Fetal brain growth and infant autistic traits.

BACKGROUND: Structural differences exist in the brains of autistic individuals. To date only a few studies have explored the relationship between fetal brain growth and later infant autistic traits, and some have used fetal head circumference (HC) as a proxy for brain development. These findings have been inconsistent. Here we investigate whether fetal subregional brain measurements correlate with autistic traits in toddlers. METHODS: A total of 219 singleton pregnancies (104 males and 115 females) were recruited at the Rosie Hospital, Cambridge, UK. 2D ultrasound was performed at 12-, 20- and between 26 and 30 weeks of pregnancy, measuring head circumference (HC), ventricular atrium (VA) and transcerebellar diameter (TCD). A total of 179 infants were followed up at 18-20 months of age and completed the quantitative checklist for autism in toddlers (Q-CHAT) to measure autistic traits. RESULTS: Q-CHAT scores at 18-20 months of age were positively associated with TCD size at 20 weeks and with HC at 28 weeks, in univariate analyses, and in multiple regression models which controlled for sex, maternal age and birth weight. LIMITATIONS: Due to the nature and location of the study, ascertainment bias could also have contributed to the recruitment of volunteer mothers with a higher than typical range of autistic traits and/or with a significant interest in the neurodevelopment of their children. CONCLUSION: Prenatal brain growth is associated with toddler autistic traits and this can be ascertained via ultrasound starting at 20 weeks gestation.

Fetal anogenital distance using ultrasound.

OBJECTIVE: This study measured anogenital distance (AGD) during late second/early third trimester of pregnancy to confirm previous findings that AGD can be measured noninvasively in the fetus using ultrasound and further showed differences in reference ranges between populations. METHOD: Two hundred ten singleton pregnancies were recruited at the Rosie Hospital, Cambridge, UK. A 2D ultrasound was performed between 26 and 30 weeks of pregnancy. AGD was measured from the centre of the anus to the base of the scrotum in males and to the posterior convergence of the fourchette in females. RESULTS: A significant difference in AGD between males and females (P < .0001) was found, replicating previous results with a significant correlation between estimated fetal weight (EFW) and AGD in males only (P = .006). A comparison of AGD using reference data from an Israeli sample (n = 118) and our UK sample (n = 208) showed a significant difference (P < .0001) in both males and females, after controlling for gestational age (GA). CONCLUSION: Our results confirm that AGD measurement in utero using ultrasound is feasible. In addition, there are strong sex differences, consistent with previous suggestions that AGD is influenced by prenatal androgen exposure. AGD lengths differ between the UK and Israel; therefore, population-specific normative values may be required for accurate clinical assessments.

Prenatal versus postnatal sex steroid hormone effects on autistic traits in children at 18 to 24 months of age.

BACKGROUND: Studies of prenatal exposure to sex steroid hormones predict autistic traits in children at 18 to 24 and at 96 months of age. However, it is not known whether postnatal exposure to these hormones has a similar effect. This study compares prenatal and postnatal sex steroid hormone levels in relation to autistic traits in 18 to 24-month-old children.Fetal testosterone (fT) and fetal estradiol (fE) levels were measured in amniotic fluid from pregnant women (n = 35) following routine second-trimester amniocentesis. Saliva samples were collected from these children when they reached three to four months of age and were analyzed for postnatal testosterone (pT) levels. Mothers were asked to complete the Quantitative Checklist for Autism in Toddlers (Q-CHAT), a measure of autistic traits in children 18 to 24 months old. FINDING: fT (but not pT) levels were positively associated with scores on the Q-CHAT. fE and pT levels showed no sex differences and no relationships with fT levels. fT levels were the only variable that predicted Q-CHAT scores. CONCLUSIONS: These preliminary findings are consistent with the hypothesis that prenatal (but not postnatal) androgen exposure, coinciding with the critical period for sexual differentiation of the brain, is associated with the development of autistic traits in 18 to 24 month old toddlers. However, it is recognized that further work with a larger sample population is needed before the effects of postnatal androgen exposure on autistic traits can be ruled out. These results are also in line with the fetal androgen theory of autism, which suggests that prenatal, organizational effects of androgen hormones influence the development of autistic traits in later life.

Fetal programming effects of testosterone on the reward system and behavioral approach tendencies in humans.

