Analysis of Maternal Postnatal Depression, Socioeconomic Factors, and Offspring Internalizing Symptoms in a Longitudinal Cohort in South Africa

IMPORTANCE

Few studies from low-and-middle income countries have investigated long-term associations between maternal postnatal depression and offspring internalizing (ie, depressive and anxiety) symptoms, and none have investigated interactions in this association.

OBJECTIVE

To investigate the association between maternal postnatal depression and offspring internalizing symptoms from adolescence to adulthood and the interaction with exposure to socioeconomic adversity and with the child's sex.

DESIGN, SETTING, AND PARTICIPANTS

This secondary analysis used data from Birth to Twenty Plus (BT20+), a prospective birth cohort study of children born in Soweto, South Africa, and followed up until age 28 years. Data were collected from 1990 to 2018, and data were analyzed for this study from February 16 through December 15, 2020.

EXPOSURES

Maternal postnatal depression self-reported by mothers 6 months after childbirth.

MAIN OUTCOMES AND MEASURES

The main outcome was offspring internalizing symptoms, assessed at offspring ages 14 years, 22 years, and 28 years and modeled longitudinally. Participants with the highest probability of experiencing high internalizing symptoms (ie, those in the top 20% of the distribution) from age 14 to 28 years were categorized as belonging to the high internalizing symptoms trajectory (vs the low trajectory). Socioeconomic adversity was measured with an index (continuous variable) including low maternal education, household crowding, low assets, and low maternal age. This variable was further stratified into more than 1 SD above the mean index, more than 1 SD below the mean index, and from 1 SD below to 1 SD above the mean index to conduct subgroup analyses. Associations were investigated using multivariable regression models.

RESULTS

Among 1087 participants born in Soweto, South Africa (543 [50.0%] male participants; 544 [50.0%] female participants), 118 individuals (10.8%) showed a high trajectory of internalizing symptoms from age 14 to 28 years vs 969 individuals (89.1%) with a low trajectory. Children exposed to maternal postnatal depression had statistically significantly increased odds of following the high trajectory (adjusted odds ratio [aOR] per 1-SD increase in maternal postnatal depression, 1.20; 95% CI, 1.02-1.41). This increase in odds differed by exposure to socioeconomic adversity and by child sex: for male participants, the increase in odds was greater in a context of higher vs lower socioeconomic adversity (eg, for >1 SD above the mean: aOR, 3.28; 95% CI, 1.06-10.14 vs for >1 SD below the mean: aOR, 0.98; 95% CI, 0.64-1.50; P for interaction = .12), while for female participants, the increase in odds was greater in a context of lower vs higher socioeconomic adversity (eg, for >1 SD below the mean: aOR, 1.82; 95 % CI, 1.12-2.98 vs for >1 SD above the mean: aOR, 0.59; 95 % CI, 0.30-1.17; P for interaction = .002) (P for 3-way interaction = .003).

CONCLUSIONS AND RELEVANCE

This study found that postnatal depression was associated with higher odds of persistently increased internalizing symptoms among offspring from adolescence to adulthood in a middle-income country, with variation by socioeconomic adversity and sex. These findings suggest that better understanding of these associations is needed to implement targeted interventions and maximize the impact of public health initiatives aimed at breaking the intergenerational transmission of mental health problems.

Meta-Analyses of Fraternal and Sororal Birth Order Effects in Homosexual Pedophiles, Hebephiles, and Teleiophiles

This study investigated the relations between numbers of older brothers, numbers of older sisters, and the odds of homosexuality in later-born males, including males who are most attracted sexually to prepubescent or early pubescent children (pedohebephiles) and males who are most attracted sexually to adults (teleiophiles). The authors meta-analyzed data from 24 samples of homosexual and heterosexual men, originally reported in 18 studies, and totaling 18,213 subjects. The results confirmed that older brothers increase the odds of same-sex preference in pedohebephiles as they do in teleiophiles. They also replicated the recent finding that older sisters have a similar but weaker statistical association with the odds of homosexuality. These findings have two theoretical implications. First, the findings for older brothers and older sisters indicate some commonality in the factors that influence sexual preference in teleiophiles and those that influence sexual preference in pedohebephiles. Second, the finding for older sisters confirms a prediction stemming from the hypothesis that male fetuses stimulate maternal antibodies that increase the odds of homosexuality in later-born males. Such immunization could result from miscarried as well as full-term fetuses, and number of older sisters should correlate with number of male fetuses miscarried before gestation of the subject.

Reassessing the Effect of Older Sisters on Sexual Orientation in Men

This research reanalyzed questionnaire data from 8279 homosexual and 79,519 heterosexual men who participated in 2005 in an internet-based research project sponsored by the British Broadcasting Corporation. It focused on parameters of sibship composition (older brothers, older sisters, younger siblings) previously shown or hypothesized to influence sexual orientation in males. The results included the usual finding that older brothers increase the odds of homosexuality in later-born males. As predicted, older sisters also increase those odds, although by a lesser amount than older brothers. Other results confirmed that the odds of homosexuality are increased in only-children, the amount of increase being equal to that produced by one older brother and greater than that produced by one older sister. Finally, the results indicated that younger siblings have no effect on the odds of homosexuality in males. These results might be explained by the hypothesis that two different types of immune responses in pregnant women can affect the future sexual orientation of their male fetuses. One type of response affects fetuses in first pregnancies and reduces subsequent fertility. The other type affects fetuses in later pregnancies and has little or no effect on fertility. Finally, we conducted an estimate of combined sibship effects. Men who were exposed to any of the influences that we identified (being an only-child or having an older sibling) had 27% greater odds of homosexuality than did subjects who were exposed to none of these influences (i.e., the first-born of two or more children).

Blessed are the first: The long-term effect of birth order on trust

Acknowledging childhood as a crucial period for the formation of social preferences, we investigate whether the order of birth predicts trust in adult life. We find that laterborns trust on average 5% less than their older siblings, independently from personality traits, family ties, risk aversion and parental inputs. Family random- and fixed-effects estimates suggest that the variation in trust is mostly explained by within- rather than between-family characteristics. The effect of birth order is mediated by education outcomes only for women, while it is moderated by mother's education for the entire sample, thereby leading to relevant policy implications.

