geospatial distribution and climate variables in relation to age at menarche for 87 modern human populations.

RESULTS

We found the strongest predictor of a later age at menarche was higher fertility followed by a later mean age at death. In addition, higher annual rainfall, higher precipitation seasonality, and lower annual mean temperature were moderate predictors of age at menarche.

CONCLUSIONS

We propose that later ages at menarche in countries with high fertility may be a life-history strategy developed in response to climatic conditions that have resulted in higher immunological load. In these conditions, females may prioritize growth rather than reproduction. Shifts in climate and global population growth may change the future biological landscape of age at menarche.

Sexual minority status is associated with earlier recalled age of menarche: Evidence from the 2005-2016 National Health and Nutrition Examination Survey

INTRODUCTION

Menarcheal timing is associated with growth, development, health, wellbeing, and reproduction across the lifespan. Although sexual orientation is a known correlate of health and developmental inequities, relatively little evolutionarily framed research has investigated sexual orientation-based variation in maturational timing. To improve our understanding of menarcheal timing among sexual minority (SM) people, we use a biocultural-evolutionary life history lens that takes into account the stresses of minoritization to examine the relationship between sexual orientation and self-reported age at menarche in a sample of American adults.

METHODS

Using the U.S. National Health and Nutrition Examination Survey (NHANES), a large, nationally representative dataset (n = 9757), we fit multiple logistic regression models and survival curves to evaluate associations between sexual orientation, indicators of somatic and material resources during adolescence (e.g., education, citizenship, upper arm length), and self-reported menarche.

RESULTS

SM respondents were more likely to report earlier (by 4-5 months) ages of menarche (p < .001). Post-hoc tests revealed that these differences were driven by bisexual (p < .001) and same-sex experienced (p < .001) relative to heterosexual and lesbian/gay respondents. Earlier menarcheal timing among SM respondents persisted after adjusting for socio-demographic factors and proxies of developmental conditions.

DISCUSSION

Our findings reveal that SM status is associated with earlier ages of menarche, an important social and reproductive milestone. We argue that uniting life history theory with the minority stress hypothesis better explains differences in menarcheal timing by sexual orientation than previous paradigms. Investigators should attend to sexual orientation-based variation in maturational timing using holistic, inclusive approaches.

The impact of market integration on arranged marriages in Matlab, Bangladesh

Success in marriage markets has lasting impacts on women's wellbeing. By arranging marriages, parents exert financial and social powers to influence spouse characteristics and ensure optimal marriages. While arranging marriages is a major focus of parental investment, marriage decisions are also a source of conflict between parents and daughters in which parents often have more power. The process of market integration may alter parental investment strategies, however, increasing children's bargaining power and reducing parents' influence over children's marriage decisions. We use data from a market integrating region of Bangladesh to (a) describe temporal changes in marriage types, (b) identify which women enter arranged marriages and (c) determine how market integration affects patterns of arranged marriage. Most women's marriages were arranged, with love marriages more recent. We found few predictors of who entered arranged vs. love marriages, and family-level market integration did not predict marriage type at the individual level. However, based on descriptive findings, and findings relating women's and fathers' education to groom characteristics, we argue that at the society-level market integration has opened a novel path in which daughters use their own status, gained via parental investments, to facilitate good marriages under conditions of reduced parental assistance or control.

Fertility Dynamics and Life History Tactics Vary by Socioeconomic Position in a Transitioning Cohort of Postreproductive Chilean Women

Globally, mortality and fertility rates generally fall as resource abundance increases. This pattern represents an evolutionary paradox insofar as resource-rich ecological contexts can support higher numbers of offspring, a component of biological fitness. This paradox has not been resolved, in part because the relationships between fertility, life history strategies, reproductive behavior, and socioeconomic conditions are complex and cultural-historically contingent. We aim to understand how we might make sense of this paradox in the specific context of late-twentieth-century, mid–demographic transition Chile. We use distribution-specific generalized linear models to analyze associations between fertility-related life-history traits—number of offspring, ages at first and last reproduction, average interbirth interval, and average number of live births per reproductive span year—and socioeconomic position (SEP) using data from a cohort of 6,802 Chilean women born between 1961 and 1970. We show that Chilean women of higher SEP have shorter average interbirth intervals, more births per reproductive span year, later age at first reproduction, earlier ages at last reproduction, and, ultimately, fewer children than women of lower SEP. Chilean women of higher SEP consolidate childbearing over a relatively short time span in the middle of their reproductive careers, whereas women of lower SEP tend to reproduce over the entirety of their reproductive lifespans. These patterns may indicate that different SEP groups follow different pathways toward declining fertility during the demographic transition, reflecting different life-history trade-offs in the process.

Maternal age at marriage and child nutritional status and development: evidence from Serbian Roma communities

OBJECTIVE

This study aimed to assess whether maternal age at first marriage is associated with nutritional and developmental penalties in Roma children.

DESIGN

Roma nationally representative population-based study. Proxies for child nutritional outcomes included children's individual-level height-for-age z (HAZ) and weight-for-age z (WAZ) scores, HAZ and WAZ scores below two standard deviations from the median of WHO's reference population (children aged 0-59 months), and Early Child Development (children aged 36-59 months). Multiple and logistic regressions were used to estimate the association between maternal age at marriage and the outcomes, and other sociodemographic determinants as possible confounders.

SETTING

Aggregated data from UNICEF's fifth and sixth Multiple Indicator Cluster Surveys for Serbian Roma settlements.

SUBJECTS

Children (n= 2652) aged 0-59 months born to ever-married women aged 15-48.

RESULTS

64% of women married before age 18, 19% of children were stunted, 9% wasted, and Early Child Development score was low. Maternal age at first marriage was not associated with either nutritional status or early development of Roma children. Weight at birth (children aged 0-24) emerged as the main predictor of children's nutritional status. Boys were more likely to be shorter, more stunted and wasted than girls. Child's age, maternal parity and unimproved toilet facility negatively impacted nutritional status, while maternal literacy mitigated against poor nutritional and developmental outcomes.

CONCLUSIONS

Roma children up to 5 years of age bear no negative consequences of maternal early marriage. The underlying determinants of children's wellbeing include improved sanitation, child characteristics, maternal literacy and reproductive behavior, and parental investment.

Placental Iron Content Is Lower than Previously Estimated and Is Associated with Maternal Iron Status in Women at Greater Risk of Gestational Iron Deficiency and Anemia

BACKGROUND

Based on limited data, it is estimated that the placenta retains 90 mg of iron. Little is known about determinants of placental iron content. Animal data indicate that the placenta prioritizes iron for its own needs, but this hypothesis has not been evaluated in humans.

OBJECTIVES

To characterize placental iron content and placental iron concentration (p[Fe]) in pregnant women at risk of iron insufficiency and identify determinants of p[Fe].

METHODS

Placentas were collected from 132 neonates born to teens carrying singletons (≤18 y) and 101 neonates born to 48 women carrying multiples (20-46 y). Maternal and neonatal iron status indicators [hemoglobin, serum ferritin (SF), soluble transferrin receptor (sTfR), serum iron, total body iron (TBI)] and hormones (erythropoietin, hepcidin) were measured. p[Fe] was measured using inductively coupled plasma-mass spectrometry. Correlation analyses and mixed-effects models were constructed to identify determinants of p[Fe].

