Does having siblings really protect against childhood atopic diseases? A total population and within-family analysis.

The association between having older siblings and decreased risk for atopic symptoms is well-established. This has been interpreted as evidence for the microbiota hypothesis, i.e. that increased early-childhood microbial exposure caused by siblings protects from immune hypersensitivities. However, possible confounders of the association have received little attention. We used register data on Finnish cohorts born in 1995-2004 (N = 559,077) to assess medication purchases for atopic diseases: antihistamines, eczema medication, asthma medication and Epinephrine. We modelled the probability of atopic medication purchases at ages 0-15 by birth order controlling for important observed confounders and all unobserved genetic and environmental characteristics shared by siblings in a within-family fixed effects model. We further studied medication purchases among first-borns according to the age difference with younger siblings to assess whether having younger siblings in early childhood is beneficial. Having older siblings was associated with a lower probability of atopic medication purchases. Compared to first-borns, the probability was 10-20% lower among second-borns, 20-40% lower among third-borns, and 30-70% lower among subsequent children, depending on medication type. Confounding accounted for up to 75% of these differences, particularly for asthma and eczema medication, but significant differences by birth order remained across all medication types. Among first-borns, a smaller age difference with younger siblings was related to a lower likelihood of atopic medication use. Our results, based on designs that account for unobserved confounding, show that exposure to siblings in early childhood, protects from atopic diseases, and thus strongly support the microbiota hypothesis.

Birth Order and Family Size of UK Biobank Subjects Identified as Asexual, Bisexual, Heterosexual, or Homosexual According to Self-Reported Sexual Histories.

This study used a recently developed statistical technique to investigate the relations between various elements of a subject's family background and the odds of that subject reporting a sexual history indicative of a minority sexual orientation. The subjects were 78,983 men and 92,150 women who completed relevant questionnaire items in the UK Biobank, a large-scale biomedical database of volunteers aged 40-69 years. The men were divided into three sexual minority groups-homosexual, bisexual, and asexual-and a comparison group of heterosexual men. The same was done for the women. The analytic procedure consisted of logistic regressions specifically designed to disentangle the effects of birth order and family size. The results showed that older brothers increased the odds of homosexuality in both men and women, and that older sisters increased the odds in men. In contrast, neither older brothers or older sisters affected the odds of bisexuality or asexuality in men or in women. These results suggest that birth order effects may be specific to homosexuality and not common to all minority orientations. The only family size finding was the negative association between family size and the odds of asexuality in both men and women. The outcomes of this study indicate that the maternal immune hypothesis, which was advanced to explain the relation between older brothers and homosexuality in later-born males, might have to be abandoned or else expanded to explain the findings concerning females. A few such modifications are considered.

Ideal Family Size and Reproductive Orientations: An Exploration of Change Over Time in the United States.

Drawing on more than 30 years of nationally representative microdata from the General Social Survey, this article comprehensively updates recent trends in ideal family size in the United States. It first documents stability in ideal family sizes between the mid-1980s and 2018, even in the face of a recent fertility decline. Next, the study adopts a latent class approach that identifies typologies of "reproductive orientations," defined as multidimensional mental models of reproduction encompassing ideal family size, attitudes toward reproductive labor, and views on reproduction contexts. The findings indicate three distinct classes of reproductive orientations: Progressive Familialists, Conservative Familialists, and Blended Egalitarians. Further analyses suggest that the prevalence of these classes has changed over time and that class membership is associated with distinct patterns of childbearing and marriage. These findings deepen contemporary understandings of ideal family size in the United States and have broader implications for how demographers conceptualize and measure fertility preferences across diverse contexts.

Prader-Willi syndrome in a large sample from Spain: general features, obesity and regular use of psychotropic medication.

