The association between perinatal testosterone concentration and early vocabulary development: A prospective cohort study

Sex differences during development in cortical temporal processing and event related potentials in wild-type and fragile X syndrome model mice

BACKGROUND

Autism spectrum disorder (ASD) is currently diagnosed in approximately 1 in 44 children in the United States, based on a wide array of symptoms, including sensory dysfunction and abnormal language development. Boys are diagnosed ~ 3.8 times more frequently than girls. Auditory temporal processing is crucial for speech recognition and language development. Abnormal development of temporal processing may account for ASD language impairments. Sex differences in the development of temporal processing may underlie the differences in language outcomes in male and female children with ASD. To understand mechanisms of potential sex differences in temporal processing requires a preclinical model. However, there are no studies that have addressed sex differences in temporal processing across development in any animal model of ASD.

METHODS

To fill this major gap, we compared the development of auditory temporal processing in male and female wildtype (WT) and Fmr1 knock-out (KO) mice, a model of Fragile X Syndrome (FXS), a leading genetic cause of ASD-associated behaviors. Using epidural screw electrodes, we recorded auditory event related potentials (ERP) and auditory temporal processing with a gap-in-noise auditory steady state response (ASSR) paradigm at young (postnatal (p)21 and p30) and adult (p60) ages from both auditory and frontal cortices of awake, freely moving mice.

RESULTS

The results show that ERP amplitudes were enhanced in both sexes of Fmr1 KO mice across development compared to WT counterparts, with greater enhancement in adult female than adult male KO mice. Gap-ASSR deficits were seen in the frontal, but not auditory, cortex in early development (p21) in female KO mice. Unlike male KO mice, female KO mice show WT-like temporal processing at p30. There were no temporal processing deficits in the adult mice of both sexes.

CONCLUSIONS

These results show a sex difference in the developmental trajectories of temporal processing and hypersensitive responses in Fmr1 KO mice. Male KO mice show slower maturation of temporal processing than females. Female KO mice show stronger hypersensitive responses than males later in development. The differences in maturation rates of temporal processing and hypersensitive responses during various critical periods of development may lead to sex differences in language function, arousal and anxiety in FXS.

Evaluation of apparently healthy Egyptian infants and toddlers on the bayley-III scales according to age and sex

BACKGROUND

Child development is shaped throughout the first years of life through the interaction of genetics and the environment. Bayley-III is valuably used to determine early developmental delay (DD). The aim of this study was to detect the differences in performance of a sample of apparently healthy Egyptian infants and toddlers on the Bayley-III scales in relation to their age and gender.

METHODS

This was a cross-sectional study. Bayley scales were applied to 270 of the 300 recruited children following the inclusion criteria; to avoid potential risk factors affecting development. Assessment included cognitive, language and motor skills. Engaged children aged 18-42 months were divided into 4 age groups with six-month intervals.

RESULTS

Approximately 78.4%, 76.2%, and 72% of the participants had average and above average scores in the cognitive, motor, and language domains, respectively. The language domain was characteristically impacted. The oldest age group (36-42 months) scored the highest means composite scores, while the 2nd group aged 24 - <30 months, scored the lowest means in the three evaluated domains. In general, girls had non-significantly higher composite scores than boys, with a small effect size (d = 0.2-0.4). In the language domain, girls aged 30 to < 36 months scored significantly higher composite scores than boys (p < 0.05), with a medium effect size (d = 0.73).

CONCLUSION

The study indicates that the performance of apparently healthy Egyptian children on the Bayley III evaluation differs in relation to age and sex. The most vulnerable age group at potential risk of DD was children aged 24-30 months. Efforts must be directed to investigate the nutritional, physical, psychological and safety needs of this group. Attention must be paid to early childhood intervention programs that stimulate development, especially language development, and they must be tailored on the basis of age and gender. Gender-specific norms may be needed in the evaluation of language development.

Talking to talkers: Infants' talk status, but not their gender, is related to language input

Prior research points to gender differences in some early language skills, but is inconclusive about the mechanisms at play, providing evidence that both infants' early input and productions may differ by gender. This study examined the linguistic input and early productions of 44 American English-learning infants (93% White) in a longitudinal sample of home recordings collected at 6-17 months (in 2014-2016). Girls produced more unique words than boys (Cohen's d = .67) and this effect grew with age, but there were no significant gender differences in language input (d = .22-.24). Instead, caregivers talked more to infants who had begun to talk (d = .93-.97), regardless of gender. Therefore, prior results highlighting gender-based input differences may have been due, at least partly, to this talking-to-talkers effect.

Dynamic Changes of Reproductive Hormones in Male Minipuberty: Temporal Dissociation of Leydig and Sertoli Cell Activity

CONTEXT

The male hypothalamic-pituitary-gonadal (HPG) axis is transiently active during the first months of life with surging serum concentrations of reproductive hormones. This period, termed minipuberty, appears to be essential for priming testicular function. Despite the central role for male reproductive function, longitudinal data on HPG axis activation in infancy is sparse.

OBJECTIVE

To explore the dynamics of HPG hormone activity in healthy male infants, to assess the association of HPG axis activity and testicular volume, and to establish reference curves for serum levels of reproductive hormones.

DESIGN

Prospective, longitudinal birth cohort (the COPENHAGEN Minipuberty Study, 2016-2018, 1-year follow-up).

SETTING

Population-based.

PATIENTS OR OTHER PARTICIPANTS

Healthy, male, term, singleton newborns were followed from birth on with repeated clinical examinations including blood sampling during a 1-year follow-up. A total of 128 boys contributed to this study, while 119 participated in the postnatal follow-up.

MAIN OUTCOME MEASURES

Serum reproductive hormone concentrations and testicular volume.