RESULTS

Mean placental iron content was 23 mg per placenta (95% CI: 15, 33 mg) in the multiples and 40 mg (95% CI: 31, 51 mg) in the teens (P = 0.03). Mean p[Fe] did not differ between the cohorts. p[Fe] was higher in anemic (175 μg/g; 95% CI: 120, 254 μg/g) compared with nonanemic (46 μg/g; 95% CI: 26, 82 μg/g) women carrying multiples (P = 0.009), but did not differ between anemic (62 μg/g; 95% CI: 40, 102 μg/g) and nonanemic (73 μg/g; 95% CI: 56, 97 μg/g) teens. In women carrying multiples, low maternal iron status [lower SF (P = 0.002) and lower TBI (P = 0.01)] was associated with higher p[Fe], whereas in teens, improved iron status [lower sTfR (P = 0.03) and higher TBI (P = 0.03)] was associated with higher p[Fe].

CONCLUSIONS

Placental iron content was ∼50% lower than previously estimated. p[Fe] is significantly associated with maternal iron status. In women carrying multiples, poor maternal iron status was associated with higher p[Fe], whereas in teens, improved iron status was associated with higher p[Fe]. More data are needed to understand determinants of p[Fe] and the variable iron partitioning in teens compared with mature women.

Sex differences in adipose development in a hunter-gatherer population

OBJECTIVE

Humans are unusually sexually dimorphic in body composition, with adult females having on average nearly twice the fat mass as males. The development of adipose sex differences has been well characterized for children growing up in food-abundant environments, with less known about cross-cultural variation, particularly in populations without exposure to market foods, mechanized technologies, schooling, vaccination, or other medical interventions.

METHODS

To add to the existing cross-cultural data, we fit multiple growth curves to body composition and anthropometric data to describe adipose development for the Savanna Pumé, South American hunter-gatherers.

RESULTS

(1) Little evidence is found for an adiposity 'rebound' at the end of early childhood among either Savanna Pumé girls or boys. (2) Rather, fat deposition fluctuates during childhood, from age ~4 to ~9 years, with no appreciable accumulation until the onset of puberty, a pattern also observed among Congo Baka hunter-gatherers. (3) Body fat fluctuations are more pronounced for girls than boys. (4) The age of peak skeletal, weight, and adipose gains are staggered to a much greater extent among the Savanna Pumé compared to the National Health and Nutrition Examination Survey (NHANES III) reference, suggesting this is an important developmental strategy in lean populations.

CONCLUSION

Documenting growth patterns under diverse preindustrial energetic conditions provides an important baseline for understanding sex differences in body fat emerging today under food abundance.

Does Nubility Indicate More Than High Reproductive Value? Nubile Primiparas' Pregnancy Outcomes in Evolutionary Perspective

The idea that human males are most strongly attracted to traits that peak in women in the nubile age group raises the question of how well women in that age group contend with the potential hazards of a first pregnancy. Using data for 1.7 million first births from 1990 U.S. natality and mortality records, we compared outcomes for women with first births (primiparas) aged 16-20 years (when first births typically occur in forager and subsistence groups) with those aged 21-25 years. The younger primiparas had a much lower risk of potentially life-threatening complications of labor and delivery and, when evolutionarily novel risk factors were controlled, fetuses which were significantly more likely to survive despite lower birth weights. Thus, nubile primiparas were more likely to have a successful reproductive outcome defined in an evolutionarily relevant way (an infant of normal birth weight and gestation, surviving to one year, and delivered without a medically necessary cesarean delivery). This suggests that prior to the widespread availability of surgical deliveries, men who mated with women in the nubile age group would have reaped the benefit of having a reproductive partner more likely to have a successful first pregnancy.

Married Too Young? The Behavioral Ecology of ‘Child Marriage’

For girls and women, marriage under 18 years is commonplace in many low-income nations today and was culturally widespread historically. Global health campaigns refer to marriage below this threshold as ‘child marriage’ and increasingly aim for its universal eradication, citing its apparent negative wellbeing consequences. Here, we outline and evaluate four alternative hypotheses for the persistence of early marriage, despite its associations with poor wellbeing, arising from the theoretical framework of human behavioral ecology. First, early marriage may be adaptive (e.g., it maximizes reproductive success), even if detrimental to wellbeing, when life expectancy is short. Second, parent–offspring conflict may explain early marriage, with parents profiting economically at the expense of their daughter’s best interests. Third, early marriage may be explained by intergenerational conflict, whereby girls marry young to emancipate themselves from continued labor within natal households. Finally, both daughters and parents from relatively disadvantaged backgrounds favor early marriage as a ‘best of a bad job strategy’ when it represents the best option given a lack of feasible alternatives. The explanatory power of each hypothesis is context-dependent, highlighting the complex drivers of life history transitions and reinforcing the need for context-specific policies addressing the vulnerabilities of adolescence worldwide.

Postpartum amenorrhea duration by sex of the newborn in two natural fertility populations

OBJECTIVES

Postpartum amenorrhea (PA) affects the length of interbirth intervals and thus is intimately related to human life history strategies. PA duration appears to be influenced by maternal energetic status. In humans, as in other mammals, sons are costlier than daughters. Thus, we hypothesize that, in energetically constrained environments, a newborn's sex should be associated with PA duration.

METHODS

We analyzed data from two natural fertility populations in which mothers have differing energy budgets: Qom women (n = 121) from a periurban village in Argentina, who have a comparatively calorically dense diet and are sedentary (prepregnancy mean BMI = 24.8 ± 4.5 kg/m² in 1997), and agropastoral Kaqchikel Maya women (n = 88), who have a comparatively calorically restricted diet and high physical activity levels (mean BMI = 21.8 ± 3.7 kg/m² ). We predict that (a) mothers of sons exhibit longer PA duration than mothers of daughters and (b) this association between offspring sex and PA duration is stronger in the Maya, who have smaller energy budgets.

RESULTS

Maya mothers with sons exhibited estimated mean and median PA durations that were 1.34 times the estimated mean and median PA duration of mothers with daughters (p = 0.02). Among the Qom, mean, and median PA duration did not differ significantly in relation to offspring sex (p = 0.94).

CONCLUSIONS

Maya mothers with sons exhibited longer PA duration than those with daughters. This phenomenon was not observed in the well-nourished Qom, possibly due to "buffering" effects from larger energy budgets. Offspring sex may influence birth spacing and maternal life history strategies in energetically constrained environments.

What does the American public know about child marriage?

Global efforts to eradicate ‘child marriage’ (<18 years) increasingly target governments, the private sector and the general public as agents of change. However, understanding of child marriage may be subject to popular misconceptions, particularly because of ambiguity in the age threshold implied by the term ‘child’, and because awareness campaigns routinely emphasize extreme scenarios of very young girls forcibly married to much older men. Here, we ascertain public knowledge of child marriage via an online survey. Half of those surveyed mistakenly believed that the cut-off for child marriage is younger than the threshold of 18 years, and nearly three-quarters incorrectly believed that most child marriages occur at 15 years or below (it primarily occurs in later adolescence). Most participants also incorrectly believed that child marriage is illegal throughout the USA (it’s illegal in only 4/50 states), substantially overestimated its global prevalence, and mistakenly believed that it primarily takes place among Muslim-majority world regions. Our results highlight important popular misconceptions of child marriage that may ultimately undermine global health goals and perpetuate harmful stereotypes. Organizations seeking to empower women by reducing child marriage should be cautious of these misunderstandings, and wary of the potential for their own activities to seed misinformation.

