Development and growth of bovine calves demi-embryos

The aim of this study was to investigate the growth and development of animals produced from demi-embryos and compare them with whole embryos from fetus to adult life. To achieve this, calves produced from fresh demi-embryos and whole embryos were individually transferred and monitored from 60 days of pregnancy until slaughter at 550 days. Ultrasound scans were conducted on fetuses at 60 and 90 days to evaluate the biparietal, abdominal, umbilical cord, orbital, and aorta diameters. Subsequently, morphological traits of newborn calves were measured at 0, 7, and 21 days (N = 18). Live weight was recorded at birth, weaning, and every 30 days thereafter until slaughter at 550 days. The growth curve of each group was modeled using logistic regression, and the factors of the respective functions were compared. As early as 60 days of pregnancy, ultrasound evaluations revealed no morphometric differences between fetuses produced from demi-embryos and those from whole embryos. This lack of differentiation persisted in the morphometric evaluations of newborns up to 21 days of age, as well as in live weight and the growth curve from birth to slaughter. Moreover, there were no significant differences between the groups in terms of rib eye area and fat thickness evolution. Consequently, individuals from demi-embryos exhibited no discernible disparities to those whole embryos in growth and development from 60 days of gestation, through birth, and into adulthood.

Fetal brain MRI atlases and datasets: A review

Fetal brain development is a complex process involving different stages of growth and organization which are crucial for the development of brain circuits and neural connections. Fetal atlases and labeled datasets are promising tools to investigate prenatal brain development. They support the identification of atypical brain patterns, providing insights into potential early signs of clinical conditions. In a nutshell, prenatal brain imaging and post-processing via modern tools are a cutting-edge field that will significantly contribute to the advancement of our understanding of fetal development. In this work, we first provide terminological clarification for specific terms (i.e., "brain template" and "brain atlas"), highlighting potentially misleading interpretations related to inconsistent use of terms in the literature. We discuss the major structures and neurodevelopmental milestones characterizing fetal brain ontogenesis. Our main contribution is the systematic review of 18 prenatal brain atlases and 3 datasets. We also tangentially focus on clinical, research, and ethical implications of prenatal neuroimaging.

Autophagy and Exocytosis of Lipofuscin Into the Basolateral Extracellular Space of Human Retinal Pigment Epithelium From Fetal Development to Adolescence

Purpose

To undertake the first ultrastructural characterization of human retinal pigment epithelial (RPE) differentiation from fetal development to adolescence.

Methods

Ten fetal eyes and three eyes aged six, nine, and 17 years were examined in the temporal retina adjacent to the optic nerve head by transmission electron microscopy. The area, number, and distribution of RPE organelles were quantified and interpreted within the context of adjacent photoreceptors, Bruch's membrane, and choriocapillaris maturation.

Results

Between eight to 12 weeks' gestation (WG), pseudostratified columnar epithelia with apical tight junctions differentiate to a simple cuboidal epithelium with random distribution of melanosomes and mitochondria. Between 12 to 26 WG, cells enlarge and show long apical microvilli and apicolateral junctional complexes. Coinciding with eye opening at 26 WG, melanosomes migrate apically whereas mitochondria distribute to perinuclear regions, with the first appearance of phagosomes, complex granules, and basolateral extracellular space (BES) formation. Significantly, autophagy and heterophagy, as evidenced by organelle recycling, and the gold standard of ultrastructural evidence for autophagy of double-membrane autophagosomes and mitophagosomes were evident from 32 WG, followed by basal infoldings of RPE cell membrane at 36 WG. Lipofuscin formation and deposition into the BES evident at six years increased at 17 years.

Conclusions

We provide compelling ultrastructural evidence that heterophagy and autophagy begins in the third trimester of human fetal development and that deposition of cellular byproducts into the extracellular space of RPE takes place via exocytosis. Transplanted RPE cells must also demonstrate the capacity to subserve autophagic and heterophagic functions for effective disease mitigation.

Exploring the Influence of Fetal Sex on Heart Rate Dynamics Using Fetal Magnetocardiographic Recordings

Fetal sex has been associated with different development trajectories that cause structural and functional differences between the sexes throughout gestation. Fetal magnetocardiography (fMCG) recordings from 123 participants (64 females and 59 males; one recording/participant) from a database consisting of low-risk pregnant women were analyzed to explore and compare fetal development trajectories of both sexes. The gestational age of the recordings ranged from 28 to 38 weeks. Linear metrics in both the time and frequency domains were applied to study fetal heart rate variability (fHRV) measures that reveal the dynamics of short- and long-term variability. Rates of linear change with GA in these metrics were analyzed using general linear model regressions with assessments for significantly different variances and GA regression slopes between the sexes. The fetal sexes were well balanced for GA and sleep state. None of the fHRV measures analyzed exhibited significant variance heterogeneity between the sexes, and none of them exhibited a significant sex-by-GA interaction. The absence of a statistically significant sex-by-GA interaction on all parameters resulted in none of the regression slope estimates being significantly different between the sexes. With high-precision fMCG recordings, we were able to explore the variation in fHRV parameters as it relates to fetal sex. The fMCG-based fHRV parameters did not show any significant difference in rates of change with gestational age between sexes. This study provides a framework for understanding normal development of the fetal autonomic nervous system, especially in the context of fetal sex.

Developmental Windows for Effects of Choline and Folate on Excitatory and Inhibitory Neurotransmission During Human Gestation

Choline and folate are critical nutrients for fetal brain development, but the timing of their influence during gestation has not been previously characterized. At different periods during gestation, choline stimulation of α7-nicotinic receptors facilitates conversion of γ-aminobutyric acid (GABA) receptors from excitatory to inhibitory and recruitment of GluR1-R2 receptors for faster excitatory responses to glutamate. The outcome of the fetal development of inhibition and excitation was assessed in 159 newborns by P50 cerebral auditory-evoked responses. Paired stimuli, S1, S2, were presented 500 msec apart. Higher P50 amplitude in response to S1 (P50S1microV) assesses excitation, and lower P50S2microV assesses inhibition in this paired-stimulus paradigm. Development of inhibition was related solely to maternal choline plasma concentration and folate supplementation at 16 weeks' gestation. Development of excitation was related only to maternal choline at 28 weeks. Higher maternal choline concentrations later in gestation did not compensate for earlier lower concentrations. At 4 years of age, increased behavior problems on the Child Behavior Checklist 1½-5yrs were related to both newborn inhibition and excitation. Incomplete development of inhibition and excitation associated with lower choline and folate during relatively brief periods of gestation thus has enduring effects on child development.

Early life corticosteroid overexposure: Epigenetic and fetal origins of adult diseases

The relationship between events occurring during intrauterine development and later-life predisposition to long-term disease, has been described. The fetus responds to excess intrauterine exposure to high levels of corticosteroids, modifying their physiological development and stopping their growth. Fetal exposure to elevated levels of either endogenous (alterations in fetal hypothalamic-pituitary-adrenal axis) or synthetic corticosteroids, is one model of early-life adversity; to developing adult disease. At the molecular level, there are transcriptional changes in metabolic and growth pathways. Epigenetic mechanisms participate in transgenerational inheritance, not genomic. Exposures that change 11β-hydroxysteroid dehydrogenase type 2 enzyme methylation status in the placenta can result in transcriptional repression of the gene, causing the fetus to be exposed to higher levels of cortisol. More precise diagnosis and management of antenatal corticosteroids for preterm birth, would potentially decrease the risk of long-term adverse outcomes. More studies are needed to understand the potential roles of factors to alter fetal corticosteroid exposure. Long-term infant follow-up is required to determine whether methylation changes in placenta may represent useful biomarkers of later disease risk. This review, summarize recent advances in the programming of fetal effects of corticosteroid exposure, the role of corticosteroids in epigenetic gene regulation of placental 11β-hydroxysteroid dehydrogenase type 2 enzyme expression and transgenerational effects.

[Association between maternal plasma one-carbon biomarkers during pregnancy and fetal growth in twin pregnancies]