RESULTS

Reproductive hormone concentrations showed marked dynamics during the first 6 months of age. Gonadotropins, total testosterone, and insulin-like factor 3 peaked at around 1 month of age. Inhibin B, anti-Müllerian hormone, and testicular volume peaked at around 4 to 5 months. Correlations largely recapitulated typical HPG axis pathways but also differed significantly from adult men.

CONCLUSIONS

We demonstrate a temporal dissociation of Leydig and Sertoli cell activity during male minipuberty and provide reference curves for reproductive hormones.

Is there an association between prenatal testosterone and autistic traits in adolescents?

Prenatal testosterone (pT) is a crucial component in physiological masculinization in humans. In line with the Prenatal Sex Steroid Theory of autism, some studies have found a positive correlation between pT and autistic traits in childhood. However, effects in adolescence have not been explored. Hormonal and environmental changes occurring during puberty may alter the strength or the nature of prenatal effects on autistic traits. The current study examines if pT relates to autistic traits in a non-clinical sample of adolescents and young adults (N = 97, 170 observations; age 13-21 years old). It also explores pT interactions with pubertal stage and timing. PT concentrations were measured from amniotic fluid extracted in the 2nd trimester of gestation via amniocentesis conducted for clinical purposes. Autistic traits were measured by self- and parent-reports on the Autism Spectrum Quotient (AQ) which provides a total score and 5 sub-scores (social skills, communication, imagination, attention switching and attention to detail). Self-reported pubertal stage was regressed on age to provide a measure of relative timing. We found no statistical evidence for a direct association between pT and autistic traits in this adolescent sample (males, females or full sample). Exploratory analyses suggested that pT correlated positively with autistic traits in adolescents with earlier puberty-onset, but statistical robustness of this finding was limited. Further exploratory post-hoc tests suggested the pT-by-pubertal timing interaction was stronger in males relative to females, in self-reported compared to parent-reported AQ and specifically for social traits. These findings require replication in larger samples. Findings have implications for understanding the effects of pT on human behavior, specifically existence of effects in adolescence.

Sex differences in early language delay and in developmental language disorder

Developmental language disorder (DLD) is a neurodevelopmental condition, occurring in about 3% to 7% of preschoolers, that can impair communication and negatively impact educational and social attainments, in spite of adequate neurological, cognitive, emotional, social development, and educational opportunities for language learning. Significant risk factors for DLD are male sex, familial history of early language delay, low parental education, and various perinatal factors. A strong sex effect with a higher prevalence of language delay and DLD in males than in females has been consistently reported. Neurobiological and environmental risk factors, interacting with each other, are probably responsible for the phenotypic expression of DLD. The aim of this brief review is to further the knowledge of the role of sex in early language delay and DLD by analyzing the evidence from four significant sources: epidemiological studies, studies on twins, family aggregation studies, and studies on sex chromosome trisomies. Data pertaining only to sex differences (biological and physiological characteristics of females and males) will be analyzed. Studies on family aggregations and twins confirm the role of genetic factors and of sex in determining language abilities and disabilities, but genes alone do not determine outcomes. Sex chromosome trisomies represent a unique example of the relationship between a genetic alteration and a language disorder. Clarification of how sex acts in determining DLD could provide new information on early risk factors and, thus, contribute to improve diagnosis and clinical management.

Sex and gender difference in cognitive and behavioral studies in developmental age: An introduction

This paper introduces a special issue focused on sex and gender (s/g) cognitive/behavioral differences at developmental ages providing an overview of this multifaceted and debated topic. It will provide a description of the biological systems that are strongly interconnected to generate s/g differences, that is, genetic determinants, sex hormones, differences in brain structure, organization, and/or function, inherited or modifiable under environmental pressures. Developmental studies are rare. Some addressed whether s/g differences in cognitive/behavioral characteristics are evident early in life and are consistent throughout development, entailing that s/g differences can follow the evolving steps in girls and boys in different domains. The data are far from being homogeneous and consistent about s/g difference in language, social skills, and visuo/spatial abilities. The differences are small, often with overlapping performances, similar to what is seen in adulthood. Given that several variables and the interactions between them are implicated, further longitudinal studies adopting adequate assessment tools, very large size multicultural samples stratified in different, well-sized and precise age groups, considering biological and sociocultural variables, are needed. Due to the complexity of the issue, there is still the need to support and adopt an s/g difference approach also in cognitive and behavioral studies at developmental ages. Finally, these studies have not only scientific importance and relevant cultural, anthropological, and social implications, but are also useful for pedagogical programming as well as for the study of the different susceptibility to develop CNS diseases and consequently to promote different therapies and treatments.

Associations Between Hormonal Biomarkers and Preterm Infant Health and Development During the First 2 Years After Birth

BACKGROUND

Testosterone levels have been used to examine infant boys' vulnerability to health and developmental problems, following the general theories of gender differences and the theory of extreme male brain of autism.

OBJECTIVES

As testosterone is a representative androgen hormone and is higher in preterm than full-term infants, we used this steroid to determine if hypothalamic pituitary hormones, testosterone, and cortisol, were related to physical growth, health, and development of very-low-birthweight (VLBW, BW < 1,500 g) infants.

METHOD

For this comparative longitudinal study, 40 VLBW infants were recruited from a neonatal intensive care unit of a tertiary medical center. Data were collected from medical record reviews, questionnaires, and assessments of infant development at 6, 12, and 24 months. We collected saliva at the three time points and measured hormones using enzyme-immunoassays.

RESULTS

General and generalized mixed models showed that a 1pg/ml increment of testosterone was related to a -0.42% decrease in body weight, a -0.18% decrease in length, and a -0.10% decrease in head circumference. Cortisol levels were not associated with any outcome variable. The interactions between testosterone and time on physical growth and socioemotional development also occurred.

