Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Birth Order”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed2000

Schizophrenia and birth order in Pakistan.

The paper describes a two stage study. In Stage I the birth orders of 453 adult patients with different diagnoses, seen in the routine work of a general hospital psychiatry department, were compared. Patients with schizophrenia had significantly higher average birth positions than patients with other diagnoses, even after controlling for sibship size.In Stage II, the birth positions of 64 patients with schizophrenia (DSMIIIR) were subjected to a goodness-of-fit chi-square test. Over-representation of eldest siblings was highly significant for both sexes. When patients aged 30 and above were analysed separately, there was still a significant excess of first-born. These findings are in contrast to birth order studies of schizophrenia in western populations. In the authors' opinion, they can not be accounted for by the biases to which birth order studies are prone. They indicate a need for further community-based studies.

Adolescent↗
PubMed1986

The viability of birth order studies in substance abuse research.

Examinations of the birth order literature for drug and alcohol abuse reveals equivocal and contradictory findings, many of which are methodologically suspect. The findings based on the 12-year follow-up of the Drug Abuse Reporting Program (DARP) suggest that there is very little support for birth order differences among drug abusers for age of initial drug use, severity of drug use, achievement of abstinence, or alcohol consumption. Finally, it is suggested that birth position is probably not a strong hypothesis for further research. Methodological difficulties, the likelihood of very small effect sizes (if any), and the uncertain theoretical status of birth position all detract from the viability of such investigations.

Adult↗
PubMed2004

An intergenerational study of birthweight: investigating the birth order effect.

In a two-generation study of the nationwide 1958 British cohort and their offspring, we investigated the intergenerational influence of birth order on birthweight. Despite increases in own birthweight by birth order and a positive parent-offspring correlation in birthweights, there was a suggestion that parental birth order was inversely associated with offspring birthweight. This paradoxical finding was due to differential intergenerational birthweight associations, with a weaker association in later-born compared with first-born parents. Our findings suggest that underlying causes of a given birthweight should be taken into account in studies that investigate long term health outcomes.

Birth Order↗
PubMed2006

Does paternal antigen-induced secretion of interleukin-10 by T regulatory cells mediate the birth order effect?

Childhood allergy constitutes a significant burden of disease in the Western world. The prevalence of this condition is highest in first born children, an as yet unresolved phenomenon called the "birth order effect". The hygiene hypothesis attempted to explain this differential risk by stating that less exposure to microbial agents at an early age of first born children would result in reduced activation of the immune system and subsequent polarization towards a Th2 phenotype. However, no conclusive evidence for or against the hygiene hypothesis has been found so far. Another, not necessarily conflicting, theory states that the birth order effect is already established during prenatal life and that the fetal-maternal interaction changes during successive pregnancies. Combining this theory with research on preeclampsia, another disease originating in pregnancy and also related to birth order, could suggest clues about the mechanisms underlying the birth order effect. Recent research on preeclampsia showed that preeclamptic women have higher levels of pro-inflammatory IL-6 and lower paternal antigen-induced secretion of IL-10 compared to normal pregnant women, indicating a lower number or lower functional activity of T regulatory (Treg) cells. These Treg cells play an important role in maintaining tolerance to fetal antigens in pregnancy and they are found in high numbers at the maternal-fetal interface. We hypothesize that nulliparous women have a lower activity of Treg cells specific to paternal antigens compared to parous women, either in peripheral blood or in the decidua (maternal part of the fetal-maternal interface). If this hypothesis is true, this would mean that the allergen suppressor mechanism of Treg cells is sub-optimal in first born children. This would explain at least a part of the mechanism of the birth order effect and would give us directions for developing preventive measures to prevent possibly 30% of future childhood allergies.

Antigens↗
PubMed2000

Resolving the debate over birth order, family size, and intelligence.

Hundreds of research articles have addressed the relationship between birth order and intelligence. Virtually all have used cross-sectional data, which are fundamentally flawed in the assessment of within-family (including birth order) processes. Although within-family models have been based on patterns in cross-sectional data, a number of equally plausible between-family explanations also exist. Within-family (preferably intact-family) data are prerequisite for separating within- and between-family causal processes. This observation reframes an old issue in a way that can be easily addressed by studying graphical patterns. Sibling data from the National Longitudinal Survey of Youth are evaluated, and the results are compared with those from other studies using within-family data. It appears that although low-IQ parents have been making large families, large families do not make low-IQ children in modern U.S. society. The apparent relation between birth order and intelligence has been a methodological illusion.

