Showing papers on "Fetus published in 2013"

Perinatal morbidity and mortality in early-onset fetal growth restriction: cohort outcomes of the trial of randomized umbilical and fetal flow in Europe (TRUFFLE)

Abstract: Objectives Few data exist for counseling and perinatal management of women after an antenatal diagnosis of early-onset fetal growth restriction. Yet, the consequences of preterm delivery and its attendant morbidity for both mother and baby are far reaching. The objective of this study was to describe perinatal morbidity and mortality following early-onset fetal growth restriction based on time of antenatal diagnosis and delivery. Methods We report cohort outcomes for a prospective multicenter randomized management study of fetal growth restriction (Trial of Randomized Umbilical and Fetal Flow in Europe (TRUFFLE)) performed in 20 European perinatal centers between 2005 and 2010. Women with a singleton fetus at 26–32 weeks of gestation, with abdominal circumference 95th percentile, were recruited. The main outcome measure was a composite of fetal or neonatal death or severe morbidity: survival to discharge with severe brain injury, bronchopulmonary dysplasia, proven neonatal sepsis or necrotizing enterocolitis. Results Five-hundred and three of 542 eligible women formed the study group. Mean ± SD gestational age at diagnosis was 29 ± 1.6 weeks and mean ± SD estimated fetal weight was 881 ± 217 g; 12 (2.4%) babies died in utero. Gestational age at delivery was 30.7 ± 2.3 weeks, and birth weight was 1013 ± 321 g. Overall, 81% of deliveries were indicated by fetal condition and 97% were by Cesarean section. Of 491 liveborn babies, outcomes were available for 490 amongst whom there were 27 (5.5%) deaths and 118 (24%) babies suffered severe morbidity. These babies were smaller at birth (867 ± 251 g) and born earlier (29.6 ± 2.0 weeks). Death and severe morbidity were significantly related to gestational age, both at study entry and delivery and also with the presence of maternal hypertensive morbidity. The median time to delivery was 13 days for women without hypertension, 8 days for those with gestational hypertension, 4 days for pre-eclampsia and 3 days for HELLP syndrome. Conclusions Fetal outcome in this study was better than expected from contemporary reports: perinatal death was uncommon (8%) and 70% survived without severe neonatal morbidity. The intervals to delivery, death and severe morbidity were related to the presence and severity of maternal hypertensive conditions. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

Fetal fraction in maternal plasma cell‐free DNA at 11–13 weeks' gestation: relation to maternal and fetal characteristics

Abstract: Objective To examine the possible effects of maternal and fetal characteristics on the fetal fraction in maternal plasma cell-free (cf) DNA at 11–13 weeks’ gestation and estimate the proportion of pregnancies at high risk of non-invasive prenatal testing (NIPT) failure because the fetal fraction is less than 4%. Methods In 1949 singleton pregnancies at 11–13 weeks’ gestation cf-DNA was extracted from maternal plasma. Chromosome-selective sequencing of non-polymorphic and polymorphic loci, where fetal alleles differ from maternal alleles, was used to determine the proportion of cf-DNA that was of fetal origin. Multivariable regression analysis was used to determine significant predictors of the fetal fraction among maternal and fetal characteristics. Results The fetal fraction decreased with increased maternal weight, it was lower in women of Afro-Caribbean origin than in Caucasians and increased with fetal crown–rump length, serum pregnancy-associated plasma protein-A, serum free β-human chorionic gonadotropin, smoking and trisomy 21 karyotype. The median fetal fraction was 10.0% (interquartile range, 7.8–13.0%) and this decreased with maternal weight from 11.7% at 60 kg to 3.9% at 160 kg. The estimated proportion with fetal fraction below 4% increased with maternal weight from 0.7% at 60 kg to 7.1% at 100 kg and 51.1% at 160 kg.

Impacts of arginine nutrition on embryonic and fetal development in mammals.