Objective: To characterize the relationship between the levels of plasma methyl donor and related metabolites (including choline, betaine, methionine, dimethylglycine and homocysteine) and fetal growth in twin pregnancies. Methods: A hospital-based cohort study was used to collect clinical data of 92 pregnant women with twin pregnancies and their fetuses who were admitted to Peking University Third Hospital from March 2017 to January 2018. Fasting blood was collected from the pregnant women with twin pregnancies (median gestational age: 18.9 weeks). The levels of methyl donors and related metabolites in plasma were quantitatively analyzed by high-performance liquid chromatography combined with mass spectrometry. The generalized estimation equation was used to analyze the relationship between maternal plasma methyl donors and related metabolites levels and neonatal outcomes of twins, and the generalized additive mixed model was used to analyze the relationship between maternal plasma methyl donors and related metabolites levels and fetal growth ultrasound indicators. Results: (1) General clinical data: of the 92 women with twin pregnancies, 66 cases (72%) were dichorionic diamniotic (DCDA) twin pregnancies, and 26 cases (28%) were monochorionic diamniotic (MCDA) twin pregnancies. The comparison of the levels of five plasma methyl donors and related metabolites in twin pregnancies with different basic characteristics showed that the median levels of plasma choline and betaine in pregnant women ≥35 years old were higher than those in pregnant women <35 years old, and the differences were statistically significant (all P<0.05). (2) Correlation between plasma methyl donor and related metabolites levels and neonatal growth indicators: after adjusting for confounding factors, plasma homocysteine level in pregnant women with twins was significantly negatively correlated with neonatal birth weight (β=-47.9, 95%CI:-94.3- -1.6; P=0.043). Elevated methionine level was significantly associated with decreased risks of small for gestational age infants (SGA; OR=0.5, 95%CI: 0.3-0.9; P=0.021) and low birth weight infants (OR=0.6, 95%CI: 0.4-0.9; P=0.020). Increased homocysteine level was associated with increased risks of SGA (OR=1.5, 95%CI: 1.0-2.2; P=0.029) and inconsistent growth in twin fetuses (OR=1.9, 95%CI: 1.0-3.7; P=0.049). (3) Correlation between the levels of plasma methyl donors and related metabolites and intrauterine growth indicators of twins pregnancies: for every 1 standard deviation increase in plasma choline level in pregnant women with twin pregnancies, fetal head circumference, abdominal circumference, femoral length and estimated fetal weight in the second trimester increased by 1.9 mm, 2.6 mm, 0.5 mm and 20.1 g, respectively, and biparietal diameter, abdominal circumference and estimated fetal weight increased by 0.7 mm, 3.0 mm and 38.4 g in the third trimester, respectively, and the differences were statistically significant (all P<0.05). (4) Relationship between plasma methyl donor and related metabolites levels in pregnant women with different chorionicity and neonatal birth weight and length: the negative correlation between plasma homocysteine level and neonatal birth weight was mainly found in DCDA twin pregnancy (β=-65.9, 95%CI:-110.6- -21.1; P=0.004). The levels of choline, betaine and dimethylglycine in plasma of MCDA twin pregnancy were significantly correlated with the birth weight and length of newborns (all P<0.05). Conclusion: Homocysteine level is associated with low birth weight in twins, methionine is associated with decreased risk of SGA, and choline is associated with fetal growth in the second and third trimesters of pregnancy.

Shared developmental pathways of the placenta and fetal heart

Congenital heart defects (CHD) remain the most common class of birth defect worldwide, affecting 1 in every 110 live births. A host of clinical and morphological indicators of placental dysfunction are observed in pregnancies complicated by fetal CHD and, with the recent emergence of single-cell sequencing capabilities, the molecular and physiological associations between the embryonic heart and developing placenta are increasingly evident. In CHD pregnancies, a hostile intrauterine environment may negatively influence and alter fetal development. Placental maldevelopment and dysfunction creates this hostile in-utero environment and may manifest in the development of various subtypes of CHD, with downstream perfusion and flow-related alterations leading to yet further disruption in placental structure and function. The adverse in-utero environment of CHD-complicated pregnancies is well studied, however the specific etiological role that the placenta plays in CHD development remains unclear. Many mouse and rat models have been used to characterize the relationship between CHD and placental dysfunction, but these paradigms present substantial limitations in the assessment of both the heart and placenta. Improvements in non-invasive placental assessment can mitigate these limitations and drive human-specific investigation in relation to fetal and placental development. Here, we review the clinical, structural, and molecular relationships between CHD and placental dysfunction, the CHD subtype-dependence of these changes, and the future of Placenta-Heart axis modeling and investigation.

Investigating the association of maternal heart rate variability with fetal birth weight

Maternal heart rate (HR) was reported to affect birth weight and birth outcomes. Low birth weight constitutes a major health problem, and it is estimated that around 15% to 20% of births worldwide are low weight. In our previous study, we discussed the presence of similarities between maternal and fetal HRs, therefore, here, we propose to develop a parameter based on maternal and fetal HR variability (HRV) to divide data into two patterns to investigate the association of fetal birth weight with maternal HR and HRV. The parameter was derived from non-invasive records of maternal and fetal electrocardiograms (ECGs) that were collected from 78 subjects (age: 22 - 44 years old, gestational age (GA): 19 - 40 weeks). The HRV parameter was calculated by first evaluating the standard deviation (SD) of the number of R peaks occurring per 2 seconds (snRpp2s). Then, the difference between maternal and fetal snRpp2s (dmf) was calculated. The correlation between our derived parameter [dmf] with GA revealed a significant correlation that suggested the dmf's association with fetal development. The association analysis results between birthweight with maternal HR and HRV per pattern showed that significant negative correlations exist between them in one pattern. Still, the same correlations were not observed in the other pattern. This study's findings emphasise maternal health's role in fetal development assessment. In addition, this study highlights the importance of developing novel factors for properly assessing fetal development and birth outcomes.

Sexual dimorphism in placental development and function: Comparative physiology with an emphasis on the pig

Across mammalian species, it has been demonstrated that sex influences birth weight, with males being heavier than females; a characteristic that can be observed from early gestation. Male piglets are more likely to be stillborn and have greater preweaning mortality than their female littermates, despite the additional maternal investment into male fetal growth. Given the conserved nature of the genome between the sexes, it is hypothesized that these developmental differences between males and females are most likely orchestrated by differential placental adaptation. This review summarizes the current understanding of fetal sex-specific differences in placental and endometrial structure and function, with an emphasis on pathways found to be differentially regulated in the pig including angiogenesis, apoptosis, and proliferation. Given the importance of piglet sex in agricultural enterprises, and the potential for skewed litter sex ratios, it is imperative to improve understanding of the relationship between fetal sex and molecular signaling in both the placenta and endometria across gestation.

Mechanisms regulating the initiation of porcine conceptus elongation

Significant increases in litter size within commercial swine production over the past decades have led to increases in preweaning piglet mortality due to increase within-litter birthweight variation, typically due to mortality of the smallest littermate piglets. Therefore, identifying mechanisms to reduce variation in placental development and subsequent fetal growth are critical to normalizing birthweight variation and improving piglet survivability in high-producing commercial pigs. A major contributing factor to induction of within-litter variation occurs during the peri-implantation period as the pig blastocyst elongates from spherical to filamentous morphology in a short period of time and rapidly begins superficial implantation. During this period, there is significant within-litter variation in the timing and extent of elongation among littermates. As a result, delays and deficiencies in conceptus elongation not only contribute directly to early embryonic mortality, but also influence subsequent within-litter birthweight variation. This study will highlight key aspects of conceptus elongation and provide some recent evidence pertaining to specific mechanisms from -omics studies (i.e., metabolomics of the uterine environment and transcriptomics of the conceptus) that may specifically regulate the initiation of conceptus elongation to identify potential factors to reduce within-litter variation and improve piglet survivability.

Effect of Musical Stimulation on Placental Programming and Neurodevelopment Outcome of Preterm Infants: A Systematic Review

BACKGROUND

The fetal environment is modulated by the placenta, which integrates and transduces information from the maternal environment to the fetal developmental program and adapts rapidly to changes through epigenetic mechanisms that respond to internal (hereditary) and external (environmental and social) signals. Consequently, the fetus corrects the trajectory of own development. During the last trimester of gestation, plasticity shapes the fetal brain, and prematurity can alter the typical developmental trajectories. In this period, prevention through activity-inducing (e.g., music stimulation) interventions are currently tested. The purpose of this review is to describe the potentialities of music exposure on fetus, and on preterm newborns in the Neonatal Intensive Care Unit evaluating its influence on neurobehavioral development.

METHODS

Databases were searched from 2010 to 2022 for studies investigating mechanisms of placental epigenetic regulation and effects of music exposure on the fetus and pre-term neonates.

RESULTS

In this case, 28 selected papers were distributed into three research lines: studies on placental epigenetic regulation (13 papers), experimental studies of music stimulation on fetus or newborns (6 papers), and clinical studies on premature babies (9 papers). Placental epigenetic changes of the genes involved in the cortisol and serotonin response resulted associated with different neurobehavioral phenotypes in newborns. Prenatal music stimulation had positive effects on fetus, newborn, and pregnant mother while post-natal exposure affected the neurodevelopment of the preterm infants and parental interaction.

CONCLUSIONS

The results testify the relevance of environmental stimuli for brain development during the pre- and perinatal periods and the beneficial effects of musical stimulation that can handle the fetal programming and the main neurobehavioral disorders.

Role of Hormones During Gestation and Early Development: Pathways Involved in Developmental Programming

Accumulating evidence suggests that an altered maternal milieu and environmental insults during the intrauterine and perinatal periods of life affect the developing organism, leading to detrimental long-term outcomes and often to adult pathologies through programming effects. Hormones, together with growth factors, play critical roles in the regulation of maternal-fetal and maternal-neonate interfaces, and alterations in any of them may lead to programming effects on the developing organism. In this chapter, we will review the role of sex steroids, thyroid hormones, and insulin-like growth factors, as crucial factors involved in physiological processes during pregnancy and lactation, and their role in developmental programming effects during fetal and early neonatal life. Also, we will consider epidemiological evidence and data from animal models of altered maternal hormonal environments and focus on the role of different tissues in the establishment of maternal and fetus/infant interaction. Finally, we will identify unresolved questions and discuss potential future research directions.