Adolescent↗
PubMedDate not supplied

[Concise measures of period fertility by birth order. An application to Italian data].

"In recent studies several authors have shown how fertility tables and concise measures by birth order, strictly and exclusively related to the period fertility conditions, can be derived on the basis of parity progression rates.... The many indicators derivable from the fertility tables compiled as stated above are described systematically and completely in relation to their different features. On the basis of a 'complementary' model [I show] a further category of concise measures referring to fertility tables which are formally identical to the classical life tables with regard to each order of birth. The study includes applications to concrete data concerning North Central and Southern divisions of Italy (1980-1982 and 1988-1990)." (SUMMARY IN ENG AND FRE)

Birth Order↗
PubMed1985

Parental age and birth order effects in children with febrile convulsions.

This is a study of the parental age and birth order of 100 Chinese children with febrile convulsions compared with 100 controls. The birth order of children with febrile convulsions (1.6 +/- 0.8) was found to be lower than that of the controls (2.1 +/- 1.0), a difference significant at P less than 0.001, whereas there was no significant difference for both paternal and maternal age. Using multiple regression analysis, it was found that the birth order effect was significant at P less than 0.0001. This finding suggests that perinatal factors may play a role in the pathogenesis of febrile convulsions.

Adult↗
PubMed2000

Effects of gender difference and birth order on perceived parenting styles, measured by the EMBU scale, in Japanese two-sibling subjects.

The relationship between Egna Minnen av Barndoms Uppforstran (EMBU) scaling and gender, birth order and parents' gender was previously investigated in a large volunteer sample; significant interactions among the variables were found. In the present study, 730 Japanese volunteers with one sibling were used as subjects in order to control the number of siblings: the effect of gender of subjects and siblings and birth order on the perceived parenting style was examined. Based on gender and birth orders, 730 subjects were grouped into the following categories: (i) male with a younger brother; (ii) male with a younger sister; (iii) male with an older brother; (iv) male with an older sister; (v) female with a younger brother; (vi) female with a younger sister; (vii) female with an older brother; and (viii) female with an older sister. One-way ANOVA was performed with each EMBU subscale used as a dependent variable and these eight groups as independent variables. The scores for rejection and emotional warmth of father were influenced significantly by the pattern of siblings (P<0.006 and P<0.0012, respectively), and scores for emotional warmth of mother were influenced significantly by the pattern of siblings (P<0.0012). The elder male children strongly experienced parenting style as more rejecting than others, and female children (elder sisters with brother, or younger sisters with sister) recognized parenting style as more caring and demonstrated more warmth than others. The results confirmed a significant interaction of gender of subjects and siblings and birth order of perceived parental rearing behavior.

Adolescent↗
PubMed1998

The relation of birth order to sexual orientation in men and women.

Homosexual men have a higher mean birth order than do heterosexual men, primarily because they have a greater number of older brothers. The purpose of this study was to determine whether the same difference occurs in homosexual vs heterosexual women. The probands were 964 homosexual and heterosexual, male and female volunteers, from whom birth order data were collected with self-administered questionnaires. The homosexual men had more older brothers than the heterosexual men, but they did not have more older sisters, younger brothers, or younger sisters. The homosexual women did not differ from the heterosexual women with regard to any class of sibling. These results are consistent with the hypothesis that the high birth order of homosexual men reflects the progressive immunization of certain mothers to H-Y antigen by succeeding male fetuses, and the increasing effects of H-Y antibodies on sexual differentiation of the brain in succeeding male fetuses.

Adult↗
PubMed1979

Parental age and birth order in homosexual patients: a replication of Slater's study.

Parental age (at patient's birth) and birth order were studied in 623 male and 89 female patients diagnosed as homosexual, who were born in England and Wales and first attended the Maudsley Hospital between the years 1961-1975. For male patients, mean parental ages were significantly higher than expectation, and mean birth order was significantly later. Regression analysis indicated that the raised fathers' age was probably of more aetiological importance than the raised mothers' age. The results confirm those of previous studies. The female patients did not show a raised parental age or late birth order.