Abstract: Embryonic loss and intrauterine growth restriction (IUGR) are significant problems in humans and other animals. Results from studies involving pigs and sheep have indicated that limited uterine capacity and placental insufficiency are major factors contributing to suboptimal reproduction in mammals. Our discovery of the unusual abundance of the arginine family of amino acids in porcine and ovine allantoic fluids during early gestation led to the novel hypothesis that arginine plays an important role in conceptus (embryo and extra-embryonic membranes) development. Arginine is metabolized to ornithine, proline, and nitric oxide, with each having important physiological functions. Nitric oxide is a vasodilator and angiogenic factor, whereas ornithine and proline are substrates for uterine and placental synthesis of polyamines that are key regulators of gene expression, protein synthesis, and angiogenesis. Additionally, arginine activates the mechanistic (mammalian) target of rapamycin cell signaling pathway to stimulate protein synthesis in the placenta, uterus, and fetus. Thus, dietary supplementation with 0.83 % L-arginine to gilts consuming 2 kg of a typical gestation diet between either days 14 and 28 or between days 30 and 114 of pregnancy increases the number of live-born piglets and litter birth weight. Similar results have been reported for gestating rats and ewes. In sheep, arginine also stimulates development of fetal brown adipose tissue. Furthermore, oral administration of arginine to women with IUGR has been reported to enhance fetal growth. Collectively, enhancement of uterine as well as placental growth and function through dietary arginine supplementation provides an effective solution to improving embryonic and fetal survival and growth.

Neurogenesis Continues in the Third Trimester of Pregnancy and Is Suppressed by Premature Birth

Abstract: Premature infants exhibit neurodevelopmental delay and reduced growth of the cerebral cortex. However, the underlying mechanisms have remained elusive. Therefore, we hypothesized that neurogenesis in the ventricular and subventricular zones of the cerebral cortex would continue in the third trimester of pregnancy and that preterm birth would suppress neurogenesis. To test our hypotheses, we evaluated autopsy materials from human fetuses and preterm infants of 16-35 gestational weeks (gw). We noted that both cycling and noncycling Sox2(+) radial glial cells and Tbr2(+) intermediate progenitors were abundant in human preterm infants until 28 gw. However, their densities consistently decreased from 16 through 28 gw. To determine the effect of premature birth on neurogenesis, we used a rabbit model and compared preterm [embryonic day 29 (E29), 3 d old] and term (E32, <2 h old) pups at an equivalent postconceptional age. Glutamatergic neurogenesis was suppressed in preterm rabbits, as indicated by the reduced number of Tbr2(+) intermediate progenitors and the increased number of Sox2(+) radial glia. Additionally, hypoxia-inducible factor-1α, vascular endothelial growth factor, and erythropoietin were higher in term than preterm pups, reflecting the hypoxic intrauterine environment of just-born term pups. Proneural genes, including Pax6 and Neurogenin-1 and -2, were higher in preterm rabbit pups compared with term pups. Importantly, neurogenesis and associated factors were restored in preterm pups by treatment with dimethyloxallyl glycine, a hypoxia mimetic agent. Hence, glutamatergic neurogenesis continues in the premature infants, preterm birth suppresses neurogenesis, and hypoxia-mimetic agents might restore neurogenesis, enhance cortical growth, and improve neurodevelopmental outcome of premature infants.

Maternal thyroid hormone parameters during early pregnancy and birth weight: the Generation R Study.

Abstract: Context: Maternal hyperthyroidism during pregnancy is associated with an increased risk of low birth weight, predisposing to neonatal morbidity and mortality. However, the effects of variation in maternal serum thyroid parameters within the normal range on birth weight are largely unknown. Objective: The aim was to study the effects of early pregnancy maternal serum thyroid parameters within the normal range on birth weight, as well as the relation between umbilical cord thyroid parameters and birth weight. Design, Setting, and Participants: In early pregnancy, serum TSH, FT4 (free T4), and thyroid peroxidase antibody levels were determined in 4464 pregnant women. Cord serum TSH and FT4 levels were determined in 2724 newborns. Small size for gestational age at birth (SGA) was defined as a gestational age-adjusted birth weight below the 2.5th percentile. The associations between normal-range maternal and cord thyroid parameters, birth weight, and SGA were studied using regression analyses. Results: In moth...

Fetal Ventricular Pacing for Hydrops Secondary to Complete

Abstract: The advent of ultrasound recording has expanded thecapabilities for treatment of the fetus in utero. The di­agnosis of specific disease processes has allowed for pre­natal intervention by new techniques designed to im­prove fetal survival. The application of ventricular pacingin a hydropic fetus with complete atrioventricular (AV)block is reported. Complete AV block resulted frommaternal collagen vascular disease. The application ofventricular pacing was to allow for further in utero de­velopment and for reversal of hydrops fetalis after im­provement in cardiacoutput. Despite fetal death 4 hoursComplete atrioventricular (AV) block is usually well tol­erated in utero during the third trimester unless the ventric­ular rate is extremely slow or associated cardiac defectsresult in AV valve regurgitation. Nonimmunologic hydropsfetalis may result (1,2), which represents severe fetal cardiacdecompensation due to congestive heart failure. The hy­dropic fetus with complete AV block will die in utero ifleft untreated in almost all cases. At present, a viable hy­dropic fetus with complete AV block is delivered by ce­sarean section, and temporary ventricular pacing is initiatedduring perinatal resuscitation (3). However, even after thiscourse, perinatal mortality exceeds 80% (3,4). Because theprognosis for the hydropic fetus is poor, we have applied a