BACKGROUND: Prader-Willi syndrome (PWS), a genetically determined disorder, the most frequent cause of early onset obesity, is associated with physical and cognitive dysfunctions and behavioural disturbances; these disturbances are frequently treated with psychotropic medication. The aim of this cross-sectional study was to describe the characteristics of the first large national sample of persons with PWS in Spain and analyse the relationships of those characteristics with key demographic and clinical factors, particularly with obesity and the regular use of psychotropic medication. METHODS: Participants were recruited among all members of the Spanish Prader-Willi Association who agreed to take part in the study and fulfilled its inclusion criteria. Family and patient demographic features, family size and birth order, intelligence quotient (IQ), anthropometric measures, lifestyle habits, behavioural disturbances (with the Aberrant Behavior Checklist) and clinical data, as well as use of psychotropic drugs and their side effects (with the UKU scale), were collected in genetically confirmed cases of PWS. Bivariate and logistic regression analyses were used for determining the associations of demographic and clinical factors with both obesity and the regular use of psychotropic medication. RESULTS: The cohort included 177 participants (aged 6-48 years), that is, 90 (50.8%) males and 87 (49.2%) females. Behavioural disturbances were present in a range of 75% to 93% of participants; psychotropic medication was prescribed to 81 (45.8%) of them. Number of siblings showed a direct correlation with IQ, especially among males, and inappropriate speech was more intense in only-child females. Obesity was, in parallel, strongly associated with ascending age and with not being currently under growth hormone (GH) treatment. Participants taking any psychotropic medication were characterised by more frequent age ≥30 years, high level of hyperactivity and a psychiatric diagnosis. CONCLUSIONS: Characterisation of persons with PWS in Spain confirms their physical and behavioural phenotype and supports the long-term application of GH therapy and the rational use of psychotropic medication.

ART and the forgotten siblings: a call for research.

A broader definition of infertility is the incapacity to have the intended number of children. However, most literature on ART exclusively focuses on live birth as an outcome, rather than on the capacity to fully realize the reproductive wishes of the couples. This issue has probably received scant attention because the total fertility rate is below replacement levels in affluent countries, and one may simplistically assume that only a minority of couples may be interested in more than one child. This assumption, however, is unproven and presumably erroneous. Unfortunately, evidence on the rate of return in couples who conceived their first child with ART is scant and information on the intended number of children in infertile couples is lacking. In general, we plea for more research on this subject. The documentation of an intended number of children above two and a high return rate in infertile couples may lead to changes in clinical practice, such as the storage of oocytes or embryos prior to initiating embryo transfers. This could improve the chance of conceiving the second child when the couple comes back some years later. In addition, the identification of the determinants for non-return as well as those explaining the gap between the intended and the realized number of children may reveal specific barriers and possibly how to tackle them. However, at present, available evidence is insufficient to advocate any intervention. Thorough research is warranted.

Association of serum vitamin D levels on Helicobacter pylori infection: a retrospective study with real-world data.

OBJECTIVE: The aim of this study was to determine whether serum vitamin D levels are associated with H. pylori infection and whether low serum vitamin D levels are an independent risk factor for H. pylori infection. METHODS: We conducted a retrospective analysis of a multicenter cohort study from 2017 to 2019. A total of 415 H. pylori+ patients and 257 H. pylori- patients aged between 18 and 75 years with both 13 C-urea breath test and serum vitamin D level results were included from four hospitals. A questionnaire was used to collect information on potential factors influencing H. pylori infection. RESULTS: Serum vitamin D levels were significantly lower in the H. pylori+ group than in the H. pylori- group (16.7 ± 6.6 ng/ml vs. 19.2 ± 8.0 ng/ml, p < 0.05). Using a cutoff value of 20 ng/ml, the H. pylori infection rate was significantly higher in the vitamin D-deficient group (< 20 ng/ml) than in the vitamin D-nondeficiency group (≥ 20 ng/ml) (66.5% vs. 51.0%, p < 0.001). Ordered logistic regression analysis showed that serum vitamin D levels < 20 ng/ml (OR: 1.652, 95% CI: 1.160-2.351, p = 0.005), higher education levels (OR: 1.774, 95% CI: 1.483-2.119, p < 0.001), family size ≥ 4 (OR: 1.516, 95% CI: 1.081-2.123, p = 0.016), and lower annual income (OR: 1.508, 95% CI: 1.289-1.766, p < 0.001) were independent risk factors for H. pylori infection. CONCLUSION: Lower serum vitamin D levels may be associated with an increased risk of H. pylori infection, and lower serum vitamin D levels are an independent risk factor for increasing H. pylori infection rates. Randomized controlled trials are needed to determine whether supplementation with vitamin D can reduce H. pylori infection rates.