BACKGROUND: Sex differences are present in many neuropsychiatric conditions that affect emotion and approach-avoidance behavior. One potential mechanism underlying such observations is testosterone in early development. Although much is known about the effects of testosterone in adolescence and adulthood, little is known in humans about how testosterone in fetal development influences later neural sensitivity to valenced facial cues and approach-avoidance behavioral tendencies. METHODS: With functional magnetic resonance imaging we scanned 25 8-11-year-old children while viewing happy, fear, neutral, or scrambled faces. Fetal testosterone (FT) was measured via amniotic fluid sampled between 13 and 20 weeks gestation. Behavioral approach-avoidance tendencies were measured via parental report on the Sensitivity to Punishment and Sensitivity to Rewards questionnaire. RESULTS: Increasing FT predicted enhanced selectivity for positive compared with negatively valenced facial cues in reward-related regions such as caudate, putamen, and nucleus accumbens but not the amygdala. Statistical mediation analyses showed that increasing FT predicts increased behavioral approach tendencies by biasing caudate, putamen, and nucleus accumbens but not amygdala to be more responsive to positive compared with negatively valenced cues. In contrast, FT was not predictive of behavioral avoidance tendencies, either through direct or neurally mediated paths. CONCLUSIONS: This work suggests that testosterone in humans acts as a fetal programming mechanism on the reward system and influences behavioral approach tendencies later in life. As a mechanism influencing atypical development, FT might be important across a range of neuropsychiatric conditions that asymmetrically affect the sexes, the reward system, emotion processing, and approach behavior.

Perinatal postmortems: what is important to parents and how do they decide?

BACKGROUND: Falling consent rates for postmortems, regardless of age of death, have been widely reported in recent years. The aim of this study was to explore parental attitudes to, and decision-making about, a perinatal postmortem after termination for fetal abnormality, late miscarriage, or stillbirth. METHODS: A prospective self-completion questionnaire was given to 35 women and their partners. The participants had experienced second or third trimester pregnancy loss in a single fetal medicine and delivery unit in the United Kingdom and were making decisions about having a postmortem. They were asked to complete a questionnaire about their attitudes to, and expectations of, a perinatal postmortem. RESULTS: Thirty-one questionnaires were received from parents of 17 babies (49% of those asked; 16 from mothers, 15 from fathers). Parents of nine babies (53%) said they would agree to a full postmortem, of three babies to a limited postmortem, and of four babies to an external examination only; one couple were undecided. The most important issues for the parents in this study that related to their decisions about a postmortem centered on the need for information, both for future planning and about what had happened. Moderately important issues related to altruism, which is, improving medical knowledge and helping other parents experiencing similar bereavement. Among the lowest scoring issues were potential barriers, such as concerns about cultural or religious acceptability of a postmortem, funeral delays, and what would happen to the baby's body. CONCLUSIONS: Bereaved parents who participated in this study, where postmortem consent rates were relatively high, thought that their need for knowledge eclipsed assumed barriers when deciding whether or not to have a postmortem for their baby.

Fetal testosterone influences sexually dimorphic gray matter in the human brain.

In nonhuman species, testosterone is known to have permanent organizing effects early in life that predict later expression of sex differences in brain and behavior. However, in humans, it is still unknown whether such mechanisms have organizing effects on neural sexual dimorphism. In human males, we show that variation in fetal testosterone (FT) predicts later local gray matter volume of specific brain regions in a direction that is congruent with sexual dimorphism observed in a large independent sample of age-matched males and females from the NIH Pediatric MRI Data Repository. Right temporoparietal junction/posterior superior temporal sulcus (RTPJ/pSTS), planum temporale/parietal operculum (PT/PO), and posterior lateral orbitofrontal cortex (plOFC) had local gray matter volume that was both sexually dimorphic and predicted in a congruent direction by FT. That is, gray matter volume in RTPJ/pSTS was greater for males compared to females and was positively predicted by FT. Conversely, gray matter volume in PT/PO and plOFC was greater in females compared to males and was negatively predicted by FT. Subregions of both amygdala and hypothalamus were also sexually dimorphic in the direction of Male > Female, but were not predicted by FT. However, FT positively predicted gray matter volume of a non-sexually dimorphic subregion of the amygdala. These results bridge a long-standing gap between human and nonhuman species by showing that FT acts as an organizing mechanism for the development of regional sexual dimorphism in the human brain.