Viral Infection of the Pregnant Cervix Predisposes to Ascending Bacterial Infection

Abstract: Preterm birth is the major cause of neonatal mortality and morbidity, and bacterial infections that ascend from the lower female reproductive tract are the most common route of uterine infection leading to preterm birth. The uterus and growing fetus are protected from ascending infection by the cervix, which controls and limits microbial access by the production of mucus, cytokines, and antimicrobial peptides. If this barrier is compromised, bacteria may enter the uterine cavity, leading to preterm birth. Using a mouse model, we demonstrate, to our knowledge for the first time, that viral infection of the cervix during pregnancy reduces the capacity of the female reproductive tract to prevent bacterial infection of the uterus. This is due to differences in susceptibility of the cervix to infection by virus during pregnancy and the associated changes in TLR and antimicrobial peptide expression and function. We suggest that preterm labor is a polymicrobial disease, which requires a multifactorial approach for its prevention and treatment.

Matrix metalloproteinase-9 deficiency phenocopies features of preeclampsia and intrauterine growth restriction

Abstract: The pregnancy complication preeclampsia (PE), which occurs in approximately 3% to 8% of human pregnancies, is characterized by placental pathologies that can lead to significant fetal and maternal morbidity and mortality. Currently, the only known cure is delivery of the placenta. As the etiology of PE remains unknown, it is vital to find models to study this common syndrome. Here we show that matrix metalloproteinase-9 (MMP9) deficiency causes physiological and placental abnormalities in mice, which mimic features of PE. As with the severe cases of this syndrome, which commence early in gestation, MMP9-null mouse embryos exhibit deficiencies in trophoblast differentiation and invasion shortly after implantation, along with intrauterine growth restriction or embryonic death. Reciprocal embryo transfer experiments demonstrated that embryonic MMP9 is a major contributor to normal implantation, but maternal MMP9 also plays a role in embryonic trophoblast development. Pregnant MMP9-null mice bearing null embryos exhibited clinical features of PE as VEGF dysregulation and proteinuria accompanied by preexisting elevated blood pressure and kidney pathology. Thus, our data show that fetal and maternal MMP9 play a role in the development of PE and establish the MMP9-null mice as a much-needed model to study the clinical course of this syndrome.

Paracetamol, aspirin, and indomethacin induce endocrine disturbances in the human fetal testis capable of interfering with testicular descent.

Abstract: Context: Masculinization depends on the fetal testis. Exposure of the human fetus during pregnancy to paracetamol and/or to other mild analgesics is associated with an increased risk of cryptorchidism. Objective: We aimed to determine whether mild analgesics disrupted the morphology and endocrine function of the human testis. Design: We used an in vitro system based on the culture of human fetal testes exposed or not to paracetamol, its metabolite N-(4-hydroxyphenyl)-arachidonoylethanolamide (AM404), aspirin, indomethacin, and ketoconazole at 10−4 to 10−7 M. Setting: The study was conducted at the University of Rennes I. Patients/Participants: Human fetal testes were from pregnant women after induced abortion, between 7 and 12 weeks of gestation (GW). Main Outcome Measures: Testosterone (RIA), anti-Mullerian hormone (ELISA), insulin-like factor 3 (RIA), and prostaglandin (PG) D2 and PGE2 (ELISA) were assayed in the medium. Testicular cells were counted using histology and image analysis. The possible nucl...

Early-Life Glucocorticoid Exposure: The Hypothalamic-Pituitary-Adrenal Axis, Placental Function, and Long-term Disease Risk

Abstract: An adverse early-life environment is associated with long-term disease consequences. Adversity early in life is hypothesized to elicit developmental adaptations that serve to improve fetal and postnatal survival and prepare the organism for a particular range of postnatal environments. These processes, although adaptive in their nature, may later prove to be maladaptive or disadvantageous if the prenatal and postnatal environments are widely discrepant. The exposure of the fetus to elevated levels of either endogenous or synthetic glucocorticoids is one model of early-life adversity that contributes substantially to the propensity of developing disease. Moreover, early-life glucocorticoid exposure has direct clinical relevance because synthetic glucocorticoids are routinely used in the management of women at risk of early preterm birth. In this regard, reports of adverse events in human newborns have raised concerns about the safety of glucocorticoid treatment; synthetic glucocorticoids have detrimental effects on fetal growth and development, childhood cognition, and long-term behavioral outcomes. Experimental evidence supports a link between prenatal exposure to synthetic glucocorticoids and alterations in fetal development and changes in placental function, and many of these alterations appear to be permanent. Because the placenta is the conduit between the maternal and fetal environments, it is likely that placental function plays a key role in mediating effects of fetal glucocorticoid exposure on hypothalamic-pituitary-adrenal axis development and long-term disease risk. Here we review recent insights into how the placenta responds to changes in the intrauterine glucocorticoid environment and discuss possible mechanisms by which the placenta mediates fetal hypothalamic-pituitary-adrenal development, metabolism, cardiovascular function, and reproduction.

