Number Of Older Siblings Research Articles

Characterizing the risk of respiratory syncytial virus in infants with older siblings: a population-based birth cohort study.

From a population-based birth cohort of 245 249 children born in Western Australia during 1996-2005, we used linkage of laboratory and birth record datasets to obtain data including all respiratory syncytial virus (RSV) detections during infancy from a subcohort of 87 981 singleton children born in the Perth metropolitan area from 2000 to 2004. Using log binomial regression, we found that the risk of infant RSV detection increases with the number of older siblings, with those having ⩾3 older siblings experiencing almost three times the risk (relative risk 2·83, 95% confidence interval 2·46-3·26) of firstborn children. We estimate that 45% of the RSV detections in our subcohort were attributable to infection from an older sibling. The sibling effect was significantly higher for those infants who were younger during the season of peak risk (winter) than those who were older. Although older siblings were present in our cohort, they had very few RSV detections which could be temporally linked to an infant's infection. We conclude that RSV infection in older children leads to less severe symptoms but is nevertheless an important source of infant infection. Our results lend support to a vaccination strategy which includes family members in order to provide maximum protection for newborn babies.

Association of living in a farming environment with asthma incidence in Canadian children

ABSTRACTObjective: The objective of this population-based 14-year follow-up study was to examine the effect of living in a farm environment on asthma incidence in children. Methods: A total of 10,941 children of ages 0 to 11 years who were free of asthma and wheeze at the baseline (1994–1995) in the National Longitudinal Survey of Children and Youth were considered in the study. Children's living environment was classified, based on interviewer's observation, into three categories: non-rural, rural non-farming, and farming. An incidence of asthma was obtained from health-professional diagnosed asthma reported either by the person most knowledgeable for children under 15 years or by the children themselves if they were of ages 16 years and over. Results: The 14-year cumulative incidence of asthma among children living in farming environments was 10.18%, which was significantly lower than that observed for children living in rural non-farming (13.12%) and non-rural environments (16.50%). After adjusting for age group, number of older siblings, allergy, parental history of asthma, dwelling in need of repairs and SES index, a dose-response relationship was observed with children living in rural non-farming and farming environments having significantly reduced risk of asthma [hazard ratio (HR): 0.77; 95% confidence interval (CI): (0.60, 1.00); p = 0.047 and HR: 0.56; 95% CI: (0.41,0.77); p < 0.001] in comparison to those living in non-rural environments. Conclusion: This cohort study provides further evidence that living in a farming environment during childhood is protective of asthma incidence in adolescence and adulthood and this finding provides further support for the hygiene hypothesis.

Differential effects of factors influencing cognitive development at the age of 5-to-6 years

This study aims to determine whether early predictors of cognitive development affect some cognitive functions more than others. Children (N=1129) from the EDEN mother-child cohort were assessed at the age of 5-to-6 years using verbal and nonverbal cognitive tests. We used structural equation modeling to simultaneously examine the effects of a broad range of predictors on each cognitive dimension and to test to what extent each predictor differentially affected these dimensions. Effects of family stimulation, breastfeeding duration and number of older siblings were more strongly related to verbal than nonverbal cognitive measure. Our findings provide robust evidence that some modifiable aspects of the early environment are associated with children’s cognitive development and may be more strongly associated with their verbal than nonverbal skills.

The effect of siblings and family dog ownership on children's independent mobility to neighbourhood destinations

ObjectiveTo investigate the effect of sibling age, gender and dog ownership on children's independent mobility and how this varies according to the destination visited. MethodsParents reported whether their child had an older sibling; if the child and older sibling were of the same gender; the number of older siblings; if they owned a dog; and whether their child was allowed to independently travel to school, friends’ or family house, park/oval/sporting field and local shop. Data were analysed for 181 children aged 8–15 years. ResultsThe strongest significant sibling effect for independently mobility to school, local shop and ≥3 destinations was for having an older sibling of the same gender (p≤0.05). For independent mobility to a friend's house and park, the strongest significant sibling effect was for having one older sibling (p≤0.05). Dog ownership was associated with increased odds of being independently mobile to ≥3 destinations (OR=2.43; 95%CI=1.03–5.74). ConclusionsParents may be more likely to grant children licence to travel to local places if they are accompanied by an older sibling or the family dog. ImplicationsUnderstanding the effects of siblings and dog ownership on children's independent mobility will assist in identifying strategies through which independent mobility can be encouraged.