Epigenetics Beyond Fetal Growth Restriction: A Comprehensive Overview

Fetal growth restriction is a pathological condition occurring when the fetus does not reach the genetically determined growth potential. The etiology of fetal growth restriction is expected to be multifactorial and include fetal, maternal, and placental factors, the latter being the most frequent cause of isolated fetal growth restriction. Severe fetal growth restriction has been related to both an increased risk of perinatal morbidity and mortality, and also a greater susceptibility to developing diseases (especially cardio-metabolic and neurological disorders) later in life. In the last decade, emerging evidence has supported the hypothesis of the Developmental Origin of Health and Disease, which states that individual developmental 'programming' takes place via a delicate fine tuning of fetal genetic and epigenetic marks in response to a large variety of 'stressor' exposures during pregnancy. As the placenta is the maternal-fetal interface, it has a crucial role in fetal programming, such that any perturbation altering placental function interferes with both in-utero fetal growth and also with the adult life phenotype. Several epigenetic mechanisms have been highlighted in modulating the dynamic placental epigenome, including alterations in DNA methylation status, post-translational modification of histones, and non-coding RNAs. This review aims to provide a comprehensive and critical overview of the available literature on the epigenetic background of fetal growth restriction. A targeted research strategy was performed using PubMed, MEDLINE, Embase, and The Cochrane Library up to January 2022. A detailed and fully referenced synthesis of available literature following the Scale for the Assessment of Narrative Review Articles guidelines is provided. A variety of epigenetic marks predominantly interfering with placental development, function, and metabolism were found to be potentially associated with fetal growth restriction. Available evidence on the role of environmental exposures in shaping the placental epigenome and the fetal phenotype were also critically discussed. Because of the highly dynamic crosstalk between epigenetic mechanisms and the extra level of complexity in interpreting the final placental transcriptome, a full comprehension of these phenomenon is still lacking and advances in multi-omics approaches are urgently needed. Elucidating the role of epigenetics in the developmental origins of health and disease represents a new challenge for the coming years, with the goal of providing early interventions and prevention strategies and, hopefully, new treatment opportunities.

Why is human uterine artery blood flow during pregnancy so high?

In healthy near-term women, blood flow to the uteroplacental circulation is estimated as 841 mL/min, which is greater than in other mammalian species. We argue that as uterine venous Po2 sets the upper limit for O2 diffusion to the fetus, high uterine artery blood flow serves to narrow the maternal arterial-to-uterine venous Po2 gradient and thereby raise uterine vein Po2. In support, we show that the reported levels for uterine artery blood flow agree with what is required to maintain normal fetal growth. Although residence at high altitudes (>2,500 m) depresses fetal growth, not all populations are equally affected; Tibetans and Andeans have higher levels of uterine artery blood flow than newcomers and exhibit normal fetal growth. Estimates of uterine venous Po2 from the umbilical blood-gas data available from healthy Andean pregnancies indicate that their high levels of uterine artery blood flow are consistent with their reported, normal birth weights. Unknown, however, are the effects on placental gas exchange of the lower levels of uterine artery blood flow seen in high-altitude newcomers or hypoxia-associated pregnancy complications. We speculate that, by widening the maternal artery to uterine vein Po2 gradient, lower levels of uterine artery blood flow prompt metabolic changes that slow fetal growth to match O2 supply.

Association between fetal abdominal growth trajectories, maternal metabolite signatures early in pregnancy, and childhood growth and adiposity: prospective observational multinational INTERBIO-21st fetal study

BACKGROUND

Obesity predominantly affects populations in high-income countries and those countries facing epidemiological transition. The risk of childhood obesity is increased among infants who had overweight or obesity at birth, but in low-resource settings one in five infants are born small for gestational age. We aimed to study the relationships between: (1) maternal metabolite signatures; (2) fetal abdominal growth; and (3) postnatal growth, adiposity, and neurodevelopment.

METHODS

In the prospective, multinational, observational INTERBIO-21st fetal study, conducted in maternity units in Pelotas (Brazil), Nairobi (Kenya), Karachi (Pakistan), Soweto (South Africa), Mae Sot (Thailand), and Oxford (UK), we enrolled women (≥18 years, with a BMI of less than 35 kg/m², natural conception, and a singleton pregnancy) who initiated antenatal care before 14 weeks' gestation. Ultrasound scans were performed every 5±1 weeks until delivery to measure fetal growth and feto-placental blood flow, and we used finite mixture models to derive growth trajectories of abdominal circumference. The infants' health, growth, and development were monitored from birth to age 2 years. Early pregnancy maternal blood and umbilical cord venous blood samples were collected for untargeted metabolomic analysis.

FINDINGS

From Feb 8, 2012, to Nov 30, 2019, we enrolled 3598 pregnant women and followed up their infants to 2 years of age. We identified four ultrasound-derived trajectories of fetal abdominal circumference growth that accelerated or decelerated within a crucial 20-25 week gestational age window: faltering growth, early accelerating growth, late accelerating growth, and median growth tracking. These distinct phenotypes had matching feto-placental blood flow patterns throughout pregnancy, and different growth, adiposity, vision, and neurodevelopment outcomes in early childhood. There were 709 maternal metabolites with positive effect for the faltering growth phenotype and 54 for the early accelerating growth phenotype; 31 maternal metabolites had a negative effect for the faltering growth phenotype and 76 for the early accelerating growth phenotype. Metabolites associated with the faltering growth phenotype had statistically significant odds ratios close to 1·5 (ie, suggesting upregulation of metabolic pathways of impaired fetal growth). The metabolites had a reciprocal relationship with the early accelerating growth phenotype, with statistically significant odds ratios close to 0.6 (ie, suggesting downregulation of fetal growth acceleration). The maternal metabolite signatures included 5-hydroxy-eicosatetraenoic acid, and 11 phosphatidylcholines linked to oxylipin or saturated fatty acid sidechains. The fungicide, chlorothalonil, was highly abundant in the early accelerating growth phenotype group.

INTERPRETATION

Early pregnancy lipid biology associated with fetal abdominal growth trajectories is an indicator of patterns of growth, adiposity, vision, and neurodevelopment up to the age of 2 years. Our findings could contribute to the earlier identification of infants at risk of obesity.

FUNDING

Bill & Melinda Gates Foundation.

Placental structure, function, and mitochondrial phenotype relate to fetal size in each fetal sex in mice†

Fetal growth depends on placental function, which requires energy from mitochondria. Here we investigated whether mitochondrial function in the placenta relates to the growth of the lightest and heaviest fetuses of each sex within the litter of mice. Placentas from the lightest and heaviest fetuses were taken to evaluate placenta morphology (stereology), mitochondrial energetics (high-resolution respirometry), mitochondrial regulators, nutrient transporters, hormone handling, and signaling pathways (qPCR and Western blotting). We found that mitochondrial complex I and II oxygen consumption rate was greater for placentas supporting the lightest female fetuses, although placental complex I abundance of the lightest females and complexes III and V of the lightest males were decreased compared to their heaviest counterparts. Expression of mitochondrial biogenesis (Nrf1) and fission (Drp1 and Fis1) genes was lower in the placenta from the lightest females, whilst biogenesis-related gene Tfam was greater in the placenta of the lightest male fetuses. In addition, placental morphology and steroidogenic gene (Cyp17a1 and Cyp11a1) expression were aberrant for the lightest females, but glucose transporter (Slc2a1) expression was lower in only the lightest males versus their heaviest counterparts. Differences in intra-litter placental phenotype were related to changes in the expression of hormone-responsive (androgen receptor) and metabolic signaling (AMPK, AKT, and PPARγ) pathways. Thus, in normal mouse pregnancy, placental structure, function, and mitochondrial phenotype are differentially responsive to the growth of the female and male fetus. This study may inform the design of sex-specific therapies for placental insufficiency and fetal growth abnormalities with life-long benefits for the offspring.

Potassium Channels in the Transition from Fetal to the Neonatal Pulmonary Circulation

The transition from the fetal to the neonatal circulation includes dilatation of the pulmonary arteries (PA) and closure of the Ductus Arteriosus Botalli (DAB). The resting membrane potential and various potassium channel activities in smooth muscle cells (SMC) from fetal and neonatal PA and DAB obtained from the same species has not been systematically analyzed. The key issue addressed in this paper is how the resting membrane potential and the whole-cell potassium current (IK) change when PASMC or DABSMC are transitioned from hypoxia, reflecting the fetal state, to normoxia, reflecting the post-partal state. Patch-clamp measurements were employed to characterize whole-cell K⁺ channel activity in fetal and post-partal (newborn) PASMC and DABSMC. The main finding of this paper is that the SMC from both tissues use a similar set of K⁺ channels (voltage-dependent (Kv), calcium-sensitive (KCa), TASK-1 and probably also TASK-2 channels); however, their activity level depends on the cell type and the oxygen level. Furthermore, we provide the first evidence for pH-sensitive non-inactivating K⁺ current in newborn DABSMC and PASMC, suggesting physiologically relevant TASK-1 and TASK-2 channel activity, the latter particularly in the Ductus Arteriosus Botalli.

Programming of cardiometabolic health: the role of maternal and fetal hyperinsulinaemia

Obesity and gestational diabetes during pregnancy have multiple short- and long-term consequences for both mother and child. One common feature of pregnancies complicated by maternal obesity and gestational diabetes is maternal hyperinsulinaemia, which has effects on the mother and her adaptation to pregnancy. Even though insulin does not cross the placenta insulin can act on the placenta as well affecting placental growth, angiogenesis and lipid metabolism. Obese and gestational diabetic pregnancies are often characterised by maternal hyperglycaemia resulting in exposure of the fetus to high levels of glucose, which freely crosses the placenta. This leads to stimulation of fetal ß-cells and insulin secretion in the fetus. Fetal hyperglycaemia/hyperinsulinaemia has been shown to cause multiple complications in fetal development, such as altered growth trajectories, impaired neuronal and cardiac development and early exhaustion of the pancreas. These changes could increase the susceptibility of the offspring to develop cardiometabolic diseases later in life. In this review, we aim to summarize and review the mechanisms by which maternal and fetal hyperinsulinaemia impact on (i) maternal health during pregnancy; (ii) placental and fetal development; (iii) offspring energy homeostasis and long-term cardiometabolic health; (iv) how interventions can alleviate these effects.