Gender differences in vision health-seeking behavior and vision health outcomes among rural Chinese schoolchildren by birth order and family size.

BACKGROUND: The gender gap remains a major impediment in the path toward equality, and it is especially wide in low-income countries. Gender differences in health-seeking behaviors may be a factor. Family size and childbirth order are two critical factors affecting family resource allocation. This study examines gender differences in healthcare-seeking behaviors among children with visual impairment in rural China across different family structures (birth order and family size). METHODS: We draw on a dataset containing 19,934 observations constructed by combining data from 252 different school-level surveys spanning two provinces. The surveys were all conducted in 2012 using uniform survey instruments and data collection protocols in randomly selected schools across western provinces in rural China. The sample children range in grades from 4 to 5. Our analysis compares rural girls with rural boys regarding vision health outcome and behavior (vision examination and correction). RESULTS: The findings revealed that girls have worse vision than boys. Regarding vision health behaviors, girls have a lower overall vision examination rate than boys. There is no gender difference when the sample student is the only child or the youngest child in the family, but there is still a gender difference when the sample student is the oldest child in the family or the middle child in the birth order. When it comes to vision correction behavior, boys are more likely to own eyeglasses than girls are for groups of students with mild visual impairment, even when the sample student is the only child in the family. However, when the sample student has another brother or sister (the sample student is the youngest, the oldest child in the family, or the middle child in the birth order), the gender difference disappears. CONCLUSIONS: Gender differences in vision health outcomes are correlated with gender differences in vision health-seeking behaviors among rural children. Depending on the birth order and family size, gender disparities in visual health practices vary. In the future, consideration should be given to providing medical subsidies to reduce the cost of vision health behaviors and to provide information interventions to change gender inequality in households and promote equality in children's vision health behaviors. TRIAL REGISTRATION: The trial was approved by the Stanford University Institutional Review Board (Protocol No. ISRCTN03252665). Permission was received from local Boards of Education in each region and the principals of all schools. The principles of the Declaration of Helsinki were followed throughout. Written informed consent was obtained from at least one parent for all child participants.

Household food insecurity, family size and their interactions on depression prevalence among teenage pregnant girls in Ghana, a population based cluster survey.