Environmental Factors Associated with Altered Gut Microbiota in Children with Eczema: A Systematic Review.

Eczema is a common skin condition that impairs children’s daily life activities and quality of life. Previous research shows that gut microbiome composition plays an important role in the development of eczema. The present review summarizes evidence on environmental factors related to altered gut microbiota in children with eczema. We searched Medline, PubMed, Embase, and the Cochrane database of Systematic Reviews through October 2015. The search strategy focused on articles published in peer-reviewed, English-language journals with no publication year limit. Only original studies and review articles that reported environmental factors on gut microbiome specific to eczema were included in this review. We selected six studies (total 1990 participants) for full review and identified that the composition of gut microbiota specific to eczema could be influenced by the following environmental factors: length of gestation, mode of delivery, type of feeding, method of treatment, number of older siblings, and other lifestyle factors. There has been inconsistent empirical evidence as to the modulatory effects of gut microbiota on immunological functions in children with eczema. Further research on the environmental-host-microbial interaction is needed to develop a strong base of knowledge for the development and implementation of prevention strategies and policies for eczema.

Effects of Breastfeeding on Respiratory Symptoms in Infancy

To assess the impact of potential risk factors on the development of respiratory symptoms and their specific modification by breastfeeding in infants in the first year of life. We prospectively studied 436 healthy term infants from the Bern-Basel Infant Lung Development cohort. The breastfeeding status, and incidence and severity of respiratory symptoms (score) were assessed weekly by telephone interview during the first year of life. Risk factors (eg, pre- and postnatal smoking exposure, mode of delivery, gestational age, maternal atopy, and number of older siblings) were obtained using standardized questionnaires. Weekly measurements of particulate matter <10μg were provided by local monitoring stations. The associations were investigated using generalized additive mixed model with quasi Poisson distribution. Breastfeeding reduced the incidence and severity of the respiratory symptom score mainly in the first 27weeks of life (risk ratio 0.70; 95% CI 0.55-0.88). We found a protective effect of breastfeeding in girls but not in boys. During the first 27weeks of life, breastfeeding attenuated the effects of maternal smoking during pregnancy, gestational age, and cesarean delivery on respiratory symptoms. There was no evidence for an interaction between breastfeeding and maternal atopy, number of older siblings, child care attendance, or particulate matter <10μg. This study shows the risk-specific effect of breastfeeding on respiratory symptoms in early life using the comprehensive time-series approach.

Relative Importance and Additive Effects of Maternal and Infant Risk Factors on Childhood Asthma.

BackgroundEnvironmental exposures that occur in utero and during early life may contribute to the development of childhood asthma through alteration of the human microbiome. The objectives of this study were to estimate the cumulative effect and relative importance of environmental exposures on the risk of childhood asthma.MethodsWe conducted a population-based birth cohort study of mother-child dyads who were born between 1995 and 2003 and were continuously enrolled in the PRIMA (Prevention of RSV: Impact on Morbidity and Asthma) cohort. The individual and cumulative impact of maternal urinary tract infections (UTI) during pregnancy, maternal colonization with group B streptococcus (GBS), mode of delivery, infant antibiotic use, and older siblings at home, on the risk of childhood asthma were estimated using logistic regression. Dose-response effect on childhood asthma risk was assessed for continuous risk factors: number of maternal UTIs during pregnancy, courses of infant antibiotics, and number of older siblings at home. We further assessed and compared the relative importance of these exposures on the asthma risk. In a subgroup of children for whom maternal antibiotic use during pregnancy information was available, the effect of maternal antibiotic use on the risk of childhood asthma was estimated.ResultsAmong 136,098 singleton birth infants, 13.29% developed asthma. In both univariate and adjusted analyses, maternal UTI during pregnancy (odds ratio [OR] 1.2, 95% confidence interval [CI] 1.18, 1.25; adjusted OR [AOR] 1.04, 95%CI 1.02, 1.07 for every additional UTI) and infant antibiotic use (OR 1.21, 95%CI 1.20, 1.22; AOR 1.16, 95%CI 1.15, 1.17 for every additional course) were associated with an increased risk of childhood asthma, while having older siblings at home (OR 0.92, 95%CI 0.91, 0.93; AOR 0.85, 95%CI 0.84, 0.87 for each additional sibling) was associated with a decreased risk of childhood asthma, in a dose-dependent manner. Compared with vaginal delivery, C-section delivery increased odds of childhood asthma by 34% (OR 1.34, 95%CI 1.29, 1.39) in the univariate analysis and 11% after adjusting for other environmental exposures and covariates (AOR 1.11, 95%CI 1.06, 1.15). Maternal GBS was associated with a significant increased risk of childhood asthma in the univariate analysis (OR 1.27, 95%CI 1.19, 1.35), but not in the adjusted analysis (AOR 1.03, 95%CI 0.96, 1.10). In the subgroup analysis of children whose maternal antibiotic use information was available, maternal antibiotic use was associated with an increased risk of childhood asthma in a similar dose-dependent manner in the univariate and adjusted analyses (OR 1.13, 95%CI 1.12, 1.15; AOR 1.06, 95%CI 1.05, 1.08 for every additional course). Compared with infants with the lowest number of exposures (no UTI during pregnancy, vaginal delivery, at least five older siblings at home, no antibiotics during infancy), infants with the highest number of exposures (at least three UTIs during pregnancy, C-section delivery, no older siblings, eight or more courses of antibiotics during infancy) had a 7.77 fold increased odds of developing asthma (AOR: 7.77, 95%CI: 6.25, 9.65). Lastly, infant antibiotic use had the greatest impact on asthma risk compared with maternal UTI during pregnancy, mode of delivery and having older siblings at home.ConclusionEarly-life exposures, maternal UTI during pregnancy (maternal antibiotic use), mode of delivery, infant antibiotic use, and having older siblings at home, are associated with an increased risk of childhood asthma in a cumulative manner, and for those continuous variables, a dose-dependent relationship. Compared with in utero exposures, exposures occurring during infancy have a greater impact on the risk of developing childhood asthma.