The adverse maternal and perinatal outcomes of adolescent pregnancy: a cross sectional study in Hebei, China

Background

The adverse pregnancy outcomes caused by teenage pregnancy are major public health problems with significant social impact. While China is the most populous country in the world, and 8.5% of the women aged 10–50 years are adolescent women, we aimed to analyze the adverse maternal and perinatal outcomes of the adolescent pregnancy in Hebei Province, China.

Methods

There were 238,598 singleton pregnant women aged 10–34 years from January 1, 2013 to December 31, 2017 in the database of Hebei Province Maternal Near Miss Surveillance System (HBMNMSS). The 238,598 pregnant women were divided into two groups: adolescent group (aged 10–19 years) and adult group (aged 20–34 years). The adolescent group was divided into two subgroups (aged 10–17 years, aged 18–19 years), the adult group was divided into two subgroups (aged 20–24 years, aged 25–34 years). We compared the risk of adverse pregnancy outcomes using univariate and multivariate logistic regression. We also made a stratified analysis of nulliparous and multiparous adolescent pregnancy.

Results

Compared with women aged 20–34 years, women aged 10–19 years had lower risk of cesarean delivery [adjusted risk ratio (aRR): 0.75, 95% confidence interval (CI): 0.70–0.80], gestational diabetes mellitus (GDM) (aRR: 0.55, 95%CI: 0.41–0.73). Women aged 10–19 years had higher risk of preterm delivery (aRR: 1.76, 95%CI: 1.54–2.01), small for gestational age (SGA) (aRR: 1.19, 95%CI: 1.08–1.30), stillbirth (aRR: 2.58, 95%CI: 1.83–3.62), neonatal death (aRR: 2.63, 95%CI: 1.60–4.32). The adolescent women aged 10–17 years had significantly higher risk of stillbirth (aRR: 5.69, 95%CI: 3.36–9.65) and neonatal death (aRR: 7.57, 95%CI: 3.74–15.33) compared with the women aged 25–34 years. Younger adults (20–24 years) also had higher risks of preterm delivery (aRR: 1.26, 95%CI: 1.20–1.32), stillbirth (aRR: 1.45, 95%CI: 1.23–1.72), and neonatal death (aRR: 1.51, 95%CI: 1.21–1.90) compared with women aged 25–34 years. The structural equation model showed that preterm delivery and cesarean delivery had an indirect effect on neonatal death in adolescent pregnancy.

Conclusions

The adolescent pregnancy was related to adverse perinatal (fetal and neonatal) outcomes, such as preterm delivery, stillbirth and neonatal death, especially in younger adolescent pregnancies.

Deprivation and mortality related to pediatric respiratory tract infection: a cohort study in 3 high-income jurisdictions

BACKGROUND

Deaths from respiratory tract infections (RTIs) in children are preventable through timely access to public health and medical interventions. We aimed to assess whether socioeconomic disparities in mortality related to pediatric RTI persisted after accounting for health status at birth.

METHODS

We compared the prevalence of and risk factors for RTI-related death in singletons aged 28 days to 4 years across Ontario (Canada), Scotland and England (jurisdictions with universal health care) using linked administrative data for 2003-2013. We estimated rates of RTI-related mortality for children living in deprived areas and those born to teenage girls; we estimated both crude rates and those adjusted for health status at birth.

RESULTS

A total of 1 299 240 (Ontario), 547 556 (Scotland) and 3 910 401 (England) children were included in the study. Across all jurisdictions, children born in the most deprived areas experienced the highest rates of RTI-related mortality. After adjustment for high-risk chronic conditions and prematurity, we observed differences in mortality according to area-level deprivation in Ontario and England but not in Scotland. In Ontario, teenage motherhood was also an independent risk factor for RTI-related mortality.

INTERPRETATION

Socioeconomic disparities played a substantial role in child mortality related to RTI in all 3 jurisdictions. Context-specific investigations around the mechanisms of this increased risk and development of programs to address socioeconomic disparities are needed.

Sociodemographic Determinants of Preterm Birth and Small for Gestational Age in Rural West Bengal, India

Preterm birth and small for gestational age (SGA) are major contributors to neonatal mortality in India. However, social determinates of preterm births and SGA are poorly characterized. We use population-based data from a health and demographic surveillance system (HDSS) in rural West Bengal, India, to examine risk factors for preterm birth and SGA. HDSS pregnancy cohort data for 2430 pregnant women were used in this analysis. Of 2430 pregnancies, 16% were preterm births and 38.2% were SGA. Results from logistic regression reveal that higher maternal education (≥11 years) was associated with reduced risk of preterm births and SGA. Greater wealth quintile was also associated with decreased risk of preterm births and SGA (p-value for trend: <0.05). In light of the findings, ensuring effective coverage of preterm and SGA interventions among women of low socioeconomic status will be essential to mitigate the large burden of preterm births and SGA.

Maternal hyperuricemia superimposed on maternal hypertension aggravates the risk of small-for-gestational-age fetus

AIMS

Small-for-gestational-age (SGA) fetus is an important public health issue because of its high mortality and long-term effects on health. Maternal hyperuricemia is associated with diverse adverse pregnant outcomes and neonatal disturbance. We aimed to evaluate whether maternal hyper-uric acid (HUA) is associated with the risk of SGA fetus and to explore whether it can modify the association between maternal hyper-blood pressure (HBP) and SGA fetus.

MATERIALS AND METHODS

We performed a population-based cross-section retrospective study, a total of 6715 pregnant females were recruited. Multiple logistic regression analysis was performed to identify risk factors significantly correlated with SGA fetus, and then studied the effect of maternal HUA on the association between maternal HBP and SGA fetus.

KEY FINDINGS

We collected 537 SGA fetuses among 6715 pregnant females. Maternal HUA was an independent risk factor for SGA delivery (odds ratio (OR), 2.737; 95% confidence interval (CI), 2.110-3.551). A dose-response association between maternal uric acid and SGA delivery was found among normotensive and hypertensive group. Compared with those whose uric acid was lower than 270 μmo/L with normal-blood pressure (NBP), the risk for SGA delivery in those whose uric acid was higher than 370 μmo/L with stage 2 or 3 hypertension increased 12.695-fold.

SIGNIFICANCE

Our results suggest that maternal HUA could increase the risk of neonatal SGA, and maternal HUA could be superimposed upon pre-existing maternal HBP and increase the risk for SGA fetus.

Adolescent pregnancy and linear growth of infants: a birth cohort study in rural Ethiopia

BACKGROUND

Evidences indicate that the risk of linear growth faltering is higher among children born from young mothers. Although such findings have been documented in various studies, they mainly originate from cross-sectional data and demographic and health surveys which are not designed to capture the growth trajectories of the same group of children. This study aimed to assess the association between young maternal age and linear growth of infants using data from a birth cohort study in Ethiopia.