The relationship between intrauterine foetal growth trajectories and blood pressure in young adults

BACKGROUND

Previous studies have reported an association between low birthweight and elevated blood pressure (BP) in adulthood, but few have examined the relationship between foetal growth and adult BP.

METHOD

The study examined the association between intrauterine growth trajectories determined by serial ultrasound and BP of the adult offspring in the Raine Study. Foetal growth trajectories for abdominal circumference, femur length and head circumference z-scores were developed using group-based trajectory modelling from 1440 women with serial ultrasounds from 15-weeks pregnancy to birth. Seven abdominal circumference, five femur length and five head circumference trajectory groups were identified. Longitudinal linear mixed modelling examined the association between trajectory groups and offspring BP at 20 (n = 487), 22 (n = 419) and 27 (n = 436) years.

RESULTS

Higher SBP in adulthood significantly associated with two abdominal circumference trajectories, one with the most restricted foetal growth [3.52 mmHg, 95% confidence interval (95% CI) = 1.20-5.83] and the other with sustained low-growth (1.92 mmHg, 95% CI = 0.11-3.73) compared with an average growth trajectory, after adjusting for sex, age, alcohol consumption and BMI. Foetal head circumference trajectories with sustained low-growth or average-to-falling growth significantly associated with higher adult systolic (3.45 mmHg, 95% CI = 1.77-5.14 and 1.54 mmHg, 95% CI = 0.30-2.78, respectively) and diastolic (2.28 mmHg, 95% CI = 0.77-3.78 and 1.47 mmHg, 95% CI = 0.54-2.39, respectively) BP compared with average growth. Low femur length growth associated with higher adult DBP after adjusting for sex, but not after accounting for adult BMI.

CONCLUSION

Our results show that restricted foetal head and abdominal circumference associated with higher adult SBP over two decades later, reinforcing the importance of the early intrauterine environment and its influence on adult BP.

Corpus callosum size by neurosonography in fetuses with congenital heart defect and relationship with expected pattern of brain oxygen supply

OBJECTIVE

To evaluate corpus callosum (CC) size by neurosonography (NSG) in fetuses with an isolated major congenital heart defect (CHD) and explore the association of CC size with the expected pattern of in-utero oxygen supply to the brain.

METHODS

A total of 56 fetuses with postnatally confirmed isolated major CHD and 56 gestational-age-matched controls were included. Fetuses with CHD were stratified into two categories according to the main expected pattern of cerebral arterial oxygen supply: Class A, moderately to severely reduced oxygen supply (left outflow tract obstruction and transposition of the great arteries) and Class B, near normal or mildly impaired oxygenated blood supply to the brain (other CHD). Transvaginal NSG was performed at 32-36 weeks in all fetuses to evaluate CC length, CC total area and areas of CC subdivisions in the midsagittal plane.

RESULTS

CHD fetuses had a significantly smaller CC area as compared to controls (7.91 ± 1.30 vs 9.01 ± 1.44 mm² ; P < 0.001), which was more pronounced in the most posterior part of the CC. There was a significant linear trend for reduced CC total area across the three clinical groups, with CHD Class-A cases showing more prominent changes (controls, 9.01 ± 1.44 vs CHD Class B, 8.18 ± 1.21 vs CHD Class A, 7.53 ± 1.33 mm² ; P < 0.05).

CONCLUSIONS

Fetuses with major CHD had a smaller CC compared with controls, and the difference was more marked in the CHD subgroup with expected poorer brain oxygenation. Sonographic CC size could be a clinically feasible marker of abnormal white matter development in CHD. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

External validation of prognostic models to predict stillbirth using International Prediction of Pregnancy Complications (IPPIC) Network database: individual participant data meta-analysis

OBJECTIVE

Stillbirth is a potentially preventable complication of pregnancy. Identifying women at high risk of stillbirth can guide decisions on the need for closer surveillance and timing of delivery in order to prevent fetal death. Prognostic models have been developed to predict the risk of stillbirth, but none has yet been validated externally. In this study, we externally validated published prediction models for stillbirth using individual participant data (IPD) meta-analysis to assess their predictive performance.

METHODS

MEDLINE, EMBASE, DH-DATA and AMED databases were searched from inception to December 2020 to identify studies reporting stillbirth prediction models. Studies that developed or updated prediction models for stillbirth for use at any time during pregnancy were included. IPD from cohorts within the International Prediction of Pregnancy Complications (IPPIC) Network were used to validate externally the identified prediction models whose individual variables were available in the IPD. The risk of bias of the models and cohorts was assessed using the Prediction study Risk Of Bias ASsessment Tool (PROBAST). The discriminative performance of the models was evaluated using the C-statistic, and calibration was assessed using calibration plots, calibration slope and calibration-in-the-large. Performance measures were estimated separately in each cohort, as well as summarized across cohorts using random-effects meta-analysis. Clinical utility was assessed using net benefit.

RESULTS

Seventeen studies reporting the development of 40 prognostic models for stillbirth were identified. None of the models had been previously validated externally, and the full model equation was reported for only one-fifth (20%, 8/40) of the models. External validation was possible for three of these models, using IPD from 19 cohorts (491 201 pregnant women) within the IPPIC Network database. Based on evaluation of the model development studies, all three models had an overall high risk of bias, according to PROBAST. In the IPD meta-analysis, the models had summary C-statistics ranging from 0.53 to 0.65 and summary calibration slopes ranging from 0.40 to 0.88, with risk predictions that were generally too extreme compared with the observed risks. The models had little to no clinical utility, as assessed by net benefit. However, there remained uncertainty in the performance of some models due to small available sample sizes.

CONCLUSIONS

The three validated stillbirth prediction models showed generally poor and uncertain predictive performance in new data, with limited evidence to support their clinical application. The findings suggest methodological shortcomings in their development, including overfitting. Further research is needed to further validate these and other models, identify stronger prognostic factors and develop more robust prediction models. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Endothelial GTPCH (GTP Cyclohydrolase 1) and Tetrahydrobiopterin Regulate Gestational Blood Pressure, Uteroplacental Remodeling, and Fetal Growth

[Figure: see text].

Third-trimester growth diversity in small fetuses classified as appropriate-for-gestational age or small-for-gestational age at birth

OBJECTIVE

We have shown previously that third-trimester growth in small fetuses (estimated fetal weight (EFW) < 10^th percentile) with birth weight (BW) < 10^th percentile is heterogeneous using individualized growth assessment (IGA). We aimed to test our hypothesis that individual growth patterns in small fetuses with BW > 10^th percentile are also variable but in different ways.

METHODS

This was a study of 191 cases with EFW < 10^th percentile and BW > 10^th percentile (appropriate-for-gestational-age (AGA) cohort), derived from the PORTO study. Composite size parameters were used to quantify growth pathology at individual third-trimester timepoints (individual composite prenatal growth assessment score (-icPGAS)). The fetal growth pathology score 1 (-FGPS1), calculated cumulatively from serial -icPGAS values, was used to characterize third-trimester growth patterns. Vascular-system evaluation included umbilical artery (UA) and middle cerebral artery (MCA) Doppler velocimetry. Outcome variables were birth age (preterm/term delivery) and BW (expressed as growth potential realization index for weight (GPRI_WT ) and percentile). The findings from the AGA cohort were compared with those from small fetuses (EFW < 10^th percentile) with BW < 10^th percentile (small-for-gestational-age (SGA) cohort).

RESULTS

The AGA cohort was found to have 134 fetuses (70%) with normal growth pattern and 57 (30%) with growth restriction based on IGA criteria. Seven growth-restriction -FGPS1 patterns were observed, including the previously defined progressive, late, adaptive and recovering types. The recovering type was the most common growth pattern in the AGA cohort (50.9%). About one-third of fetuses without any evidence of growth restriction had significant unexplained abnormalities in the UA (34%) and MCA (31%) and elevated mean GPRI_WT values (113 ± 12.5%). Comparison of the AGA and SGA cohorts indicated a significant difference in the distribution of -FGPS1 growth patterns (P = 0.0001). Compared with the SGA cohort, the AGA cohort had more fetuses with a normal growth pattern (70% vs 38%) and fewer cases with growth restriction (30% vs 62%). While the recovering type was the most common growth-restriction pattern in the AGA cohort (51%), the progressive type was the primary growth-restriction pattern in the SGA cohort (44%). No difference in the incidence of MCA or UA abnormality was found between the SGA and AGA cohorts when comparing subgroups of more than 10 fetuses.

CONCLUSIONS

Both normal-growth and growth-restriction patterns were observed in the AGA cohort using IGA, as seen previously in the SGA cohort. The seven types of growth restriction defined in the SGA cohort were also identified in AGA cases, but their distribution was significantly different. In one-third of cases without evidence of growth pathology in the AGA cohort, Doppler abnormalities in the UA and MCA were seen. This heterogeneity underscores the difficulty of accurate classification of fetal and neonatal growth status using conventional population-based methods. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Pancreas deficiency modifies bone development in the ovine fetus near term

Hormones have an important role in the regulation of fetal growth and development, especially in response to nutrient availability in utero. Using micro-CT and an electromagnetic three-point bend test, this study examined the effect of pancreas removal at 0.8 fraction of gestation on the developing bone structure and mechanical strength in fetal sheep. When fetuses were studied at 10 and 25 days after surgery, pancreatectomy caused hypoinsulinaemia, hyperglycaemia and growth retardation which was associated with low plasma concentrations of leptin and a marker of osteoclast activity and collagen degradation. In pancreatectomized fetuses compared to control fetuses, limb lengths were shorter, and trabecular (Tb) bone in the metatarsi showed greater bone volume fraction, Tb thickness, degree of anisotropy and porosity, and lower fractional bone surface area and Tb spacing. Mechanical strength testing showed that pancreas deficiency was associated with increased stiffness and a greater maximal weight load at fracture in a subset of fetuses studied near term. Overall, pancreas deficiency in utero slowed the growth of the fetal skeleton and adapted the developing bone to generate a more compact and connected structure. Maintenance of bone strength in growth-retarded limbs is especially important in a precocial species in preparation for skeletal loading and locomotion at birth.