A lost family-planning regime in eighteenth-century Ceylon

Based on Dutch colonial registers (thombos), this paper reconstructs fertility for two districts in Ceylon, 1756–68. It overcomes challenges in data quality by establishing the outer bounds of plausible estimates in a series of scenarios. Among these, total fertility rates (TFRs) averaged 5.5 in one district, but only 2.7 in the other. These figures exclude the victims of infanticide, a custom noted in European travelogues between about 1660 and 1820. Sex ratios among children differed depending on the number of older siblings, and overall, 27 per cent of girls are missing in one district and 57 per cent in the other. There was little significant variation either in the TFR or the sex ratio by socio-economic status, suggesting that poverty was not a key factor in motivating infanticides. Instead, we argue that at least parts of Ceylon had a forward-looking culture of family planning in the eighteenth century, which was lost in subsequent decades.

Maternal depression and risk of injuries in children aged 0–4 years: a population-based cohort study

BackgroundThe association between maternal depression and childhood injuries is underexplored, with existing studies relying on maternal reporting of injury occurrences. We aimed to assess the association between the incidence of three common childhood injuries and exposure to maternal antenatal depression, postnatal depression, or both. MethodsUsing a cohort of 209 418 mother–child pairs who had linked data from the Clinical Practice Research Datalink and Hospital Episode Statistics for 1997–2014, we estimated incidence of poisonings, fractures, and burns per 10 000 person-years from birth to the child's fifth birthday, stratified by whether the mother had antenatal depression, postnatal depression, or both. One child was randomly selected per mother to prevent clustering. Using Poisson regression, we estimated incidence rate ratios (IRRs), adjusted for maternal age at delivery, socioeconomic status, number of older siblings, and number of children aged 0–4 years in the household. The study was approved by the Independent Scientific Advisory Committee for the Medicines and Healthcare products Regulatory Agency in February, 2014. FindingsCrude injury rates were higher for each injury type among children whose mothers had antenatal depression, postnatal depression, or both. Poisoning incidence per 10 000 person-years was 59·6 (95% CI 48·7–72·8) for children of mothers with antenatal depression, 64·4 (57·4–72·2) for children of mothers with postnatal depression, and 74·2 (63·2–87·1) for children of mothers with both, compared with 36·3 (34·8–37·8) for those unexposed to either antenatal or postnatal depression. Similar patterns were seen for fractures and burns. After adjustment, IRRs remained significant for poisonings and burns, with the greatest risk for children whose mothers had both antenatal and postnatal depression (poisonings 1·94, 95% CI 1·63–2·32; burns 1·32, 1·13–1·55). However, there was no significant association between fractures and perinatal depression. InterpretationAntenatal and postnatal depression were associated with a higher risk of child poisonings and burns, suggesting that maternal depression could be a modifiable risk factor for these types of injury. By using routinely collected health data we only identified women who sought medical attention for depression, and were unable to adjust for other variables such as child behaviour. Differences in the ascertainment of injury events between mothers with and without perinatal depression could lead to an overestimation of injury risk. Further work could include assessing certain injuries (eg, long-bone fractures) for which ascertainment is likely to be almost complete. FundingRB is funded by the National Institute for Health Research (NIHR) School for Primary Care Research and the University of Nottingham.