METHODS

A total of 1423 mother-infant pairs, from a birth cohort study in rural Ethiopia were included in this study. They were followed for five time points, with three months interval until the infants were 12 months old. However, the analysis was based on 1378 subjects with at least one additional follow-up measurement to the baseline. A team of data collectors including nurses collected questionnaire based data and anthropometric measurements from the dyads. We fitted linear mixed-effects model with random intercept and random slope to determine associations of young maternal age and linear growth of infants over the follow-up period after adjusting for potential confounders.

RESULTS

Overall, 27.2% of the mothers were adolescents (15-19 years) and the mean ± SD age of the mothers was 20 ± 2 years. Infant Length for Age Z score (LAZ) at birth was negatively associated with maternal age of 15-19 years (β = - 0.24, P = 0.032). However, young maternal age had no significant association with linear growth of the infants over the follow-up time (P = 0.105). Linear growth of infants was associated positively with improved maternal education and iron-folate intake during pregnancy and negatively with infant illness (P < 0.05).

CONCLUSION

Young maternal age had a significant negative association with LAZ score of infants at birth while its association over time was not influential on their linear growth. The fact that wide spread socio economic and environmental inequalities exist among mothers of all ages may have contributed to the non-significant association between young maternal age and linear growth faltering of infants. This leaves an opportunity to develop comprehensive interventions targeting for the infants to attain optimal catch-up growth.

Parent-offspring conflict unlikely to explain 'child marriage' in northwestern Tanzania

Approximately 40% of women in sub-Saharan Africa marry before their eighteenth birthday¹. Within the international development sector, this phenomenon is referred to as 'child marriage', widely equated to forced marriage, and recognized as damaging to multiple dimensions of female well-being^1,2. An escalating global campaign to end early marriage typically assumes that its high prevalence is driven by a conflict of interests between parents and daughters, with parents coercing daughters to marry early for the parents' economic benefit³. However, a parent-offspring conflict model of early marriage has not been explicitly tested. Here we present a study of marriage transitions in rural Tanzania, where marriage before or just after 18 years of age is normative. Consistent with parental coercion, we find that bridewealth transfers are highest for younger brides. However, autonomy in partner choice is very common at all ages, relationships between age at marriage and female well-being are largely equivocal, and women who marry early achieve relatively higher reproductive success. We conclude that, in contexts in which adolescents have autonomy in marriage choices and in which marriage promotes economic and social security, early marriage may be better understood as serving the strategic interests of both parents and daughters.

The problems associated with adolescent pregnancy in Romania: A cross-sectional study

RATIONALE

The extent of pregnancy in adolescents and young adults, especially in low and middle-income countries, is a source of increasing concern given its social and economic impact.

AIMS AND OBJECTIVE

We hypothesized that there would be correlations between female patients becoming pregnant at a young age and practices such as harmful alcohol misuse, cigarette smoking, and drug use, the use of toxic substances, low educational attainment, and an essential absence of health care seeking about the outcome of adolescent pregnancies.

METHODS

We performed a prospective cross-sectional study of patients who gave birth between August and November 2017 at St. Pantelimon Emergency Hospital in Bucharest, Romania. Seventy-four patients aged 14 to 20 years, with a mean maternal age of 18.07 years, were enrolled in the study and answered a 15-item questionnaire about their social, educational, and medical background.

RESULTS

Fifty-three patients (71.6%) gave birth by caesarean section and 21 (28.3%) by vaginal delivery. Notably, patients aged 14 to 16 years had a lower rate of caesarean delivery compared with those aged 17 to 20 years. Moreover, 83.0% of the caesarean sections and 76.1% of the vaginal deliveries were at term. With reference to age and type of delivery, women are more likely to give birth by caesarean section at any age group (the association is not statistically significant at P < .05), except for the age of 15 years (five out of six patients in our sample had a spontaneous birth). Smoking was the most common risk behavior in the sample (45.9%, n = 34), followed by alcohol consumption (17.5%, n = 13) and drug use (5.40%, n = 4).

CONCLUSIONS

A high percentage of caesarean delivery was reported, particularly in patients aged >17 years. The percentage of female participants who underwent a caesarean delivery for their second pregnancy was significantly higher than compared with primipara participants. Patients receiving consistent antenatal care visits compared with those who did not monitor their pregnancy did not differ in the likelihood of undergoing a caesarean section.

Influence of maternal height on children's health status and mortality: A cross-sectional study in poor Roma communities in rural Serbia

To determine possible variations in children's health status and mortality associated with variations in maternal stature, an anthropometric and demographic study was conducted in a Roma population of poor socio-economic status in rural Serbia. Data were collected during several years of anthropological fieldwork. The sample consisted of 691 women, ranging from 16 to 80 years of age. In addition to stature, Roma women's demographics, reproductive history, reproductive outcomes and health status of their children were collected. The results provide evidence of a significant association between mother's stature and their children's health and mortality, with a shorter mother's stature predisposing children to poor health and survival outcomes. The findings could prompt development of a definition of short stature among Roma women to evaluate the risk based on height distribution among the general Roma population.

The Association of Maternal Age With Fetal Growth and Newborn Measures: The Mumbai Maternal Nutrition Project (MMNP)

Background:

Young maternal age is associated with poorer birth outcomes, but the mechanisms are incompletely understood. Using data from a prospective cohort of pregnant women living in Mumbai slums, India, we tested whether lower maternal age was associated with adverse fetal growth.

Methods:

Fetal crown-rump length (CRL) was recorded at a median (interquartile range, IQR) of 10 weeks’ gestation (9-10 weeks). Head circumference (HC), biparietal diameter (BPD), femur length (FL), and abdominal circumference (AC) were recorded at 19 (19-20) and 29 (28-30) weeks. Newborns were measured at a median (IQR) of 2 days (1-3 days) from delivery. Gestation was assessed using prospectively collected menstrual period dates.

Results:

The sample comprised 1653 singleton fetuses without major congenital abnormalities, of whom 1360 had newborn measurements. Fetuses of younger mothers had smaller CRL (0.01 standard deviation [SD] per year of maternal age; 95% confidence interval CI: 0.00-0.02¹; P = .04), and smaller HC, FL, and AC at subsequent visits. Fetal growth of HC (0.04 cm; 95% CI: 0.02-0.05; P < .001), BPD (0.01 cm; 95% CI: 0.00-0.01; P = .009), FL (0.04 cm; 95% CI: 0.02-0.06; P < .001), and AC (0.01 cm; 95% CI: 0.00-0.01; P = .003) up to the third trimester increased with maternal age. Skinfolds, head, and mid-upper arm circumferences were smaller in newborns of younger mothers. Adjusting for maternal prepregnancy socioeconomic status, body mass index, height, and parity attenuated the associations between maternal age and newborn size but did not change those with fetal biometry.

Conclusion:

Fetuses of younger mothers were smaller from the first trimester onward and grew slower, independently of known confounding factors.