Adolescent↗
PubMedDate not supplied

Proportion of homosexual men who owe their sexual orientation to fraternal birth order: An estimate based on two national probability samples.

Homosexuality in men correlates with an individual's number of older brothers, greater numbers of older brothers being associated with a greater probability of homosexuality. There are reasons to believe that this relationship is causal rather than merely statistical, that is, that older brothers produce the increase in the probability of homosexuality for later-born males. It is possible, under this assumption, to estimate the proportion of homosexual men who can attribute their sexual orientation to their birth order among their brothers (fraternal birth order). This statistic, the population attributable fraction (PAF), was computed on the combined archival data of 2,256 heterosexual and 71 homosexual men examined in survey studies of sexual behavior in the UK and the USA. The PAF was 28.6%, with 95% confidence limits of 14.8% and 48.0%. These limits encompass the PAF of 15.1% previously estimated with a Canadian sample. The results indicate that the proportion of homosexual men whose sexual orientation is attributable to fraternal birth order constitutes a minority, but not a negligible minority, of all homosexual men. The fraternal birth order effect may reflect the progressive immunization of some mothers to Y-linked antigens by each succeeding male fetus, and the concomitantly increasing effects of antimale antibodies on the sexual differentiation of the brain in each succeeding male fetus.

Birth Order↗
PubMed2002

Birth order and ankylosing spondylitis: no increased risk of developing ankylosing spondylitis among first-born children.

OBJECTIVE: In the HLA-B27 transgenic mouse model the first litters have been shown to have a higher percentage of diseased offspring than later litters. First-born children (n = 162) have also been shown to have a higher risk of ankylosing spondylitis (AS) than later-born children. We examined this effect of birth order using similar methods but larger numbers. METHODS: Patients from the Bath AS database (n = 4517; M:F = 2.5:1) were examined according to position of birth within the family. Chi-squared analysis was used to examine if AS was more prevalent among first-born than later-born children. RESULTS: The first-born child was not significantly more likely to have AS than later-born children (p = 0.295). [Observed compared to expected: 1607 (36%) compared to 1641.13 (36%) for first-born children and 2910 (64%) compared to 2876.3 (64%) for later-born children, respectively.] There was no biological gradient (i.e., inverse correlation between birth order and disease risk). CONCLUSION: There was no statistically significant effect of birth order based on our data. Findings suggesting a birth order effect may be skewed, as it is possible that those parents who do have AS will be less likely to have a large family and yet it is their offspring who will be at greatest risk of developing disease. This will affect the data, as those children born into a large family (i.e., high birth order children) will be at a lower risk of AS than any child born into a small but family-history-positive unit.

Adult↗
PubMed1993

Birth order and risk of sudden infant death syndrome: is the true relationship negative?

The risk of SIDS has been reported consistently as being positively related to parity or birth order. However, the reports in question have failed to take into account the possible confounding effects of sibship size. In the present study it was reasoned that if this were done the relationship would be negative, not positive. In an analysis of births stratified by sibship size positive. In an analysis of births stratified by sibship size occurring in the years 1975-84 in the state of Oregon, it was found that the risk of SIDS in the age range 7-364 days did indeed tend to decrease with increasing birth order when sibship size was held constant. An expected tendency for SIDS rates to increase with increasing sibship size when birth order was held constant was also confirmed. This tendency is probably explained by a negative correlation between family size and socio-economic status. Non-SIDS rates behaved in a similar manner to SIDS rates. The tendency for the risk of SIDS to decrease with increasing birth order was more evident when births following a pregnancy interval of less than 12 months were excluded.

Birth Order↗
PubMed2004

No major birth order effect on the risk of multiple sclerosis.

In the present study, we found no association between multiple sclerosis (MS; definite and probable, n = 211) and birth order (p = 0.1411). The observed number of first-born patients did not differ significantly from the expected number (p = 0.0871). While there was a significantly high birth order (n = 258, p = 0.0381) and a marginally significant low number of first-borns (p = 0.0475) when possible MS cases were included, an artefact due to the population structure may have accentuated this result. In comparison with the control birth cohort, there was no significant association with birth order (p = 0.0742) or the proportion of first-borns (p = 0.220) in a subgroup from the MS incidence cohort born between 1915 and 1929 (n = 158). Birth order had no major impact on the risk of subsequent MS in this study.