Effects of fetal testosterone on visuospatial ability.

This study investigated whether fetal testosterone (FT) measured from second trimester amniotic fluid was related to specific aspects of visuospatial ability, in children aged 7-10 years (35 boys, 29 girls). A series of tasks were used: the children's Embedded Figures Test (EFT) (a test of attention to detail), a ball targeting task (measuring hand-eye coordination), and a computerized mental rotation task (measuring rotational ability). FT was a significant predictor for EFT scores in both boys and girls, with boys also showing a clear advantage for this task. No significant sex differences were observed in targeting. Boys scored higher than girls on mental rotation. However, no significant relationships were observed between FT and targeting or mental rotation. Girls' performance on the mental rotation and targeting tasks was significantly related to age, indicating that these tasks may have been too difficult for the younger children. These results indicate that FT has a significant role in some aspects of cognitive development but that further work is needed to understand its effect on the different aspects of visuospatial ability.

Frequency and clinical significance of placental histological lesions in an unselected population at or near term.

Associations between specific placental histological abnormalities and obstetric outcomes are reported. However, most data are based either on high-risk cases or relate to case-control studies selected from those with abnormal placental histology findings, with the unavoidable biases that these approaches entail. This study reports the frequency of the several common, objective and predefined histological abnormalities of the placenta as identified by pathologists blinded to all clinical information. A total 1,153 women were recruited from an unselected population delivering at 34-43 weeks. Histological findings in common obstetric outcome groups were compared to those of the unselected population, and odds ratios and predictive values were calculated. Normal histological findings were present in 72.1% of pregnancies with normal outcomes and in 79.1%, 66.6%, 80%, and 74.8% of pregnancies affected by pre-eclampsia (PET), pregnancy-induced hypertension (PIH), gestational diabetes (GDM), and small for gestational age (SGA), respectively. Chronic placental underperfusion was seen more frequently in PIH (odds ratio (OR) 2) and SGA (OR 1.4), while villitis of unknown aetiology was observed more commonly in cases with PIH (OR 3.2). Fetal thrombotic vasculopathy was twice as common in cases with GDM whilst massive perivillous fibrin deposition was much more frequent in those with PET (OR 20.2) and SGA (OR 8.9). Chorangiomata were 13 times more common in pregnancies with PET. However, in all cases, positive predictive values were low, with the majority of cases with histological abnormalities being associated with normal outcome. At term, specific placental histological lesions are significantly more common in complicated pregnancies, but the clinical significance of such lesions in a specific case remains uncertain, since the majority will be identified from clinically uncomplicated normal pregnancies.

Relationship between placental morphology and histological findings in an unselected population near term.

Whilst individual histological features are well described, there are no universally agreed criteria as to what constitutes a clinically significant histological lesion of the placenta in an uncomplicated pregnancy, nor has the presence of such histological findings been systematically related to quantitative morphological characteristics of the placenta (such as placental shape, cord insertion and cord coiling). This study aims to explore this relationship and further to describe the incidence of predefined categories of histological lesions of the placenta in an unselected obstetric population recruited prior to delivery. The study is based upon the placental examination of 1,156 women with singleton pregnancies recruited prospectively in a single unit. Placentas were analysed where deliveries occurred between 34-43 weeks. The incidence of normal histological findings and specific histological categories, such as ascending genital tract infection, chronic placental underperfusion, intervillous thrombus and villitis of unknown aetiology, were noted. The relationship between placental morphological indices: coiling index, cord centrality index (distance of cord insertion on the chorionic plate from the centre) and eccentricity (shape of the placenta) and histological lesions was investigated. There were no significant differences between cord centrality and eccentricity between placentas with and without histological lesions except an association between hypercoiling of the umbilical cord and intervillous thrombosis and villitis of unknown aetiology (p = 0.024 and p = 0.009, respectively). The macroscopic morphological features of the placenta cannot predict the presence or absence of the histological placental lesions, nor are these lesions in general associated with differences in cord centrality, placental eccentricity or cord coiling.

Attitudes to perinatal postmortem: parental views about research participation.