Relationship between menarche and fertility in long-tailed macaques (Macaca fascicularis)

We attempted to elucidate female reproduction in long-tailed macaques (Macaca fascicularis). These monkeys have a non-seasonal menstruation cycle, which makes them suitable subjects for studies in a variety fields including medical science and regenerative medicine. We analyzed individual breeding data including time of menarche, start of regular menstruation, and first pregnancy. These three events are related to the maturation of female long-tailed macaques. All research subjects were female long-tailed macaques bred at the Tsukuba Primate Research Center. The study comprised 45 females; we included time of menstruation, male-female cohabitation, and first pregnancy in their growth records. We extracted age and weight data relating to menarche, start of regular menstruation, and first pregnancy from these records. In the two years typically required from menarche to first pregnancy, the body weight increased by approximately 500 g (21% of the weight at menarche); it is clear that there is a significant physical change after menarche. Our findings suggest that female monkeys are not necessarily mature enough for pregnancy at menarche. Therefore, the use of the word "maturity" in terms of fecundity may be more accurate after the start of regular menstruation. This is what we term "adolescence" in the developmental process. Therefore, M. fascicularis monkeys are candidates for an animal model of human adolescence.

SELF-RATED HEALTH AND TEENAGE PREGNANCIES IN ROMA WOMEN: INCREASING HEIGHT IS ASSOCIATED WITH BETTER HEALTH OUTCOMES

This paper reports on the association between early marriage, age at first reproduction and height, as an indicator of childhood environment, and maternal health outcomes among traditional Roma women in Serbia. Demographic data, marital and reproductive histories, height, weight and self-rated health were collected from 414 Roma women living in rural settlements in Serbia in 2015-2017. Data analysis showed that higher age and weight were associated with a greater risk of poor health, greater height contributed to reduced risk of poor health while reproductive variables were insignificant. The study provides evidence that the long-term effects of early childbearing may not always be associated with poorer health status. As indicated by the differences in height, it is likely that women who were capable of reproducing very early on and staying healthy in later life were probably very healthy to begin with. The results probably reflect both the biological and social differences of early childhood. Aside from height, the traditional Roma marriage pattern and social benefits may have an additional protective effect on the health of women.

Trends and birth outcomes in adolescent refugees and migrants on the Thailand-Myanmar border, 1986-2016: an observational study

Background: Currently there are more adolescents (10-19 years old) and young adults (20-24 years old) than ever. Reproductive health among this age group is often overlooked, although it can have a profound impact on the future. This is especially the case in conflict zones and refugee settings, where there is a heightened need for reproductive health care, and where both the resources and possibility for data collation are usually limited.

Methods: Here we report on pregnancies, birth outcomes and risk factors for repeat pregnancies among adolescent and young adult refugees and migrants from antenatal clinics on the Thailand-Myanmar border across a 30 year time span.

Results: Pregnancy and fertility rates were persistently high. Compared with 20-24-year-olds, 15-19-year-olds who reported being unable to read had 2.35 (CI: 1.97 – 2.81) times the odds for repeat pregnancy (gravidity >2). In primigravidae, the proportion of small for gestational age (SGA) and preterm births (PTB), and neonatal deaths (NND) decreased with increasing maternal age (all p <0.001). After adjustment, this association retained significance for PTB (cut-off point, ≤18 years) but not for SGA and NND.

Conclusions: There is considerable room for improvement in adolescent pregnancy rates in these border populations, and educational opportunities may play a key role in effective interventions.

Prenatal arsenic exposure, child marriage, and pregnancy weight gain: Associations with preterm birth in Bangladesh

BACKGROUND

Preterm birth is a disease of multifactorial etiologies that has environmental, social, and maternal health components. Individual studies have shown that exposure to arsenic contaminated drinking water, child marriage, and low maternal weight gain during pregnancy contribute to preterm birth. These factors are highly prevalent and often co-exist in Bangladesh, a country in South Asia with one of the world's highest prevalences of preterm birth.

OBJECTIVE

To evaluate the individual and interactive effects of prenatal arsenic exposure, child marriage, and pregnancy weight gain on preterm birth in a prospective birth cohort in Bangladesh.

METHODS

During 2008-2011, we recruited 1613 pregnant women aged ≥18years at ≤16weeks of gestation and followed them until 1-month post-partum. We measured total arsenic in drinking water (n=1184) and in maternal toenails (n=1115) collected at enrollment and ≤1-month post-partum, respectively using inductively coupled plasma mass spectrometry. Child marriage (<18years old) was defined using self-report, and 2nd and 3rd trimester pregnancy weight gain was calculated using monthly records. Gestational age was determined at enrollment by ultrasound.

RESULTS

In multivariate adjusted Poisson regression models, the risk ratios (RR) for preterm birth were 1.12 (95% CI: 1.07-1.18) for a unit change in natural log water arsenic exposure, 2.28 (95% CI: 1.76-2.95) for child marriage, and 0.64 (95% CI: 0.42-0.97) for a pound per week increase in maternal weight during the 2nd and 3rd trimesters. In stratified analysis by child marriage, pregnancy weight gain was inversely associated with preterm birth among women with a history of child marriage (RR=0.58; 95% CI: 0.37-0.92), but not among women with no history of child marriage (RR=86; 95% CI: 0.37-2.01). Mediation analysis revealed that both arsenic exposure and child marriage had small but significant associations with preterm birth via lowering pregnancy weight gain. Similar associations were observed when arsenic exposure was assessed using maternal toenail arsenic concentrations.

CONCLUSIONS

Reducing arsenic exposure and ending child marriage could reduce the risk of preterm birth in Bangladesh. Furthermore, enhancing nutritional support to ensure adequate weight gain during pregnancy may provide additional benefits especially for women with a history of child marriage.

Effects of a Parenting Program Among Women Who Began Childbearing as Adolescents and Young Adults

PURPOSE

The purpose of the study was to examine whether access to an at-scale, group-based parenting education program ("Educación Inicial") had differential effects on parenting behaviors and child cognitive development according to mother's age at the birth of her first child, with a focus on adolescent mothers in rural Mexico.

METHODS

This was a secondary analysis of a cluster-randomized controlled trial (n = 728 households, n = 106 communities). We conducted intent-to-treat analyses and examined the interaction between treatment group and mother's age at first birth. The primary outcomes were parenting behaviors (Family Care Indicators) and children's cognitive development (McCarthy Scales of Children's Abilities) at ages 3-5 years.

RESULTS

We found that children of mothers who began childbearing in adulthood (20-30 years) scored higher on tests of cognitive development when randomized to weekly parenting support than their counterparts in the comparison group. Whereas, the children of mothers who began childbearing in adolescence (≤16 years) did not have higher scores associated with the parenting program (difference in magnitude of associations: Verbal = -8.19; 95% CI = -15.50 to -.88; p = .03; Memory = -7.22; 95% CI = -14.31 to -.14; p = .05). The higher scores among the children of mothers who began childbearing in adulthood were only significant when Educación Inical was supported by Prospera, the conditional cash transfer program.

CONCLUSIONS

Our study results suggest that the Educación Inicial parenting intervention did not adequately address the needs of women who began childbearing in adolescence. One reason may be that adolescent mothers are more socially marginalized and less able to benefit from parenting programs.

Age at reproductive debut: Developmental predictors and consequences for lactation, infant mass, and subsequent reproduction in rhesus macaques (Macaca mulatta)

OBJECTIVES

The age at which females initiate their reproductive career is a critical life-history parameter with potential consequences on their residual reproductive value and lifetime fitness. The age at reproductive debut may be intimately tied to the somatic capacity of the mother to rear her young, but relatively little is known about the influence of age of first birth on milk synthesis within a broader framework of reproductive scheduling, infant outcomes, and other life-history tradeoffs.