Associations between maternal depressive symptoms and child feeding practices in a cross-sectional study of low-income mothers and their young children.

BackgroundMaternal depression may influence feeding practices important in determining child eating behaviors and weight. However, the association between maternal depressive symptoms and feeding practices has been inconsistent, and most prior studies used self-report questionnaires alone to characterize feeding. The purpose of this study was to identify feeding practices associated with maternal depressive symptoms using multiple methodologies, and to test the hypothesis that maternal depressive symptoms are associated with less responsive feeding practices.MethodsIn this cross-sectional, observational study, participants (n = 295) included low-income mothers and their 4- to 8-year-old children. Maternal feeding practices were assessed via interviewer-administered questionnaires, semi-structured narrative interviews, and videotaped observations in home and laboratory settings. Maternal depressive symptoms were measured using the Center for Epidemiologic Studies-Depression scale (CES-D). Regression analyses examined associations between elevated depressive symptoms (CES-D score ≥16) and measures of maternal feeding practices, adjusting for: child sex, food fussiness, number of older siblings; and maternal age, body mass index (BMI), education, race/ethnicity, single parent status, perceived child weight, and concern about child weight.ResultsThirty-one percent of mothers reported depressive symptoms above the screening cutoff. Mothers with elevated depressive symptoms reported more pressuring of children to eat (β = 0.29; 95% Confidence Interval (CI): 0.03, 0.54) and more overall demandingness (β = 0.16; 95% CI: 0.03, 0.29), and expressed lower authority in child feeding during semi-structured narrative interview (Odds Ratio (OR) for low authority: 2.82; 95% CI: 1.55, 5.12). In homes of mothers with elevated depressive symptoms, the television was more likely audible during meals (OR: 1.91; 95% CI: 1.05, 3.48) and mothers were less likely to eat with children (OR: 0.48; 95% CI: 0.27, 0.85). There were no associations between maternal depressive symptoms and encouragement or discouragement of food in laboratory eating interactions.ConclusionsMothers with elevated depressive symptoms demonstrated less responsive feeding practices than mothers with lower levels of depressive symptoms. These results suggest that screening for maternal depressive symptoms may be useful when counseling on healthy child feeding practices. Given inconsistencies across methodologies, future research should include multiple methods of characterizing feeding practices and direct comparisons of different methodologies.

Geographical variation in the prevalence of sensitization to common aeroallergens in adults: the GA2LEN survey

Geographical variation in the prevalence of sensitization to aeroallergens may reflect differences in exposure to risk factors such as having older siblings, being raised on a farm or other unidentified exposures. We wanted to measure geographical variation in skin prick test positivity and assess whether it was explained by differences in family size and/or farm exposure. We also compared prevalence in younger and older subjects. Within the Global Allergy and Asthma European Network (GA(2) LEN) survey, we measured the prevalence of skin prick positivity to a panel of allergens, and geometric mean serum total immunoglobulin E (IgE), in 3451 participants aged 18-75years in 13 areas of Europe. Estimated prevalence was standardized to account for study design. We compared prevalence estimates in younger and older subjects and further adjusted for age, gender, smoking history, farm exposure, number of older siblings and body mass index (BMI). Skin prick test positivity to any one of the measured allergens varied within Europe from 31.4% to 52.9%. Prevalence of sensitization to single allergens also varied. Variation in serum total IgE was less marked. Younger participants had higher skin prick sensitivity prevalence, but not total IgE, than older participants. Geographical variation remained even after adjustment for confounders. Geographical variation in the prevalence of skin prick test positivity in Europe is unlikely to be explained by geographical variation in gender, age, smoking history, farm exposure, family size and BMI. Higher prevalence in younger, compared to older, adults may reflect cohort-associated increases in sensitization or the influence of ageing on immune or tissue responses.