Handedness and Birth Order Among Heterosexual Men, Gay Men, and Sao Praphet Song in Northern Thailand

Previous research has examined handedness and birth order to inform sexual orientation and gender identity/role expression development; however, sexual orientation and gender identity/role expression have rarely been disentangled to provide a more nuanced perspective. In Thailand, we investigated sexual orientation and gender identity simultaneously via comparison of 282 heterosexual men, 201 gay men, and 178 sao praphet song-i.e., androphilic, markedly feminine males recognized as a "third" gender. Handedness was examined as: extremely left-handed, moderately left-handed, ambidextrous, moderately right-handed, or extremely right-handed. Birth order was examined as numbers of older and younger brothers and sisters, by using Berglin's, fraternal, and sororal indices, and by examining the older brother odds ratio and sibling sex ratio. Compared with heterosexual men, gay men and sao praphet song were more likely to be extremely right-handed. Sao praphet song were also more likely to be extremely left-handed than heterosexual and gay men. Heterosexual men and sao praphet song had later sororal birth order compared with the expected Thai population value, suggesting stopping rules influenced when probands' mothers ceased having children. These findings provide new insights and replicate previous findings in a non-Western sample. Regarding handedness, in males, mechanisms related to extreme right-handedness likely influence the development of androphilia, whereas mechanisms related to both extreme right- and extreme left-handedness likely explain the combination of androphilia and feminine gender identity/role expression. Regarding birth order, similar to the conclusions of some prior research, stopping rules pose a challenge for testing the fraternal birth order effect.

The levels and trends of contraceptive use before first birth in India (2015-16): a cross-sectional analysis

BACKGROUND

Indian women are more prone to first birth at a relatively younger age after marriage. Also, we do not have sufficient literature available that focuses on contraceptive use before first birth. The analysis of the present study was done using data from the fourth round of National Family Health Survey (2015-16), India. The objectives of the present study were to measure the levels and trends of contraceptive use before first birth among Indian ever married women, aged 15-34 years.

METHODS

The study includes 279,896 ever married women aged 15-34 years at the time of the NFHS-4 survey. To identify the socio-demographic determinants governing the pioneering study behavior, multivariable techniques have been used in the analysis. The statistical significance of the relationship between socio-demographic factors and contraceptive use prior to first birth was tested using a chi-squared test for association. Hosmer Lemeshow statistics and Nagelkerke R square have been used to check how well the logistic regression model fits the data. Map of India showing different zonal classification is made using the ArcGIS software version 10.3.

RESULT

The trends of contraceptive usage show a decline in use before first birth and the various socio-demographic factors affecting the use of contraceptive before first birth are religion, caste, education, wealth index, media exposure, age at marriage and the zonal classifications.

CONCLUSION

The noticeable result in this study is the comparative decline in contraceptive use by women in India before first birth in NFHS-4 with respect to previous NFHS done in India. The likelihood of using contraception before first birth is significantly affected by factors like place of residence, religion, caste, current age of women, age at marriage, education level of women, wealth index, media exposure and zonal classification.

Time trends in and factors associated with repeat adolescent birth in Uganda: Analysis of six demographic and health surveys

Background

Information on repeat adolescent birth remains scarce in sub-Sahara Africa. We investigated the prevalence and time trends in repeat adolescent birth in Uganda, and associated factors.

Methods

We analyzed Uganda Demographic and Health Survey data of women age 20–24 years collected on 6 surveys (1988/89-2016) to estimate repeat adolescent birth (first live birth <18 years of age followed by another live birth(s) <20 years). Further, we estimated the wantedness of the second order birth and the prevalence of short birth intervals birth (<13 months) between the first and second such birth. On the 2016 survey, we examined factors associated with repeat adolescent birth using bivariate and multivariate modified Poisson regression.

Results

At the 1988/89 survey, 58.9% of women with first birth <18 years reported a repeat adolescent birth. This percentage increased to 66.8% in 2006 (+7.9 percentage points [pp], p = 0.010) and thereafter declined to 55.6% by 2016 (-11.2 pp, p<0.001), nevertheless, no change occurred between 1988/89 and 2016 (-3.3pp, p = 0.251). Among women with repeat adolescent births, the mean number of live births by exact age 20 years (2.2 births) and prevalence of short birth intervals (3.5% in 1988/89, 5.4% in 2016) (+1.9pp, p = 0.245) did not change. Increasingly more women with repeat adolescent births preferred to have had the second child later, 22.5% in 1995 and 43.1% in 2016 (+20.6pp, p = <0.001). On the 2016 survey, women from poorer households and those of younger age at first birth were significantly more likely to report repeat adolescent birth.

Conclusion

Following a first birth <18 years, more than half of the women report a repeat adolescent birth (<20 years), with no decline observed in 30 years. Increasingly more women wanted the second adolescent pregnancy later, highlighting the need to support adolescents with improved family planning services at each contact.

A short review of biological research on the development of sexual orientation

We review research supporting biological mechanisms in the development of sexual orientation. This research includes studies on neural correlates, prenatal hormones and related physical/behavioral correlates, genetics, and the fraternal birth order effect (FBOE). These studies, taken together, have provided substantial support for biological influences underlying the development of sexual orientation, but questions remain unanswered, including how biological mechanisms may differ in contributing to men's and women's sexual orientation development.

On the Mathematics of the Fraternal Birth Order Effect and the Genetics of Homosexuality

Mathematicians have always been attracted to the field of genetics. The mathematical aspects of research on homosexuality are especially interesting. Certain studies show that male homosexuality may have a genetic component that is correlated with female fertility. Other studies show the existence of the fraternal birth order effect, that is, the correlation of homosexuality with the number of older brothers. This article is devoted to the mathematical aspects of how these two phenomena are interconnected. In particular, we show that the fraternal birth order effect implies a correlation between homosexuality and maternal fecundity. Vice versa, we show that the correlation between homosexuality and female fecundity implies the increase in the probability of the younger brothers being homosexual.