MATERIAL AND METHODS

Our study investigated the predictors of age at first reproduction among 108 captive rhesus macaque (Macaca mulatta) females, and associations with their milk synthesis at peak lactation, infant mass, and ability to subsequently conceive and reproduce.

RESULTS

The majority of females reproduced in their fourth year (typical breeders); far fewer initiated their reproductive career one year earlier or one year later (respectively early and late breeders). Early breeders (3-year-old) benefited from highly favorable early life development (better juvenile growth, high dominance rank) to accelerate reproduction, but were impaired in milk synthesis due to lower somatic resources and their own continued growth. Comparatively, late breeders suffered from poor developmental conditions, only partially compensated by their delayed reproduction, and evinced compromised milk synthesis. Typical breeders not only produced higher available milk energy but also had best reproductive performance during the breeding and birth seasons following primiparity.

DISCUSSION

Here, we refine and extend our understanding of how life-history tradeoffs manifest in the magnitude, sources, and consequences of variation in age of reproductive debut. These findings provide insight into primate reproductive flexibility in the context of constraints and opportunities.

Rate of teenage pregnancy in Jordan and its impact on maternal and neonatal outcomes

Objective Research regarding the adverse outcomes of adolescent childbearing has suffered from many limitations such as a small sample size and non-representative samples. This study was conducted to determine the rate of teenage pregnancy among Jordanian adolescents and its associated adverse maternal and neonatal outcomes. Methods The study is a part of a comprehensive national study of perinatal mortality that was conducted between 2011 and 2012 in Jordan. All women who gave birth after 20 weeks of gestation in 18 maternity hospitals in Jordan between 2011 and 2012 were invited to participate in the study. Consenting women were interviewed by the trained midwives in these hospitals using a structured questionnaire prepared for the purpose of this study. Additional information was also collected based on the physical examination by the midwife and the obstetrician at admission and at discharge. Data on the newborn were also collected by the pediatric nurses and the neonatologists in these hospitals. Results The overall rate of teenage pregnancy [95% confidence interval (CI) was 6.2% (5.9%, 6.5%)]. Of the studied maternal and neonatal outcomes, women aged <20 years were more likely to deliver prematurely compared to women aged 20-35 years [odds ratio (OR)=1.5, 95% CI: 1.2, 1.9; p < 0.005)]. However, the two groups of women did not differ significantly in low birth weight delivery (OR = 1.2, 95% CI: 0.9, 1.5; p = 0.167) and neonatal mortality (OR = 1.2, 95% CI: 0.8, 1.3; p = 0.491) in the multivariate analysis. Conclusion Teenage pregnancy was associated with increased risk of premature delivery, apart from the effects of socioeconomic factors.

The ex-pat effect: presence of recent Western immigrants is associated with changes in age at first birth and birth rate in a Maya population from rural Guatemala

BACKGROUND

Economic transitions expose indigenous populations to a variety of ecological and cultural challenges, especially regarding diet and stress. These kinds of challenges are predicted by evolutionary ecological theory to have fitness consequences (differential reproduction) and, indeed, are often associated with changes in fertility dynamics. It is currently unclear whether international immigration might impact the nature of such an economic transition or its consequences for fertility.

AIM

To examine measures of fertility, diet and stress in two economically transitioning Maya villages in Guatemala that have been differentially exposed to immigration by Westerners.

SUBJECTS AND METHODS

This study compared Maya women's ages at first birth and birth rates between villages and investigated whether these fertility indicators changed through time. It also explored whether the villages differed in relation to diet and/or a proxy of stress.

RESULTS

It was found that, in the village directly impacted by immigration, first births occurred earlier, but birth rate was slower. In both villages, over the sampled time window, age at first birth increased, while birth rate decreased. The villages do not differ significantly in dietary indicators, but the immigration-affected village scored higher on the stress proxy.

CONCLUSION

Immigration can affect fertility in host communities. This relationship between immigration and fertility dynamics may be partly attributable to stress, but this possibility should be evaluated prospectively in future research.

Fertility rates and perinatal outcomes of adolescent pregnancies: a retrospective population-based study

Objective

analyze trends in fertility rates and associations with perinatal outcomes for adolescents in Santa Catarina, Brazil.

Methods

a population-based study covering 2006 to 2013 was carried out to evaluate associations between perinatal outcomes and age groups, using odds ratios, and Chi-squared tests.

Results

differences in the fertility rate among female adolescents across regions and time period were observed, ranging from 40.9 to 72.0 per 1,000 in mothers aged 15-19 years. Adolescents had fewer prenatal care appointments than mothers ≥20 years, and a higher proportion had no partner. Mothers aged 15-19 years were more likely to experience preterm birth (OR:1.1; CI:1.08-1.13; p<0.001), have an infant with low birthweight (OR:1.1; CI:1.10-1.15; p<0.001) and low Apgar score at 5 minutes (OR:1.4; CI:1.34-1.45; p<0.001) than mothers ≥20 years, with the odds for adverse outcomes greater for those aged 10-14 years.

Conclusion

this study provides evidence of fertility rates among adolescents remaining higher in regions of social and economic deprivation. Adolescent mothers and their infants more likely to experience adverse perinatal outcomes. Nurses, public health practitioners, health and social care professionals and educators need to work collaboratively to better target strategies for adolescents at greater risk; to help reduce fertility rates and improve outcomes.

Adolescent Pregnancy

Adolescent pregnancy, although on the decline, represents a significant public health concern. Often adolescents present late to prenatal care, either from lack of knowledge, fear of consequences, limited access, stigma, or all of the above. Although multifaceted, there are many risks both to mother and child that are increased in adolescent pregnancy. Many are unintended and are at risk for repeat adolescent pregnancy, especially within the first 2 years. Risks include but are not limited to: low birth weight, preterm delivery, stillbirth, and preeclampsia, as well as feelings of social isolation, delayed or neglected educational goals, and maternal depression.

Exploring unobserved heterogeneity in perinatal and neonatal mortality risks: The case of an Italian sharecropping community, 1900-39

Previous researchers have found that traditional determinants explain only a limited part of the variation in perinatal and infant mortality at the family level. In the study reported in this paper, we explored the factors that make the perinatal/neonatal death risk more heterogeneous across families. We estimated logistic regressions with cluster random effects at the maternal level, using data from the Italian village of Granarolo from 1900 to 1939. We estimated the effects of selected predictors on perinatal/neonatal mortality and unexplained inter-family variation. We found that non-rural skilled and lower-skilled workers experienced higher perinatal and neonatal mortality risks. Unexplained heterogeneity at the maternal level was lower for women living in sharecropper families than for those in landless labourer and non-rural worker families. Unexplained perinatal and neonatal mortality components were also due to socio-economic differences and were not necessarily related only to maternal biological features or shared genetic frailty.

Differential effects of young maternal age on child growth

BACKGROUND

The association of early maternal birthing age with smaller children has been widely observed. However, it is unclear if this is due to confounding by factors such as socioeconomic status, or the age at which child growth restriction first occurs.

OBJECTIVE

To examine the effect of early maternal birthing age on the first-born child's height-for-age in a sample of developing countries in Africa, Asia, and Latin America.

