Sex-specific differences in fetal and infant growth patterns: a prospective population-based cohort study

Epigenetic Clock at Birth and Childhood Blood Pressure Trajectory: A Prospective Birth Cohort Study

BACKGROUND

The impact of methylation gestational age (GAmAge; a biomarker of fetal maturity) at birth on childhood blood pressure (BP) trajectories is unknown.

METHODS

This cohort study included 500 boys and 440 girls with data on cord blood DNA methylation and BP at 3 to 15 years of age. Systolic BP (SBP) and diastolic BP percentiles were calculated based on clinical guidelines. Time-series K-means clustering identified 4 distinct SBP and diastolic BP percentile trajectories: high-steady, high-decrease, normal-increase, and normal-steady. GAmAge was estimated using an existing pediatric epigenetic clock. Extrinsic age acceleration was calculated as residuals of associations between GAmAge and chronological gestational age. Intrinsic age acceleration was calculated using the same method adjusting for cord blood cell compositions.

RESULTS

Extrinsic age acceleration and intrinsic age acceleration were inversely associated with repeated measures of BP percentiles. Significant inverse associations were observed between extrinsic age acceleration and SBP percentiles in boys (β=-2.02; P=0.02) but not in girls (β=-0.49; P=0.58). Both extrinsic age acceleration and intrinsic age acceleration were inversely associated with SBP percentiles in girls born preterm (<37 weeks; βEAA=-2.95; βIAA=-3.00; P<0.05). Compared with the normal-steady SBP trajectory, significant inverse associations were observed between intrinsic age acceleration and high-steady, high-decrease, and normal-increase SBP trajectories in boys (odds ratio, 0.73-0.81; P<0.03), and significant positive associations were observed for high-decrease and normal-increase SBP trajectories in girls (odds ratio, 1.26-1.38; P<0.01). Significant sex differences were observed (Psex-interaction<2×10-16).

CONCLUSIONS

GAmAge acceleration at birth was inversely associated with child BP, and such association was more pronounced in boys than in girls. Our findings may shed new light on the developmental origins of high BP and sex differences in cardiovascular risk.

The ontogeny of human fetal trabecular bone architecture occurs in a limb-specific manner

Gestational growth and development of bone is an understudied process compared to soft tissues and has implications for lifelong health. This study investigated growth and development of human fetal limb bone trabecular architecture using 3D digital histomorphometry of microcomputed tomography data from the femora and humeri of 35 skeletons (17 female and 18 male) with gestational ages between 4 and 9 months. Ontogenetic data revealed: (i) fetal trabecular architecture is similar between sexes; (ii) the proximal femoral metaphysis is physically larger, with thicker trabeculae and greater bone volume fraction relative to the humerus, but other aspects of trabecular architecture are similar between the bones; (iii) between 4 and 9 months gestation there is no apparent sexual or limb dimorphism in patterns of growth, but the size of the humerus and femur diverges early in development. Additionally, both bones exhibit significant increases in mean trabecular thickness (and for the femur alone, bone volume fraction) but minimal trabecular reorganisation (i.e., no significant changes in degree of anisotropy, connectivity density, or fractal dimension). Overall, these data suggest that in contrast to data from the axial skeleton, prenatal growth of long bones in the limbs is characterised by size increase, without major reorganizational changes in trabecular architecture.

Birth outcomes and survival by sex among newborns and children under 2 in the Birhan Cohort: a prospective cohort study in the Amhara Region of Ethiopia

INTRODUCTION

Despite the progress in reducing child mortality, the rate remains high, particularly in sub-Saharan African countries. Limited data exist on child survival and other birth outcomes by sex. This study compared survival rates and birth outcomes by sex among neonates and children under 2 in Ethiopia.

METHODS

Women who gave birth after 28 weeks of gestation and their newborns were included in the analysis. Survival probabilities were estimated for males and females in the neonatal period as well as the 2-year period following birth using Kaplan-Meier curves. HRs and 95% CIs were compared between males and females under 2. Descriptive statistics and χ2 tests were used to determine the sex-disaggregated variation in the birth outcomes of preterm birth, low birth weight (LBW), stillbirth, small for gestational age (SGA) and large for gestational age (LGA).

RESULTS

The study included a total of 3904 women and child pairs. The neonatal mortality rate for males (3.4%, 95% CI 2.6% to 4.2%) was higher compared with females (1.7%, 95% CI 1.1% to 2.3%). The hazard of death during the first 28 days of life was approximately two times higher for males compared with females (HR 1.99, 95% CI 1.30 to 3.06) but was not significantly different after this period. While there was a non-significant difference between males and females in the proportion of preterm, LBW and LGA births, we found a significantly higher proportion of stillbirth (2.7% vs 1.3%, p=0.003) and SGA (20.5% vs 15.6%, p<0.001) for males compared with females.

CONCLUSIONS

This study identified a significant sex difference in mortality and birth outcomes. We recommend focusing future research on the mechanisms of these sex differences in order to better design intervention programmes to reduce disparities and improve outcomes for neonates.

Long-term effects on growth in preterm and small for gestational age infants: A national birth cohort study

BACKGROUND

Premature and small-for-gestational-age (SGA) infants tend to have long-term growth morbidities such as short stature, failure to thrive, and obesity. Although most of these infants show catch-up growth at 2-4 years of age, they are still more susceptible to childhood obesity and related metabolic disorders. Those who fail to achieve catch-up will suffer from pathological short stature and neurodevelopmental impairment through adulthood. This study aims to depict the growth pattern of premature or SGA infants and their growth morbidities in Taiwan.

METHODS

Data were obtained from a nationally representative cohort of 24,200 pairs of postpartum women and newborns in the Taiwan Birth Cohort Study (TBCS), using structured questionnaire interviews. A total of 16,358 infants were included and three follow-up surveys were completed at 6, 18, and 36 months after the deliveries. We constructed growth curves to conduct an in-depth investigation into anthropometric data, applying a linear mixed model. Logistic regression was used to model the relevant outcomes, with adjustment for various potential confounding factors.

RESULTS

Despite being born shorter and lighter, preterm and SGA infants generally showed catch-up growth and had no higher odds ratios (ORs) of developing short stature or failure to thrive compared to appropriate-for-gestational-age (AGA) term infants before 3 years of age. Preterm SGA infants, particularly females, had higher ORs for obesity at the 36-month follow-up.

CONCLUSION

This is the first nationwide population-based study depicting the growth of SGA infants in Taiwan. The growth patterns of preterm and term SGA infants are different from those of preterm and term AGA infants. Further research is necessary to understand the growth trajectories of preterm and SGA infants and their associations with later diseases.

Epigenetic developmental mechanisms underlying sex differences in cancer

Cancer risk is modulated by hereditary and somatic mutations, exposures, age, sex, and gender. The mechanisms by which sex and gender work alone and in combination with other cancer risk factors remain underexplored. In general, cancers that occur in both the male and female sexes occur more commonly in XY compared with XX individuals, regardless of genetic ancestry, geographic location, and age. Moreover, XY individuals are less frequently cured of their cancers, highlighting the need for a greater understanding of sex and gender effects in oncology. This will be necessary for optimal laboratory and clinical cancer investigations. To that end, we review the epigenetics of sexual differentiation and its effect on cancer hallmark pathways throughout life. Specifically, we will touch on how sex differences in metabolism, immunity, pluripotency, and tumor suppressor functions are patterned through the epigenetic effects of imprinting, sex chromosome complement, X inactivation, genes escaping X inactivation, sex hormones, and life history.

Pituitary gland height evaluated with magnetic resonance imaging in premature twins: the impact of growth and sex

BACKGROUND

Pituitary gland height reflects secretory activity of the hypothalamo-pituitary axis.

OBJECTIVE

To assess the cumulative impact of fetal growth and sex on pituitary gland height in premature twins, dissociated from prematurity.

MATERIALS AND METHODS

A retrospective study was conducted, assessing the pituitary gland height in 63 pairs of preterm twins, measured from T1-weighted magnetic resonance imaging (MRI). Auxological parameters, including body weight, body length, and head circumference, at birth and at the time of MRI, were used as proxies for fetal and postnatal growth, respectively. The study population was divided into two groups, using corrected age at around term equivalent as the cutoff point. Statistical analysis was performed using mixed-effects linear regression models.

RESULTS

When pituitary gland height was evaluated at around term equivalent, a greater pituitary gland height, suggesting a more immature hypothamo-pituitary axis, was associated with the twin exhibiting lower auxological data at birth. The same association was observed when body weight and length at MRI were used as covariants. In the group evaluated after term equivalent, a smaller pituitary gland height, suggesting a more mature hypothamo-pituitary axis, was associated with male sex. This difference was observed in twin pairs with higher average body weight at birth, and in babies exhibiting higher auxological data at MRI.