Fraternal Birth Order, Only-Child Status, and Sibling Sex Ratio Related to Sexual Orientation in the Add Health Data: A Re-analysis and Extended Findings

The fraternal birth order (FBO) effect related to men's sexual orientation refers to the finding that the number of older brothers that a man has increases his chance of being androphilic. The FBO effect has generally been well replicated in diverse samples; one instance of non-replication was by Francis (2008) using Waves I and III of the Add Health data. We attempted to replicate the FBO effect in the Add Health data taking into account family size and other limitations of Francis' (2008) analyses. Also, we examined other sibling characteristics related to the FBO effect: sibling sex ratio and only-child status. We used two subsamples from Waves I (n = 20,745) and IV (n = 15,701) of the Add Health data, consisting of adolescents who were followed longitudinally from 1994 to 1995 until 2008. Wave I data were used to compute numbers of younger and older brothers and sisters from household roster information. Wave IV information about sexual orientation identity was used. Analyses were conducted within men and within women. We found modest support for the FBO effect in men, but not in women, using the older brother odds ratio, logistic regression analyses, and sibling sex ratio, which provided the strongest support for FBO. We found that gynephilic/biphilic women, but not androphilic/biphilic men, were more likely to be only-children compared to androphilic women and gynephilic men, respectively. We discuss limitations of the Add Health data and purported mechanisms for the FBO effect in men and the only-child effect in women.

Does Fraternal Birth Order Predict Male Homosexuality, Bisexuality, and Heterosexual Orientation with Same-Sex Attraction? Evidence from a Greek-Speaking Sample from Greece

Studies have established that having older brothers is associated with an increased incidence of male homosexuality. This so-called fraternal birth order effect has been found in different times and cultural settings. The current study attempted to examine whether this effect was present in the Greek cultural context and whether it could also predict bisexuality or heterosexuality with occasional same-sex attractions. On the basis of an online sample of 1617 Greek-speaking participants, it was found that, for men, a higher number of older brothers were associated with an increased probability to be homosexual, but it had no effect on the probability to be bisexual or heterosexual with same-sex attractions. In women, the number of older brothers had not any effect on sexual orientation.

Associations between birth order with mental wellbeing and psychological distress in midlife: Findings from the 1970 British Cohort Study (BCS70)

BACKGROUND

Previous research indicated that birth order was associated with physical health outcomes in adulthood. However, evidence on its association with mental health was lacking. The aim of this study was to investigate if birth order was associated with mental wellbeing and psychological distress at mid-life, stratified by gender, and taking into account confounding factors in childhood and adulthood.

METHOD

The sample consisted of 9,354 participants of the 1970 British Cohort Study (BCS70). The Warwick Edinburgh Mental Wellbeing Scale (WEMWBS), the Malaise Index and attending a doctor's consultation in the past year for a mental health issue at age forty-two were used to assess mental wellbeing and psychological distress in midlife. Birth order was ascertained via a parental questionnaire and referred to the numerical birth position of the participants. The associations between birth order, mental wellbeing and psychological distress were tested using linear and logistic regression adjusting for birth characteristics: smoking during pregnancy, maternal age, mother's marital status, father's employment, region of birth, parental years of education and parental social class, and factors at age 42: years of education, employment status and partnership status. Potential mediating variables including breastfeeding and birthweight at birth and parental separation and conduct disorder measured at age ten were also taken into account.

RESULTS

We find no evidence to support an association between birth order and midlife psychological distress or attending a doctor's consultation in both men and women. In unadjusted analysis, there was an association between birth order four and above and a reduced WEMWBS score of -0.79 (95% CI -1.57, -0.02) in men only. This association was attenuated after adjusting for birth characteristics and mediators at birth (0.86, 95% -1.78, 0.07) but was maintained once conduct disorder at age 10 was accounted for (-1.19, 95% CI -2.28, -0.09). However, this association was attenuated once again after adjusting for employment status, years in education and partnership status in adulthood (-1.04, 95% CI -2.11, 0.03).

CONCLUSIONS

In this study, birth order was not associated with psychological distress or having a mental health issue at midlife. Accounting for employment status, years of education and partnership status in adulthood attenuated the relationship between birth order and mental wellbeing.

Adult attachment and testosterone reactivity: Fathers' avoidance predicts changes in testosterone during the strange situation procedure

We assessed parents' testosterone reactivity to the Strange Situation Procedure (SSP), a moderately stressful parent-infant interaction task that pulls for parental nurturance and caregiving behavior. Parents (146 mothers, 154 fathers) interacted with their 1-year-old infants, and saliva samples were obtained pre- and post-task to assess changes in testosterone. We examined whether testosterone reactivity differed between mothers and fathers, the extent to which parents' characteristic approaches to closeness (i.e., adult attachment orientation) contributed to testosterone changes, and whether any influences of adult attachment orientation were independent of more general personality characteristics (i.e., the Big Five personality dimensions). Results revealed that mothers and fathers showed comparable declines in testosterone during the SSP, and that these declines were attenuated among fathers with a more avoidant attachment orientation (i.e., those less comfortable with closeness). Associations between fathers' avoidance and testosterone reactivity were statistically independent of broader personality traits. Our findings provide some of the first evidence for short-term changes in both mothers' and fathers' testosterone in contexts that pull for nurturance. Moreover, these findings demonstrate that individual differences in adult attachment may play an important role in understanding such changes. We discuss possible explanations for gender differences in associations between adult attachment and parents' testosterone reactivity, and the extent to which testosterone reactivity might be sensitive to changes in context for mothers versus fathers.

The Association Between Fraternal Birth Order and Anal-Erotic Roles of Men Who Have Sex with Men

The fraternal birth order effect (FBOE) describes the phenomenon that homosexual men tend to have a greater number of older brothers than do heterosexual men. The FBOE is a marker for an innate, biological predisposition for androphilia in genotypic males. The FBOE has been studied since the 1930s and is the most consistent biodemographic correlate of sexual orientation in men. This study sought to determine whether the FBOE applies equally to all men who have sex with men (MSM), or disproportionately to MSM whose anal intercourse behavior is predominantly receptive (Bottoms). Participants included 243 North American adult MSM who responded to advertisements posted on a Web site and other electronic media associated with the GALA festival, a quadrennial gathering of gay and lesbian choruses. Each was asked whether his anal intercourse behavior during the preceding year was predominantly receptive, predominantly penetrative, or about equally receptive and penetrative. Those who indicated their behavior was predominantly receptive were coded "Bottoms"; all others were coded "Not-Bottoms." Participants were also surveyed as to their sibship composition. Bottoms had a significantly greater mean number of older brothers than did Not-Bottoms. There was no significant difference with respect to older or younger sisters or younger brothers. Further, the older sibling sex ratio (OSSR) for the Bottom cohort, but not for the Not-Bottom cohort, was significantly higher than the expected OSSR for the general male population (OSSR = No. older brothers/No. older sisters × 100; expected OSSR for general population = 106). Thus, late fraternal birth order was correlated with receptive anal-erotic behavior among MSM.