OBJECTIVE: To study parental attitudes to participating in questionnaire research about perinatal postmortem immediately after late miscarriage, stillbirth and termination for fetal abnormality. DESIGN: Prospective self-completion questionnaire. SETTING: UK fetal medicine and delivery unit. PATIENTS: 35 women and their partners after second or third trimester pregnancy loss, making decisions about having a postmortem. METHODS: Participants were asked to complete a questionnaire about postmortem decision-making which included questions about their attitudes to taking part in research. Prior to giving full approval for the study, the Research Ethics Committee (REC) requested feedback after 10 questionnaires had been returned. RESULTS: Responses from the first 10 participants were positive about the research and the REC allowed the study to continue. 31 questionnaires were received from parents of 17 babies (49% of those asked; 16 from mothers, 15 from fathers). Of the 22 participants who answered a question about the impact of participating in this research, 73% stated that completing the questionnaire had helped them feel better about the decision whether or not to consent to postmortem and none reported any adverse effect of completing the questionnaire. Additional comments made by 19 participants supported this finding. CONCLUSION: Research into this sensitive area of perinatal medicine where there is a poor outcome is possible and is indeed well received by many parents. RECs should not automatically take a negative stance towards studies of this type.

Foetal testosterone and autistic traits in 18 to 24-month-old children.

BACKGROUND: Autism spectrum conditions have been characterised as an extreme presentation of certain male-typical psychological traits. In addition, several studies have established a link between prenatal exposure to testosterone and cognitive sex differences in later life, and one study found that foetal testosterone (FT) is positively correlated to autistic traits in 6 to 10 year-old children. In this study, we tested whether FT is positively correlated with autistic traits in toddlers aged 18-24 months. METHODS: Levels of FT were analysed in amniotic fluid and compared with autistic traits, measured using the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in 129 typically developing toddlers aged between 18 and 24 months (mean +/- SD 19.25 +/- 1.52 months). RESULTS: Sex differences were observed in Q-CHAT scores, with boys scoring significantly higher (indicating more autistic traits) than girls. In addition, we confirmed a significant positive relationship between FT levels and autistic traits. CONCLUSIONS: The current findings in children between 18 and 24 months of age are consistent with observations in older children showing a positive association between elevated FT levels and autistic traits. Given that sex steroid-related gene variations are associated with autistic traits in adults, this new finding suggests that the brain basis of autistic traits may reflect individual differences in prenatal androgens and androgen-related genes. The consistency of findings in early childhood, later childhood and adulthood suggests that this is a robust association.

The NTplus method of screening for Down syndrome: achieving the 2010 targets?

INTRODUCTION: The performance of pregnancy-associated plasma protein-A (PAPP-A) as a first trimester trisomy 21 marker is hypothesized to improve below 11 weeks, whereas beta-human chorionic gonadotrophin (hCG) is better after 14 weeks. We audited a model combining early PAPP-A (9-10 weeks) with NT (11-13 weeks and 6 days) and early triple test (>14 weeks). METHODS: A total of 1507 women with viable ongoing pregnancies were screened during 2007-2008. First-stage 'screen-positive' risk was based on combined PAPP-A and NT cut-off >or=1 : 100. Where first-stage risk was <1 : 100 or invasive testing declined, triple test was performed and a combined second-stage risk given with cut-off >or=1 : 250 being screen positive. RESULTS: Median age of women was 35.4 years. Sixty-four (4.2%) were 'screen positive'. Of these, 11 had a fetus with trisomy 21. Twelve pregnancies were affected with trisomy 21, giving a detection rate of 11/12 (92%) with a false-positive rate (FPR) of 3.2%. The screen-positive rate (SPR) and FPR were 1.93 and 1.44%, respectively, standardized to median maternal age 29. CONCLUSIONS: Early PAPP-A, NT and later triple testing offers comparable detection for trisomy 21 to published data for first trimester combined testing but feasibly achieve the national target for 2010 of 90% detection of trisomy 21 for < 2% SPR.

Fetal testosterone predicts sexually differentiated childhood behavior in girls and in boys.