BACKGROUND: Household food insecurity is the situation where individuals and families have limited/uncertain access to nutritionally adequate and safe foods for healthy living. Family size is the number of persons in the family. Household food insecurity and family size are risk factors for depression. However, their synergistic and/or multiplicative effect on depression is not well investigated. This study investigated/examined household food insecurity, family size and their interaction on depression prevalence among teenaged pregnant girls in Ghana. METHODS: Population based cluster survey was conducted among 225 teenaged pregnant girls in 20-electoral areas at Twifo-Atti-Morkwa district in the central region of Ghana. Simple random sampling was used to recruit study participants and structured questionnaire used to collect demographic variables. Household Food Insecurity Access Scale (HFIAS) and Revised Children's Anxiety and Depression Scale (RCADS-25) were used to collect data. Multinomial logistic regression models were used to analyzed the data. RESULTS: Moderate and high depression prevalence reported among teenaged pregnant girls in Twifo-Atti-Morkwa district were 35.1(28.1-42.1) and 33.5 (26.5-40.5) respectively. Moderate family size (AOR = 1.08, 95%CI = 1.17-3.71) and large-family-size (AOR = 2.78, 95%CI = 3.98-10.19) were significant for depression. Moderate food insecurity (AOR = 0.12, 95%CI = 0.41 - 0.35) and high food insecurity (AOR = 0.27, 95%CI = 0.11-0.71) were significant for depression. Interaction between moderate food insecurity and moderate family size (AOR = 1.69, 95%CI = 2.79-17.51), interaction between high food insecurity and low family size (AOR = 1.24, 95%CI 1.57-11.41) and interaction between high food insecurity and large family size (AOR = 1.01, 95%CI = 1.72-14.57) were significant for depression among teenaged pregnant girls. CONCLUSION: There is moderate and high depression prevalence among teenaged pregnant girls in Twifo-Atti-Morkwa district. Interaction between household food insecurity and family size are the major predictors for depression among the teenaged girls in the district. We therefore recommend that public health officers should be up with health education campaigns in the district to create awareness on the depression prevalence among teenaged girls, and urge them to come out and seek support to prevent the catastrophic effect of depression.

Health outcomes of only children across the life course: An investigation using Swedish register data.

Only children (with no full biological siblings) are a growing subgroup in many high-income settings. Previous studies have largely focused on the short-term developmental outcomes of only children, but there is limited evidence on their health outcomes. Using Swedish population register data for cohorts born 1940-75, we compare the health of only children with that of children from multi-child sibling groups, taking into account birth order, family size, and presence of half-siblings. Only children showed lower height and fitness scores, were more likely to be overweight/obese in late adolescence, and experienced higher later-life mortality than those with one or two siblings. However, only children without half-siblings were consistently healthier than those with half-siblings, suggesting that parental disruption confers additional disadvantages. The health disadvantage was attenuated but not fully explained by adjustment for parental characteristics and after using within-family maternal cousin comparison designs.

How genuine are sub-replacement ideal family sizes in urban China?

Ideal family sizes remain at or above two in most low-fertility settings, but sub-replacement fertility ideals have been reported for urban China. The presence of restrictive family planning policies has led to a debate as to whether such ideals are genuine. This study exploits the ending of the one-child policy and the beginning of a universal two-child policy in October 2015 to investigate whether relaxing the restrictions led to an increase in ideal family size. We apply difference-in-differences and individual-level fixed-effect models to longitudinal data from a near-nationwide survey. For married individuals aged 20-39, relaxing the restrictions from one to two children increased the mean ideal family size by around 0.2 and the proportion who desired two or more children by around 19 percentage points. Findings suggest that although reported ideal family sizes have been reduced by policy restrictions, sub-replacement ideal family sizes in urban China appear to be genuine.

Alcohol consumption at age 18-25 and number of children at a 33-year follow-up: Individual and within-pair analyses of Finnish twins.

BACKGROUND: Do drinking patterns in late adolescence/early adulthood predict lifetime childlessness and number of children? Research on this question has been only tangentially relevant and the results inconsistent. The designs used to date have been compromised by genetic and environmental confounds that are poorly controlled; covariate effects of smoking and education that are often ignored; males being understudied; population-based sampling rare, and long-term prospective studies with genetically informative designs yet to be reported. METHOD: In a 33-year follow-up, we linked the drinking patterns of >3500 Finnish twin pairs, assessed at ages 18-25, to registry data on their eventual number of children. Analyses distinguished associations of early drinking patterns with lifetime childlessness from those predictive of family size. Within-twin pair analyses used fixed-effects regression models to account for shared familial confounds and genetic liabilities. Childlessness was analyzed with Cox proportional hazards models and family size with Poisson regression. Analyses within-pairs and of twins as individuals were run before and after adjustment for smoking and education, and for oral contraceptive (OC) use in individual-level analyses of female twins. RESULTS: Baseline abstinence and heavier drinking both significantly predicted lifetime childlessness in individual-level analyses. Few abstinent women used OCs, but they were nonetheless more often eventually childless; adjusting for smoking and education did not affect this finding. Excluding childless twins, Poisson models of family size showed heavier drinking at 18-25 to be predictive of fewer children in both men and women. Those associations were replicated in within-pair analyses of dizygotic twins, each level of heavier drinking being associated with smaller families. Among monozygotic twins, associations of drinking with completed family size yielded effects of similar magnitude, reaching significance at the highest levels of consumption, ruling out familial confounds. CONCLUSIONS: Compared to moderate levels of drinking, both abstinence and heavier drinking in late adolescence/early adulthood predicted a greater likelihood of lifetime childlessness and eventual number of children. Familial confounds do not fully explain these associations.