Testosterone, oxytocin, and the development of human parental care

The steroid testosterone (T) and neuropeptide oxytocin (OT) have each been implicated in the development of parental care in humans and animals, yet very little research addressed the interaction between these hormones at the transition to parenthood in mothers and fathers. One hundred and sixty mothers and fathers (80 couples) were visited 1 and 6months after the birth of their first child, plasma OT and T were assayed at each time-point, and interactions between each parent and the infant were observed and micro-coded for two key parental behaviors; affectionate touch and parent-infant synchrony. T showed gender-specific effects. While paternal T was individually stable across the first six months of parenting and predicted lower father-infant synchrony, maternal T was neither stable nor predictive of maternal behavior. An interaction of OT and T showed that T has complex modulatory effects on the relations of OT and parenting. Slope analysis revealed that among fathers, only when T was high (+1SD), negative associations emerged between OT and father affectionate touch. In contrast, among mothers, the context of high T was related to a positive association between OT and maternal touch. Our findings, the first to test the interaction of OT and T in relation to observed maternal behavior, underscore the need for much further research on the complex bidirectional effects of steroid and neuropeptide systems on human mothering and fathering.

Pre-eclampsia and first-onset postpartum psychiatric episodes: a Danish population-based cohort study

BACKGROUND

Recent evidence suggests that postpartum psychiatric episodes may share similar etiological mechanisms with immune-related disorders. Pre-eclampsia is one of the most prevalent immune-related disorders of pregnancy. Multiple clinical features are shared between pre-eclampsia and postpartum psychiatric disorders, most prominently a strong link to first pregnancies. Therefore, we aimed to study if pre-eclampsia is a risk factor for first-onset postpartum psychiatric episodes.

METHOD

We conducted a cohort study using the Danish population registry, with a total of 400 717 primiparous women with a singleton delivery between 1995 and 2011. First-lifetime childbirth was the main exposure variable and the outcome of interest was first-onset postpartum psychiatric episodes. The main outcome measures were monthly incidence rate ratios (IRRs), with the period 11-12 months after birth as the reference category. Adjustments were made for age, calendar period, reproductive history, and perinatal maternal health including somatic and obstetric co-morbidity.

RESULTS

Primiparous women were at particularly high risk of first-onset psychiatric episodes during the first month postpartum [IRR 2.93, 95% confidence interval (CI) 2.53-3.40] and pre-eclampsia added to that risk (IRR 4.21, 95% CI 2.89-6.13). Having both pre-eclampsia and a somatic co-morbidity resulted in the highest risk of psychiatric episodes during the 3-month period after childbirth (IRR 4.81, 95% CI 2.72-8.50).

CONCLUSIONS

We confirmed an association between pre-eclampsia and postpartum psychiatric episodes. The possible explanations for this association, which are not mutually exclusive, include the psychological impact of a serious medical condition such as pre-eclampsia and the neurobiological impact of pre-eclampsia-related vascular pathology and inflammation.

Birth Order and Sibling Sex Ratio in a Population with High Fertility: Are Turkish Male to Female Transsexuals Different?

Western studies have consistently found that androphilic (sexually attracted to men) male-to-female transsexuals have a later birth order and a relative excess of brothers compared with appropriate control participants. However, non-Western studies on birth order and sibling sex ratio in androphilic males (transsexual or non-transsexual) are rare. The objective of the study was to test the hypothesis that androphilic male-to-female transsexuals have a late birth order and a relative excess of brothers in a non-Western culture with a higher fertility rate. The participants were 60 androphilic male-to-female transsexuals and 61 male heterosexual controls. The transsexual participants had significantly more older brothers than the control participants, but the groups did not differ in their numbers of older sisters, younger brothers, or younger sisters. The foregoing pattern is usually referred to as the "fraternal birth order effect." Slater's and Berglin's Indexes both showed that the mean birth order of the control participants was very close to that expected from a random sample drawn from a demographically stable population whereas the mean birth order of the transsexual participants was later. A measure of sibship composition, brothers/all siblings, showed that the transsexual group had a higher proportion of male siblings compared with the control group. In conclusion, the present study found that Turkish androphilic male-to-female transsexuals show the same high fraternal birth order that has been found in comparable androphilic samples in Western Europe, North America, and the South Pacific, which suggests a common underlying biological causal mechanism.

Fraternal Birth Order and Extreme Right-Handedness as Predictors of Sexual Orientation and Gender Nonconformity in Men

The present study explored whether there were relationships between number of older brothers, handedness, recalled childhood gender nonconformity (CGN), and sexual orientation in men. We used data from previous British studies conducted in our laboratory (N = 1,011 heterosexual men and 921 gay men). These men had completed measures of demographic variables, number and sex of siblings, CGN, and the Edinburgh Handedness Inventory. The results did not replicate the fraternal birth order effect. However, gay men had fewer "other siblings" than heterosexual men (even after controlling for the stopping-rule and family size). In a sub-sample (425 gay men and 478 heterosexual men) with data available on both sibling sex composition and handedness scores, gay men were found to show a significantly greater likelihood of extreme right-handedness and non-right-handedness compared to heterosexual men. There were no significant effects of sibling sex composition in this sub-sample. In a further sub-sample (N = 487) with data available on sibling sex composition, handedness, and CGN, we found that men with feminine scores on CGN were more extremely right-handed and had fewer other-siblings compared to masculine scoring men. Mediation analysis revealed that handedness was associated with sexual orientation directly and also indirectly through the mediating factor of CGN. We were unable to replicate the fraternal birth order effect in our archived dataset but there was evidence for a relationship among handedness, sexual orientation, and CGN. These data help narrow down the number of possible neurodevelopmental pathways leading to variations in male sexual orientation.