Co-occurrence of preconception maternal childhood adversity and opioid use during pregnancy: Implications for offspring brain development

Understanding of the effects of in utero opioid exposure on neurodevelopment is a priority given the recent dramatic increase in opioid use among pregnant individuals. However, opioid abuse does not occur in isolation-pregnant individuals abusing opioids often have a significant history of adverse experiences in childhood, among other co-occurring factors. Understanding the specific pathways in which these frequently co-occurring factors may interact and cumulatively influence offspring brain development in utero represents a priority for future research in this area. We highlight maternal history of childhood adversity (CA) as one such co-occurring factor that is more prevalent among individuals using opioids during pregnancy and which is increasingly shown to affect offspring neurodevelopment through mechanisms beginning in utero. Despite the high incidence of CA history in pregnant individuals using opioids, we understand very little about the effects of comorbid prenatal opioid exposure and maternal CA history on fetal brain development. Here, we first provide an overview of current knowledge regarding effects of opioid exposure and maternal CA on offspring neurodevelopment that may occur during gestation. We then outline potential mechanistic pathways through which these factors might have interactive and cumulative influences on offspring neurodevelopment as a foundation for future research in this area.

Maternal One-Carbon Metabolism during the Periconceptional Period and Human Foetal Brain Growth: A Systematic Review

The maternal environment during the periconceptional period influences foetal growth and development, in part, via epigenetic mechanisms moderated by one-carbon metabolic pathways. During embryonic development, one-carbon metabolism is involved in brain development and neural programming. Derangements in one-carbon metabolism increase (i) the short-term risk of embryonic neural tube-related defects and (ii) long-term childhood behaviour, cognition, and autism spectrum disorders. Here we investigate the association between maternal one-carbon metabolism and foetal and neonatal brain growth and development. Database searching resulted in 26 articles eligible for inclusion. Maternal vitamin B6, vitamin B12, homocysteine, and choline were not associated with foetal and/or neonatal head growth. First-trimester maternal plasma folate within the normal range (>17 nmol/L) associated with increased foetal head size and head growth, and high erythrocyte folate (1538-1813 nmol/L) with increased cerebellar growth, whereas folate deficiency (<7 nmol/L) associated with a reduced foetal brain volume. Preconceptional folic acid supplement use and specific dietary patterns (associated with increased B vitamins and low homocysteine) increased foetal head size. Although early pregnancy maternal folate appears to be the most independent predictor of foetal brain growth, there is insufficient data to confirm the link between maternal folate and offspring risks for neurodevelopmental diseases.

Isolated fetal neural tube defects associate with increased risk of placental pathology: Evidence from the Collaborative Perinatal Project

INTRODUCTION

Neural tube defects (NTDs) are amongst the most common congenital anomalies and are associated with significant postnatal morbidity, but also with a higher incidence of low birthweight and fetal growth restriction. Despite the placenta being a critical determinant of fetal growth, placental development has not been extensively studied in fetuses with NTDs.

METHODS

We performed a matched case-cohort study using data from the Collaborative Perinatal Project to assess the risk of placental pathology in pregnancies with an isolated fetal NTD (cases; n = 74) compared to those without any congenital anomalies (controls; n = 148). We hypothesised that cases would be at an increased risk of placental pathology compared to controls. Data were analysed using adjusted generalized linear and nominal logistic regression models. Results are presented as adjusted β or adjusted odds ratio (aOR; 95% confidence interval).

RESULTS

Cases had lower placental weight (β = -22.2 g [-37.8 to -6.6]), surface area (β = -9.6 cm² [-18.3 to -1.0]) and birth length z-scores (β = -0.4 [-0.7 to -0.001]) compared to controls. Cases were more likely to have a single umbilical artery (vs. two; 6 [8.1%] vs. 1 [0.7%]; aOR = 301 [52.6-1726]), placental hypermaturity (9 [12.2%] vs. 5 [3.4%]; aOR = 6.8 [3.1-14.7]), many (vs. few) Hofbauer cells (9 [12.2%] vs. 7 [4.7%]; aOR = 3.02 [1.2-7.3]), and stromal fibrosis (9 [12.2%] vs. 10 [6.8%]; aOR = 3.0 [1.4-6.3]) in placental terminal villi compared to controls.

CONCLUSIONS

Fetuses with isolated NTDs may be at increased risk of placental pathology, which could be contributing to poor fetal growth in these pregnancies and subsequent postnatal morbidities.

A Life Course Approach to the Relationship Between Fetal Growth and Hypothalamic-Pituitary-Adrenal Axis Function

CONTEXT

Human and animal studies suggest that hypothalamic-pituitary-adrenal axis (HPA-A) function may be programmed in utero; however, these findings are inconsistent. Given the powerful metabolic actions of cortisol, it is important to clarify the influence of early life on adult HPA-A function.

OBJECTIVE

To determine the relationship between fetal growth and HPA-A stress response to a psychosocial stressor in young adults.

DESIGN

Multigenerational, prospective cohort study (the Raine Study) conducted between 1989 and 1991.

SETTING

King Edward Memorial Hospital, Perth, Western Australia, Australia.

PARTICIPANTS

A total of 917 participants aged 18 years from Gen2 of the Raine Study.

MAIN OUTCOME MEASURES

Measures of hypothalamic-pituitary-adrenal axis function before and after exposure to the Trier Social Stress Test.

RESULTS

In fully adjusted models, an inverse linear relationship was observed between birthweight and plasma measures of (1) baseline cortisol (β = -0.90%, 95% CI: -1.73 to -0.07; P = 0.03); (2) peak cortisol (β = -0.78%, 95% CI -1.51 to -0.06; P = 0.03); (3) area under the curve with respect to ground (β = -0.89%, 95% CI -1.60 to -0.18; P = 0.01); and (4) adrenal sensitivity (β = -1.02, 95% CI: -1.85 to -0.18; P = 0.02). Similar results were demonstrated for percent optimal birthweight. No consistent quadratic relationships were identified. No associations were found between measures of fetal adiposity and HPA-A function at age 18 years, or fetal growth and HPA-A response pattern. Removal of anticipatory responders from the models substantially attenuated the observed relationships.

CONCLUSION

We observed an inverse linear relationship between fetal growth and HPA-A function at age 18 years. This differs from the inverse parabolic relationship (inverted U curve) reported in adults of advanced age. Altered adrenal sensitivity may underlie this relationship.

Pre-gestational diabetes: Maternal body mass index and gestational weight gain are associated with augmented umbilical venous flow, fetal liver perfusion, and thus birthweight

OBJECTIVES

To assess how maternal body mass index and gestational weight gain are related to on fetal venous liver flow and birthweight in pregnancies with pre-gestational diabetes mellitus.

METHODS

In a longitudinal observational study, 49 women with pre-gestational diabetes mellitus were included for monthly assessments (gestational weeks 24-36). According to the Institute Of Medicine criteria, body mass index was categorized to underweight, normal, overweight, and obese, while gestational weight gain was classified as insufficient, appropriate or excessive. Fetal size, portal flow, umbilical venous flow and distribution to the fetal liver or ductus venosus were determined using ultrasound techniques. The impact of fetal venous liver perfusion on birthweight and how body mass index and gestational weight gain modified this effect, was compared with a reference population (n = 160).

RESULTS

The positive association between umbilical flow to liver and birthweight was more pronounced in pregnancies with pre-gestational diabetes mellitus than in the reference population. Overweight and excessive gestational weight gain were associated with higher birthweights in women with pre-gestational diabetes mellitus, but not in the reference population. Fetuses of overweight women with pre-gestational diabetes mellitus had higher umbilical (p = 0.02) and total venous liver flows (p = 0.02), and a lower portal flow fraction (p = 0.04) than in the reference population. In pre-gestational diabetes mellitus pregnancies with excessive gestational weight gain, the umbilical flow to liver was higher than in those with appropriate weight gain (p = 0.02).

CONCLUSIONS

The results support the hypothesis that umbilical flow to the fetal liver is a key determinant for fetal growth and birthweight modifiable by maternal factors. Maternal pre-gestational diabetes mellitus seems to augment this influence as shown with body mass index and gestational weight gain.

Analysis of Maternal Prenatal Weight and Offspring Cognition and Behavior: Results From the Promotion of Breastfeeding Intervention Trial (PROBIT) Cohort

IMPORTANCE

Prenatal experiences can influence fetal brain development.

OBJECTIVE

To examine associations of maternal prenatal body mass index (BMI) with cognition and behavior of offspring born full-term.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined follow-up data from a breastfeeding promotion intervention at 31 hospitals and affiliated polyclinics in the Republic of Belarus. Participants included 11 276 children who were evaluated from birth (1996-1997) to adolescence (2017-2019), with maternal BMI information available in prenatal medical records.

EXPOSURES

Maternal BMI, calculated as weight in kilograms divided by height in meters squared, after 35 weeks gestation; secondary analyses examined maternal BMI at other time points and paternal BMI.