CONCLUSION

After isolating the effect of prematurity, at around term equivalent, pituitary gland height reflects the cumulative impact of fetal growth on the hypothalamo-pituitary axis. Subsequently, pituitary gland height shows effects of sex and of fetal and postnatal growth.

Significant differences in the length and weight measurements of Jordanian infants compared to the World Health Organization 2006 growth standards

BACKGROUND

In 2006, the World Health Organization (WHO) introduced new growth standards based on data derived globally from optimally nourished breastfed infants. The aim of this study was to assess the effects of implementing WHO growth standards on the growth patterns of Jordanian infants. In addition, it was to ascertain the necessity of establishing country-specific growth standards and charts tailored to Jordanian infants.

MATERIALS AND METHODS

The data of 102,846 infants (50.1% boys, 49.9% girls) aged 0-24 months, from 115 primary healthcare centers across the country were retrieved from a National E-health Program. Weight and length measurements were analyzed, and age- and sex-specific z-scores were calculated relative to the WHO growth standards. Data was analyzed using SPSS version 26. Mann-Whitney U test was performed to determine significant differences between the measurements for boys and girls in terms of age, length, and weight.

RESULTS

Jordanian infants exhibited significantly shorter length-for-age measurements than WHO standards with mean z-scores of -0.56 and -0.38, for boys and girls, respectively. Weight-for-age measurements showed a good fit and were comparable to the WHO growth standards for boys (mean z score = -0.05) and girls (mean z score = 0.04). Notably, Jordanian infants displayed higher weight-for-length measurements, with mean z-scores of 0.51 for boys and 0.47 for girls.

CONCLUSION

The availability of Jordanian-specific growth standards will improve the accuracy of assessing infant growth and enhance the monitoring and evaluation of their health and development.

Prenatal Exposure to Cannabis: Effects on Childhood Obesity and Cardiometabolic Health

PURPOSE OF REVIEW

To consolidate information on the obesogenic and cardiometabolic effects of prenatal exposure to cannabis.

RECENT FINDINGS

A PubMed search strategy updated from January 1, 2014, through 14 June 2023, produced a total of 47 epidemiologic studies and 12 animal studies. Prenatal exposure to cannabis is consistently associated with small for gestational age and low birth weight. After birth, these offspring gain weight rapidly and have increased adiposity and higher glucose (fat mass percentage) in childhood. More preclinical and prospective studies are needed to deepen our understanding of whether these associations vary by sex, dose, timing, and composition of cannabis (e.g., ratio of delta-Δ9-tetrahydrocannabinol [Δ9-THC] to cannabidiol [CBD]). Addressing these gaps may help to solidify causality and identify intervention strategies. Based on the available data, clinicians and public health officials should continue to caution against cannabis use during pregnancy to limit its potential obesogenic and adverse cardiometabolic effects on the offspring.

A novel qPCR-based technique for identifying avian sex: An illustration within embryonic craniofacial bone

Sex is a biological variable important to consider in all biomedical experiments. However, doing so in avian embryos can be challenging as sex can be morphologically indistinguishable. Unlike humans, female birds are the heterogametic sex with Z and W sex chromosomes. The female-specific W chromosome has previously been identified in chick using a species-specific polymerase chain reaction (PCR) technique. We developed a novel reverse transcription quantitative PCR (RT-qPCR) technique that amplifies the W chromosome gene histidine triad nucleotide-binding protein W (HINTW) in chick, quail, and duck. Accuracy of the HINTW RT-qPCR primer set was confirmed in all three species using species-specific PCR, including a novel quail-specific HINTW PCR primer set. Bone development-related gene expression was then analyzed by sex in embryonic lower jaws of duck and quail, as adult duck beak size is known to be sexually dimorphic while quail beak size is not. Trends toward sex differences were found in duck gene expression but not in quail, as expected. With these novel RT-qPCR and PCR embryo sexing methods, sex of chick, quail, and duck embryos can now be assessed by either/both RNA and DNA, which facilitates analysis of sex as a biological variable in studies using these model organisms.

Maternal Vitamin C Intake during Pregnancy Influences Long-Term Offspring Growth with Timing- and Sex-Specific Effects in Guinea Pigs

Our previous work in guinea pigs revealed that low vitamin C intake during preconception and pregnancy adversely affects fertility, pregnancy outcomes, and foetal and neonatal growth in a sex-dependent manner. To investigate the long-term impact on offspring, we monitored their growth from birth to adolescence (four months), recorded organ weights at childhood equivalence (28 days) and adolescence, and assessed physiological parameters like oral glucose tolerance and basal cortisol concentrations. We also investigated the effects of the timing of maternal vitamin C restriction (early vs. late gestation) on pregnancy outcomes and the health consequences for offspring. Dunkin Hartley guinea pigs were fed an optimal (900 mg/kg feed) or low (100 mg/kg feed) vitamin C diet ad libitum during preconception. Pregnant dams were then randomised into four feeding regimens: consistently optimal, consistently low, low during early pregnancy, or low during late pregnancy. We found that low maternal vitamin C intake during early pregnancy accelerated foetal and neonatal growth in female offspring and altered glucose homeostasis in the offspring of both sexes at an age equivalent to early childhood. Conversely, low maternal vitamin C intake during late pregnancy resulted in foetal growth restriction and reduced weight gain in male offspring throughout their lifespan. We conclude that altered vitamin C during development has long-lasting, sex-specific consequences for offspring and that the timing of vitamin C depletion is also critical, with low levels during early development being associated with the development of a metabolic syndrome-related phenotype, while later deprivation appears to be linked to a growth-faltering phenotype.

Sex-based differences in placental DNA methylation profiles related to gestational age: an NIH ECHO meta-analysis

The placenta undergoes many changes throughout gestation to support the evolving needs of the foetus. There is also a growing appreciation that male and female foetuses develop differently in utero, with unique epigenetic changes in placental tissue. Here, we report meta-analysed sex-specific associations between gestational age and placental DNA methylation from four cohorts in the National Institutes of Health (NIH) Environmental influences on Child Health Outcomes (ECHO) Programme (355 females/419 males, gestational ages 23-42 weeks). We identified 407 cytosine-guanine dinucleotides (CpGs) in females and 794 in males where placental methylation levels were associated with gestational age. After cell-type adjustment, 55 CpGs in females and 826 in males were significant. These were enriched for biological processes critical to the immune system in females and transmembrane transport in males. Our findings are distinct between the sexes: in females, associations with gestational age are largely explained by differences in placental cellular composition, whereas in males, gestational age is directly associated with numerous alterations in methylation levels.

Normative spatiotemporal fetal brain maturation with satisfactory development at 2 years

Maturation of the human fetal brain should follow precisely scheduled structural growth and folding of the cerebral cortex for optimal postnatal function1. We present a normative digital atlas of fetal brain maturation based on a prospective international cohort of healthy pregnant women2, selected using World Health Organization recommendations for growth standards3. Their fetuses were accurately dated in the first trimester, with satisfactory growth and neurodevelopment from early pregnancy to 2 years of age4,5. The atlas was produced using 1,059 optimal quality, three-dimensional ultrasound brain volumes from 899 of the fetuses and an automated analysis pipeline6-8. The atlas corresponds structurally to published magnetic resonance images9, but with finer anatomical details in deep grey matter. The between-study site variability represented less than 8.0% of the total variance of all brain measures, supporting pooling data from the eight study sites to produce patterns of normative maturation. We have thereby generated an average representation of each cerebral hemisphere between 14 and 31 weeks' gestation with quantification of intracranial volume variability and growth patterns. Emergent asymmetries were detectable from as early as 14 weeks, with peak asymmetries in regions associated with language development and functional lateralization between 20 and 26 weeks' gestation. These patterns were validated in 1,487 three-dimensional brain volumes from 1,295 different fetuses in the same cohort. We provide a unique spatiotemporal benchmark of fetal brain maturation from a large cohort with normative postnatal growth and neurodevelopment.

The impact of chromosomal sex on cardiometabolic health and disease

Many aspects of metabolism are sex-biased, from gene expression in metabolic tissues to the prevalence and presentation of cardiometabolic diseases. The influence of hormones produced by male and female gonads has been widely documented, but recent studies have begun to elucidate the impact of genetic sex (XX or XY chromosomes) on cellular and organismal metabolism. XX and XY cells have differential gene dosage conferred by specific genes that escape X chromosome inactivation or the presence of Y chromosome genes that are absent from XX cells. Studies in mouse models that dissociate chromosomal and gonadal sex have uncovered mechanisms for sex-biased epigenetic, transcriptional, and post-transcriptional regulation of gene expression in conditions such as obesity, atherosclerosis, pulmonary hypertension, autoimmune disease, and Alzheimer's disease.