Coparenting and children's temperament predict firstborns' cooperation in the care of an infant sibling

This study examined how coparenting and firstborn children's temperament predicted children's cooperative behavior in response to maternal requests for assistance in the care of a 1-month-old infant sibling. Children's cooperative responding was observed during a diaper change session for 216 firstborns (ages 13 to 70 months; M = 32). Parents also completed questionnaires assessing coparenting and children's temperament. Results suggested that coparenting quality moderated the association between children's temperament (i.e., soothability) and children's cooperation as revealed in a Temperament × Cooperative Coparenting × Undermining Coparenting interaction. Specifically, low soothability predicted low levels of children's cooperation in families with high undermining and low cooperative coparenting, over and above the effects of child age, gender, and mothers' education. Findings further our understanding of how temperamental characteristics and coparenting quality conjointly predict individual differences in firstborn children's positive adjustment across the transition to siblinghood.

First childbirth and motherhood at post natural fertile age: a persistent and intergenerational experience of personal and social anomaly?

This study was aimed at understanding long-term psychosocial implications of first childbirth at post natural fertile age following assisted reproductive treatment. Twenty women, whose average age at childbirth was 45, participated. Findings show that the sense of anomaly experienced prior to pregnancy and childbirth related to infertility and advanced age continued during treatment, pregnancy, and motherhood. Participants associated their advanced age as cause for what they perceived as a similar sense of anomaly experienced by their children. The issue of a continuing and intergenerational sense of anomaly should be addressed when counseling women considering fertility treatment at advanced age.

Contraceptive confidence and timing of first birth in Moldova: an event history analysis of retrospective data

OBJECTIVES

To test the contraceptive confidence hypothesis in a modern context. The hypothesis is that women using effective or modern contraceptive methods have increased contraceptive confidence and hence a shorter interval between marriage and first birth than users of ineffective or traditional methods. We extend the hypothesis to incorporate the role of abortion, arguing that it acts as a substitute for contraception in the study context.

SETTING

Moldova, a country in South-East Europe. Moldova exhibits high use of traditional contraceptive methods and abortion compared with other European countries.

PARTICIPANTS

Data are from a secondary analysis of the 2005 Moldovan Demographic and Health Survey, a nationally representative sample survey. 5377 unmarried women were selected.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome measure was the interval between marriage and first birth. This was modelled using a piecewise-constant hazard regression, with abortion and contraceptive method types as primary variables along with relevant sociodemographic controls.

RESULTS

Women with high contraceptive confidence (modern method users) have a higher cumulative hazard of first birth 36 months following marriage (0.88 (0.87 to 0.89)) compared with women with low contraceptive confidence (traditional method users, cumulative hazard: 0.85 (0.84 to 0.85)). This is consistent with the contraceptive confidence hypothesis. There is a higher cumulative hazard of first birth among women with low (0.80 (0.79 to 0.80)) and moderate abortion propensities (0.76 (0.75 to 0.77)) than women with no abortion propensity (0.73 (0.72 to 0.74)) 24 months after marriage.

CONCLUSIONS

Effective contraceptive use tends to increase contraceptive confidence and is associated with a shorter interval between marriage and first birth. Increased use of abortion also tends to increase contraceptive confidence and shorten birth duration, although this effect is non-linear-women with a very high use of abortion tend to have lengthy intervals between marriage and first birth.

Birth order and suicide in adulthood: evidence from Swedish population data

Each year, almost 1 million people die from suicide, which is among the leading causes of death in young people. We studied how birth order was associated with suicide and other main causes of death. A follow-up study based on the Swedish population register was conducted for sibling groups born from 1932 to 1980 who were observed during the period 1981-2002. Focus was on the within-family variation in suicide risk, meaning that we studied sibling groups that consisted of 2 or more children in which at least 1 died from suicide. These family-fixed effects analyses revealed that each increase in birth order was related to an 18% higher suicide risk (95% confidence interval (CI): 1.14, 1.23, P = 0.000). The association was slightly lower among sibling groups born in 1932-1955 (hazard ratio = 1.13, 95% CI: 1.06, 1.21, P = 0.000) than among those born in 1967-1980 (hazard ratio = 1.24, 95% CI: 0.97, 1.57, P = 0.080). Further analyses suggested that the association between birth order and suicide was only modestly influenced by sex, birth spacing, size of the sibling group, own socioeconomic position, own marital status, and socioeconomic rank within the sibling group. Causes of death other than suicide and other external causes were not associated with birth order.

Mothers, fathers, sons and daughters: parental sensitivity in families with two children

Most studies on early childhood parenting include only mothers. Fathers are rarely observed in interaction with their young children, although they play an important role in the socialization of their children. In this study, we observed parenting of mothers and fathers toward their sons and daughters in families with two children, using a within-family approach in a sample with systematically varying family constellations. Participants included 389 families with two children (1 and 3 years of age). Parenting practices were coded during free play using the Emotional Availability Scales (Biringen, 2008). Findings revealed that mothers showed higher levels of sensitivity and lower levels of intrusiveness toward their children than fathers. Furthermore, mothers and fathers were more sensitive and less intrusive toward their oldest child than toward their youngest child. Fathers' higher intrusiveness toward the youngest child was only found in the case of a youngest boy. Child gender was not related to parenting in any of the other analyses. Our results suggest that parent gender is more salient than child gender in the prediction of parenting practices in early childhood.

Family transitions following the birth of a sibling: an empirical review of changes in the firstborn's adjustment

Nearly 80% of children in the United States have at least 1 sibling, indicating that the birth of a baby sibling is a normative ecological transition for most children. Many clinicians and theoreticians believe the transition is stressful, constituting a developmental crisis for most children. Yet, a comprehensive review of the empirical literature on children's adjustment over the transition to siblinghood (TTS) has not been done for several decades. The current review summarizes research examining change in first borns' adjustment to determine whether there is evidence that the TTS is disruptive for most children. Thirty studies addressing the TTS were found, and of those studies, the evidence did not support a crisis model of developmental transitions, nor was there overwhelming evidence of consistent changes in firstborn adjustment. Although there were decreases in children's affection and responsiveness toward mothers, the results were more equivocal for many other behaviors (e.g., sleep problems, anxiety, aggression, regression). An inspection of the scientific literature indicated there are large individual differences in children's adjustment and that the TTS can be a time of disruption, an occasion for developmental advances, or a period of quiescence with no noticeable changes. The TTS may be a developmental turning point for some children that portends future psychopathology or growth depending on the transactions between children and the changes in the ecological context over time. A developmental ecological systems framework guided the discussion of how child, parent, and contextual factors may contribute to the prediction of firstborn children's successful adaptation to the birth of a sibling.