Association between Number of Siblings and Cardiovascular Risk Factors in Childhood and in Adulthood: The Cardiovascular Risk in Young Finns Study.

OBJECTIVE: To determine the association of number of siblings on cardiovascular risk factors in childhood and in adulthood. STUDY DESIGN: In total, 3554 participants (51% female) from the Cardiovascular Risk in Young Finns Study with cardiovascular disease risk factor data at baseline 1980 (age 3-18 years) and 2491 participants with longitudinal risk factor data at the 2011 follow-up. Participants were categorized by number of siblings at baseline (0, 1, or more than 1). Risk factors (body mass index, physical activity, hypertension, dyslipidemia, and overweight, and metabolic syndrome) in childhood and in adulthood were used as outcomes. Analyses were adjusted for age and sex. RESULTS: In childhood, participants without siblings had higher body mass index (18.2 kg/m2, 95% CI 18.0-18.3) than those with 1 sibling (17.9 kg/m2, 95% CI 17.8-18.0) or more than 1 sibling (17.8 kg/m2, 95% CI 17.7-17.9). Childhood physical activity index was lower among participants without siblings (SD -0.08, 95% CI -0.16-0.00) compared with participants with 1 sibling (SD 0.06, 95%CI 0.01-0.11) or more than 1 sibling (SD -0.02, 95% CI -0.07-0.03). OR for adulthood hypertension was lower among participants with 1 sibling (OR 0.73, 95% CI 0.54-0.98) and more than 1 sibling (OR 0.71, 95% CI 0.52-0.97) compared with participants with no siblings. OR for obesity was lower among participants with 1 sibling (OR 0.72, 95% CI 0.54-0.95) and more than 1 sibling (OR 0.75, 95% CI 0.56-1.01) compared with those with no siblings. CONCLUSIONS: Children without siblings had poorer cardiovascular risk factor levels in childhood and in adulthood. The number of siblings could help identify individuals at increased risk that might benefit from early intervention.

Improved selection of participants in genetic longevity studies: family scores revisited.

BACKGROUND: Although human longevity tends to cluster within families, genetic studies on longevity have had limited success in identifying longevity loci. One of the main causes of this limited success is the selection of participants. Studies generally include sporadically long-lived individuals, i.e. individuals with the longevity phenotype but without a genetic predisposition for longevity. The inclusion of these individuals causes phenotype heterogeneity which results in power reduction and bias. A way to avoid sporadically long-lived individuals and reduce sample heterogeneity is to include family history of longevity as selection criterion using a longevity family score. A main challenge when developing family scores are the large differences in family size, because of real differences in sibship sizes or because of missing data. METHODS: We discussed the statistical properties of two existing longevity family scores: the Family Longevity Selection Score (FLoSS) and the Longevity Relatives Count (LRC) score and we evaluated their performance dealing with differential family size. We proposed a new longevity family score, the mLRC score, an extension of the LRC based on random effects modeling, which is robust for family size and missing values. The performance of the new mLRC as selection tool was evaluated in an intensive simulation study and illustrated in a large real dataset, the Historical Sample of the Netherlands (HSN). RESULTS: Empirical scores such as the FLOSS and LRC cannot properly deal with differential family size and missing data. Our simulation study showed that mLRC is not affected by family size and provides more accurate selections of long-lived families. The analysis of 1105 sibships of the Historical Sample of the Netherlands showed that the selection of long-lived individuals based on the mLRC score predicts excess survival in the validation set better than the selection based on the LRC score . CONCLUSIONS: Model-based score systems such as the mLRC score help to reduce heterogeneity in the selection of long-lived families. The power of future studies into the genetics of longevity can likely be improved and their bias reduced, by selecting long-lived cases using the mLRC.