Sex differences in innate and adaptive immunity impact fetal, placental, and maternal health†

The differences between males and females begin shortly after birth, continue throughout prenatal development, and eventually extend into childhood and adult life. Male embryos and fetuses prioritize proliferation and growth, often at the expense of the fetoplacental energy reserves. This singular focus on growth over adaptability leaves male fetuses and neonates vulnerable to adverse outcomes during pregnancy and birth and can have lasting impacts throughout life. Beyond this prioritization of growth, male placentas and fetuses also respond to infection and inflammation differently than female counterparts. Pregnancies carrying female fetuses have a more regulatory immune response, whereas pregnancies carrying male fetuses have a stronger inflammatory response. These differences can be seen as early as the innate immune response with differences in cytokine and chemokine signaling. The sexual dimorphism in immunity then continues into the adaptive immune response with differences in T-cell biology and antibody production and transfer. As it appears that these sex-specific differences are amplified in pathologic pregnancies, it stands to reason that differences in the placental, fetal, and maternal immune responses in pregnancy contribute to increased male perinatal morbidity and mortality. In this review, we will describe the genetic and hormonal contributions to the sexual dimorphism of fetal and placental immunity. We will also discuss current research efforts to describe the sex-specific differences of the maternal-fetal interface and how it impacts fetal and maternal health.

Sex differences in placenta-derived markers and later autistic traits in children

Autism is more prevalent in males and males on average score higher on measures of autistic traits. Placental function is affected significantly by the sex of the fetus. It is unclear if sex differences in placental function are associated with sex differences in the occurrence of autistic traits postnatally. To assess this, concentrations of angiogenesis-related markers, placental growth factor (PlGF) and soluble fms-like tyrosine kinase (sFlt-1) were assessed in maternal plasma of expectant women in the late 1^st (mean= 13.5 [SD = 2.0] weeks gestation) and 2^nd trimesters (mean=20.6 [SD = 1.2] weeks gestation), as part of the Generation R Study, Rotterdam, the Netherlands. Subsequent assessment of autistic traits in the offspring at age 6 was performed with the 18-item version of the Social Responsiveness Scale (SRS). Associations of placental protein concentrations with autistic traits were tested in sex-stratified and cohort-wide regression models. Cases with pregnancy complications or a later autism diagnosis (n = 64) were also assessed for differences in placenta-derived markers. sFlt-1 levels were significantly lower in males in both trimesters but showed no association with autistic traits. PlGF was significantly lower in male pregnancies in the 1^st trimester, and significantly higher in the 2^nd trimester, compared to female pregnancies. Higher PlGF levels in the 2^nd trimester and the rate of PlGF increase were both associated with the occurrence of higher autistic traits (PlGF-2^nd: n = 3469,b = 0.24 [SE = 0.11], p = 0.03) in both unadjusted and adjusted linear regression models that controlled for age, sex, placental weight and maternal characteristics. Mediation analyses showed that higher autistic traits in males compared to females were partly explained by higher PlGF or a faster rate of PlGF increase in the second trimester (PlGF-2^nd: n = 3469, ACME: b = 0.005, [SE = 0.002], p = 0.004). In conclusion, higher PlGF levels in the 2^nd trimester and a higher rate of PlGF increase are associated with both being male, and with a higher number of autistic traits in the general population.

Normal human craniofacial growth and development from 0 to 4 years

Knowledge of human craniofacial growth (increase in size) and development (change in shape) is important in the clinical treatment of a range of conditions that affects it. This study uses an extensive collection of clinical CT scans to investigate craniofacial growth and development over the first 48 months of life, detail how the cranium changes in form (size and shape) in each sex and how these changes are associated with the growth and development of various soft tissues such as the brain, eyes and tongue and the expansion of the nasal cavity. This is achieved through multivariate analyses of cranial form based on 3D landmarks and semi-landmarks and by analyses of linear dimensions, and cranial volumes. The results highlight accelerations and decelerations in cranial form changes throughout early childhood. They show that from 0 to 12 months, the cranium undergoes greater changes in form than from 12 to 48 months. However, in terms of the development of overall cranial shape, there is no significant sexual dimorphism in the age range considered in this study. In consequence a single model of human craniofacial growth and development is presented for future studies to examine the physio-mechanical interactions of the craniofacial growth.

Maturational patterns of the infant gut mycobiome are associated with early-life body mass index

Unlike the bacterial microbiome, the role of early-life gut fungi in host metabolism and childhood obesity development remains poorly characterized. To address this, we investigate the relationship between the gut mycobiome of 100 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study and body mass index Z scores (BMIz) in the first 5 years of life. An increase in fungal richness during the first year of life is linked to parental and infant BMI. The relationship between richness pattern and early-life BMIz is modified by maternal BMI, maternal diet, infant antibiotic exposure, and bacterial beta diversity. Further, the abundances of Saccharomyces, Rhodotorula, and Malassezia are differentially associated with early-life BMIz. Using structural equation modeling, we determine that the mycobiome's contribution to BMIz is likely mediated by the bacterial microbiome. This demonstrates that mycobiome maturation and infant growth trajectories are distinctly linked, advocating for inclusion of fungi in larger pediatric microbiome studies.

Non-intuitive trends of fetal fraction development related to gestational age and fetal gender, and their practical implications for non-invasive prenatal testing

Discovery of fetal cell-free DNA fragments in maternal blood revolutionized prenatal diagnostics. Although non-invasive prenatal testing (NIPT) is already a matured screening test with high specificity and sensitivity, the accurate estimation of the proportion of fetal fragments, called fetal fraction, is crucial to avoid false-negative results. In this study, we collected 6999 samples from women undergoing NIPT testing with a single male fetus to demonstrate the influence of fetal fraction by the maternal and fetal characteristics. We show several fetal fraction discrepancies that contradict the generally presented conventional view. At first, the fetal fraction is not consistently rising with the maturity of the fetus due to a drop in 15 weeks of maturation. Secondly, the male samples have a lower fetal fraction than female fetuses, arguably due to the smaller gonosomal chromosomes. Finally, we discuss not only the possible reasons why this inconsistency exists but we also outline why these differences have not yet been identified and published. We demonstrate two non-intuitive trends to better comprehend the fetal fraction development and more precise selection of patients with sufficient fetal fraction for accurate testing.

Maternal height and child health and schooling in sub-Saharan Africa: Decomposition and heterogeneity

Maternal height is associated with mortality and anthropometry in low-and-middle-income countries. This paper explored residual associations and potential underlying mechanisms linking maternal height to several child outcomes using regression models with neighborhood and half-sibling fixed effects and Gelbach decomposition on 108 Demographic and Health Surveys from 37 sub-Saharan African countries. When adjusting for time of birth, twinning, sex, and survey, a single z-score (6.5 cm) increase in mother's height was associated with a 22% reduction in the average deficit in height-for-age among children under five (according to the WHO 2006 growth standard), 16% lower neonatal mortality (age <1 month) , 10% lower postneonatal mortality (age 1-11 months), 11% lower child mortality (age 12-59 months) , and 2% increase in school attendance among 7-16-year-olds. Adjusting further for maternal education, household living standards, maternal fertility and birth related factors, and neighborhood reduced the coefficients for maternal height by 22% for child height-for-age, 26% for neonatal mortality, 46% for postneonatal mortality, 56% for child mortality, and 90% for school attendance. The decomposition showed that adjusting for neighborhood had a substantial impact on the association of maternal height with all outcomes, especially child mortality. Adjusting for unobserved father and household factors also had a particularly large impact on the association with child mortality. The robustness of the relationship with neonatal mortality suggests that pregnancy and perinatal factors are an important link between maternal height and child outcomes. Adult living standards and socioeconomic and related behavioral factors likely play a small role. Genetics may also play a large role in linking maternal height and child height-for-age, especially for educated mothers, whose height was presumably impacted less by early life adversity.

Automatic measurements of fetal intracranial volume from 3D ultrasound scans

Three-dimensional fetal ultrasound is commonly used to study the volumetric development of brain structures. To date, only a limited number of automatic procedures for delineating the intracranial volume exist. Hence, intracranial volume measurements from three-dimensional ultrasound images are predominantly performed manually. Here, we present and validate an automated tool to extract the intracranial volume from three-dimensional fetal ultrasound scans. The procedure is based on the registration of a brain model to a subject brain. The intracranial volume of the subject is measured by applying the inverse of the final transformation to an intracranial mask of the brain model. The automatic measurements showed a high correlation with manual delineation of the same subjects at two gestational ages, namely, around 20 and 30 weeks (linear fitting R2(20 weeks) = 0.88, R2(30 weeks) = 0.77; Intraclass Correlation Coefficients: 20 weeks=0.94, 30 weeks = 0.84). Overall, the automatic intracranial volumes were larger than the manually delineated ones (84 ± 16 vs. 76 ± 15 cm3; and 274 ± 35 vs. 237 ± 28 cm3), probably due to differences in cerebellum delineation. Notably, the automated measurements reproduced both the non-linear pattern of fetal brain growth and the increased inter-subject variability for older fetuses. By contrast, there was some disagreement between the manual and automatic delineation concerning the size of sexual dimorphism differences. The method presented here provides a relatively efficient way to delineate volumes of fetal brain structures like the intracranial volume automatically. It can be used as a research tool to investigate these structures in large cohorts, which will ultimately aid in understanding fetal structural human brain development.