DISCUSSION

Elevated testosterone levels can be a biological risk factor for poor infant growth and development. Theories about the effects of elevated prenatal testosterone could be useful in predicting health and developmental outcomes among VLBW infants. Research beyond the first 2 years will be needed as infants show more socioemotional and behavioral problems as they grow older.

Androgens During Infancy, Childhood, and Adolescence: Physiology and Use in Clinical Practice

We provide an in-depth review of the role of androgens in male maturation and development, from the fetal stage through adolescence into emerging adulthood, and discuss the treatment of disorders of androgen production throughout these time periods. Testosterone, the primary androgen produced by males, has both anabolic and androgenic effects. Androgen exposure induces virilization and anabolic body composition changes during fetal development, influences growth and virilization during infancy, and stimulates development of secondary sexual characteristics, growth acceleration, bone mass accrual, and alterations of body composition during puberty. Disorders of androgen production may be subdivided into hypo- or hypergonadotropic hypogonadism. Hypogonadotropic hypogonadism may be either congenital or acquired (resulting from cranial radiation, trauma, or less common causes). Hypergonadotropic hypogonadism occurs in males with Klinefelter syndrome and may occur in response to pelvic radiation, certain chemotherapeutic agents, and less common causes. These disorders all require testosterone replacement therapy during pubertal maturation and many require lifelong replacement. Androgen (or gonadotropin) therapy is clearly beneficial in those with persistent hypogonadism and self-limited delayed puberty and is now widely used in transgender male adolescents. With more widespread use and newer formulations approved for adults, data from long-term randomized placebo-controlled trials are needed to enable pediatricians to identify the optimal age of initiation, route of administration, and dosing frequency to address the unique needs of their patients.

Morphometric traits predict educational attainment independently of socioeconomic background

Background

Aim of this study is to describe the relationship between anthropometric traits and educational attainment among Estonian schoolchildren born between 1937 and 1962. We asked whether height, cranial volume and face width (a testosterone-dependent trait), measured in childhood predict later educational attainment independently of each other, family socioeconomic position (SEP) and sex. Associations between morphometric traits and education and their interactions with biosocial variables are of scholarly importance because higher education is nearly universally associated with low fertility in women, and often with high fertility in men. Hence, morphometric traits associated with educational attainment are targeted by natural selection and describing the exact nature of these associations is relevant for understanding the current patterns of evolution of human body size.

Methods

Data on morphometric measurements and family background of 11,032 Estonian schoolchildren measured between seven and 19 years of age were obtained from the study performed by Juhan Aul between 1956 and 1969. Ordinal logistic regression was used for testing the effects of morphometric traits, biosocial variables and their interaction on the cumulative probability of obtaining education beyond primary level.

Results

Of biosocial variables, family SEP was the most important determinant of educational attainment, followed by the sex, rural vs urban origin and the number of siblings. No significant interactions with morphometric traits were detected, i.e., within each category of SEP, rural vs urban origin and sex, taller children and those with larger heads and relatively narrower faces were more likely to proceed to secondary and/or tertiary education. The effect of height on education was independent of cranial volume, indicating that taller children did not obtain more educations because their brains were larger than those of shorter children; height per se was important.

Conclusions

Our main finding – that adjusting for other morphometric traits and biosocial variables, morphometric traits still robustly predicted educational attainment, is relevant for understanding the current patterns of evolution of human body size. Our findings suggest that fecundity selection acting on educational attainment could be partly responsible for the concurrent selection for smaller stature and cranial volume in women and opposite trends in men.

Sex-specific variation in facial masculinity/femininity associated with autistic traits in the general population

Reports linking prenatal testosterone exposure to autistic traits and to a masculinized face structure have motivated research investigating whether autism is associated with facial masculinization. This association has been reported with greater consistency for females than for males, in studies comparing groups with high and low levels of autistic traits. In the present study, we conducted two experiments to examine facial masculinity/femininity in 151 neurotypical adults selected for either low, mid-range, or high levels of autistic traits. In the first experiment, their three-dimensional facial photographs were subjectively rated by 41 raters for masculinity/femininity and were objectively analysed. In the second experiment, we generated 6-face composite images, which were rated by another 36 raters. Across both experiments, findings were consistent for ratings of photographs and composite images. For females, a linear relationship was observed where femininity ratings decreased as a function of higher levels of autistic traits. For males, we found a U-shaped function where males with mid-range levels of traits were rated lowest on masculinity. Objective facial analyses revealed that higher levels of autistic traits were associated with less feminine facial structures in females and less masculine structures in males. These results suggest sex-specific relationships between autistic traits and facial masculinity/femininity.

Does gender affect Bayley-III scores and test-taking behavior?

The developmental test Bayley-III is widely used in clinical and research settings, but there are no published gender-specific norms. The purpose of the present study was to investigate gender differences in Bayley-III scores in a sample of 55 typically developing children assessed repeatedly at ages 4, 7, 10, 13, 24 and 36 months, and to investigate gender differences in the test-taking behavior of the children as measured with the BRS at 36 months. The results of the study demonstrated gender differences at 24 and 36 months for the Cognitive Scale, at 10, 13, 24 and 36 months for the Language Scale and at 36 months for the Motor Scale. On a subtest level, gender differences were found for the Receptive Communication subtest at 13, 24 and 36 months and for the Fine Motor subtest at 7 and 36 months. In all cases where significant gender differences were found, girls achieved higher mean scores than boys. No gender differences were found in the children's test-taking behavior at 36 months on any of the BRS scales, but independently of gender, higher Bayley-III Cognitive and Motor Scale scores were associated with more compliant test-taking behavior.