Aged↗
PubMedDate not supplied

Is there a relationship between non-insulin diabetes mellitus and birth order?

Our objective was to determine the prevalence of non-insulin dependent diabetes mellitus Type 2 Diabetes, in the province of Leon, Spain, and to investigate the relationship between birth order and the presence of diabetes. A cross-sectional study was therefore carried out on a stratified sample of the adult population (n = 569). The participants completed a socio-demographic questionnaire and an analysis of their basal capillary glycaemia and an oral glucose tolerance test (OGTT) after a 75 g load according to WHO recommendations. Type 2 diabetes prevalence was 5.62%. It was higher in subjects with a birth order above 4 than among those with a birth order below or equal to 4. (16.81% vs 2.85%, p < 0.001). This remained after adjusting for age. It was not proved that either sex, obesity or a family history of diabetes could amount to confusion factors. Greater values of fasting glycaemia (5.12 vs 4.73 mmol/l, p < 0.001) and less satisfactory post-OGTT glycaemic curves were also shown is subjects with a birth order > 4. Although it was not-possible to definitely conclude, from our study, that children born after the fourth birth have a greater risk of presenting alterations in their carbohydrate metabolism, there are indicators arguing for a more detailed study of such a possibility.

Adolescent↗
PubMed2004

Birth order, sibship size, and housing density in relation to tooth loss and periodontal disease: a cohort study among Swedish twins.

For diseases with an infectious etiology, birth order may dictate the age of exposure to childhood infection, while sibship size may be a proxy for the probability of exposure. The authors examined whether birth order, sibship size, and childhood housing density affect risk of tooth loss and periodontal disease. The study included 28,690 adults aged > or = 42 years who were participating in a 1998-2002 follow-up of persons listed in the Swedish Twin Registry. Logistic regression was used to calculate odds ratios and 95% confidence intervals, with adjustment for age, sex, education, and smoking and mutual adjustment for family composition (sibship size and/or birth order). Tooth loss and periodontal disease affected 8% and 19% of the twins, respectively. Each additional sibling increased the odds of tooth loss by 10% (95% confidence interval (CI): 1.06, 1.15) and the odds of periodontal disease by 5% (95% CI: 1.02, 1.08). Later birth order was associated with lower odds of periodontal disease. Each additional person per room in the childhood home increased the odds of tooth loss (odds ratio = 1.28, 95% CI: 1.03, 1.60) but lowered the odds of periodontal disease (odds ratio = 0.65, 95% CI: 0.48, 0.89). These findings are compatible with the hypotheses that adult oral diseases are associated with the probability of exposure in childhood and that earlier age at exposure lowers risk.

Adult↗
PubMed1987

Birth order in obsessive-compulsive disorder.

Birth order and family size were studied in 392 cases of obsessive-compulsive disorder (OCD) seen in the decade 1975-84. On the basis of Slater's index, there was a nonsignificant excess of earlier-born children in the sample. However, this excess was not present in each individual family size, and was not due to either age of onset or sex. Smaller families had more earlier-born index cases, and larger families had more later-born index cases. First-born and only children were not overrepresented in the sample.

Adolescent↗
PubMed2000

Fraternal birth order and sexual orientation in pedophiles.

Whether homosexual pedophiles have more older brothers (a higher fraternal birth order) than do heterosexual pedophiles was investigated. Subjects were 260 sex offenders (against children age 14 or younger) and 260 matched volunteer controls. The subject's relative attraction to male and female children was assessed by phallometric testing in one analysis, and by his offense history in another. Both methods showed that fraternal birth order correlates with homosexuality in pedophiles, just as it does in men attracted to physically mature partners. Results suggest that fraternal birth order (or the underlying variable it represents) may prove the first identified universal factor in homosexual development. Results also argue against a previous explanation of the high prevalence of homosexuality in pedophiles (25% in this study), namely, that the factors that determine sexual preference in pedophiles are different from those that determine sexual preference in men attracted to adults. An alternative explanation in terms of canalization of development is suggested.

Adolescent↗