Birth weight was associated with maternal exposure to intimate partner violence during pregnancy in southern Ethiopia: A prospective cohort study

Introduction

Birth weight is defined as the first weight of the newborn, ideally measured soon after birth. A recent Ethiopian survey estimated that 48% of births took place in health facilities. Data for women exposed to intimate partner violence (IPV) may be lacking in official statistics because these women may prefer to deliver at home, where data from non-institutional births, including reporting of birth weights, are not routinely recorded.

Objective

The aim of this study was to investigate the association between maternal exposure to IPV during pregnancy and birth weight in a community in the Wondo Genet district of southern Ethiopia.

Methods

We carried out a community-based prospective cohort study from February to December 2017. We followed up with 505 pregnant women and their newborns until after delivery. An interview about partner violence was done during pregnancy at home when enrolled. Field assistants who visited the homes measured the birth weight of each baby in grams. Twins and late birth weight measurements were excluded. Factors associated with birth weight were assessed by multiple linear regression.

Results

Birth weight was assessed within 48 h for 477 (94.5%) newborns and between 48 and 72 h for an additional 28 (5.5%). There were 365 (72.3%) institutional deliveries. In an adjusted regression analysis (IPV adjusted for socio-economic status), birth weight was 203 g lower (B -203 95% CI -320 to -87) among newborns of women exposed to IPV than among the unexposed. Birth weight was also lower in girls than in boys, in newborns delivered at home rather than in a health facility, and in babies with a younger gestational age.

Conclusion

Maternal exposure to IPV during pregnancy was associated with lower baby birth weights. Antenatal clinics should consider routinely identifying IPV-exposed women, and identifying babies with lower birth weights at home is an important indicator.

Association of geographic distribution and birth weight with sociodemographic factors of the maternal and newborn child of hilly and mountain regions of eastern Nepal: a cross-sectional study

OBJECTIVES

To determine the association of geographic distribution, and birth weight with sociodemographic factors of the maternal and newborn child of hilly region (lower altitude) and mountain region (high altitude) of eastern Nepal as well as the prevalence of low birth weight (LBW) and large for gestational age (LGA) among term singleton deliveries in eastern Nepal.

METHODOLOGY

A cross-sectional study was conducted in the district-level hospitals of Dhankuta, Tehrathum, Solukhumbu and Taplejung districts of eastern Nepal of Province 1. Mothers with preterm or post-term delivery, multiple pregnancies, stillbirth/intrauterine fetal death and incomplete records were excluded from the study with only 1386 term pregnancies (37-42 weeks) delivered at the respective facilities between 17 July 2019 and 16 July 2020 were included. The appropriate data were entered in Microsoft Excel 2019 V.16.0 and statistical analysis was performed by using the statistical package for social sciences, IBM SPSS V.29.

RESULTS

The low maternal age, Dalit ethnic group, low gravidity, low parity, higher antenatal care (ANC) visits (≥4), incomplete deworming and dT vaccination status, breech deliveries and LBW newborns were significantly attributed to hilly region (lower altitude) (p value <0.05). Similarly, the hilly region, lower and/or no ANC visits and early term gestation had significant negative association with birth weight at the lower quantiles only. Meanwhile, the female newborn had significant and negative association with birth weight distribution at all seven quantiles. The prevalence of the LBW, average for gestational age and LGA newborn child among term singleton deliveries in Eastern Nepal is 6.6%, 85.8% and 7.6%, respectively.

CONCLUSIONS

The local organisations should focus on adequate antenatal care visits in mountain region and coverage of dT vaccine and deworming medications in hilly region. Appropriate measures and programmes should be initiated to bring down LBW in hilly region.

Adjusting growth standards for fetal sex improves correlation of small babies with stillbirth and adverse perinatal outcomes: A state-wide population study

OBJECTIVES

Sex impacts birthweight, with male babies heavier on average. Birthweight charts are thus sex specific, but ultrasound fetal weights are often reported by sex neutral standards. We aimed to identify what proportion of infants would be re-classified as SGA if sex-specific charts were used, and if this had a measurable impact on perinatal outcomes.

METHODS

Retrospective cohort study including all infants born in Victoria, Australia, from 2005-2015 (529,261 cases). We applied GROW centiles, either adjusted or not adjusted for fetal sex. We compared overall SGA populations, and the populations of males considered small by sex-specific charts only (SGAsex-only), and females considered small by sex-neutral charts only (SGAunadjust-only).

RESULTS

Of those <10th centile by sex-neutral charts, 39.6% were male and 60.5% female, but using sex-specific charts, 50.3% were male and 49.7% female. 19.2% of SGA females were reclassified as average for gestational age (AGA) using sex-specific charts. These female newborns were not at increased risk of stillbirth, combined perinatal mortality, NICU admissions, low Apgars or emergency CS compared with an AGA infant, but were at greater risk of being iatrogenically delivered on suspicion of growth restriction. 25.0% male infants were reclassified as SGA by sex-specific charts. These male newborns, compared to the AGAall infant, were at greater risk of stillbirth (RR 1.94, 95%CI 1.30-2.90), combined perinatal mortality (RR 1.80, 95%CI 1.26-2.57), NICU admissions (RR 1.38, 95%CI 1.12-1.71), Apgars <7 at 5 minutes (RR 1.40, 95%CI 1.25-1.56) and emergency CS (RR 1.12, 95%CI 1.06-1.18).

CONCLUSIONS

Use of growth centiles not adjusted for fetal sex disproportionately classifies female infants as SGA, increasing their risk of unnecessary intervention, and fails to identify a cohort of male infants at increased risk of adverse outcomes, including stillbirth. Sex-specific charts may help inform decisions and improve outcomes.

Prenatal programming of developmental trajectories for obesity risk and early pubertal timing

The thrifty phenotype and fetal overnutrition hypotheses are two developmental hypotheses that originated from the developmental origins of health and disease (DOHaD) perspective. The DOHaD posits that exposures experienced prenatally and early in life may influence health outcomes through altering form and function of internal organs related to metabolic processes. Obesity risk and early pubertal timing might be influenced by similar mechanisms. The thrifty phenotype hypothesis is primarily characterized by experiencing a deprivation of nutrients during gestation paired with an energy rich postnatal environment. The fetal overnutrition hypothesis says that obesity experienced prenatally will be associated with increased lifetime risk of obesity in the offspring. Both hypotheses were tested by examining developmental pathways from genetic and prenatal risk through early growth trajectories (birth to 7 years) to pubertal timing at age 11 years. Participants included 361 children adopted at birth (57% male; 57% non-Hispanic White, 11% Black, 9% Hispanic; adoptive family income Mdn = $70,000-$100,000, birth family income Mdn = < $15,000). Associations between boys' childhood body mass index (BMI) and pubertal timing were confounded by genetics, prenatal risk, and early growth. The thrifty phenotype hypothesis was partially supported for boys' childhood BMI (at ages 4 to 7 years). Both hypotheses were partially supported for girls' childhood BMI but not pubertal timing. A novel Gene × Prenatal Risk interaction showed that genetic risk predicted girls' childhood BMI most strongly at adequate compared with at excessive levels of gestational weight gain. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Determinants of rapid infant weight gain: A pooled analysis of seven cohorts

OBJECTIVE

Rapid weight gain (RWG) in infancy is strongly associated with subsequent obesity risk, but little is known about the factors driving RWG. This study explored the child and maternal factors associated with infant RWG.

METHODS

Data from seven Australian and New Zealand cohorts were used (n = 4542). Infant RWG was defined as a change in weight z-score ≥0.67 from birth to age 1 year. Univariable and multivariable logistic regression assessed the association between child and maternal factors and infant RWG in each cohort. Meta-analysis was conducted to obtain pooled effect sizes.

RESULTS

Multivariable analyses revealed boys were more likely to experience RWG (OR 1.42 95% CI 1.22, 1.66) than girls. Higher birth weight in kg (OR 0.09, 95% CI 0.04, 0.20) and gestational age in weeks (OR 0.69, 95% CI 0.48, 0.98) were associated with lower RWG risk. Children who were breastfed for ≥6 months showed lower RWG risk (OR 0.45, 95% CI 0.38, 0.53). Children of native-born versus overseas-born women appeared to have higher RWG risk (OR 1.37, 95% CI 0.99, 1.90). Maternal smoking during pregnancy increased RWG risk (OR 1.60, 95% CI 1.28, 2.01), whereas children who started solids ≥6 months (OR 0.77, 95% CI 0.63, 0.93) and children with siblings (OR 0.68, 95% CI 0.57, 0.81) showed lower RWG risk in univariable analysis, but these associations were attenuated in multivariable analysis. No association was found for maternal age, education, marital status and pre-pregnancy BMI.