Cord blood Per- and polyfluoroalkyl substances, placental steroidogenic enzyme, and cord blood reproductive hormone

BACKGROUND

Per- and polyfluoroalkyl substances (PFASs) are widely used in China, but little is known about the association between prenatal PFASs exposure and fetal reproductive development as well as its potential mechanism.

OBJECTIVE

We investigated the effects of cord blood PFASs on fetal reproductive hormones and its potential mechanism in relation to steroidogenic enzymes.

METHODS

Ten selected PFASs (n = 351) including PFOS, PFOA, PFBS, PFDA, PFDoA, PFHpA, PFHxS, PFNA, PFOSA, and PFUA, and two reproductive hormones estradiol (E2) (n = 351) and testosterone (T) (n = 349) were measured in 351 cord blood serum samples from a Chinese birth cohort between 2010 and 2013. Three steroidogenic enzymes including P450arom (n = 125), 3β-HSD1 (n = 123), and 17β-HSD1 (n = 116) were measured in 125 placental tissue samples. Linear regression tested the associations between cord blood PFASs and reproductive hormones in cord blood. Mediation analysis assessed the role of placental steroidogenic enzymes between cord blood PFASs and reproductive hormones.

RESULTS

The positive associations between PFOA, PFHxS and E2 levels, PFOS, PFUA, PFNA and T levels, and PFOS, PFUA and T/E2 ratio were significant. PFUA, PFNA, PFDA, PFHxS, and ∑PFASs were associated with higher P450arom levels. PFHxS was also associated with increased 3β-HSD1 and 17β-HSD1 levels. These associations were more pronounced in females than males when stratified by gender. Furthermore, 17β-HSD1 demonstrated mediating effects in the positive association between cord blood PFHxS and E2 levels in females.

CONCLUSION

Our findings suggested the potential impacts of cord blood PFASs on fetal reproductive hormones, in which steroidogenic enzymes may play important roles. These associations were more pronounced in females than males.

Sex differences in early communication development: behavioral and neurobiological indicators of more vulnerable communication system development in boys

Perhaps due to different roles they have had in social groups during evolution, men and women differ in their verbal abilities. These differences are also (if not even more) present in children, both in the course of typical and pathological development. Beside the fact that girls have a well-documented advantage in early language development, almost all developmental disorders primarily affecting communication, speech, and language skills are more frequent in boys. The sex-related difference in the prevalence of these disorders is especially pronounced in autism spectrum disorder (1 girl for each 4-5 boys is affected). The aim of this review is to present the sex differences in typical communication and language development and in the prevalence of communication-related neurodevelopmental disorders. Also, a special focus is put on data from the field of neuroscience that might provide insight into the neurobiological mechanisms that can add to the understanding of this phenomenon. We argue that the functional organization of the female brain gives women an inherent advantage in the acquisition of communication and language system over men.

Sex differences in early communication development: behavioral and neurobiological indicators of more vulnerable communication system development in boys

Perhaps due to different roles they have had in social groups during evolution, men and women differ in their verbal abilities. These differences are also (if not even more) present in children, both in the course of typical and pathological development. Beside the fact that girls have a well-documented advantage in early language development, almost all developmental disorders primarily affecting communication, speech, and language skills are more frequent in boys. The sex-related difference in the prevalence of these disorders is especially pronounced in autism spectrum disorder (1 girl for each 4-5 boys is affected). The aim of this review is to present the sex differences in typical communication and language development and in the prevalence of communication-related neurodevelopmental disorders. Also, a special focus is put on data from the field of neuroscience that might provide insight into the neurobiological mechanisms that can add to the understanding of this phenomenon. We argue that the functional organization of the female brain gives women an inherent advantage in the acquisition of communication and language system over men.

Prenatal bisphenol A exposure is associated with language development but not with ADHD-related behavior in toddlers from the Odense Child Cohort

Bisphenol A (BPA) is a non-persistent chemical with endocrine disrupting abilities widely used in a variety of consumer products. The fetal brain is particularly sensitive to chemical exposures due to its rapid growth and complexity. Some studies have reported associationbetween maternal BPA exposure and behavior but few have assessed impact on cognitive development, and to our knowledge no studies have specifically assessed the impact on language development. We therefore assessed whether maternal urinary BPA concentration during pregnancy was associated with language development and attention-deficit and hyperactivity disorder (ADHD) symptoms in offspring aged 18-36 months in the prospective Odense Child Cohort. BPA was analyzed in 3rd trimester maternal fasting urine spot samples. Language development was addressed among 535 children using the Danish adaptation of the MacArthur-Bates Communicative Development Inventories at median age 21 months; ADHD traits were assessed by parents of 658 children using the Child Behavior Checklist for ages 1½-5 years at mean age 2.7 years. Associations were assessed using logistic regression models comparing children below the 15th percentile score for language and above the 85 percentiles score for ADHD with the other children while stratifying by sex and adjusting for maternal education, duration of breastfeeding and maternal urine phthalates. BPA was detected in 85.3% of the urine samples (median 1.2 ng/ml). Boys of mothers with BPA exposure in the highest tertile had an odds ratio of 3.70 (95% CI 1.34-10.21) of being in the lowest 15th percentile of vocabulary score compared to boys of mothers within the lowest tertile of BPA exposure after adjustment, whereas no association was found in girls. No clear dose-response relationship between maternal BPA and ADHD scores above the 85th percentile was found for either sex. Since early language development is a predictor of future reading skills and educational success, more epidemiological studies assessing BPA exposure and language skills are needed to confirm our findings.