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.

[Role of eldest in a destructured family context: clinical case report from Fann Hospital in Dakar, Senegal]

In a Senegalese family, the role of the eldest, i.e. the one who must lead the way, is particularly difficult. The eldest is the only one required to excel and wield power in the family. To ensure his status and maintain his identity, the elder must be acknowledged as such by the father, mother, and younger siblings. The purpose of this report is to describe a case demonstrating the psychological frailness associated with elder status. The patient developed depressive breakdown when his mother dismayed by his professional failure ceased to acknowledgement his status and implicitly disqualified him. Discussion includes the psychopathological dimension revolving mainly around an Oedipal relationship with the father.

Why do mothers breastfeed girls less than boys? Evidence and implications for child health in India

Breastfeeding is negatively correlated with future fertility because nursing temporarily reduces fecundity and because mothers usually wean on becoming pregnant again. We model breastfeeding under son-biased fertility preferences and show that breastfeeding duration increases with birth order, especially near target family size; is lowest for daughters and children without older brothers because their parents try again for a son; and exhibits the largest gender gap near target family size, when gender is most predictive of subsequent fertility. Data from India confirm each prediction. Moreover, child survival exhibits similar patterns, especially in settings where the alternatives to breastmilk are unsanitary.

Structural and psychosocial correlates of birth order anomalies in schizophrenia and homicide

Birth order--a unique index of both neurodevelopmental and/or psychosocial factors in the pathogenesis of psychiatric disorder--remains largely unexplored in violent schizophrenia. We examined whether murderers with schizophrenia would demonstrate birth order anomalies, distinguishing them from both nonviolent schizophrenia patients and murderers without schizophrenia. Self-report birth order, psychosocial history data (i.e., maternal birth age, family size, parental criminality, parental SES), and structural magnetic resonance imaging data were collected from normal controls, nonviolent schizophrenia patients, murderers with schizophrenia, murderers without schizophrenia, and murderers with psychiatric conditions other than schizophrenia at a brain hospital in Nanjing, China. Results indicated that murderers with schizophrenia were characterized by significantly increased (i.e., later) birth order compared with both nonviolent schizophrenia patients and murderers without schizophrenia. Additionally, birth order was negatively correlated with gray matter volume in key frontal subregions for schizophrenic murderers, and was negatively correlated with parental SES. Findings may suggest biological, psychosocial, or interactional trajectories which may lead to a homicidally violent outcome in schizophrenia.

Predictors of early precocious talking: a prospective population study

This study examines potential predictors of 'precocious talking' (expressive language ≥90th percentile) at one and two years of age, and of 'stability' in precocious talking across both time periods, drawing on data from a prospective community cohort comprising over 1,800 children. Logistic regression was used to examine the relationship between precocious talking and the following potential predictors: gender, birth order, birth weight, non-English speaking background, socioeconomic status, maternal age, maternal mental health scores, and vocabulary and educational attainment of parents. The strongest predictors of precocity (being female and having a younger mother) warrant further exploration. Overall, however, it appears that precocity in early vocabulary development is not strongly influenced by the variables examined, which together explained just 2.6% and 1% of the variation at 1;0 and 2;0 respectively.

The relative risk and timing of divorce in families of children with an autism spectrum disorder

We compared the occurrence and timing of divorce in 391 parents of children with an autism spectrum disorder (ASD) and a matched representative sample of parents of children without disabilities using a survival analysis. Parents of children with an ASD had a higher rate of divorce than the comparison group (23.5% vs. 13.8%). The rate of divorce remained high throughout the son's or daughter's childhood, adolescence, and early adulthood for parents of children with an ASD, whereas it decreased following the son's or daughter's childhood (after about age 8 years) in the comparison group. Younger maternal age when the child with ASD was born and having the child born later in the birth order were positively predictive of divorce for parents of children with an ASD. Findings have implications for interventions focused on ameliorating ongoing and long-term marital strains for parents of children with an ASD.

A longitudinal study of family obligation and depressive symptoms among Chinese American adolescents

The purpose of this 2-year, 3-wave longitudinal study of Chinese American adolescents was to examine how family obligation behaviors and attitudes change over time; how gender, nativity, and birth order predict these trajectories; and whether family obligation relates to depressive symptoms. Findings suggest that family obligation behaviors decreased over the 2-year period but that family obligation attitudes were stable. Moreover, foreign-born adolescents reported higher levels of family obligation behavior than U.S.-born adolescents, and firstborn adolescents reported higher family obligation attitudes than laterborn adolescents. There were no gender differences in family obligation behaviors or attitudes. The findings also suggest that initial higher levels of family obligation were associated with subsequently fewer depressive symptoms. Finally, changes in family obligation behaviors related to changes in depressive symptoms over time such that increasing family obligation behaviors related to decreasing depressive symptoms. The results highlight the importance of understanding the role of family obligation to Chinese American adolescents' mental health.

Extreme right-handedness, older brothers, and sexual orientation in men

Two of the most consistent correlates of sexual orientation in men are handedness and fraternal birth order (i.e., number of older brothers). In the present study, the relationship among handedness, older brothers, and sexual orientation was studied in 4 samples of heterosexual and gay or bisexual men (N = 944). Unlike previous studies, which have only observed an increased rate of non-right-handedness in gay or bisexual men relative to heterosexual men, an elevated rate of extreme right-handedness was found in gay or bisexual men relative to heterosexual men. The results also demonstrated that older brothers moderate the relationship between handedness and sexual orientation. Specifically, older brothers increase the odds of being gay or bisexual in moderate right-handers only; in both non-right-handers and extreme right-handers, older brothers do not affect (or decrease) the odds of being gay or bisexual. The results have implications for an early neurodevelopmental origin to sexual orientation in men.