CONCLUSION

Maternal country of birth, smoking status, child sex, birth weight, gestational age, infant feeding and parity were potential determinants of infant RWG.

Association of prenatal exposure to ambient air pollution with adverse birth outcomes and effect modification by socioeconomic factors

BACKGROUND

Maternal exposure to air pollution has been associated with birth outcomes; however, few studies examined biologically critical exposure windows shorter than trimesters or potential effect modifiers.

OBJECTIVES

To examine associations of prenatal fine particulate matter (PM_2.5), by trimester and in biologically critical windows, with birth outcomes and assess potential effect modifiers.

METHODS

This study used two pregnancy cohorts (CANDLE and TIDES; N = 2099) in the ECHO PATHWAYS Consortium. PM_2.5 was estimated at the maternal residence using a fine-scale spatiotemporal model, averaged over pregnancy, trimesters, and critical windows (0-2 weeks, 10-12 weeks, and last month of pregnancy). Outcomes were preterm birth (PTB, <37 completed weeks of gestation), small-for-gestational-age (SGA), and continuous birthweight. We fit multivariable adjusted linear regression models for birthweight and Poisson regression models (relative risk, RR) for PTB and SGA. Effect modification by socioeconomic factors (maternal education, household income, neighborhood deprivation) and infant sex were examined using interaction terms.

RESULTS

Overall, 9% of births were PTB, 10.4% were SGA, and mean term birthweight was 3268 g (SD = 558.6). There was no association of PM_2.5 concentration with PTB or SGA. Lower birthweight was associated with higher PM_2.5 averaged over pregnancy (β -114.2, 95%CI -183.2, -45.3), during second (β -52.9, 95%CI -94.7, -11.2) and third (β -45.5, 95%CI -85.9, -5.0) trimesters, and the month prior to delivery (β -30.5, 95%CI -57.6, -3.3). Associations of PM_2.5 with likelihood of SGA and lower birthweight were stronger among male infants (p-interaction ≤0.05) and in those with lower household income (p-interaction = 0.09).

CONCLUSIONS

Findings from this multi city U.S. birth cohort study support previous reports of inverse associations of birthweight with higher PM_2.5 exposure during pregnancy. Findings also suggest possible modification of this association by infant sex and household income.

Head circumference trajectories during the first two years of life and cognitive development, emotional, and behavior problems in adolescence: a cohort study

The associations of early-life head circumference (HC) with child neurodevelopmental and mental health among generally healthy population remain unclear. We aimed to examine the associations of early-life HC trajectories with cognitive development and emotional and behavioral problems in adolescence and to identify the HC growth-sensitive period. We conducted a prospective, community-based birth cohort study in rural western China, and 745 adolescents aged 10-14 years were followed between June and December 2016. We assessed their HC eight times during the first 2 years of life and their adolescent cognitive, emotional, and behavioral outcomes using the Wechsler Intelligence Scale for Children-IV and Youth Self-Report-2001, respectively. We applied group-based trajectory modeling to identify the HC trajectories and conditional growth to derive the HC growth-sensitive periods. We identified five distinct HC trajectories characterized as Start below average-then decrease (7.8% of the sample), Start below average-then increase (6.8%), Start average-then decrease (33%), Consistently average (38%), and Consistently above average (14%). Infants in the trajectory of consistently above average had higher cognitive scores in adolescence compared to those from suboptimal trajectories, with adjusted mean differences ranging from 2.84 to 8.99 points. The conditional gains showed that the HC growth-sensitive period was between 0 and 18 months for child cognition. We found null associations between HC measures and adolescent emotional and behavioral problem scores.

CONCLUSION

Early-life HC trajectories were associated with adolescent cognitive development. HC may serve as an inexpensive screening tool to monitor child development at risk during the first 18 months, particularly in resource-limited settings.

WHAT IS KNOWN

• Postnatal head circumference (HC) has been shown to be associated with cognitive development in infants who were born premature and/or fetal growth restriction, while inconsistent associations were reported among generally healthy populations, especially in low- and middle- income countries, challenging its utility in public health practices.

WHAT IS NEW

• Adolescents in the HC growth trajectory of consistently above average had higher cognitive scores compared to those with other suboptimal trajectories, while null findings were observed for adolescent emotional and behavioral health. • HC may serve as an inexpensive screening tool to monitor child development at risk during the first 18 months of life, particularly in resource-limited settings.

Sex differences in preterm nutrition and growth: the evidence from human milk associated studies

Sexual dimorphism of the fetus manifests itself even during pregnancy. Preterm births are more common in pregnancies with male fetuses. Intrauterine and postnatal growth nomograms are sex-specific. The human milk composition in term infants appears to be sex-specific. Early nutrition has sex-specific effects and neurodevelopmental outcomes. A large same-sex twin study suggests that a mother's own milk (MOM) provides sex-specific growth advantages probably related to the calibration of a mother's milk based on her newborn's sex. Formula composition does not vary with infant sex, which may be one reason why body composition data favors the use of MOM over formula. However, given the lack of data on this subject, we need more detailed information on how the sex-specific micronutrients in MOM influence infant well-being. We also need more information to ascertain the sex differences in infants' macronutrient requirements, such as whether preterm females have higher fat requirements and preterm males have higher protein requirements for optimal growth and neurodevelopmental outcomes. This information may also influence milk banking and the use of donor human milk (DBM). Further research may help us determine if we should provide sex-specific DBM to those preterm infants who cannot get their MOM.

2D:4D digit ratio and its relationship to BMI, sporting choices and physiological predispositions among women

The 2D:4D digit ratio has been established as a biomarker of the level of exposure to prenatal sex hormones’ balancebetween prenatal testosterone (PT) and estrogenne levels. Higher 2D:4D indicates lower PT exposure and vice versa. Data suggests that PT exposure is linked to a risk-taking attitude and physical aggressiveness, both of which are requirements in contact sport. A possible correlation between 2D:4D and human body mass index has also been identified. The aim of the study was to examine the relation between 2D:4D ratio and choice of sport. It was assumed that female soccer players who choose a contact sport would have a lower 2D:4D ratio (thus experiencing higher exposure to PT) than female volleyball players (selecting non-contact sport). The analysis was also aimed at identifying whether a correlation between prenatal testosterone level and BMI exists. The participant sample consisted of 103 women – 36 volleyball players, 33 soccer players and a control group (N=34). Measurements were collected in 2019–2020. The results suggest that 2D:4D was significantly different in women practicing various sports (contact and non-contact sports). Women engaged in contact sports had lower 2D:4D than women engaged in non-contact sports, and vice versa (p<0.05). 2D:4D correlated positively with BMI and body weight – the higher the 2D:4D ratio, the higher the BMI and body weight (and vice versa) (p<0.05). Low 2D:4D (high PT exposure) may predict the choice of more risky, aggressive contact sports, and vice versa. High 2D:4D may predict a higher BMI and body weight, and vice versa.

Estimation of gestational age in neonates using clavicular-pubis length on routine chest-abdomen radiographs

BACKGROUND

Neonatal diseases differ depending on gestational age and weight. In the setting of an emergency in the neonatal intensive care unit (NICU), relevant clinical information is often not available when the first neonatal radiograph is obtained. When reading an initial chest-abdomen radiograph, the paediatric radiologist needs gestational age data for best radiologic practice. A transverse diameter of the chest has been previously described to estimate gestational age (GA).

OBJECTIVES

To determine the strength of the correlation between GA/weight and clavicular-pubis length (CPL) on admission radiographs; to obtain a quadratic formula based on the correlation of CPL with GA and to demonstrate if a more simplified formula used by our group works as efficiently as the formula provided by the regression analysis.

MATERIALS AND METHODS

A retrospective study was approved by the institutional review board and informed consent was waived. The length from the medial aspect of the clavicle to the pubic bone was measured on the initial portable chest-abdomen radiographs of 260 patients admitted to the NICU in 2016. Regression analysis was performed to investigate the association between CPL and GA/birth weight.

RESULTS

One hundred eleven females and 149 males with GA between 23 and 42 weeks were evaluated. CPL was statistically associated with both GA (P<0,01) and birth weight. The estimation can be expressed with an equation of the model: GA (weeks) = (CPL in cm - 1.98)/0.42. A simplified formula: GA (weeks) = (CPL in cm) ×2+2, strongly correlates with the equation model.

CONCLUSION

In patients in whom it is not known, GA can be estimated by measuring the length between medial clavicle and symphysis pubis using the formulae we propose.

Are there sex differences in fetal growth strategies and in the long-term effects of pregnancy complications on cognitive functioning?