Mammals, including humans, show sex differences in juvenile play behavior. In rodents and nonhuman primates, these behavioral sex differences result, in part, from sex differences in androgens during early development. Girls exposed to high levels of androgen prenatally, because of the genetic disorder congenital adrenal hyperplasia, show increased male-typical play, suggesting similar hormonal influences on human development, at least in females. Here, we report that fetal testosterone measured from amniotic fluid relates positively to male-typical scores on a standardized questionnaire measure of sex-typical play in both boys and girls. These results show, for the first time, a link between fetal testosterone and the development of sex-typical play in children from the general population, and are the first data linking high levels of prenatal testosterone to increased male-typical play behavior in boys.

Fetal testosterone and autistic traits.

Studies of amniotic testosterone in humans suggest that fetal testosterone (fT) is related to specific (but not all) sexually dimorphic aspects of cognition and behaviour. It has also been suggested that autism may be an extreme manifestation of some male-typical traits, both in terms of cognition and neuroanatomy. In this paper, we examine the possibility of a link between autistic traits and fT levels measured in amniotic fluid during routine amniocentesis. Two instruments measuring number of autistic traits (the Childhood Autism Spectrum Test (CAST) and the Child Autism Spectrum Quotient (AQ-Child)) were completed by these women about their children (N=235), ages 6-10 years. Intelligence Quotient (IQ) was measured in a subset of these children (N=74). fT levels were positively associated with higher scores on the CAST and AQ-Child. This relationship was seen within sex as well as when the sexes were combined, suggesting this is an effect of fT rather than of sex per se. No relationships were found between overall IQ and the predictor variables, or between IQ and CAST or AQ-Child. These findings are consistent with the hypothesis that prenatal androgen exposure is related to children exhibiting more autistic traits. These results need to be followed up in a much larger sample to test if clinical cases of ASC have elevated fT.

Obstetric and neonatal outcomes in severe fetal ventriculomegaly.

OBJECTIVE: To determine the early outcome and the incidence of associated structural anomalies in pregnancies complicated by severe fetal ventriculomegaly (VM). METHODS: A review of cases of severe fetal VM (posterior horn of lateral ventricle > 15 mm at referral or during prenatal follow-up) referred to a fetal medicine centre in Eastern England over 4 years from 2001 was made. Results of specialist prenatal investigations including ultrasound (US), karyotype, antiplatelet antibodies and congenital infection screen were noted. Neonatal clinical and cranial US findings, autopsy findings and neurodevelopmental follow-up at 4 months were obtained. RESULTS: Twenty cases of severe VM were identified, including 3 with spina bifida. Median gestation at diagnosis was 28 weeks (range 16-36 weeks). Twelve cases had additional intra-cranial abnormalities and two had abnormalities outside the central nervous system. One case was complicated by toxoplasmosis. There was one case of trisomy 21. Ten pregnancies were terminated. Ten babies were live born, all of whom had VM confirmed, and two of these babies died within 4 months. Of the remaining eight, seven have abnormal neurodevelopment. CONCLUSIONS: Severe VM is often diagnosed after the threshold of viability. Termination of pregnancy was requested in about half the cases owing to the risk of long-term neurodisability, and in all cases diagnosed before 24 weeks. In those live born, there was abnormal outcome in all but one.

Fetal testosterone and empathy.

BACKGROUND: In animals, fetal testosterone (fT) plays a central role in organizing the brain and in later social behavior. In humans, exposure to atypical levels of prenatal androgens may result in masculine behavior and ability patterns. Normal inter-individual variation in fT levels has also been correlated with later sex-typed behavior. METHODS: In the current study, 38 children (24 male, 14 female), whose fT was analyzed in amniotic fluid, were followed up at age 4. They were asked to describe cartoons with 2 moving triangles whose interactions with each other suggested social relationships and psychological motivations. RESULTS: Females used more mental and affective state terms to describe the cartoons than males. fT was not associated with the frequency of mental or affective state terms. Females also used more intentional propositions than males. fT was negatively correlated with the frequency of intentional propositions, taking sex differences into account. fT was also negatively correlated with the frequency of intentional propositions when males were examined separately. Males used more neutral propositions than females. fT was directly correlated with the frequency of neutral propositions, taking sex differences into account. This relationship was not seen when males and females were examined separately. CONCLUSIONS: These findings implicate fT in human social development. The relevance of our findings to the 'extreme male brain' theory of autism is also discussed.