DESIGN

Cross-sectional data from Demographic Health Surveys from 18 countries were used, to select the first-born child of mothers aged 15-24 years and a range of potential confounding factors, including maternal height. Child length/height-for-age z-scores (HAZs) was estimated in age bands of 0-11, 12-23, 24-35, 36-47, and 48-59 months; HAZ was first compared between maternal age groups of 15-17, 18-19, and 20-24 years.

RESULTS

1) There were significant bivariate associations between low child HAZ and young maternal age (71 of 180 possible cases; at p<0.10), but the majority of these did not persist when controlling for confounders (41 cases, 23% of the 180). 2) For children <12 months, when controlling for confounders, three out of seven Asian countries showed a significant association between lower infant HAZ and low maternal age, as did six out of nine African countries (15-17 or 15-19 years vs. the older group). 3) The association (adjusted) continued after 24 months in 12 of the 18 countries, in Africa, Asia, and Latin America. 4) The stunting differences for children between maternal age groups were around 9 percentage points (ppts) in Asia, 14 ppts in Africa, and 10 ppts in Latin America. These data do not show whether this is due to, for example, socioeconomic factors that were not included, an emerging effect of intrauterine growth restriction, or the child feeding or caring behaviors of young mothers. The latter is considered to be the most likely.

CONCLUSIONS

The effect of low maternal age on child height restriction from 0 to 11 months occurred in half the countries studied after adjusting for confounders. Poorer growth continuing after 24 months in children of younger mothers was observed in all regions, but needs further research to determine the causes. The effects were about double (in stunting prevalence terms) in Africa, where there was an increase in 10 ppts in stunting for children of young mothers.

Risk factors for small-for-gestational-age and preterm births among 19,269 Tanzanian newborns

Background

Few studies have differentiated risk factors for term-small for gestational age (SGA), preterm-appropriate for gestational age (AGA), and preterm-SGA, despite evidence of varying risk of child mortality and poor developmental outcomes.

Methods

We analyzed birth outcome data from singleton infants, who were enrolled in a large randomized, double-blind, placebo-controlled trial of neonatal vitamin A supplementation conducted in Tanzania. SGA was defined as birth weight <10th percentile for gestation age and sex using INTERGROWTH standards and preterm birth as delivery at <37 complete weeks of gestation. Risk factors for term-SGA, preterm-AGA, and preterm-SGA were examined independently using log-binomial regression.

Results

Among 19,269 singleton Tanzanian newborns included in this analysis, 68.3 % were term-AGA, 15.8 % term-SGA, 15.5 % preterm-AGA, and 0.3 % preterm-SGA. In multivariate analyses, significant risk factors for term-SGA included maternal age <20 years, starting antenatal care (ANC) in the 3^rd trimester, short maternal stature, being firstborn, and male sex (all p < 0.05). Independent risk factors for preterm-AGA were maternal age <25 years, short maternal stature, firstborns, and decreased wealth (all p < 0.05). In addition, receiving ANC services in the 1^st trimester significantly reduced the risk of preterm-AGA (p = 0.01). Significant risk factors for preterm-SGA included maternal age >30 years, being firstborn, and short maternal stature which appeared to carry a particularly strong risk (all p < 0.05).

Conclusion

Over 30 % of newborns in this large urban and rural cohort of Tanzanian newborns were born preterm and/or SGA. Interventions to promote early attendance to ANC services, reduce unintended young pregnancies, increased maternal height, and reduce poverty may significantly decrease the burden of SGA and preterm birth in sub-Saharan Africa.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR) – ACTRN12610000636055, registered on 3^rd August 2010.

Growth trajectories in wild geladas (Theropithecus gelada)

Life history and socioecological factors have been linked to species-specific patterns of growth across female vertebrates. For example, greater maternal investment in offspring has been associated with more discrete periods of growth and reproduction. However, in primates it has been difficult to test such hypotheses because very few studies have obtained growth measurements from wild populations. Here we utilize a promising noninvasive photogrammetric method-parallel lasers-to examine shoulder-rump (SR) growth in a wild primate, the gelada (Theropithecus gelada, Simien Mountains National Park, Ethiopia). In this species, a graminivorous diet coupled with high extrinsic infant mortality risk suggests that maternal investment in neonates is low. Therefore, in contrast with other closely related papionins, we expected female geladas to exhibit less discrete periods of growth and reproduction. For both sexes, we compared size-for-age patterns (N = 154 females; N = 110 males) and changes in growth velocity relative to major life history milestones. Female geladas finished 88.5% of SR growth by first sexual swelling, and 97.2% by first reproduction, reaching adult body size by 7.72 years of age. Compared to closely related papionins, gelada females finished more growth by first reproduction, despite producing relatively small, and presumably "cheap," neonates. Male geladas finished 85.4% of growth at dispersal, and 96.0% at estimated first birth. Contrary to other polygynous primates, males are larger than females because they grow for a longer period of time (not because they grow faster), surpassing females around 6 years of age when female growth slows. Our results demonstrate that parallel lasers are an easy and promising new method that can be used to construct comprehensive life history perspectives that were once out of reach for wild populations. Am. J. Primatol. 78:707-719, 2016. © 2016 Wiley Periodicals, Inc.

Applying evolutionary anthropology

Evolutionary anthropology provides a powerful theoretical framework for understanding how both current environments and legacies of past selection shape human behavioral diversity. This integrative and pluralistic field, combining ethnographic, demographic, and sociological methods, has provided new insights into the ultimate forces and proximate pathways that guide human adaptation and variation. Here, we present the argument that evolutionary anthropological studies of human behavior also hold great, largely untapped, potential to guide the design, implementation, and evaluation of social and public health policy. Focusing on the key anthropological themes of reproduction, production, and distribution we highlight classic and recent research demonstrating the value of an evolutionary perspective to improving human well-being. The challenge now comes in transforming relevance into action and, for that, evolutionary behavioral anthropologists will need to forge deeper connections with other applied social scientists and policy-makers. We are hopeful that these developments are underway and that, with the current tide of enthusiasm for evidence-based approaches to policy, evolutionary anthropology is well positioned to make a strong contribution.

Adolescent childbearing and women's attitudes towards wife beating in 25 sub-Saharan African countries

Preventing unwanted adolescent pregnancy is key for keeping girls in school, leading to a more productive and healthier workforce in sub-Saharan Africa. Gender norms are an important indicator of the status of women and more conservative gender norms are associated with experiencing domestic violence, and poorer maternal and reproductive health care. This paper examines the association between adolescent childbearing and norms towards wife beating in sub-Saharan Africa, and the role of education in moderating this association. Data come from the most recent Demographic and Health Surveys-nationally representative cross-sectional surveys conducted every 5 years. Country-by-country multivariable logistic regressions were conducted in 25 countries, and country and regional estimates were obtained using meta-analytical techniques. More than half of sub-Saharan African adolescents have a child, with levels ranging from 23% in Rwanda to 69% in Niger. Between 12 and 87% of women believed wife beating is acceptable. In 20 of the 25 countries, women with a birth during adolescence were significantly more likely to believe wife beating is justified [OR = 1.39; 95% confidence interval (CI) 130-1.39]. After multivariate adjustment, the overall finding remains statistically significant [AOR = 1.09; 95% CI 105-1:13]. Education attenuates the observed association. Overall, the effects are strongest and most consistent in West Africa. Results suggest that women who have an adolescent birth more likely to hold more conservative attitudes. Working with adolescents to improve their attitudes on relationship expectations and the importance of furthering their education even after a pregnancy could be integrated into life skills and sexual education curricula.