Pregnancy intention data completeness, quality and utility in population-based surveys: EN-INDEPTH study.

BACKGROUND: An estimated 40% of pregnancies globally are unintended. Measurement of pregnancy intention in low- and middle-income countries relies heavily on surveys, notably Demographic and Health Surveys (DHS), yet few studies have evaluated survey questions. We examined questions for measuring pregnancy intention, which are already in the DHS, and additional questions and investigated associations with maternity care utilisation and adverse pregnancy outcomes. METHODS: The EN-INDEPTH study surveyed 69,176 women of reproductive age in five Health and Demographic Surveillance System sites in Ghana, Guinea-Bissau, Ethiopia, Uganda and Bangladesh (2017-2018). We investigated responses to survey questions regarding pregnancy intention in two ways: (i) pregnancy-specific intention and (ii) desired-versus-actual family size. We assessed data completeness for each and level of agreement between the two questions, and with future fertility desire. We analysed associations between pregnancy intention and number and timing of antenatal care visits, place of delivery, and stillbirth, neonatal death and low birthweight. RESULTS: Missing data were <2% in all questions. Responses to pregnancy-specific questions were more consistent with future fertility desire than desired-versus-actual family size responses. Using the pregnancy-specific questions, 7.4% of women who reported their last pregnancy as unwanted reported wanting more children in the future, compared with 45.1% of women in the corresponding desired family size category. Women reporting unintended pregnancies were less likely to attend 4+ antenatal care visits (aOR 0.73, 95% CI 0.64-0.83), have their first visit during the first trimester (aOR 0.71, 95% CI 0.63-0.79), and report stillbirths (aOR 0.57, 95% CI 0.44-0.73) or neonatal deaths (aOR 0.79, 95% CI 0.64-0.96), compared with women reporting intended pregnancies. We found no associations for desired-versus-actual family size intention. CONCLUSIONS: We found the pregnancy-specific intention questions to be a much more reliable assessment of pregnancy intention than the desired-versus-actual family size questions, despite a reluctance to report pregnancies as unwanted rather than mistimed. The additional questions were useful and may complement current DHS questions, although these are not the only possibilities. As women with unintended pregnancies were more likely to miss timely and frequent antenatal care, implementation research is required to improve coverage and quality of care for those women.

Typhoon eye effect versus ripple effect: the role of family size on mental health during the COVID-19 pandemic in Pakistan.

BACKGROUND: The recent outbreak of COVID-19 has impacted adversely upon the mental health of millions of people worldwide. Impacts on the mental health conditions and the associated predictors relating to adults in Pakistan, the fifth most populous country in the world, during the COVID-19 remain understudied. Our aim was to investigate distress, anxiety, and overall mental health and their associated predictors among Pakistani adults in this pandemic. We specifically examine mental health issues based on the distance from the epicenter, (a predictor that has revealed opposing evidence in other countries) based on the theories of typhoon eye effect and ripple effect. The sample consisted of 601 adults who were surveyed online about 2.5 months into the outbreak across Pakistan with varying distances from the epicenter of COVID-19 of Karachi. RESULTS: The results showed that 9.2 and 19.0% of the participants surpassed the cut-off criteria for distress and anxiety disorders, respectively. Overall, the distance from the epicenter positively predicted the mental health of adults in Pakistan, and family size negatively moderated this effect. The distance from the epicenter negatively predicted distress and anxiety disorders for adults in large families, which are quite common in Pakistan. CONCLUSION: The evidence of the study interestingly finds that the prediction of the mental health of people by their distance from the epicenter depends on family size. The evidence of this study can help to provide initial indicators for mental health care providers to screen vulnerable groups in Pakistan, a populous country that continues struggling to cope with the COVID-19 pandemic.