PD45 ‐ BCG vaccination and childhood asthma: preliminary results from the Québec Birth Cohort on Immunity and Health

It remains unclear whether Bacillus Calmette-Guerin (BCG) vaccination is related to the development of childhood asthma. Meta-analyses on this topic have come to mixed conclusions. Between 1949 and 1974, a BCG vaccination program was conducted in Quebec targeting neonates and school-age children. To investigate the effect of BCG vaccination on asthma, we assembled a retrospective cohort of subjects born in Quebec in 1974 through the linkage of several administrative medical and demographic databases. BCG vaccination status, asthma-related events (medical services, hospitalizations, emergency department visits), and potential confounders were obtained for each subject until 1994. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusting for gender, birth weight for gestational age, number of older siblings, parents’ age, family income, and urban/rural residency. Among 90,060 individuals born in Quebec in 1974, at or after 32 weeks of gestation, probabilistic linkage resulted in a cohort of 81,496 subjects (90.5%). Vaccination or asthma status could not be determined for 4,566 subjects. Among the remaining 76,930 subjects, 51% were males. Subjects vaccinated with BCG within their first year constituted 43% of the cohort, whereas those vaccinated later amounted to 3.5%. Those who had 2 or more asthma-related medical services or at least 1 hospitalization were considered asthmatics, representing 7.7% of the cohort. A slightly lower asthma risk was observed among those vaccinated as compared with non-vaccinated subjects; the adjusted OR was 0.94 (95% CI: 0.89, 0.99). The lack of information on some potential confounding factors is a limitation. Such information has been gathered by telephone interviews with a subset of subjects, and will allow further adjustment of the measure of association. So far, these preliminary results are in support of the immunological hypothesis that BCG vaccination in early life may influence immune maturation and prevent asthma.

Biological Markers of Asexuality: Handedness, Birth Order, and Finger Length Ratios in Self-identified Asexual Men and Women

Human asexuality is defined as a lack of sexual attraction to anyone or anything and it has been suggested that it may be best conceptualized as a sexual orientation. Non-right-handedness, fraternal birth order, and finger length ratio (2D:4D) are early neurodevelopmental markers associated with sexual orientation. We conducted an Internet study investigating the relationship between self-identification as asexual, handedness, number of older siblings, and self-measured finger-lengths in comparison to individuals of other sexual orientation groups. A total of 325 asexuals (60 men and 265 women; M age, 24.8 years), 690 heterosexuals (190 men and 500 women; M age, 23.5 years), and 268 non-heterosexuals (homosexual and bisexual; 64 men and 204 women; M age, 29.0 years) completed online questionnaires. Asexual men and women were 2.4 and 2.5 times, respectively, more likely to be non-right-handed than their heterosexual counterparts and there were significant differences between sexual orientation groups in number of older brothers and older sisters, and this depended on handedness. Asexual and non-heterosexual men were more likely to be later-born than heterosexual men, and asexual women were more likely to be earlier-born than non-heterosexual women. We found no significant differences between sexual orientation groups on measurements of 2D:4D ratio. This is one of the first studies to test and provide preliminary empirical support for an underlying neurodevelopmental basis to account for the lack of sexual attraction characteristic of asexuality.

Early-life hygiene-related factors affect risk of central nervous system demyelination and asthma differentially

The increasing prevalence of immune-related diseases, including multiple sclerosis, may be partly explained by reduced microbial burden during childhood. Within a multi-centre case-control study population, we examined: (i) the co-morbid immune diseases profile of adults with a first clinical diagnosis of central nervous system demyelination (FCD) and (ii) sibship structure in relation to an autoimmune (FCD) and an allergic (asthma) disease. FCD cases (n = 282) were aged 18-59 years; controls (n = 558) were matched on age, sex and region. Measures include: history of doctor-diagnosed asthma; sibling profile (number; dates of birth); and regular childcare attendance. FCD cases did not differ from controls with regard to personal or family history of allergy, but had a greater likelihood of chronic fatigue syndrome [odds ratio (OR) = 3·11; 95% confidence interval (CI) 1·11, 8·71]. Having any younger siblings showed reduced odds of FCD (OR = 0·68; 95% CI: 0·49, 0·95) but not asthma (OR = 1·47; 95% CI: 0·91, 2·38). In contrast, an increasing number of older siblings was associated with reduced risk of asthma (P trend = 0·04) but not FCD (P trend = 0·66). Allergies were not over-represented among people presenting with FCD. Sibship characteristics influence both FCD and asthma risk but the underlying mechanisms differ, possibly due to the timing of the putative 'sibling effect'.