Subtle left-right asymmetry of gene expression profiles in embryonic and foetal human brains

Left-right laterality is an important aspect of human -and in fact all vertebrate- brain organization for which the genetic basis is poorly understood. Using RNA sequencing data we contrasted gene expression in left- and right-sided samples from several structures of the anterior central nervous systems of post mortem human embryos and foetuses. While few individual genes stood out as significantly lateralized, most structures showed evidence of laterality of their overall transcriptomic profiles. These left-right differences showed overlap with age-dependent changes in expression, indicating lateralized maturation rates, but not consistently in left-right orientation over all structures. Brain asymmetry may therefore originate in multiple locations, or if there is a single origin, it is earlier than 5 weeks post conception, with structure-specific lateralized processes already underway by this age. This pattern is broadly consistent with the weak correlations reported between various aspects of adult brain laterality, such as language dominance and handedness.

From melody to words: The role of sex hormones in early language development

Contribution to Special Issue on Fast effects of steroids. Human infants are the most proficient of the few vocal learner species. Sharing similar principles in terms of the generation and modification of complex sounds, cross-vocal learner comparisons are a suitable strategy when it comes to better understanding the evolution and mechanisms of auditory-vocal learning in human infants. This approach will also help us to understand sex differences in relation to vocal development towards language, the underlying brain mechanisms thereof and sex-specific hormonal effects. Although we are still far from being capable of discovering the "fast effects of steroids" in human infants, we have identified that peripheral hormones (blood serum) are important regulators of vocal behaviour towards language during a transitory hormone surge ("mini-puberty") that is comparable in its extent to puberty. This new area of research in human infants provides a promising opportunity to not only better understand early language acquisition from an ontogenetic and phylogenetic perspective, but to also identify reliable clinical risk-markers in infants for the development of later language disorders.

Symptom severity in autism spectrum disorder is related to the frequency and severity of nausea and vomiting during pregnancy: a retrospective case-control study

Background

Nausea and vomiting during pregnancy (NVP) is thought to be caused by changes in maternal hormones during pregnancy. Differences in hormone exposure during prenatal life have been implicated in the causal pathways for some cases of autism spectrum disorder (ASD). However, no study has investigated whether the presence and severity of NVP may be related to symptom severity in offspring with ASD.

Methods

A large sample of children with ASD (227 males and 60 females, aged 2 to 18 years) received a clinical assessment, during which parents completed questionnaires regarding their child’s social (Social Responsiveness Scale, SRS) and communication (Children’s Communication Checklist–2nd edition, CCC-2) symptoms. Parents also reported on a 5-point scale the frequency and severity of NVPs during the pregnancy of the child being assessed: (1) no NVP during the pregnancy, (2) occasional nausea, but no vomiting, (3) daily nausea, but no vomiting, (4) occasional vomiting, with or without nausea, and (5) daily nausea and vomiting.

Results

Impairments in social responsiveness in offspring, as indexed by SRS total score, significantly increased as a function of the frequency and severity of their mothers’ NVP, as did the level of language difficulties as indexed by the Global Communication Composite of the CCC-2.

Conclusions

The strong, positive association between increasing frequency and severity of NVP and ASD severity in offspring provides further evidence that exposure to an atypical hormonal environment during prenatal life may affect neurodevelopment and contribute to the ASD phenotype. Given that the measure of NVP symptoms in the current study was based on retrospective recall, replication of this finding is required before strong conclusions can be drawn.

Electronic supplementary material

The online version of this article (10.1186/s13229-018-0223-7) contains supplementary material, which is available to authorized users.

Prenatal dioxin exposure estimated from dioxins in breast milk and sex hormone levels in umbilical cord blood in Vietnamese newborn infants

Dioxin concentrations remain elevated in the environment and humans residing near the former US Air Force base in Bien Hoa city, South Vietnam. We recruited 210 mother-infant pairs for whom breast milk dioxin levels were reported in our previous study. Cord blood samples were collected from 162 mother-infant pairs. We selected 16 cord blood samples with a volume over 20mL and fat content of ≥0.03g. Toxic equivalent levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (TEQ-PCDD/Fs) and concentrations of 17 congeners, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), in cord blood were measured and compared with levels in breast milk (Study 1). Levels of 2,3,7,8-TCDD and TEQ-PCDD/Fs in cord blood samples were highly and significantly correlated with those in breast milk samples in the same pairs. This suggests dioxins in breast milk reflect prenatal dioxin exposure. Estradiol (E2) and testosterone (TS) were measured in cord blood serum from 162 samples. Associations between dioxins in breast milk and cord blood sex hormones were analyzed by infant sex, after adjusting for confounding factors (Study 2). Increased levels of TEQ-PCDD/Fs in breast milk were associated with decreased cord blood TS in girls. In boys, a significant reduction of cord blood TS was observed in those exposed to 2,3,7,8-TCDD at high levels (≥5.5pg/g lipid). There was no significant association between E2 and dioxins in breast milk in either sex. These results suggest increased prenatal dioxin exposure is associated with decreased cord TS, but in boys, only high level of 2,3,7,8-TCDD influence cord blood TS.

Umbilical cord androgens and estrogens in relation to verbal and nonverbal abilities at age 10 in the general population

Sex differences in verbal and nonverbal abilities are a contentious area of research. Prenatal steroids have been shown to have masculinizing effects on the brain that may affect the development of nonverbal and verbal abilities in later life. The current study examined a wide range of biologically active sex steroids (both androgens and estrogens) in umbilical cord blood at birth in a large pregnancy cohort in relation to performance on nonverbal (Raven's Coloured Progressive Matrices) and verbal (Clinical Evaluation of Language Fundamentals-3 and the Peabody Picture Vocabulary Test-III) measures at age 10 years. Overall, Androgen and Estrogen composites in cord blood were not found to be predictive of performance on verbal and nonverbal measures at age 10. These data suggest that late gestation sex steroids do not exert a major effect on nonverbal and verbal abilities in middle childhood.