The effect of daily fast food consumption, family size, weight-caused stress, and sleep quality on eating disorder risk in teenagers.

PURPOSE: Eating disorder (ED) is a common complication with disturbance of eating or eating-related behaviors that lead to physical and psychosocial disorders. The purpose of this study was to evaluate the association between eating disorders and daily fast food consumption, family size, weight-caused stress, and sleep quality in teenagers in Zanjan, Iran. METHODS: Adolescent girl students aged 12-15 years (n = 370), selected in a cross-sectional study, completed the Eating Attitude Test-26 and Pittsburgh Sleep Quality Index questionnaires. The cluster random sampling method was used. Statistical analysis was performed using R software version 3.6.3. Logistic regression modeling was used for investigating the relationship between factors and odds of EDs. A p value of less than 0.05 was considered significant. RESULTS: A significant relationship was found between family size (OR = 0.77, p = 0.049), fast food-daily consumption (OR = 5.42, p = 0.043), weight-caused stress (OR = 12.47, p < 0.001), and poor sleep quality (OR = 1.70, p = 0.024) and odds of eating disorder among teenage girls. CONCLUSION: A significant positive association was found between a low number of family members, daily fast food consumption, stress status, poor sleep quality and odds of EDs. However more longitudinal studies are required to confirm the results.

The role of metalinguistic awareness and character properties in early Chinese reading.

In this study, we examined the effects of phonological awareness (PA), morphological awareness (MA), two character properties (family size [i.e., the number of words that contain the character] and frequency), and the interactions between the metalinguistic awareness (i.e., PA and MA) and the character properties on character reading in early Chinese readers. In total, 206 kindergarten children from China (118 from Mainland China and 88 from Hong Kong) were tracked from the second year of kindergarten to the third year. The linear mixed-effects models revealed significant main effects of metalinguistic awareness and character properties and significant interaction effects between these two, especially for the children from Mainland China. Specifically, the interaction effects indicated that early Chinese readers were able to use metalinguistic awareness more when reading the characters with more favorable properties (i.e., large family sizes and high frequencies). The results suggest a synergistic relationship between metalinguistic awareness and character properties for character learning in early Chinese readers.

Social contexts of fertility desire among non-childbearing young men and women aged 15-24 years in Nigeria.

BACKGROUND: Reduction in ideal number of children has been suggested as a necessary precursor for fertility decline especially in high fertility countries of Western and Central Africa. In this study, we explored the social contexts of fertility desires by documenting the effects of individual, household as well as contextual characteristics among young men and women in Nigeria. METHODS: Data source was the male and female recode file of 2018 Nigeria Demographic and Health Survey. Analytical sample comprised 2674 males and 9637 females aged 15-24 years. The main outcome variable was desire for large family size (DLFS) defined as ideal number of children greater than four. Analysis involved use of descriptive statistics and random-effect logit models fitted in four stages. RESULTS: DLFS was 71% among young men and 53% in women. Individual-level factors associated with DLFS among men includes Islam religion (OR = 3.95, CI 2.68-5.83), household size (OR = 1.05) and richer (OR = 0.47, CI 0.29-0.75) or richest wealth index (OR = 0.28, CI 0.16-0.75). Geo-political region and high level of negative attitude to family planning (OR = 1.72, CI 1.23-2.40) were the main contextual factors associated with DLFS. For women, individual-level correlates were education, religion, ethnicity, marital status, household size, and wealth index. Contextual factors include geo-political region, community education (OR = 0.68, CI 0.52-0.89), child mortality experience (OR = 1.29, CI 1.11-1.51) and negative attitude to family planning (OR = 1.36, CI 1.13-1.65). The influence of religion, household wealth and attitude to family planning differ between young men and women. CONCLUSION: Active communication and programmatic interventions are needed so that desire for large family size by young men and women do not become a clog for fertility transition in Nigeria.