Breastfeeding is associated with lower risk for multiple sclerosis

Background: Multiple sclerosis (MS) is an autoimmune disease with known genetic and environmental susceptibility factors. Breastfeeding has been shown to be protective in other autoimmune diseases. Objective: This case-control study analyzed the association of breastfeeding in infancy on the risk of developing MS. Methods: A case-control study was performed in Berlin of 245 MS patients and 296 population-based controls, who completed a standardized questionnaire on their history and duration of breastfeeding in infancy and demographic characteristics. Univariable and multivariable logistic regression analysis was performed to investigate the association between breastfeeding and MS. The multivariate model was adjusted for age, gender, number of older siblings, number of inhabitants in place of domicile between ages 0 and 6 (categorized in each case), and daycare attendance between ages 0 and 3. Results: In multivariable analysis, breastfeeding showed an independent association with MS (adjusted OR 0.58; p = 0.028). However, with no breastfeeding as reference, the protective effect only emerges after four months of breastfeeding (multivariable analysis for ≤ four months adjusted OR 0.87; p = 0.614 and for > four months OR 0.51; p = 0.016). Conclusion: The results of this case-control study support the hypothesis that breastfeeding is associated with a lower risk of MS. These results are in line with findings of previous studies on other autoimmune diseases, in which breastfeeding was shown to have protective effects.

High Asthma Prevalence and Associated Factors in Urban Malagasy Schoolchildren

Introduction. Studies about bronchial asthma in Africa are impeded by the dearth of reliable data for the vast majority of countries on the continent. This study was conducted to establish the first epidemiological data concerning bronchial asthma in urban Malagasy schoolchildren. Methods. From three public and five private schools 1236 students aged 7–14 years were recruited and examined using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. In a subgroup of 111 schoolchildren from two schools, lung function tests were conducted together with bronchodilator response (BDR) to establish reversible obstruction (change in FEV1 ≥ 12%). Results. The overall prevalence of wheezing in schoolchildren was 25.2%, with strikingly more wheezing in children attending private schools than public schools (p = .0012). The risk was diminished in students with older siblings (p < .03), but was not affected by other variables like smoking habits at home, body mass index, or cooking fuel. In the schools where BDR was performed, we found a point prevalence for reversible bronchial obstruction of 9% through lung function tests. Conclusion. Bronchial asthma is of great relevance for schoolchildren living in urban Madagascar. Socioeconomic factors and air pollution seem to have a major impact in addition to the number of older siblings.

Characterization of transition diets spanning infancy and toddlerhood: a novel, multiple-time-point application of principal components analysis

The portrayal of diet over time is a natural progression from the characterization of diet at single time points. The transition dietary period, a dynamic period of rapid dietary change spanning infancy and toddlerhood when children shift from a milk-based to a food-based diet, has not been characterized. The objective was to summarize variation in dietary intakes spanning infancy and toddlerhood. A prospective principal components analysis was applied to dietary intakes from 3 successive follow-ups of children enrolled in the ALSPAC (Avon Longitudinal Study of Parents and Children). The frequency of food and beverage consumption was assessed via questionnaire at ages 6, 15, and 24 mo (n = 2169). Two types of transition diet were identified. The first transition diet was characterized by the consumption of home-prepared and raw foods ("healthy") at all time points and the second by ready-prepared and discretionary foods ("less healthy") consistently over time. Higher educational level and maternal age were associated with higher scores on the "healthy" diet, whereas younger maternal age and a lower educational level were associated with higher scores on the "less healthy" diet. Maternal BMI, number of older siblings, and lower social class were associated with the less-healthy transition diet but not with the healthy transition diet. Unique transition diets, including a less-healthy type, emerge by age 2 y. These diets are consistent with childhood and adult dietary patterns reported at single time points and show convergent validity both with known maternal sociodemographic predictors of childhood diet and with intake gradients across diet scores.