Males and females have been proposed to have different prenatal growth strategies, whereby males invest more in fetal growth and less in placental development, leaving them more susceptible to early-life adversity. We tested predictions of this hypothesis using data from the National Collaborative Perinatal Project. Male newborns were heavier than females, but there was no difference in placental weight, adjusting for birthweight. Among infants born prior to 33 weeks, the difference in birthweight between males and females was greater among those who did not survive than among those who did, potentially reflecting a strategy whereby males maintained growth in the face of prenatal insults, while females adjusted growth. However, there was no significant difference in mortality between the sexes. Being born small-for-gestational age or very preterm (prior to 33 weeks) was associated with significantly reduced performance for most of the cognitive traits examined at 7 years, although maternal preeclampsia was associated with reduced performance in fewer traits. Generally, these effects of early-life adversity (poor fetal growth, prematurity, and preeclampsia) did not differ between the sexes. However, analyzing the sexes separately (rather than testing the interaction between sex and adversity) resulted in numerous spurious sex-specific effects, whereby the effect of early-life adversity appeared to be significant in one sex but not the other. Overall, we found little support for the hypothesis that males prioritize growth more than females, and that this makes them more susceptible to early-life adversity. Furthermore, our results show that analyzing the sexes separately, rather than testing the adversity by sex interaction, can be highly misleading.

Growth patterns and nutritional status of small for gestational age infants in Malaysia during the first year of life

Purpose

This study aimed to identify small for gestational age (SGA) infants' growth patterns, nutritional status, and associated factors.

Methods

This prospective cohort study was conducted at primary-care child health clinics in Greater Kuala Lumpur, Malaysia. The sample consisted of infants who fulfilled the criteria and were born in 2019. The anthropometric data of infants were assessed at birth and at 1, 3, 6, 9, and 12 months.

Results

A total of 328 infants were analysed. In total, 27.7%(n=91) of the subjects were SGA infants, and 237 of them were not. Significant differences in the median weight-for-age and length-for-age z-scores were observed between SGA and non-SGA infants at birth, 1 month, 6 months, and 12 months. There was a significant difference between the growth patterns of SGA and non-SGA infants. Birth weight and sex significantly predicted the nutritional status(stunting and underweight) of SGA infants during their first year of life.

Conclusion

SGA infants can catch up to achieve normal growth during their first year of life. Even though the nutritional status of SGA infants trends worse than non-SGA infants, adequate infant birth weight monitoring and an emphasis on nutritional advice are crucial for maintaining well-being.

Alveolar Bone Graft Timing in Patients With Cleft Lip & Palate

ABSTRACT

Cleft lip with or without cleft palate (CLP) is the most common craniofacial condition. Alveolar clefts are present in approximately 75% of patients with a cleft lip or CLP and often do not have sufficient support of surrounding teeth. Alveolar bone graft is commonly performed to reconstruct alveolar ridge in patient with osseous defects. Objective of this review is to critically analyze the literature to provide recommendations on appropriate timing for orthodontic preparation and surgical correction of alveolar clefts in the setting of unilateral or bilateral CLP. Search of PubMed database, MEDLINE, and EMBASE was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 15 studies were included. Majority of studies used chronological age to classify patients versus dental age. Most studies reported orthodontic treatment concomitant with surgery (12/15; 80.0%), and used orthodontics before alveolar bone grafting (8/12; 66.7%). No consensus on the best method to evaluate the success of alveolar bone grafting. Alveolar bone grafting with pre- and post-operative orthodontics is currently the standard of care for treatment of alveolar defects in patients with CLP. Authors recommend grafting during early mixed dentition phase, just before the eruption of the permanent central incisors, typically between 6 and 8 years old. Preoperative orthodontics for appropriate incisor alignment around cleft, and may be resumed 6 months postoperative.

Overweight and/or obesity and its determinants among under-five children in East African countries: A multilevel analysis using Bayesian approach

INTRODUCTION

Childhood overweight and/or obesity become a significant public health problem in the 21st century. It is a double burden next to undernutrition and has a dramatic rise in low- and middle-income countries. This study aimed to determine the prevalence of overweight and/or obesity and its determinants among under-five children in East African Countries.

METHODS

Data were retrieved from the recent nationally representative demographic and health survey datasets from eleven East African Countries. A total of 89,091 weighted numbers of under-five children participated. Statistical analysis was performed using the R (Brms R-package) software. Multivariable mixed-effects logistic regression analysis using the Bayesian approach was employed to identify the factors affecting overweight and/or obesity among under-five children.

RESULTS

Overall, 4.59% (95% CI, 4.45-4.73) of under-five children in East African Countries were overweight and/or obese. Under-five children overweight and/or obesity was highest in Comoros and lowest in Burundi. Under-five children aged older than two years (Adjusted odds ratio (AOR) = 0.65, 95% credible interval (CrI), 0.57-0.73), females (AOR = 0.84, 95% CrI:, 0.75-0.94), under-five children live from rich household wealth status (AOR = 1.25, 95% CrI, 1.06-1.49), under-five children living in Malawi (AOR = 2.60, 95% CrI, 1.49-4.51), Mozambique (AOR = 5.26, 95% CrI, 3.52-7.79), Rwanda (AOR = 5.63, 95% CrI, 3.46-9.08), Tanzania (AOR = 2.15, 95% CrI, 1.47-3.12), and Uganda (AOR = 2.62, 95% CrI, 1.71-3.99) were a significant determinant for under-five overweight and/or obesity.

CONCLUSION

Overweight and/or obesity among under-five children become a problem in low and middle-income countries. Older under-five children, male sex, children who live in rich household wealth, and children who live in a country in Malawi, Mozambique, Ruanda, Tanzania, and Uganda were significantly affected by overweight and/or obesity. Therefore, in these countries, responsible stakeholders shall give primary attention to curve the alarming increase in overweight and/or obesity among under-five children.

Female specific risk factors for the development of Alzheimer's disease neuropathology and cognitive impairment: Call for a precision medicine approach

Alzheimer's disease (AD) includes a long asymptomatic stage, which precedes the formal diagnosis of dementia. AD biomarker models provide a framework for precision medicine approaches during this stage. However, such approaches have ignored the possible influence of sex on cognition and brain health, despite female sex noted as a major risk factor. Since AD-related changes may emerge in midlife, intervention efforts are being redirected around this period. Midlife coincides with several endocrinological changes, such as the menopausal transition experienced by women. In this narrative review, we discuss evidence for sex-differences in AD neuropathological burden and outline key endocrinological mechanisms for both sexes, focussing on hormonal events throughout the lifespan that may influence female susceptibility to AD neuropathology and dementia onset. We further consider common non-modifiable (genetic) and modifiable (lifestyle and health) risk factors, highlighting possible sex-dependent differential effects for the AD disease course. Finally, we evaluate the studies selected for this review demonstrating sex-differences in cognitive, pathological and health factors, summarising the state of sex differences in AD risk factors. We further provide recommendations for targeted research on female-specific risk factors, to inform personalised strategies for AD-prevention and the promotion of female brain health.

The Placenta's Role in Sexually Dimorphic Fetal Growth Strategies

Fetal sex affects the risk of pregnancy complications and the long-term effects of prenatal environment on health. Some have hypothesized that growth strategies differ between the sexes, whereby males prioritize growth whereas females are more responsive to their environment. This review evaluates the role of the placenta in such strategies, focusing on (1) mechanisms underlying sexual dimorphism in gene expression, (2) the nature and extent of sexual dimorphism in placental gene expression, (3) sexually dimorphic responses to nutrient supply, and (4) sexual dimorphism in morphology and histopathology. The sex chromosomes contribute to sex differences in placental gene expression, and fetal hormones may play a role later in development. Sexually dimorphic placental gene expression may contribute to differences in the prevalence of complications such as preeclampsia, although this link is not clear. Placental responses to nutrient supply frequently show sexual dimorphism, but there is no consistent pattern where one sex is more responsive. There are sex differences in the prevalence of placental histopathologies, and placental changes in pregnancy complications, but also many similarities. Overall, no clear patterns support the hypothesis that females are more responsive to the maternal environment, or that males prioritize growth. While male fetuses are at greater risk of a variety of complications, total prenatal mortality is higher in females, such that males exposed to early insults may be more likely to survive and be observed in studies of adverse outcomes. Going forward, robust statistical approaches to test for sex-dependent effects must be more widely adopted to reduce the incidence of spurious results.