Maternal Behavior by Birth Order in Wild Chimpanzees (Pan troglodytes): Increased Investment by First-Time Mothers

Parental investment theory predicts that maternal resources are finite and allocated among offspring based on factors including maternal age and condition, and offspring sex and parity. Among humans, firstborn children are often considered to have an advantage and receive greater investment than their younger siblings. However, conflicting evidence for this "firstborn advantage" between modern and hunter-gatherer societies raises questions about the evolutionary history of differential parental investment and birth order. In contrast to humans, most non-human primate firstborns belong to young, inexperienced mothers and exhibit higher mortality than laterborns. In this study, we investigated differences in maternal investment and offspring outcomes based on birth order (firstborn vs. later-born) among wild chimpanzees (Pan troglodyte schweinfurthii). During the critical first year of life, primiparous mothers nursed, groomed, and played with their infants more than did multiparous mothers. Furthermore, this pattern of increased investment in firstborns appeared to be compensatory, as probability of survival did not differ by birth order. Our study did not find evidence for a firstborn advantage as observed in modern humans but does suggest that unlike many other primates, differences in maternal behavior help afford chimpanzee first-borns an equal chance of survival.

The associations of parity and maternal age with small-for-gestational-age, preterm, and neonatal and infant mortality: a meta-analysis

Background

Previous studies have reported on adverse neonatal outcomes associated with parity and maternal age. Many of these studies have relied on cross-sectional data, from which drawing causal inference is complex. We explore the associations between parity/maternal age and adverse neonatal outcomes using data from cohort studies conducted in low- and middle-income countries (LMIC).

Methods

Data from 14 cohort studies were included. Parity (nulliparous, parity 1-2, parity ≥3) and maternal age (<18 years, 18-<35 years, ≥35 years) categories were matched with each other to create exposure categories, with those who are parity 1-2 and age 18-<35 years as the reference. Outcomes included small-for-gestational-age (SGA), preterm, neonatal and infant mortality. Adjusted odds ratios (aOR) were calculated per study and meta-analyzed.

Results

Nulliparous, age <18 year women, compared with women who were parity 1-2 and age 18-<35 years had the highest odds of SGA (pooled adjusted OR: 1.80), preterm (pooled aOR: 1.52), neonatal mortality (pooled aOR: 2.07), and infant mortality (pooled aOR: 1.49). Increased odds were also noted for SGA and neonatal mortality for nulliparous/age 18-<35 years, preterm, neonatal, and infant mortality for parity ≥3/age 18-<35 years, and preterm and neonatal mortality for parity ≥3/≥35 years.

Conclusions

Nulliparous women <18 years of age have the highest odds of adverse neonatal outcomes. Family planning has traditionally been the least successful in addressing young age as a risk factor; a renewed focus must be placed on finding effective interventions that delay age at first birth. Higher odds of adverse outcomes are also seen among parity ≥3 / age ≥35 mothers, suggesting that reproductive health interventions need to address the entirety of a woman’s reproductive period.

Funding

Funding was provided by the Bill & Melinda Gates Foundation (810-2054) by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group.

Profiles of Maternal Care Observed in a Group of Brazilian Mothers: an Exploratory Study

The aim of this study is to characterize profiles of maternal care in a sample of Brazilian mothers, using a culturalbiological perspective. Participants were 315 women who had at least one child younger than six years-old. They were selected from six Brazilian states. In each state, two groups of mothers were studied, one from the capital and one from a small city. They were interviewed and answered scales on allocentrism, social support, adult attachment, and practices of childcare. Mothers' characteristics, the type of context (capital vs. small city), and reported childcare practices were used in a Tree analysis. A Correspondence analysis was performed using the four clusters obtained and mothers' answers regarding their youngest child. Univariate GLM analyses were performed to compare mothers in the four clusters in terms of their scores on the different scales. Four maternal profiles presenting distinctive patterns of association between mothers' characteristics and care practices displayed to the youngest child were identified. We conclude that maternal care is a multi-determined phenomenon and that the method employed in this study can give insights into how the combination of diverse social-biological factors can result in a set of childcare practices.

Addressing the needs of adolescent mothers and their offspring in Nigeria: a community-based study

OBJECTIVE

The purpose of this study is to determine the perinatal profile of adolescent mothers with surviving offspring against the backdrop of limited community-based data on the outcomes of adolescent pregnancy in low-income countries.

METHODS

A case-control study of adolescent mothers (13-19 years) attending four community-based clinics for routine childhood immunization from July 2005 to March 2008 in Lagos, Nigeria, matched for infant age and sex. Maternal and infant factors associated with adolescent mothers were determined using unconditional and conditional multivariable logistic regression analyses.

RESULTS

A total of 241 adolescent mothers (mean age, 18.2±1.2 years) were consecutively recruited over the study period and matched with 1205 controls (mean age, 27.3±3.9 years). Adolescent mothers in this population were significantly more likely to be unmarried, of the Hausa ethnic tribe, without postsecondary education, unemployed, and primiparous. Although all received antenatal care, they were also more likely to deliver outside hospital without skilled attendants, and their offspring were likely to be undernourished.

CONCLUSIONS

Socio-demographic profile of adolescent girls who become pregnant is likely to have a significant influence on their health-seeking behavior for obstetric services. Teenagers especially from the most vulnerable ethnic groups in resource-poor countries should be educated on the developmental risks of early childbearing in their surviving offspring.

The impact of early age at first childbirth on maternal and infant health

The objective of this review was to assess whether early age at first childbirth is associated with increased risk of poor pregnancy outcomes. Early age at childbirth is variously defined in studies of its effect on maternal and infant health. In this systematic review, we limit analysis to studies of at least moderate quality that examine first births among young mothers, where young maternal age is defined as low gynaecological age (≤ 2 years since menarche) or as a chronological age ≤ 16 years at conception or delivery. We conduct meta-analyses for specific maternal or infant health outcomes when there are at least three moderate quality studies that define the exposure and outcome in a similar manner and provide odds ratios or risk ratios as their effect estimates. We conclude that the overall evidence of effect for very young maternal age (<15 years or <2 years post-menarche) on infant outcomes is moderate; that is, future studies are likely to refine the estimate of effect or precision but not to change the conclusion. Evidence points to an impact of young maternal age on low birthweight and preterm birth, which may mediate other infant outcomes such as neonatal mortality. The evidence that young maternal age increases risk for maternal anaemia is also fairly strong, although information on other nutritional outcomes and maternal morbidity/mortality is less clear. Many of the differences observed among older teenagers with respect to infant outcomes may be because of socio-economic or behavioural differences, although these may vary by country/setting. Future, high quality observational studies in low income settings are recommended in order to address the question of generalisability of evidence. In particular, studies in low income countries need to consider low gynaecological age, rather than simply chronological age, as an exposure. As well, country-specific studies should measure the minimum age at which childbearing for teens has similar associations with health as childbearing for adults. This 'tipping point' may vary by the underlying physical and nutritional health of girls and young women.