MAIN OUTCOMES AND MEASURES

Trained pediatricians assessed child cognition with the Wechsler Abbreviated Scales of Intelligence (WASI) at 6.5 years and the computerized self-administered NeuroTrax battery at 16 years, both with an approximate mean (SD) of 100 (15). Parents and teachers rated behaviors at 6.5 years using the Strengths and Difficulties Questionnaire (SDQ, range 0-40). Mixed-effects linear regression analyses corrected for clustering, adjusted for the randomized intervention group and baseline parental sociodemographic characteristics, and were considered mediation by child BMI.

RESULTS

Among 11 276 participants, 9355 women (83%) were aged 20 to 34 years, 10 128 (89.8%) were married, and 11 050 (98.0%) did not smoke during pregnancy. Each 5-unit increase in of maternal late-pregnancy BMI (mean [SD], 27.2 [3.8]) was associated with lower offspring WASI performance intelligence quotient (IQ) (-0.52 points; 95% CI, -0.87 to -0.17 points) at 6.5 years and lower scores on 5 of 7 NeuroTrax subscales and the global cognitive score at 16 years (-0.67 points; 95% CI, -1.06 to -0.29 points). Results were similar after adjustment for sociodemographic characteristics, pregnancy complications, and paternal BMI and were not mediated by child weight. Higher late pregnancy maternal BMI was also associated with more behavioral problems reported on the SDQ by teachers but not associated with parent-reported behaviors (externalizing behaviors: 0.13 points; 95% CI, 0.02 to 0.24 points; and total difficulties: 0.14 points, 95% CI, -0.02 to 0.30 points). Results were similar for maternal BMI measured in the first trimester or postpartum. In contrast, higher 6.5-year paternal BMI was associated with slightly better child cognition (WASI verbal IQ: 0.42 points; 95% CI, 0.02 to 0.82 points; NeuroTrax executive function score: 0.68 points; 95% CI, 0.24 to 1.12 points) and fewer teacher-reported behavioral problems (total difficulties: -0.29 points; 95% CI, -0.46 to -0.11 points).

CONCLUSIONS AND RELEVANCE

This cohort study supports findings from animal experiments and human observational studies in settings with higher maternal BMI and obesity rates. Higher maternal prenatal BMI may be associated with poorer offspring brain development, although residual confounding cannot be excluded.

Age-specific structural fetal brain atlases construction and cortical development quantification for chinese population

In magnetic resonance imaging (MRI) studies of fetal brain development, structural brain atlases usually serve as essential references for the fetal population. Individual images are usually normalized into a common or standard space for analysis. However, the existing fetal brain atlases are mostly based on MR images obtained from Caucasian populations and thus are not ideal for the characterization of the fetal Chinese population due to neuroanatomical differences related to genetic factors. In this paper, we use an unbiased template construction algorithm to create a set of age-specific Chinese fetal atlases between 21-35 weeks of gestation from 115 normal fetal brains. Based on the 4D spatiotemporal atlas, the morphological development patterns, e.g., cortical thickness, cortical surface area, sulcal and gyral patterns, were quantified. The fetal brain abnormalities were detected when referencing the age-specific template. Additionally, a direct comparison of the Chinese fetal atlases and Caucasian fetal atlases reveals dramatic anatomical differences, mainly in the medial frontal and temporal regions. After applying the Chinese and Caucasian fetal atlases separately to an independent Chinese fetal brain dataset, we find that the Chinese fetal atlases result in significantly higher accuracy than the Caucasian fetal atlases in guiding brain tissue segmentation. These results suggest that the Chinese fetal brain atlases are necessary for quantitative analysis of the typical and atypical development of the Chinese fetal population in the future. The atlases with their parcellations are now publicly available at https://github.com/DeepBMI/FBA-Chinese.

Placental Transcriptome Adaptations to Maternal Nutrient Restriction in Sheep

Placental development is modified in response to maternal nutrient restriction (NR), resulting in a spectrum of fetal growth rates. Pregnant sheep carrying singleton fetuses and fed either 100% (n = 8) or 50% (NR; n = 28) of their National Research Council (NRC) recommended intake from days 35–135 of pregnancy were used to elucidate placentome transcriptome alterations at both day 70 and day 135. NR fetuses were further designated into upper (NR NonSGA; n = 7) and lower quartiles (NR SGA; n = 7) based on day 135 fetal weight. At day 70 of pregnancy, there were 22 genes dysregulated between NR SGA and 100% NRC placentomes, 27 genes between NR NonSGA and 100% NRC placentomes, and 22 genes between NR SGA and NR NonSGA placentomes. These genes mediated molecular functions such as MHC class II protein binding, signaling receptor binding, and cytokine activity. Gene set enrichment analysis (GSEA) revealed significant overrepresentation of genes for natural-killer-cell-mediated cytotoxicity in NR SGA compared to 100% NRC placentomes, and alterations in nutrient utilization pathways between NR SGA and NR NonSGA placentomes at day 70. Results identify novel factors associated with impaired function in SGA placentomes and potential for placentomes from NR NonSGA pregnancies to adapt to nutritional hardship.

Circulating Insulin and IGF-1 and Frequency of Food Consumption during Pregnancy as Predictors of Birth Weight and Length

The aim of the study was to assess the relationships between maternal insulin and insulin-like growth factor-1 (IGF-1) concentration and food consumption frequency and the birth parameters of the newborn. A total of 157 mother-newborn pairs participated in the study. The study showed that more frequent consumption of sweet and salty snacks as well as fruit and fruit or vegetable juices may promote greater weight gain in pregnancy and higher newborn birth weight. A significantly higher insulin concentration was found among overweight women according to body mass index (BMI), and a significantly lower concentration of IGF-1 was demonstrated among women ≥35 years of age. There was no significant correlation between the concentration of insulin and IGF-1 in the mother’s blood plasma and the birth weight and length of the newborn. A significant relationship was only found between the concentration of IGF-1 in the mother’s blood and the Ponderal index of the newborn. A woman’s eating habits during pregnancy have a significant impact on the mother’s health and on the proper growth and development of the foetus.

Cholesterol Contributes to Male Sex Differentiation Through Its Developmental Role in Androgen Synthesis and Hedgehog Signaling

Two specialized functions of cholesterol during fetal development include serving as a precursor to androgen synthesis and supporting hedgehog (HH) signaling activity. Androgens are produced by the testes to facilitate masculinization of the fetus. Recent evidence shows that intricate interactions between the HH and androgen signaling pathways are required for optimal male sex differentiation and defects of either can cause birth anomalies indicative of 46,XY male variations of sex development (VSD). Further, perturbations in cholesterol synthesis can cause developmental defects, including VSD, that phenocopy those caused by disrupted androgen or HH signaling, highlighting the functional role of cholesterol in promoting male sex differentiation. In this review, we focus on the role of cholesterol in systemic androgen and local HH signaling events during fetal masculinization and their collective contributions to pediatric VSD.

Amino Acid Composition of Amniotic Fluid during the Perinatal Period Reflects Mother's Fat and Carbohydrate Intake

Dietary content during pregnancy is important because it is necessary for the growth of the fetus. With the assumption that the nutritional status of the fetus can be monitored by measuring amino acid concentrations in the amniotic fluid, we investigated whether the habitual dietary intake of pregnant women affected the composition of the amniotic fluid and the significance of performing amniotic fluid analysis. The subjects were 34 mothers who delivered full-term babies by cesarean section. Three biological samples were collected from the mothers: blood, cord blood, and amniotic fluid. At the same time, the mothers' prenatal nutritional intake information was also recorded. When the amino acid contents of the samples were compared with the mothers' nutrient intake, many amino acids in the amniotic fluid were positively correlated with lipid intake, but not with protein intake. There was a negative correlation between lipid intake and carbohydrate intake, and the amino acid contents of the amniotic fluid were also negatively correlated with carbohydrate intake. The results of this study were consistent with those found in animal models, suggesting that the analysis of amniotic fluid may be a useful method to investigate the effects of habitual diet during human pregnancy on the fetus.

Building a stem cell-based primate uterus

The uterus is the organ for embryo implantation and fetal development. Most current models of the uterus are centred around capturing its function during later stages of pregnancy to increase the survival in pre-term births. However, in vitro models focusing on the uterine tissue itself would allow modelling of pathologies including endometriosis and uterine cancers, and open new avenues to investigate embryo implantation and human development. Motivated by these key questions, we discuss how stem cell-based uteri may be engineered from constituent cell parts, either as advanced self-organising cultures, or by controlled assembly through microfluidic and print-based technologies.

Mediators Linking Maternal Weight to Birthweight and Neonatal Fat Mass in Healthy Pregnancies

CONTEXT

Lifestyle interventions have not efficaciously reduced complications caused by maternal weight on fetal growth, requiring insight into explanatory mediators.

OBJECTIVE

We hypothesized that maternal mediators, including adiponectin, leptin, insulin, and glucose, mediate effects of pregestational BMI (pBMI) and gestational weight gain (GWG) on birthweight and neonatal fat mass percentage (FM%) through placental weight and fetal mediators, including insulin levels (Ifv) and venous-arterial glucose difference (ΔGfva). Hypothesized confounders were maternal age, gestational age, and parity.

METHODS

A cross-sectional study of healthy mother-offspring-pairs (n = 165) applying the 4-vessel in vivo sampling method at Oslo University Hospital, Norway. We obtained pBMI, GWG, birthweight, and placental weight. FM% was available and calculated for a subcohort (n = 84). We measured circulating levels of adiponectin, leptin, glucose, and insulin and performed path analysis and traditional mediation analyses based on linear regression models.