Maternal Dietary Quality and Dietary Inflammation Associations with Offspring Growth, Placental Development, and DNA Methylation

The ‘Developmental Origins of Health and Diseases’ hypothesis posits that prenatal maternal diet influences offspring growth and later life health outcomes. Dietary assessment has focused on selected nutrients. However, this approach does not consider the complex interactions between foods and nutrients. To provide a more comprehensive approach to public health, dietary indices have been developed to assess dietary quality, dietary inflammation and risk factors for non-communicable diseases. Thus far, their use in the context of placental development is limited and associations with offspring outcomes have been inconsistent. Although epidemiological studies have focused on the role of maternal diet on foetal programming, the underlying mechanisms are still poorly understood. Some evidence suggests these associations may be driven by placental and epigenetic changes. In this narrative review, we examine the current literature regarding relationships between key validated diet quality scores (Dietary Inflammatory Index [DII], Mediterranean diet [MD], Healthy Eating Index [HEI], Alternative Healthy Eating Index [AHEI], Dietary Approaches to Stop Hypertension [DASH], Glycaemic Index [GI] and Glycaemic Load [GL]) in pregnancy and birth and long-term offspring outcomes. We summarise findings, discuss potential underlying placental and epigenetic mechanisms, in particular DNA methylation, and highlight the need for further research and public health strategies that incorporate diet quality and epigenetics.

Let's Talk about Placental Sex, Baby: Understanding Mechanisms That Drive Female- and Male-Specific Fetal Growth and Developmental Outcomes

It is well understood that sex differences exist between females and males even before they are born. These sex-dependent differences may contribute to altered growth and developmental outcomes for the fetus. Based on our initial observations in the human placenta, we hypothesised that the male prioritises growth pathways in order to maximise growth through to adulthood, thereby ensuring the greatest chance of reproductive success. However, this male-specific "evolutionary advantage" likely contributes to males being less adaptable to shifts in the in-utero environment, which then places them at a greater risk for intrauterine morbidities or mortality. Comparatively, females are more adaptable to changes in the in-utero environment at the cost of growth, which may reduce their risk of poor perinatal outcomes. The mechanisms that drive these sex-specific adaptations to a change in the in-utero environment remain unclear, but an increasing body of evidence within the field of developmental biology would suggest that alterations to placental function, as well as the feto-placental hormonal milieu, is an important contributing factor. Herein, we have addressed the current knowledge regarding sex-specific intrauterine growth differences and have examined how certain pregnancy complications may alter these female- and male-specific adaptations.

First-trimester utero-placental (vascular) development and embryonic and fetal growth: The Rotterdam periconception cohort

INTRODUCTION

Impaired placental development is a major cause of fetal growth restriction (FGR) and early detection will therefore improve antenatal care and birth outcomes. Here we aim to investigate serial first-trimester ultrasound markers of utero-placental (vascular) development in association with embryonic and fetal growth.

METHODS

In a prospective cohort, we periconceptionally included 214 pregnant women. Three-dimensional power Doppler ultrasonography at 7, 9 and 11 weeks gestational age (GA) was used to measure placental volumes (PV) and basal plate surface area by Virtual Organ Computer-aided AnaLysis™, and utero-placental vascular volume (uPVV), crown-rump length (CRL) and embryonic volume (EV) by a V-scope volume rendering application. Estimated fetal weight (EFW) was measured by ultrasound at 22 and 32 weeks GA and birth weight percentile (BW) was recorded. Linear mixed models and regression analyses were applied and appropriately adjusted. All analyses were stratified for fetal sex.

RESULTS

PV trajectories were positively associated with CRL (β_adj = 0.416, 95%CI:0.255; 0.576, p < 0.001), EV (β_adj = 0.220, 95%CI:0.058; 0.381, p = 0.008) and EFW (β_adj = 0.182, 95%CI:0.012; 0.352, p = 0.037). uPVV trajectories were positively associated with CRL (β_adj = 0.203, 95%CI 0.021; 0.384, p = 0.029). In girls, PV trajectories were positively associated with CRL (p < 0.001), EV (p = 0.018), EFW (p = 0.026), and uPVV trajectories were positively associated with BW (p = 0.040). In boys, positive associations were shown between PV trajectories and CRL (p = 0.002), and between uPVV trajectories and CRL (p = 0.046).

DISCUSSION

First-trimester utero-placental (vascular) development is associated with embryonic and fetal growth, with fetal sex specific modifications. This underlines the opportunity to monitor first-trimester placental development and supports the associations with embryonic and fetal growth.

Human Umbilical Cord: Information Mine in Sex-Specific Medicine

Biological differences between sexes should be considered in all stages of research, as sexual dimorphism starts in utero leading to sex-specific fetal programming. In numerous biomedical fields, there is still a lack of stratification by sex despite primary cultured cells retaining memory of the sex and of the donor. The sex of donors in biological research must be known because variations in cells and cellular components can be used as endpoints, biomarkers and/or targets of pharmacological studies. This selective review focuses on the current findings regarding sex differences observed in the umbilical cord, a widely used source of research samples, both in the blood and in the circulating cells, as well as in the different cellular models obtainable from it. Moreover, an overview on sex differences in fetal programming is reported. As it emerges that the sex variable is still often forgotten in experimental models, we suggest that it should be mandatory to adopt sex-oriented research, because only awareness of these issues can lead to innovative research.

Reference Charts for Neonatal Cranial Volume Based on 3D Laser Scanning to Monitor Head Growth

Background: Postnatal brain growth is an important predictor of neurodevelopmental outcome in preterm infants. A new reliable proxy for brain volume is cranial volume, which can be measured routinely by 3-D laser scanning. The aim of this study was to develop reference charts for normal cranial volume in newborn infants at different gestational ages starting from late preterm for both sexes. Methods: Cross-sectional cohort study in a German university hospital, including singleton, clinically stable, neonates born after 34 weeks of gestation. Cranial volume was measured in the first week of life by a validated 3-D laser scanner. Cranial volume data was modeled to calculate percentile values by gestational age and birth weight and to develop cranial volume reference charts for girls and boys separately. Results: Of the 1,703 included infants, 846 (50%) were female. Birth weights ranged from 1,370 to 4,830 grams (median 3,370). Median cranial volume ranged from 320 [interquartile range (IQR) 294-347] ml at 34 weeks to 469 [IQR 442-496] ml at 42 weeks and was higher in boys than in girls. Conclusions: This study presents the first reference charts of cranial volume which can be used in clinical practice to monitor brain growth between 34 and 42 weeks gestation in infants.

Amidst the COVID-19 pandemic childhood obesity is still an epidemic-spotlight on obesity's multifactorial determinants

PURPOSE

Childhood obesity is a global epidemic and a chronic disease. Multifactorial determinants have long been linked with childhood obesity. These have been challenged with the onset of COVID-19 and the associated mitigation measures. The study aimed to re-highlight these determinants while exploring the effects of the ongoing COVID-19 pandemic on these pre-existing childhood obesity determinants, while providing evidence that may be beneficial for the post-COVID-19 recovery plan.

METHODS

A PubMed literature search (2016-2021) using the keywords, "childhood obesity", "gender", "sex", "obesity in youth", "obesity in adolescents", "COVID-19″ and "SARS-CoV2" was performed.

RESULTS

Genetic predisposition, biologically low leptin levels, certain cultural beliefs and socio-economic statuses, as well as exposure to an "obesogenic" environment were found to have a positive association with childhood obesity. Additionally, the onset of COVID-19 further aggravates the childhood obesity epidemic, increasing childrens' susceptibility to obesity and all associated consequential diseases.

DISCUSSION

A possible key to the control and prevention of the burden of childhood obesity, lies in dealing with its precursors and risk factors. Certain factors, including socio-cultural norms, cultural beliefs and geographical factors are amenable. COVID-19 further challenged these and it is evident that the childhood obesity epidemic is still a critical one. Encouraging preventative interventions, such as screening programs, public awareness and policies targeting the environment, amongst others, are recommended.

X-chromosome regulation and sex differences in brain anatomy

Humans show reproducible sex-differences in cognition and psychopathology that may be contributed to by influences of gonadal sex-steroids and/or sex-chromosomes on regional brain development. Gonadal sex-steroids are well known to play a major role in sexual differentiation of the vertebrate brain, but far less is known regarding the role of sex-chromosomes. Our review focuses on this latter issue by bridging together two literatures that have to date been largely disconnected. We first consider "bottom-up" genetic and molecular studies focused on sex-chromosome gene content and regulation. This literature nominates specific sex-chromosome genes that could drive developmental sex-differences by virtue of their sex-biased expression and their functions within the brain. We then consider the complementary "top down" view, from magnetic resonance imaging studies that map sex- and sex chromosome effects on regional brain anatomy, and link these maps to regional gene-expression within the brain. By connecting these top-down and bottom-up approaches, we emphasize the potential role of X-linked genes in driving sex-biased brain development and outline key goals for future work in this field.