Interaction of birth order, handedness, and sexual orientation in the Kinsey interview data

Recent evidence indicates that 2 of the most consistently observed correlates of men's sexual orientation--handedness and older brothers--may be linked interactively in their prediction of men's sexual orientation. In this article, the authors studied the relationship among handedness, older brothers, and men's sexual orientation in the large and historically significant database originally compiled by Alfred C. Kinsey and his colleagues (A. C. Kinsey, W. B. Pomeroy, & C. E. Martin, 1948). The results demonstrated that handedness moderates the relationship between older brothers and sexual orientation. Specifically, older brothers increased the odds of homosexuality in right-handers only; in non-righthanders, older brothers did not affect the odds of homosexuality. These results refine the possible biological explanations reported to underlie both the handedness and older brother relationships to men's sexual orientation. These results also suggest that biological explanations of men's sexual orientation are likely relevant across time, as the Kinsey data comprise an older cohort relative to modern samples.

Big brothers and little sisters? Sex selection and birth order

Should you be allowed to choose the sex of your child? Even before the advent of modern reproductive technologies, people have expressed interest in producing a child of a specific sex, trying everything from herbal treatments to sexual positions that have been claimed to produce a male or female child. Modern technologies such as flow cytometry make this a realistic possibility but what might the consequences be? In India and China, a preference for male offspring has led (via abortion) to a significant sex-ratio imbalance in those populations. Do other countries express strong preferences for male or female offspring? This article will address the possible birth order implications. Will we live in a world of first-born boys and second-born girls?

The biology of human psychosexual differentiation

Most attempts to identify biological underpinnings of gender identity and sexual orientation in humans have investigated effects of sex steroids, so pivotal in the differentiation of the genitalia, showing strong parallels between animals and the human. The information on humans is derived from the so-called 'experiments of nature', clinical entities with a lesser-than-normal androgen exposure in XY subjects and a higher than normal androgen exposure in XX subjects. Prenatal androgenization appears to predispose to a male gender identity development, but apparently not decisively since 40-50% of 46,XY intersexed children with a history of prenatal androgen exposure do not develop a male gender identity. Obviously, male-to-female transsexuals, with a normal androgen exposure prenatally (there is no serious evidence to the contrary) develop a female gender identity, through unknown biological mechanisms apparently overriding the effects of prenatal androgens. The latest studies in 46, XX subjects exposed to prenatal androgens show that prenatal androgenization of 46,XX fetuses leads to marked masculinization of later gender-related behavior but does not lead to gender confusion/dysphoria. The example of female-to-male transsexuals, without evidence of prenatal androgen exposure, indicates that a male gender identity can develop without a significant androgen stimulus. So we are far away from any comprehensive understanding of hormonal imprinting on gender identity formation. Brain studies in homosexuals have not held up in replication studies or are in need of replication in transsexuals. Genetic studies and the fraternal birth order hypothesis provide indications of familial clustering of homosexuality but in many homosexuals these genetic patterns cannot be identified. The biological explanations advanced for the birth order hypothesis lack any experimental support.

Biological versus nonbiological older brothers and men's sexual orientation

The most consistent biodemographic correlate of sexual orientation in men is the number of older brothers (fraternal birth order). The mechanism underlying this effect remains unknown. In this article, I provide a direct test pitting prenatal against postnatal (e.g., social/rearing) mechanisms. Four samples of homosexual and heterosexual men (total n = 944), including one sample of men raised in nonbiological and blended families (e.g., raised with half- or step-siblings or as adoptees) were studied. Only biological older brothers, and not any other sibling characteristic, including nonbiological older brothers, predicted men's sexual orientation, regardless of the amount of time reared with these siblings. These results strongly suggest a prenatal origin to the fraternal birth-order effect.

Interaction of fraternal birth order and handedness in the development of male homosexuality

The present study investigated evidence for an interaction between two of the best established etiologic factors, or markers of etiologic factors, in the literature on male homosexuality: fraternal birth order and hand preference. By combining five samples, the authors produced study groups of 1774 right-handed heterosexuals, 287 non-right-handed heterosexuals, 928 right-handed homosexuals, and 157 non-right-handed homosexuals. The results showed a significant (P = 0.004) handedness by older brothers interaction, such that (a) the typical positive correlation between homosexuality and greater numbers of older brothers holds only for right-handed males, (b) among men with no older brothers, homosexuals are more likely to be non-right-handed than heterosexuals; among men with one or more older brothers, homosexuals are less likely to be non-right-handed than heterosexuals, and (c) the odds of homosexuality are higher for men who have a non-right hand preference or who have older brothers, relative to men with neither of these features, but the odds for men with both features are similar to the odds for men with neither. These findings have at least two possible explanations: (a) the etiologic factors associated with non-right-handedness and older brothers-hypothesized to be hyperandrogenization and anti-male antibodies, respectively-counteract each other, yielding the functional equivalent of typical masculinization, and (b) the number of non-right-handed homosexuals with older brothers is smaller than expected because the combination of the older brothers factor with the non-right-handedness factor is toxic enough to lower the probability that the affected fetus will survive.

A boy or a girl? A Hungarian survey regarding gender selection

BACKGROUND

Infertile Hungarian couples were surveyed with regard to their opinion of preconception gender selection by the separation of X- and Y-bearing sperm populations.

METHODS

Self-completion of a questionnaire. Group 1: subjects presenting for infertility examination; Group 2: presenting for homologous intrauterine insemination.

RESULTS

As concerns the gender of the firstborn, 13.8% of those in Group 1 preferred a boy and 10.3% a girl, while 75.9% had no preference. The male preference was higher in Group 2: 33.3% preferred a boy and 7.4% a girl while 59.3% had no preference (chi 2, p < 0.05). In the event of a wish for more offspring, 91% in Group 1 and 94% in Group 2 did not have a wish for only one particular gender. In Group 2, 30.8% were willing to pay the extra costs for a gender selection procedure as compared with only 10.8% of the couples in Group 1 (chi 2, p < 0.05). If the National Health Fund fully covered the costs, 53.4% in Group 1 and 38.5% in Group 2 would request the procedure for nonmedical reasons, while 94.6% and 97.4% of them, respectively would so for medical reasons.