RESULTS

The total effect of pBMI and GWG on newborn size was estimated to be 30 g (range, 16-45 g) birthweight and 0.17 FM% (range, 0.04-0.29 FM%) per kg∙m-2 pBMI and 31 g (range, 18-44 g) and 0.24 FM% (range, 0.10-0.37 FM%) per kg GWG. The placental weight was the main mediator, mediating 25-g birthweight and 0.11 FM% per kg∙m-2 pBMI and 25-g birthweight and 0.13 FM% per kg GWG. The maternal mediators mediated a smaller part of the effect of pBMI (3.8-g birthweight and 0.023 FM% per kg∙m-2 pBMI) but not GWG.

CONCLUSION

Placental weight was the main mediator linking pBMI and GWG to birthweight and FM%. The effect of pBMI, but not GWG, on birthweight and FM%, was also mediated via the maternal and fetal mediators.

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.

Maternal intermittent fasting during pregnancy induces fetal growth restriction and down-regulated placental system A amino acid transport in the rat

During Ramadan, many pregnant Muslim women fast between dawn and sunset. Although the impacts of prolonged maternal intermittent fasting (IF) on fetal growth and placental function are under-researched, reported effects include reduced placental weight and birth weight. In the present study, pregnant Wistar rats were used to model repeated cycles of IF on fetal development and placental function and to examine sex-specific effects. In the IF group, food was withdrawn daily from 17:00 to 09:00 over 21 days of gestation, while the control group received food ad libitum. Both groups had free water access. IF dams consumed less food, had significantly reduced weight compared with controls, with reduced plasma glucose and amino acids. Both fetal sexes were significantly lighter in the IF group with reduced fetal plasma amino acids. Placental weights and morphology were unchanged. The profile of placental metabolites was altered in the IF group with sex-specific responses evident. Transplacental flux of 14C-methylaminoisobutyric acid (14C-MeAIB), a system A amino acid transporter substrate, was significantly reduced in both fetal sexes in the IF group. Sodium-dependent 14C-MeAIB uptake into isolated placental plasma membrane vesicles was unchanged. The gene expression of system A transporter Slc38a1, Slc38a2 and Slc38a4 was up-regulated in IF male placentas only. No changes were observed in placental SNAT1 and SNAT2 protein expression. Maternal IF results in detrimental impacts on maternal physiology and fetal development with changes in the placental and fetal metabolite profiles. Reduced placental system A transporter activity may be responsible for fetal growth restriction in both sexes.

Thyroid Hormone Deficiency Suppresses Fetal Pituitary-Adrenal Function Near Term: Implications for the Control of Fetal Maturation and Parturition

Background: The fetal hypothalamic-pituitary-adrenal (HPA) axis plays a key role in the control of parturition and maturation of organ systems in preparation for birth. In hypothyroid fetuses, gestational length may be prolonged and maturational processes delayed. The extent to which the effects of thyroid hormone deficiency in utero on the timing of fetal maturation and parturition are mediated by changes to the structure and function of the fetal HPA axis is unknown. Methods: In twin sheep pregnancies where one fetus was thyroidectomized and the other sham-operated, this study investigated the effect of hypothyroidism on circulating concentrations of adrenocorticotrophic hormone (ACTH) and cortisol, and the structure and secretory capacity of the anterior pituitary and adrenal glands. The relative population of pituitary corticotrophs and the masses of the adrenal zones were assessed by immunohistochemical and stereological techniques. Adrenal mRNA abundances of key steroidogenic enzymes and growth factors were examined by quantitative polymerase chain reaction. Results: Hypothyroidism in utero reduced plasma concentrations of ACTH and cortisol. In thyroid-deficient fetuses, the mass of corticotrophs in the anterior pituitary gland was unexpectedly increased, while the mass of the zona fasciculata and its proportion of the adrenal gland were decreased. These structural changes were associated with lower adrenocortical mRNA abundances of insulin-like growth factor (IGF)-I and its receptor, and key steroidogenic enzymes responsible for glucocorticoid synthesis. The relative mass of the adrenal medulla and its proportion of the adrenal gland were increased by thyroid hormone deficiency in utero, without any change in expression of phenylethanolamine N-methyltransferase or the IGF system. Conclusions: Thyroid hormones are important regulators of the structure and secretory capacity of the pituitary-adrenal axis before birth. In hypothyroid fetuses, low plasma cortisol may be due to impaired adrenocortical growth and steroidogenic enzyme expression, secondary to low circulating ACTH concentration. Greater corticotroph population in the anterior pituitary gland of the hypothyroid fetus indicates compensatory cell proliferation and that there may be abnormal corticotroph capacity for ACTH synthesis and/or impaired hypothalamic input. Suppression of the development of the fetal HPA axis by thyroid hormone deficiency may contribute to the delay in fetal maturation and delivery observed in hypothyroid offspring.

The effect of umbilical cord blood spexin, free 25(OH) vitamin D3 and adipocytokine levels on intrauterine growth and anthropometric measurements in newborns

Spexin is a newly described peptide and is known to reduce the uptake of long-chain fatty acids into adipocytes. The serum spexin levels of obese children between the ages of 12-18 are lower. The effect of serum spexin and free 25(OH) vitamin D3 levels on intrauterine development in newborns is unknown. Our aims is to evaluate the effects of spexin and adipocytokin levels in the cord blood of term newborn babies on the weight of the baby according to the gestation age (GA) and anthropometric measurement results. Babies who were born in our hospital and whose GA was ≥37 weeks were evaluated in three groups as appropriate for GA (AGA), small for GA (SGA) and large for GA (LGA). A total of 84 babies, including an equal number of infants in AGA, SGA and LGA groups, were included in the study. Spexin, leptin, active ghrelin, free 25(OH) vitamin D3, glucose, and insulin levels in the cord blood of infants were examined at birth. The results were compared according to GA and birth weight (BW). There was no statistically significant difference between groups in terms of mean spexin, active ghrelin, free 25(OH) vitamin D3, and insulin levels. The mean leptin level was significantly higher in LGA group than SGA and AGA groups (p 0.004). The mean spexin and leptin levels were higher in girls than in boys (respectively p value 0.029, 0.003). Although there is a significant positive correlation between BW, head circumference, height, umbilical circumference, umbilical circumference/height ratio and the mean leptin levels (p < 0.001), there was no significant correlation between mean spexin, active ghrelin, free 25 (OH) vitamin D3, insulin, and glucose levels. This study suggests that spexin may not have an effect on intrauterine development.

Frontal lobe growth is impaired in fetuses with congenital heart disease

OBJECTIVES

The primary objective of this study was to assess whether fetuses with congenital heart disease (CHD) have smaller frontal brain areas compared with normal controls. The secondary objective was to evaluate whether there are any differences in frontal brain area between cases with different types of CHD, grouped according to their impact on hemodynamics.

METHODS

This was a retrospective cross-sectional study, including 421 normal fetuses and 101 fetuses with isolated CHD evaluated between 20 and 39 gestational weeks at our fetal medicine and surgery unit in the period January 2016-December 2019. The study group was subdivided, according to the CHD hemodynamics, as follows: (1) hypoplastic left heart syndrome and other forms of functionally univentricular heart defect; (2) transposition of the great arteries; (3) conotruncal defects and other CHDs with large shunts; (4) right ventricular outflow tract obstruction, without a hypoplastic right ventricle; (5) left outflow tract obstruction; (6) others. The transventricular axial view of the fetal head was used as the reference view, on which the frontal lobe anteroposterior diameter (FAPD) and the occipitofrontal diameter (OFD) were measured, assuming the former to be representative of the area of the frontal lobes. The FAPD/OFD ratio was then calculated as FAPD/OFD × 100. These two variables (FAPD and FAPD/OFD ratio) were then evaluated and compared between the study and control groups. Adjustment for gestational age, both via multiple linear regression and by using a-posteriori matching based on the propensity score, was employed.

RESULTS

In normal fetuses, FAPD showed a linear positive correlation with gestational age. In fetuses with CHD, the FAPD was shorter than in normal fetuses from the 20^th  gestational week onwards, with the difference increasing after 30 gestational weeks. FAPD/OFD ratio was significantly smaller in fetuses with CHD than in normal fetuses (P < 0.0001) at all gestational ages, with no apparent differences among the various CHD categories, all of which had smaller FAPD/OFD ratio compared with controls.

CONCLUSIONS

Fetuses with CHD have a shorter FAPD and a smaller FAPD/OFD ratio compared with normal fetuses. This impaired growth of the frontal area of the brain seems to occur in all types of CHD, regardless of their impact on hemodynamics. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Size for gestational age affects the risk for type 1 diabetes in children and adolescents: a Swedish national case-control study

AIM/HYPOTHESIS

Environmental factors are believed to contribute to the risk of developing type 1 diabetes. The aim of this study was to investigate how size for gestational age affects the risk of developing childhood type 1 diabetes.

METHODS

Using the Swedish paediatric diabetes quality register and the Swedish medical birth register, children with type 1 diabetes diagnosed between 2000 and 2012 (n = 9376) were matched with four control children (n = 37,504). Small for gestational age (SGA) and large for gestational age (LGA) were defined according to Swedish national standards. Data were initially analysed using Pearson's χ² and thereafter by single and multiple logistic regression models.

RESULTS

An equal proportion of children were born appropriate for gestational age, but children with type 1 diabetes were more often born LGA and less often born SGA than control children (4.7% vs 3.5% and 2.0% vs 2.6%, respectively, p < 0.001). In the multiple logistic regression analysis, being born LGA increased (adjusted OR 1.16 [95% CI 1.02, 1.32]) and SGA decreased (adjusted OR 0.76 [95% CI 0.63, 0.92]) the risk for type 1 diabetes, regardless of maternal BMI and diabetes.