Early Vocabulary in Relation to Gender, Bilingualism, Type, and Duration of Childcare

This study investigates the predictive value of child-related and environmental characteristics for early lexical development. The German productive vocabulary of 51 2-year-olds (27 girls), assessed via parental report, was analyzed taking children's gender, the type of early care they experienced, and their mono- versus bilingual language composition into consideration. The children were from an educationally homogeneous group of families and state-regulated daycare facilities with high structural quality. All investigated subgroups exhibited German vocabulary size within the expected normative range. Gender differences in vocabulary composition, but not in size, were observed. There were no general differences in vocabulary size or composition between the 2 care groups. An interaction between the predictors gender and care arrangement showed that girls without regular daycare experience before the age of 2 years had a somewhat larger vocabulary than all other investigated subgroups of children. The vocabulary size of the 2-year-old children in daycare correlated positively with the duration of their daycare experience prior to testing. The small subgroup of bilingual children investigated exhibited slightly lower but still normative German expressive vocabulary size and a different vocabulary composition compared to the monolingual children. This study expands current knowledge about relevant predictors of early vocabulary. It shows that in the absence of educational disadvantages the duration of early daycare experience of high structural quality is positively associated with vocabulary size but also points to the fact that environmental characteristics, such as type of care, might affect boys' and girls' early vocabulary in different ways.

Effects of adrenal androgens during the prenatal period on the second to fourth digit ratio in school-aged children

OBJECTIVES

We investigated the relationship between the levels of adrenal steroid hormones in cord blood and the second to fourth digit ratio (2D/4D), which is regarded as an indirect method to investigate the putative effects of prenatal exposure to androgens, in school-aged children.

MATERIALS AND METHODS

Of the 514 mother-child pairs who participated in the prospective cohort study of birth in Sapporo between 2002 and 2005, the following adrenal steroid hormone levels in 294 stored cord blood samples (135 males and 159 females) were measured; cortisol, cortisone, androstenedione and dehydroepiandrosterone (DHEA). A total of 190 out of 350 children who were currently school-aged and contactable for this survey sent back photocopies of their palms for 2D/4D measurements.

RESULTS

2D/4D in all right hands, left hands, and mean values was significantly lower in males than in females (p<0.01). DHEA levels were significantly higher in females. A multivariate regression model showed that 2D/4D negatively correlated with DHEA in males only (p<0.01). No correlations were observed in the other adrenal steroid hormones tested in males or in any adrenal steroid hormones in females.

CONCLUSION

DHEA is mainly secreted in large amounts by the adrenal gland and is transformed into active sex-steroid hormones in peripheral tissues. The present study demonstrated that sex differences in digits were influenced by adrenal androgens during the prenatal period, possibly through intracrinological processes for androgen receptors located in fetal cartilaginous tissues.

Language Impairments in ASD Resulting from a Failed Domestication of the Human Brain

Autism spectrum disorders (ASD) are pervasive neurodevelopmental disorders entailing social and cognitive deficits, including marked problems with language. Numerous genes have been associated with ASD, but it is unclear how language deficits arise from gene mutation or dysregulation. It is also unclear why ASD shows such high prevalence within human populations. Interestingly, the emergence of a modern faculty of language has been hypothesized to be linked to changes in the human brain/skull, but also to the process of self-domestication of the human species. It is our intention to show that people with ASD exhibit less marked domesticated traits at the morphological, physiological, and behavioral levels. We also discuss many ASD candidates represented among the genes known to be involved in the “domestication syndrome” (the constellation of traits exhibited by domesticated mammals, which seemingly results from the hypofunction of the neural crest) and among the set of genes involved in language function closely connected to them. Moreover, many of these genes show altered expression profiles in the brain of autists. In addition, some candidates for domestication and language-readiness show the same expression profile in people with ASD and chimps in different brain areas involved in language processing. Similarities regarding the brain oscillatory behavior of these areas can be expected too. We conclude that ASD may represent an abnormal ontogenetic itinerary for the human faculty of language resulting in part from changes in genes important for the “domestication syndrome” and, ultimately, from the normal functioning of the neural crest.

Prenatal testosterone exposure is related to sexually dimorphic facial morphology in adulthood

Prenatal testosterone may have a powerful masculinizing effect on postnatal physical characteristics. However, no study has directly tested this hypothesis. Here, we report a 20-year follow-up study that measured testosterone concentrations from the umbilical cord blood of 97 male and 86 female newborns, and procured three-dimensional facial images on these participants in adulthood (range: 21-24 years). Twenty-three Euclidean and geodesic distances were measured from the facial images and an algorithm identified a set of six distances that most effectively distinguished adult males from females. From these distances, a 'gender score' was calculated for each face, indicating the degree of masculinity or femininity. Higher cord testosterone levels were associated with masculinized facial features when males and females were analysed together (n = 183; r = -0.59), as well as when males (n = 86; r = -0.55) and females (n = 97; r = -0.48) were examined separately (p-values < 0.001). The relationships remained significant and substantial after adjusting for potentially confounding variables. Adult circulating testosterone concentrations were available for males but showed no statistically significant relationship with gendered facial morphology (n = 85, r = 0.01, p = 0.93). This study provides the first direct evidence of a link between prenatal testosterone exposure and human facial structure.

Early postnatal testosterone predicts sex-related differences in early expressive vocabulary

During the first few years of life, girls typically have a larger expressive vocabulary than boys. This sex difference is important since a small vocabulary may predict subsequent language difficulties, which are more prevalent in boys than girls. The masculinizing effects of early androgen exposure on neurobehavioral development are well-documented in nonhuman mammals. The present study conducted the first test of whether early postnatal testosterone concentrations influence sex differences in expressive vocabulary in toddlers. It was found that testosterone measured in saliva samples collected at 1-3 months of age, i.e., during the period called mini-puberty, negatively predicted parent-report expressive vocabulary size at 18-30 months of age in boys and in girls. Testosterone concentrations during mini-puberty also accounted for additional variance in expressive vocabulary after other predictors such as sex, child's age at vocabulary assessment, and paternal education, were taken into account. Furthermore, testosterone concentrations during mini-puberty mediated the sex difference in expressive vocabulary. These results suggest that testosterone during the early postnatal period contributes to early language development and neurobehavioral sexual differentiation in humans.