Sex and gender differences in childhood obesity: contributing to the research agenda

Childhood obesity is a major public health challenge and its prevalence continues to increase in many, but not all, countries worldwide. International data indicate that the prevalence of obesity is greater among boys than girls 5-19 years of age in the majority of high and upper middle-income countries worldwide. Despite this observed sex difference, relatively few studies have investigated sex-based and gender-based differences in childhood obesity. We propose several hypotheses that may shape the research agenda on childhood obesity. Differences in obesity prevalence may be driven by gender-related influences, such as societal ideals about body weight and parental feeding practices, as well as sex-related influences, such as body composition and hormones. There is an urgent need to understand the observed sex differences in the prevalence of childhood obesity; incorporation of sex-based and gender-based analysis in all childhood obesity studies may ultimately contribute to improved prevention and treatment.

Association of gestational age with MRI-based biometrics of brain development in fetuses

Background

Reported date of last menstrual period and ultrasonography measurements are the most commonly used methods for determining gestational age in antenatal life. However, the mother cannot always determine the last menstrual period with certainty, and ultrasonography measurements are accurate only in the first trimester. We aimed to assess the ability of various biometric measurements on magnetic resonance imaging (MRI) in determining the accurate gestational age of an individual fetus in the second half of gestation.

Methods

We used MRI to scan a total of 637 fetuses ranging in age from 22 to 40 gestational weeks. We evaluated 9 standard fetal 2D biometric parameters, and regression models were fitted to assess normal fetal brain development. A stepwise linear regression model was constructed to predict gestational age, and measurement accuracy was determined in a held-out, unseen test sample (n = 49).

Results

A second-order polynomial regression model was found to be the best descriptor of biometric measures including brain bi-parietal diameter, head circumference, and fronto-occipital diameter in relation to normal fetal growth. Normal fetuses showed divergent growth patterns for the cerebrum and cerebellum, where the cerebrum undergoes rapid growth in the second trimester, while the cerebellum undergoes rapid growth in the third trimester. Moreover, a linear model based on biometrics of brain bi-parietal diameter, length of the corpus callosum, vermis area, transverse cerebellar diameter, and cerebellar area accurately predicted gestational age in the second and third trimesters (cross-validation R² = 0.822, p < 0.001).

Conclusions

These results support the use of MRI biometry charts to improve MRI evaluation of fetal growth and suggest that MRI biometry measurements offer a potential estimation model of fetal gestational age in the second half of gestation, which is vital to any assessment of pregnancy, fetal development, and neonatal care.

A prospective study of placental growth factor in twin pregnancy and development of a dichorionic twin pregnancy specific reference range

OBJECTIVE

To develop a dichorionic twin pregnancy specific reference range for placental growth factor (PlGF), and to compare gestation-specific placental growth factor levels in twin pregnancies later complicated by pre-eclampsia, hypertensive disorder of pregnancy or fetal growth restriction with control pregnancies.

DESIGN

Prospective observational study.

SETTING

Single large tertiary maternity unit in Ireland.

POPULATION OR SAMPLE

Women with a twin pregnancy.

METHODS

Consenting pregnant women, across a variety of gestations, had a single blood sample taken at one time-point only during their pregnancy. The plasma was initially biobanked and PlGF was measured later in batches using the point of care Triage^® PlGF test.

MAIN OUTCOME MEASURES

Development of pre-eclampsia, hypertensive disorder of pregnancy or fetal growth restriction.

RESULTS

Placental growth factor levels in uncomplicated dichorionic twin pregnancies were significantly lower in the women who later developed pre-eclampsia than in the controls at all gestational intervals. In those that later developed any hypertensive disorder of pregnancy, median PlGF was lower only in those recruited before 24 weeks of gestation, whereas in infants with a customised birthweight below the third centile, PlGF was lower only in those sampled after 24 weeks of gestation.

CONCLUSIONS

Placental growth factor levels in twin pregnancy differ significantly between those women with a pregnancy that will later be complicated by pre-eclampsia and those that will not. This difference is present many weeks before clinical signs or symptoms of disease are present. Using cross-sectional values from uncomplicated twin pregnancies, we have developed a dichorionic twin pregnancy specific reference range for PlGF.

TWEETABLE ABSTRACT

Placental growth factor levels in twin pregnancy differ significantly between women that will later develop pre-eclampsia and those that will not.

Maternal early pregnancy dietary glycemic index and load, fetal growth, and the risk of adverse birth outcomes

Purpose

Maternal hyperglycemia is associated with adverse birth outcomes. Maternal dietary glycemic index and load influence postprandial glucose concentrations. We examined the associations of maternal early pregnancy dietary glycemic index and load with fetal growth and risks of adverse birth outcomes.

Methods

In a population-based cohort study of 3471 pregnant Dutch women, we assessed dietary glycemic index and load using a food frequency questionnaire at median 13.4 (95% range 10.6; 21.2) weeks gestation. We measured fetal growth in mid- and late-pregnancy by ultrasound and obtained birth outcomes from medical records.

Results

Mean maternal early pregnancy dietary glycemic index and load were 57.7 (SD 3.3, 95% range 52.8; 63.5) and 155 (SD 47, 95% range 87; 243), respectively. Maternal early pregnancy dietary glycemic index was not associated with fetal growth parameters. A higher maternal early pregnancy dietary glycemic load was associated with a higher fetal abdominal circumference and estimated fetal weight in late-pregnancy (p values < 0.05), but not with mid-pregnancy or birth growth characteristics. A higher maternal early pregnancy dietary glycemic index was associated with a lower risk of a large-for-gestational-age infant (p value < 0.05). Maternal early pregnancy glycemic index and load were not associated with other adverse birth outcomes.

Conclusion

Among pregnant women without an impaired glucose metabolism, a higher early pregnancy dietary glycemic load was associated with higher late-pregnancy fetal abdominal circumference and estimated fetal weight. No consistent associations of maternal dietary glycemic index and load with growth parameters in mid-pregnancy and at birth were present. A higher glycemic index was associated with a lower risk of a large-for-gestational-age infant.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02327-9) contains supplementary material, which is available to authorized users.

Association between infertility treatment and intrauterine growth: a multilevel analysis in a retrospective cohort study

OBJECTIVES

This study aimed to identify intrauterine growth differences according to infertility treatment compared with spontaneous conception and to describe intrauterine growth trajectories.

DESIGN

Retrospective cohort study.

SETTING

A single primary and tertiary medical centre in Japan.

PARTICIPANTS

This study included singleton pregnant women with prenatal check-ups and delivery at the University of Yamanashi Hospital between 1 July 2012 and 30 September 2017. Patients were divided into four groups: spontaneous conception, infertility treatment without assisted reproductive technology (ART), fresh-embryo transfer and frozen embryo transfer (FET).

INTERVENTIONS

Differences in intrauterine growth according to the infertility treatment, including ART, and birth weight were evaluated. Multilevel analysis was employed to evaluate intrauterine growth trajectories stratified by the sex of the offspring.

PRIMARY OUTCOME MEASURE

Estimated fetal weight (EFW) assessed by ultrasound examination.

RESULTS

We assessed data from 37 239 prenatal examination results from 2377 pregnant women (spontaneous conception, n=1764; infertility treatment without ART, n=171; fresh-embryo transfer, n=112; and FET, n=330) in the final analysis. Multilevel analysis was adjusted for gestation duration, gestation period, parity, hypertensive disorders of pregnancy, type of infertility treatment, maternal age, smoking status, placenta previa, thyroid disease, gestational diabetes mellitus and the interaction between each potential confounding factor and gestation duration. In male fetuses, the interaction between FET and gestational duration (estimate: 0.36; 95% CI: 0.06 to 0.67) significantly affected the EFW. Similarly, in female fetuses, FET (estimate: -69.85; 95% CI: -112.09 to -27.61) and the interaction between FET and gestation duration (estimate: 0.57; 95% CI: 0.28 to 0.87) significantly affected the EFW.

CONCLUSIONS

This study shows that FET affects intrauterine growth trajectory from the second trimester to term, particularly in female fetuses. Our findings require further prospective research to examine the effect of infertility treatment on fetal growth.

The association of sex of co-twin and birth size in twins born in Yucatan, Mexico between 2008 and 2017

Background: Birth measures of twins are potentially influenced by sex of co-twin.Aim: To analyse the association between sex of co-twin and birth weight, length and ponderal index in twin infants from Yucatan, Mexico.Subjects and methods: A total of 2057 twin pairs born during 2008-2017 were analysed. Female-female (F-F), male-male (M-M) and male-female (M-F) twin pair types were defined. Multiple linear regression models were used to analyse the association of (1) being female from M-F pairs and birth measures among overall female infants (M-F and F-F), and (2) being male from M-F pairs and birth measures among overall male infants (M-F and M-M). The length of gestation and mothers' age and level of education were used as covariates.Results: Models showed that being male from M-F pairs was associated with increases of 81 g in birth weight and 0.61 cm in length, compared to males from M-M pairs, and being female from opposite-sex pairs was associated with increases of 0.36 cm in length, compared to females from same-sex pairs.Conclusions: Males from M-F pairs show greater birth size than males from same-sex pairs, which supports the hypothesis that birth measures of twins are influenced by sex of the co-twin.