Reduction in ideal number of children has been suggested as a necessary condition for fertility decline especially in high fertility countries of Western and Central Africa. In this study, we explored the effects of individual, household as well as community characteristics on fertility desires among young men and women aged 15­24 years in Nigeria. We analysed data for 2674 males and 9637 females aged 15­24 years extracted from the 2018 Nigeria Demographic and Health Survey. The outcome variable was desire for large family size (DLFS) defined as ideal number of children greater than four. Results showed that DLFS was 71% among men and 53% in women. Individual-level factors associated with DLFS among men include Islam religion, household size and wealth status. Geo-political region and high level of negative attitude to family planning were the main community-level factors associated with DLFS. For women, individual-level positively associated with DLFS were Islam religion, and being currently married. Compared to Yoruba, other ethnic groups were more likely to favour DLFS. The negative factors associated with DLFS among young women include higher education and wealth status. At the community-level, Northern geo-political regions, child mortality experience and negative attitude to family planning were positively associated with DLFS. The influence of religion, household wealth and attitude to family planning differ between young men and women. Multi-dimensional strategies with active communication and programmatic interventions are needed so that desire for large family size by young men and women do not slow down fertility transition in Nigeria.

Body structure, muscular strength and living conditions of primary school children in Warsaw.

The aim of this study was to determine whether the living conditions of school children affects their body structure and muscular strength. Data were taken from 400 girls and 341 boys aged 7-15 years attending nine primary schools in Warsaw in 1997. A questionnaire was completed, anthropological measurements made and two muscular strength tests conducted. The questionnaire asked questions on the children's level of education, their parents' professions and monthly incomes, the number of persons in the family and the number of rooms in the family's apartment/home. Body height, body weight, chest and arm circumferences, grip strength and vertical jump height were measured and used to calculate body mass index, Marty's Index and the Sargent Vertical Jump Index. Statistical tests included Student's t-test, Principal Component Analysis (PCA) and multiple regression analysis. Body height, chest circumference, Sargent Vertical Jump Index and grip strength were significantly greater in the boys than the girls. Two factors, namely 'socioeconomic status' (F1) and 'family size' (F2), describing living conditions, were isolated after PCA. Boys from bigger families (F2) were shorter, with lower weights and BMIs, smaller chest and arm circumferences and greater grip strengths than those from smaller families, whereas girls from families of lower socioeconomic status (F1) weighed less and had greater BMIs and arm circumferences than those from higher socioeconomic status families. The results suggest that boys seem to be more 'ecosensitive' than girls.

Family size and economic wellbeing following divorce: The United States in comparative perspective.

Studies have documented the negative association between divorce and women's economic wellbeing in several countries. Less is known about whether the effects of divorce on women's economic wellbeing, and their persistency, vary by family size. We present the first comprehensive assessment of how the short-term and medium-term economic consequences of divorce vary by family size. Using data from the US (PSID) and between-within random-effects models, we estimate changes in women's gross household income up to six years following divorce, stratified by the number of children in the household in the year of divorce. We add a comparative perspective using a harmonized set of socio-economic panel surveys from Australia (HILDA), Germany (GSOEP), and the UK (BHPS). Our findings demonstrate that the household incomes of women with three or more children decrease most drastically in the US, Germany, and the UK. In these countries, divorce widens the economic gap between child-rich households and those with no or few children. While childless women's incomes do not recover in the medium-term, incomes of mothers in Germany, the UK, and to a lesser extent the US partially recuperate. We demonstrate that differences in labor market attachment, and not remarriage, partially account for the family size differences we observe.