Dietary meat and fat intake and prevalence of rhinoconjunctivitis in pregnant Japanese women: baseline data from the Kyushu Okinawa Maternal and Child Health Study

BackgroundDietary fat exerts numerous complex effects on proinflammatory and immunologic pathways. Several epidemiological studies have examined the relationships between intake of fatty acids and/or foods high in fat and allergic rhinitis, but have provided conflicting findings. The current cross-sectional study investigated such relationships in Japan.MethodsStudy subjects were 1745 pregnant women. The definition of rhinoconjunctivitis was based on criteria from the International Study of Asthma and Allergies in Childhood. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for age; gestation; region of residence; number of older siblings; number of children; smoking; secondhand smoke exposure at home and at work; family history of asthma, atopic eczema, and allergic rhinitis; household income; education; and body mass index.ResultsThe prevalence of rhinoconjunctivitis in the past 12 months was 25.9%. Higher meat intake was significantly associated with an increased prevalence of rhinoconjunctivitis: the adjusted odds ratio between extreme quartiles was 1.71 (95% confidence interval: 1.25-2.35, P for trend = 0.002). No measurable association was found between fish intake and rhinoconjunctivitis. Intake of total fat, saturated fatty acids, monounsaturated fatty acids, n-3 polyunsaturated fatty acids, α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, n-6 polyunsaturated fatty acids, linoleic acid, arachidonic acid, and cholesterol and the ratio of n-3 to n-6 polyunsaturated fatty acid intake were not evidently related to the prevalence of rhinoconjunctivitis.ConclusionsThe current results suggest that meat intake may be positively associated with the prevalence of rhinoconjunctivitis in young adult Japanese women.

Prenatal Influences on Sexual Orientation: Digit Ratio (2D:4D) and Number of Older Siblings

Prenatal androgen levels are suggested to influence sexual orientation in both sexes. The 2D:4D digit ratio has been found to associate with sexual orientation, but published findings have often been contradictory, which may partly be due to the large ethnic diversity between and within studied populations. In men, number of older brothers has been found to correlate positively with homosexuality. This phenomenon has been explained with a maternal immune reaction, which is provoked only by male fetuses and which gets stronger after each pregnancy. Here we assessed the relationship of sexual orientation to 2D:4D ratios and number of older siblings in Finland, where the population is found to be genetically relatively homogeneous. As in many previous studies, heterosexual men had lower 2D:4D than non-heterosexual men, which supports the notion that non- heterosexual men experience higher androgen levels in utero than population norms. Contrary to previous reports, non-heterosexual women had higher 2D:4D than heterosexual women. Non-heterosexual men had more older brothers and older sisters than heterosexual men. The greater number of older sisters in non-heterosexual men indicates that there are other factors that contribute to the higher birth order of homosexual men than the maternal immunization.

Sibling number and prevalence of allergic disorders in pregnant Japanese women: baseline data from the Kyushu Okinawa Maternal and Child Health Study

BackgroundAlthough an inverse relationship between number of siblings and likelihood of allergic disorders has been shown in many epidemiological studies, the biological mechanism underlying this phenomenon has not yet been identified. There is no epidemiological research regarding the sibling effect on allergic disorders in Japanese adults. The current cross-sectional study examined the relationship between number of siblings and prevalence of allergic disorders among adult women in Japan.MethodsSubjects were 1745 pregnant women. This study was based on questionnaire data. The definitions of wheeze and asthma were based on criteria from the European Community Respiratory Health Survey whereas those of eczema and rhinoconjunctivitis were based on criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age, region of residence, pack-years of smoking, secondhand smoke exposure at home and at work, family history of asthma, atopic eczema, and allergic rhinitis, household income, and education.ResultsThe prevalence values of wheeze, asthma, eczema, and rhinoconjunctivitis in the past 12 months were 10.4%, 5.5%, 13.0%, and 25.9%, respectively. A significant inverse exposure-response relationship was observed between the number of older siblings and rhinoconjunctivitis, but not wheeze, asthma, or eczema (P for trend = 0.03); however, the adjusted odds ratio (OR) for having 2 or more older siblings was not significant although the adjusted OR for having 1 older sibling was statistically significant (adjusted OR = 0.71 [95% CI: 0.56-0.91]). Number of total siblings and number of younger siblings were not related to wheeze, asthma, eczema, or rhinoconjunctivitis.ConclusionsThis study found a significant inverse relationship between the number of older siblings and the prevalence of rhinoconjunctivitis among pregnant Japanese women. Our findings are likely to support the intrauterine programming hypothesis; however, we could not rule out the hygiene hypothesis.