CONCLUSIONS/INTERPRETATION

Size for gestational age of Swedish children affects the risk of type 1 diabetes, with increased risk if the child is born LGA and decreased risk if the child is born SGA. Being born LGA is an independent risk factor for type 1 diabetes irrespective of maternal BMI and diabetes. Thus, reducing the risk for a child being born LGA might to some extent reduce the risk for type 1 diabetes.

Effects of prenatal exposure factors on birth outcomes through mediation of favorable fetal growth conditions using structural equation modeling

Background

Birth weight, birth length, and gestational age are major indicators of newborn health. Several prenatal exposure factors influence the fetal environment. The aim of the study was to investigate the effect of prenatal exposure factors, including socio-demographic, behavioural, dietary, physical activity, clinical and environmental on birth outcomes through the mediation of Favourable Fetal Growth Conditions (FFGC).

Methods

Data was obtained from six hundred and fifty-six Mother and Child in the Environment birth cohort study in Durban, South Africa from 2013 to 2017. We adopted structural equation models which evaluate the direct and indirect effects by allowing multiple simultaneous equations to incorporate confounding and mediation.

Results

A significant direct and indirect effect of FFGC on newborn weight, length, and gestational age was seen. Gestational weight gain and maternal body mass index in the first trimester exerted a mediation effect between maternal behavioural risk factors and FFGC. Similarly, the level of physical activity during pregnancy was associated with decreased gestational weight gain. The effects of maternal characteristics on newborn weight, length, and gestational age were largely indirect, operating through FFGC as a latent variable.

Conclusions

Gestational weight gain and maternal pre-gestational BMI were observed to mediate the association between prenatal behavioural risk factors and favourable fetal growth conditions.

Trial registration

Retrospectively registered from 01 March 2013.

Histochemical and Morphometrical Analyses of Scarless Wound Healing in Mouse Fetal Model

OBJECTIVE

Scar formation is an inevitable outcome after craniofacial surgery in the congenital facial anomaly. Scarless healing is the ultimate treatment after the surgery. Therefore, we elucidate the mechanism underlying scarless healing during fetal development.

METHODS

A full-thickness back skin excision (1 × 0.5 mm) was made at embryonic day 16.5 (E16.5) and 18.5 (E18.5) in fetal C57BL/6J mice and examined the histochemical and morphometrical findings of wound healing after 48 hours.

RESULTS

The wound made at E16.5 showed almost complete re-epithelialization with fine reticular dermal collagen fibers, but not at E18.5. The ratio of CK5 positive area was significantly higher in the wound of E16.5 operation than in the E18.5. The wounds made at E18.5 showed granulation tissue formation which will lead to subsequent scar formation. The collagen fibers tended to be thinner in wound than in normal skin, while the decrease in the number of fibers but the increase in the straightness of fibers were evident in the wound at E18.5.

CONCLUSION

Transition point of scarless healing seemed between E16.5 and E18.5 in mice, which may imply that the potential of epithelial regeneration and matrix formation was changed, possibly due to alteration of cell constitution and decrease in stemness, at that time.

Fetal Programming Effects of a Mild Food Restriction During Pregnancy in Mice: How Does It Compare to Intragestational Ghrelin Administration?

To explore in mice if a 15% food restriction protocol during pregnancy programs the offspring postnatal development, with emphasis on reproductive function, and to assess if ghrelin (Ghrl) administration to mouse dams exerts effects that mimic those obtained under mild caloric restriction. Mice were 15% food-restricted, injected with 4 nmol/animal/day of Ghrl, or injected with the vehicle (control) thorough pregnancy. After birth, the pups did not receive further treatment. Pups born from food-restricted dams (FR pups) were lighter than Ghrl pups at birth, but reached normal weight at adulthood. Ghrl pups were heavier at birth and gained more weight than control pups (C pups). This effect was not associated with plasma IGF-1. FR pups showed a delay in pinna detachment and eye opening, while an advance was observed in Ghrl pups. FR pups showed also impairment in the surface-righting reflex. In both female FR and Ghrl pups, there was an advance in vaginal opening and, in adulthood, FR pups showed a significant decrease in their own litter size and plasma progesterone, and an increase in embryo loss. A delay in testicular descent was evident in male Ghrl pups. Changes in puberty onset were not associated with differences in the expression of Kiss1 in hypothalamic nuclei. Finally, in adulthood, FR pups showed a significant decrease in sperm quality. In conclusion, a mild food restriction thorough gestation exerted programming effects on the offspring, affecting also their reproductive function in adulthood. These effects were not similar to those of intragestational Ghrl administration.

International gestational age-specific centiles for blood pressure in pregnancy from the INTERGROWTH-21st Project in 8 countries: A longitudinal cohort study

BACKGROUND

Gestational hypertensive and acute hypotensive disorders are associated with maternal morbidity and mortality worldwide. However, physiological blood pressure changes in pregnancy are insufficiently defined. We describe blood pressure changes across healthy pregnancies from the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st) Fetal Growth Longitudinal Study (FGLS) to produce international, gestational age-specific, smoothed centiles (third, 10th, 50th, 90th, and 97th) for blood pressure.

METHODS AND FINDINGS

Secondary analysis of a prospective, longitudinal, observational cohort study (2009 to 2016) was conducted across 8 diverse urban areas in Brazil, China, India, Italy, Kenya, Oman, the United Kingdom, and the United States of America. We enrolled healthy women at low risk of pregnancy complications. We measured blood pressure using standardised methodology and validated equipment at enrolment at <14 weeks, then every 5 ± 1 weeks until delivery. We enrolled 4,607 (35%) women of 13,108 screened. The mean maternal age was 28·4 (standard deviation [SD] 3.9) years; 97% (4,204/4,321) of women were married or living with a partner, and 68% (2,955/4,321) were nulliparous. Their mean body mass index (BMI) was 23.3 (SD 3.0) kg/m2. Systolic blood pressure was lowest at 12 weeks: Median was 111.5 (95% CI 111.3 to 111.8) mmHg, rising to a median maximum of 119.6 (95% CI 118.9 to 120.3) mmHg at 40 weeks' gestation, a difference of 8.1 (95% CI 7.4 to 8.8) mmHg. Median diastolic blood pressure decreased from 12 weeks: 69.1 (95% CI 68.9 to 69.3) mmHg to a minimum of 68.5 (95% CI 68.3 to 68.7) mmHg at 19+5 weeks' gestation, a change of -0·6 (95% CI -0.8 to -0.4) mmHg. Diastolic blood pressure subsequently increased to a maximum of 76.3 (95% CI 75.9 to 76.8) mmHg at 40 weeks' gestation. Systolic blood pressure fell by >14 mmHg or diastolic blood pressure by >11 mmHg in fewer than 10% of women at any gestational age. Fewer than 10% of women increased their systolic blood pressure by >24 mmHg or diastolic blood pressure by >18 mmHg at any gestational age. The study's main limitations were the unavailability of prepregnancy blood pressure values and inability to explore circadian effects because time of day was not recorded for the blood pressure measurements.

CONCLUSIONS

Our findings provide international, gestational age-specific centiles and limits of acceptable change to facilitate earlier recognition of deteriorating health in pregnant women. These centiles challenge the idea of a clinically significant midpregnancy drop in blood pressure.

Pregnancies in Diabetes and Obesity: The Capacity-Load Model of Placental Adaptation

Excess nutritional supply to the growing fetus, resulting from maternal diabetes and obesity, is associated with increased risks of fetal maldevelopment and adverse metabolic conditions in postnatal life. The placenta, interposed between mother and fetus, serves as the gateway between the two circulations and is usually considered to mediate maternal exposures to the fetus through a direct supply line. In this Perspective, however, we argue that the placenta is not an innocent bystander and mounts responses to fetal "signals of distress" to sustain its own adequate function and protect the fetus. We describe several types of protection that the placenta can offer the fetus against maternal metabolic perturbations and offer a theoretical model of how the placenta responds to the intrauterine environment in maternal diabetes and obesity to stabilize the fetal environment. Our approach supports growing calls for early screening and control of pregnancy metabolism to minimize harmful fetal outcomes.

Fetal Rhesus Monkey First Trimester Zika Virus Infection Impacts Cortical Development in the Second and Third Trimesters

Zika virus is a teratogen similar to other neurotropic viruses, notably cytomegalovirus and rubella. The goal of these studies was to address the direct impact of Zika virus on fetal development by inoculating early gestation fetal rhesus monkeys using an ultrasound-guided approach (intraperitoneal vs. intraventricular). Growth and development were monitored across gestation, maternal samples collected, and fetal tissues obtained in the second trimester or near term. Although normal growth and anatomical development were observed, significant morphologic changes were noted in the cerebral cortex at 3-weeks post-Zika virus inoculation including massive alterations in the distribution, density, number, and morphology of microglial cells in proliferative regions of the fetal cerebral cortex; an altered distribution of Tbr2+ neural precursor cells; increased diameter and volume of blood vessels in the cortical proliferative zones; and a thinner cortical plate. At 3-months postinoculation, alterations in morphology, distribution, and density of microglial cells were also observed with an increase in blood vessel volume; and a thinner cortical plate. Only transient maternal viremia was observed but sustained maternal immune activation was detected. Overall, these studies suggest persistent changes in cortical structure result from early gestation Zika virus exposure with durable effects on microglial cells.