Fetal testosterone and empathy: evidence from the empathy quotient (EQ) and the "reading the mind in the eyes" test.

Empathy involves an understanding of what others are thinking and feeling, and enables us to interact in the social world. According to the Empathizing-Systemizing (E-S) theory, females on average have a stronger drive to empathize than males. This sex difference may in part reflect developmental differences in brain structure and function, which are themselves under the influence of fetal testosterone (fT). Previous studies have found that fT is inversely correlated with social behaviors such as eye contact in infancy, peer relationships in preschoolers, and mentalistic interpretation of animate motion. Male fetuses are exposed to higher levels of testosterone than are female fetuses. The present study investigates empathizing in children, as a function of amniotic measures of fT. One hundred ninety-three mothers of children (100 males, 93 females) aged 6-8 years of age completed children's versions of the Empathy Quotient (EQ-C), and the children themselves were tested on "Reading the Mind in the Eyes" Task (Eyes-C). All mothers had had amniocentesis during the 2nd trimester of pregnancy. There was a significant negative correlation between fT and scores on both measures. While empathy may be influenced by post-natal experience, these results suggest that pre-natal biology also plays an important role, mediated by androgen effects in the brain. These results also have implications for the causes of disabilities involving empathy, such as autism spectrum conditions, and may explain the increased rate of such conditions among males.

Prospective audit of a one-centre combined nuchal translucency and triple test programme for the detection of trisomy 21.

OBJECTIVES: To determine detection and false-positive rates for trisomy 21 using two-stage combined nuchal translucency (NT) and triple testing, whilst disclosing abnormal nuchal measurements at the scan. METHODS: A prospective audit in a UK women's hospital, of 3188 women with singleton pregnancies, requesting screening for trisomy 21. Median age was 37 years (range 19-46). Women were offered NT screening at 11 to 14 weeks. Those with NT > or =3 mm were offered chorionic villus sampling. Those declining CVS, and those with NT <3 mm, were offered early triple tests. Women with a term combined risk of trisomy 21 > or = 1:250, based on age, NT, and triple test results were offered amniocentesis. RESULTS: Using a 3-mm NT 'cut-off' identified 16/25 cases of trisomy 21 (64%; 95% CI 38.8, 78.9). Of 2725 women who had a combined nuchal plus triple test assessment, 79 (2.6%) had a > or = 1:250 term risk of trisomy 21. Forty (1.3%) had amniocentesis identifying 6/9 remaining cases (67%:95% CI:27.9, 92.5). Overall, the detection rate was 88% (95% CI:68.8, 97.5) for a 4.8% FPR. For the screened population, to achieve an 88% detection rate using the triple test alone, the predicted FPR would be 20%. Conversely, for an FPR of 4.8% using the triple test alone, the detection rate would be only 60%. CONCLUSION: In a high-risk group, the combination of NT with triple test offers detection of trisomy 21 at least equivalent to either test, while allowing disclosure of an abnormal NT at the scan and reducing the FPR. Importantly, the FPR is less than 5%, considerably lower than expected for triple test alone for this population.

Obstetric and neonatal outcomes in apparently isolated mild fetal ventriculomegaly.

AIMS AND METHODS: To determine obstetrical and neonatal outcomes in referrals of apparently isolated mild ventriculomegaly following routine ultrasound scan, over the period 2001-2003. Specialist ultrasound and other investigations were performed. Neonatal examination and postnatal ultrasound findings were collected and local neurodevelopmental follow-up was obtained. RESULTS: 30 cases of suspected isolated mild ventriculomegaly (posterior horn of lateral ventricle 10-15 mm at diagnosis) were identified. There were two abnormal karyotypes, no abnormal TORCH screens, and only one false-positive alloimmune thrombocytopenia screen. In 21 cases, isolated ventriculomegaly was confirmed following specialist investigation. In 11 of 21 cases, ventriculomegaly resolved during antenatal follow-up, and in one case it progressed. Six of 21 had ventriculomegaly confirmed on postnatal ultrasound and lissencephaly was diagnosed in one following postnatal MRI. Of the 11 infants with antenatal resolution of ventriculomegaly, 2 have delayed development. The infant with progressive ventriculomegaly has severe developmental problems.