Baby babbling at five months linked to sex hormone levels in early infancy

Gender-dependent differentiation of the brain at morphological, neurochemical and functional levels of organization have been shown to be primarily controlled by sex differences in gonadal hormone concentrations during pre- and early postnatal development. Indeed, previous studies have reported that pre- and perinatal hormonal environments influence brain development and, consequently, affect sex specific long-term language outcomes. Herein, we investigated whether postnatal surges of estrogen (estradiol) and androgen (testosterone) may predict properties of pre-speech babbling at five months. This study is the first attempt to investigate a possible correlation between sex hormones and infants' articulatory skills during the typical postnatal period of extended hormonal activity known as 'mini-puberty.' A hierarchical, multiple regression approach revealed a significant, robust positive relationship between 4-week concentrations of estradiol and individual articulatory skills. In contrast, testosterone concentrations at five months negatively correlated with articulatory skills at the same age in both boys and girls. Our findings reinforce the assumption of the importance of sex hormones for auditory-vocal development towards language in human infants.

Testosterone affects language areas of the adult human brain

Although the sex steroid hormone testosterone is integrally involved in the development of language processing, ethical considerations mostly limit investigations to single hormone administrations. To circumvent this issue we assessed the influence of continuous high-dose hormone application in adult female-to-male transsexuals. Subjects underwent magnetic resonance imaging before and after 4 weeks of testosterone treatment, with each scan including structural, diffusion weighted and functional imaging. Voxel-based morphometry analysis showed decreased gray matter volume with increasing levels of bioavailable testosterone exclusively in Broca's and Wernicke's areas. Particularly, this may link known sex differences in language performance to the influence of testosterone on relevant brain regions. Using probabilistic tractography, we further observed that longitudinal changes in testosterone negatively predicted changes in mean diffusivity of the corresponding structural connection passing through the extreme capsule. Considering a related increase in myelin staining in rodents, this potentially reflects a strengthening of the fiber tract particularly involved in language comprehension. Finally, functional images at resting-state were evaluated, showing increased functional connectivity between the two brain regions with increasing testosterone levels. These findings suggest testosterone-dependent neuroplastic adaptations in adulthood within language-specific brain regions and connections. Importantly, deteriorations in gray matter volume seem to be compensated by enhancement of corresponding structural and functional connectivity. Hum Brain Mapp 37:1738-1748, 2016. © 2016 Wiley Periodicals, Inc.

Prenatal testosterone exposure is related to sexually dimorphic facial morphology in adulthood

Prenatal testosterone may have a powerful masculinizing effect on postnatal physical characteristics. However, no study has directly tested this hypothesis. Here, we report a 20-year follow-up study that measured testosterone concentrations from the umbilical cord blood of 97 male and 86 female newborns, and procured three-dimensional facial images on these participants in adulthood (range: 21-24 years). Twenty-three Euclidean and geodesic distances were measured from the facial images and an algorithm identified a set of six distances that most effectively distinguished adult males from females. From these distances, a 'gender score' was calculated for each face, indicating the degree of masculinity or femininity. Higher cord testosterone levels were associated with masculinized facial features when males and females were analysed together (n = 183; r = -0.59), as well as when males (n = 86; r = -0.55) and females (n = 97; r = -0.48) were examined separately (p-values < 0.001). The relationships remained significant and substantial after adjusting for potentially confounding variables. Adult circulating testosterone concentrations were available for males but showed no statistically significant relationship with gendered facial morphology (n = 85, r = 0.01, p = 0.93). This study provides the first direct evidence of a link between prenatal testosterone exposure and human facial structure.

The perinatal androgen to estrogen ratio and autistic-like traits in the general population: a longitudinal pregnancy cohort study

BACKGROUND

Prenatal androgen exposure has been hypothesized to be linked to autism spectrum disorder (ASD). While previous studies have found a link between testosterone levels in amniotic fluid and autistic-like traits, a similar relationship has not been found for testosterone in umbilical cord blood. However, it may be the net biological activity of multiple androgens and estrogens that influences postnatal effects of prenatal sex steroids. Accordingly, composite levels of androgens (A) and estrogens (E) were investigated, along with their ratio, in relation to autistic-like traits in young adulthood.

METHODS

Sex steroid data in umbilical cord blood were available from 860 individuals at delivery. Samples were analyzed for androgens (testosterone, androstenedione, and dehydroepiandrosterone) and estrogens (estrone, estradiol, estriol, and estetrol). Levels of bioavailable testosterone, estradiol, and estrone were measured and used to calculate A and E composites and the A to E ratio. Participants were approached in early adulthood to complete the autism-spectrum quotient (AQ) as a self-report measure of autistic-like traits, with 183 males (M = 20.10 years, SD = 0.65 years) and 189 females (M =19.92 years, SD = 0.68 years) providing data.

RESULTS

Males exhibited significantly higher androgen composites and A to E composite ratios than females. Males also scored significantly higher on the details/patterns subscale of the AQ. Subsequent categorical and continuous analyses, which accounted for covariates, revealed no substantial relationships between the A/E composites or the A to E ratio and the AQ total or subscale scores.

CONCLUSIONS

The current study found no link between the A/E composites or the A to E ratio in cord blood and autistic-like traits in the population as measured by the AQ. These outcomes do not exclude the possibility that these sex steroid variables may predict other neurodevelopmental traits in early development.