CONCLUSIONS

Our findings revealed a trend to preference for firstborn males, although couples wishing more than one offspring prefer equal numbers of male and female children. The utilization of preconception gender selection, therefore, would not seem to appreciably affect the natural male/female ratio. Genetic indications exert significant effects on the decision regarding sex selection procedures.

Adolescent sibling relationships in Mexican American families: exploring the role of familism

To address a significant gap in the literature on normative processes in minority families, the authors studied adolescents' sibling relationships in two-parent Mexican American families and explored connections between sibling relationship characteristics and familism. Participants were 246 adolescent Mexican American sibling pairs who participated in (a) home interviews during which adolescents described their sibling relationships and familism values and (b) a series of 7 nightly phone calls during which adolescents reported their daily activities, including time spent with siblings and family members. Siblings described their relationships as both intimate and conflictual, and daily activity data revealed that they spent an average of 17.2 hr per 7 days in shared activities. Sibling relationship qualities were linked to familism values and practices, and stronger patterns of association emerged for sisters than brothers. Discussion highlights the significance of studying the processes that underlie within-group variations among families of different cultural backgrounds.

Sibling relationships in early/middle childhood: links with individual adjustment

The overarching goal of the study was to identify links between sibling relationship quality in early/middle childhood with children's adjustment, having accounted for the effects of parent-child relationship quality. The sample consisted of 101 working and middle-class 2-parent English families with 2 children ages 4-8 years. Parents provided reports of sibling relationship quality, the parent-child relationship, and the children's prosocial and problematic behaviors. The children also provided reports of their familial relationships with a puppet interview. Results indicated that sibling relationship quality was associated with the older siblings' adjustment, controlling for the children's relationships with parents. In addition, the pattern of findings suggested that positivity within the sibling relationship was more strongly linked with child adjustment than was sibling conflict.

The transition to siblinghood: a developmental ecological systems perspective and directions for future research

The birth of a baby sibling is a normative life event for many children. Few studies address this important transition period and changes in the older sibling's adjustment and family relationships following the sibling's birth. The present article presents a developmental ecological systems model for studying changes in family life and the older child's adjustment following the birth of a baby sibling. Simultaneous changes occurring in the family and how these changes are interrelated over time to predict patterns of adaptation after the transition to siblinghood are underscored. Recommendations for designing longitudinal studies that take advantage of recent developments in multilevel modeling are also discussed.

Sibling relationship quality from birth to adolescence: the enduring contributions of friends

The purpose of the present study was to examine continuity in sibling relationships across childhood and to evaluate the degree to which children's experiences with their friends and mothers prior to their sibling's birth predict the quality of the relationship they establish with their siblings in adolescence. Twenty-eight firstborn children, who were 48 months old at the time of their sibling's birth, were observed interacting with their siblings and friends at multiple time points. The level of positive social behaviors demonstrated in their early relationships with friends continued to predict sibling relationship quality in adolescence. Firstborn children who had more positive interactions with friends prior to their sibling's birth demonstrated more prosocial interactions with both their siblings and friends in adolescence and exhibited fewer externalizing behaviors. Longitudinal associations support the hypothesis that the social competencies that young children demonstrate in their early relationships with friends may have enduring significance for their social development.

Preschool children's interactions with friends and older siblings: relationship specificity and joint contributions to problem behavior

The primary aim of the present study was to examine the extent to which friend and sibling relationship quality jointly contribute to children's behavioral adjustment. Preschool-aged children (N = 52) were observed separately with a friend and an older sibling during a free-play session and a sharing task. Mean comparisons indicated that friendship dyads, on average, engaged in more complex social play and more intense conflict (but only during free play), whereas sibling dyads were characterized by greater asymmetry. Few friend-sibling associations emerged. Friend and sibling relationship quality in the sharing task together accounted for a significant portion of variance in parent-reported aggressive-disruptive behavior, and a Sibling x Friend interaction indicated that greater relationship quality with one partner buffered children from poor behavioral adjustment when relationship quality with the other partner was low or moderate. Implications for preventive intervention efforts are discussed.

Reciprocal links among differential parenting, perceived partiality, and self-worth: a three-wave longitudinal study

This study examined reciprocal links between parental differential treatment, siblings' perception of partiality, and self-worth with 3 waves of data from 384 adolescent sibling dyads. Results suggest that birth-order status was significantly associated with self-worth and perception of maternal and paternal differential treatment. There was a consistent across-time effect of self-worth on perception of parental partiality for later born siblings, but not earlier born siblings, and a consistent effect of differential treatment on perception of partiality for earlier born but not later born siblings. The results contribute new insight into the associations between perception of differential parenting and adolescents' adjustment and the role of birth order.

Longitudinal links among parenting, self-presentations to peers, and the development of externalizing and internalizing symptoms in African American siblings

A longitudinal model that linked involved-supportive parenting and siblings' ability-camouflaging self-presentations to peers with the development of externalizing and internalizing symptoms was tested with 152 pairs of first- and second-born African American siblings (mean ages 12.7 years and 10.2 years at the first wave of data collection). Three waves of data were collected at 1-year intervals. Teachers assessed siblings' externalizing symptoms, internalizing symptoms, and academic competence; siblings reported their own self-presentations and desire for peer acceptance; and mothers and siblings provided multiinformant assessments of involved-supportive parenting. Involved-supportive parenting at Wave 1 was linked with peer-directed self-presentations at Wave 2. Wave 2 self-presentations were linked indirectly with changes from Wave 1 to Wave 3 in externalizing and internalizing symptoms through their association with academic competence.

Sibling effects, environmental influences, and university attendance: a follow-up study

In 2002 Marjoribanks examined relations among sibling variables, environmental influences, and school dropout. In this follow-up study, relations were examined between sibling variables (number of children in the family, birth order position) and university attendance. Data were collected from 8,005 (4,116 women, 3,889 men) Australian young adults (M age=20.1 yr., SD=0.5). Logistic regression analyses in the two studies indicated that (a) young adults from Asian, Middle Eastern, and middle-class families were less likely to drop out of school and more likely to attend a university than were young Australians from Anglo-Australian, English, European, and working-class backgrounds, and (b) after taking into account differences in family background and learning environment measures, there continued to be small but significant relations between the number of children in families, birth-order position, and the likelihood that young people would drop out of school or attend a university.