Effects of prenatal Leydig cell function on the ratio of the second to fourth digit lengths in school-aged children

Prenatal sex hormones can induce abnormalities in the reproductive system and adversely impact on genital development. We investigated whether sex hormones in cord blood influenced the ratio of the second to fourth digit lengths (2D/4D) in school-aged children. Of the 514 children who participated in a prospective cohort study on birth in Sapporo between 2002 and 2005, the following sex hormone levels were measured in 294 stored cord blood samples (135 boys and 159 girls); testosterone (T), estradiol (E), progesterone, LH, FSH, inhibin B, and insulin-like factor 3 (INSL3). A total of 350 children, who were of school age and could be contacted for this survey, were then requested via mail to send black-and-white photocopies of the palms of both the left and right hands. 2D/4D was calculated in 190 children (88 boys and 102 girls) using photocopies and derived from participants with the characteristics of older mothers, a higher annual household income, higher educational level, and fewer smokers among family members. 2D/4D was significantly lower in males than in females (p<0.01). In the 294 stored cord blood samples, T, T/E, LH, FSH, Inhibin B, and INSL3 levels were significantly higher in samples collected from males than those from females. A multivariate regression model revealed that 2D/4D negatively correlated with INSL3 in males and was significantly higher in males with <0.32 ng/mL of INSL3 (p<0.01). No correlations were observed between other hormones and 2D/4D. In conclusion, 2D/4D in school-aged children, which was significantly lower in males than in females, was affected by prenatal Leydig cell function.

Sex hormones in early infancy seem to predict aspects of later language development

Sex differences in the development of cognitive behavior such as language have long been of great research interest. Lately, researchers have started to associate language function and brain differences with diverse sex hormones (e.g., testosterone/estradiol). However, results concerning the impact of early postnatal sex hormone concentration on the child's later language development are rare. Here, we analyze the impact of testosterone and estradiol in girls and boys as well as their neurophysiological phonemic discrimination at age 5months on language development at age 4years. Interestingly, we found strong positive estradiol and negative testosterone impact on later language performance at age 4years, which was true for both girls and boys. These results demonstrate that postnatal sex hormone surge might be viewed as one factor determining later language development, independent of gender.

Adult digit ratio (2D:4D) is not related to umbilical cord androgen or estrogen concentrations, their ratios or net bioactivity

BACKGROUND

Ratio of second digit length to fourth digit length (2D:4D) has been extensively used in human and experimental research as a marker of fetal sex steroid exposure. However, very few human studies have measured the direct relationship between fetal androgen or estrogen concentrations and digit ratio.

AIMS

We investigated the relationships between both androgen and estrogen concentrations in umbilical cord blood and digit ratio in young adulthood. In addition we calculated measures of total serum androgen and total estrogen bioactivity and investigated their relationship to digit ratio.

STUDY DESIGN

Prospective cohort study.

SUBJECTS

An unselected subset of the Western Australian Pregnancy Cohort (Raine) Study (159 female; 182 male).

OUTCOME MEASURES

Cord serum samples were collected immediately after delivery. Samples were assayed for androgen (testosterone, Δ4-androstenedione, dehydroepiandrosterone) and estrogen (estrone, estradiol, estriol, estetrol) concentrations using liquid-chromatography mass-spectrometry. Digit ratio measurements were taken from hand photocopies at age 19-22years.

RESULTS

For both males and females, there were no significant correlations between digit ratio and any androgen or estrogen concentrations considered individually, the testosterone to estradiol ratio, total androgen bioactivity measure or ratio of androgen to estrogen bioactivity (all p>.05). In males, but not females, total estrogen bioactivity was negatively correlated with left hand digit ratio (r=-.172, p=.02), but this relationship was no longer significant when adjusted for variables known to affect sex steroid concentrations in cord blood.

CONCLUSIONS

Our findings indicate that digit ratio is not related to fetal androgens or estrogens at late gestation.

Perinatal testosterone exposure and cerebral lateralisation in adult males: evidence for the callosal hypothesis

Two competing theories address the influence of foetal testosterone on cerebral laterality: one proposing exposure to high foetal testosterone concentrations is related to atypical lateralisation (Geschwind-Galaburda hypothesis), the other that high foetal testosterone concentrations exaggerate typical lateralisation (callosal hypothesis). The current study examined the relationship between cord testosterone concentrations and cerebral laterality for language and spatial memory in adulthood. Male participants with high (>0.15nmol) and low (<0.10nmol) cord testosterone levels were invited to take part in the study (n=18 in each group). Cerebral laterality was measured using functional Transcranial Doppler ultrasonography, while participants completed word generation and visual short-term memory tasks. Typical left lateralisation of language was more common in the high-testosterone group than in the low-testosterone group, χ(2)=4.50, df=1, p=034. Spatial memory laterality was unrelated to cord testosterone level. Our findings indicate that foetal testosterone exposure is related to language laterality in a direction that supports the callosal hypothesis.

Measurement of androgen and estrogen concentrations in cord blood: accuracy, biological interpretation, and applications to understanding human behavioral development

Accurately measuring hormone exposure during prenatal life presents a methodological challenge and there is currently no "gold standard" approach. Ideally, circulating fetal hormone levels would be measured at repeated time points during pregnancy. However, it is not currently possible to obtain fetal blood samples without significant risk to the fetus, and therefore surrogate markers of fetal hormone levels must be utilized. Umbilical cord blood can be readily obtained at birth and largely reflects fetal circulation in late gestation. This review examines the accuracy and biological interpretation of the measurement of androgens and estrogens in cord blood. The use of cord blood hormones to understand and investigate human development is then discussed.