Developmental Programming: Gestational Bisphenol-A Treatment Alters Trajectory of Fetal Ovarian Gene Expression

Abstract: Bisphenol-A (BPA), a ubiquitous environmental endocrine disrupting chemical, is a component of polycarbonate plastic and epoxy resins. Because of its estrogenic properties, there is increasing concern relative to risks from exposures during critical periods of early organ differentiation. Prenatal BPA treatment in sheep results in low birth weight, hypergonadotropism, and ovarian cycle disruptions. This study tested the hypothesis that gestational exposure to bisphenol A, at an environmentally relevant dose, induces early perturbations in the ovarian transcriptome (mRNA and microRNA). Pregnant Suffolk ewes were treated with bisphenol A (0.5 mg/kg, sc, daily, produced ∼2.6 ng/mL of unconjugated BPA in umbilical arterial samples of BPA treated fetuses approaching median levels of BPA measured in maternal circulation) from days 30 to 90 of gestation. Expression of steroidogenic enzymes, steroid/gonadotropin receptors, key ovarian regulators, and microRNA biogenesis components were measured by RT-PCR using RNA derived from fetal ovaries collected on gestational days 65 and 90. An age-dependent effect was evident in most steroidogenic enzymes, steroid receptors, and key ovarian regulators. Prenatal BPA increased Cyp19 and 5α-reductase expression in day 65, but not day 90, ovaries. Fetal ovarian microRNA expression was altered by prenatal BPA with 45 down-regulated (>1.5-fold) at day 65 and 11 down-regulated at day 90 of gestation. These included microRNAs targeting Sry-related high-mobility-group box (SOX) family genes, kit ligand, and insulin-related genes. The results of this study demonstrate that exposure to BPA at an environmentally relevant dose alters fetal ovarian steroidogenic gene and microRNA expression of relevance to gonadal differentiation, folliculogenesis, and insulin homeostasis.

The role of maternal-fetal cholesterol transport in early fetal life: Current insights

Abstract: The importance of maternal cholesterol as an exogenous cholesterol source for the growing embryo was first reported in studies of Smith-Lemli-Opitz syndrome. Although most of the fetus's cholesterol is synthesized by the fetus itself, there is now growing evidence that during the first weeks of life, when most organs develop, the fetus largely depends on maternal cholesterol as its cholesterol source. The maternal-fetal cholesterol transport mechanism, by transporters in both the yolk sac and placenta, is becoming better understood. This minireview summarizes current insights on maternal-fetal cholesterol transport based on in vitro and in vivo studies. As the prevalence of maternal diseases, such as diabetes, obesity, and the metabolic syndrome that adversely affect maternal cholesterol levels, is now rapidly reaching epidemic proportions, we urgently need to determine the impact of these maternal conditions on the developing human fetus.

Normal Labor and Delivery

Abstract: LABOR: DEFINITION AND PHYSIOLOGY Labor is defined as the process by which the fetus is expelled from the uterus. More specifically, labor requires regular, effective contractions that lead to dilation and effacement of the cervix. This chapter describes the physiology and normal characteristics of term labor and delivery. The physiology of labor initiation has not been completely elucidated, but the putative mechanisms have been well reviewed by Liao and colleagues. Labor initiation is species-specific, and the mechanisms in human labor are unique. The four phases of labor from quiescence to involution are outlined in Figure 13-1. The first phase is quiescence and represents that time in utero before labor begins when uterine activity is suppressed by the action of progesterone, prostacyclin, relaxin, nitric oxide, parathyroid hormone–related peptide, and possibly other hormones. During the activation phase, estrogen begins to facilitate expression of myometrial receptors for prostaglandins (PGs) and oxytocin, which results in ion channel activation and increased gap junctions. This increase in the gap junctions between myometrial cells facilitates effective contractions. In essence, the activation phase readies the uterus for the subsequent stimulation phase, when uterotonics, particularly PGs and oxytocin, stimulate regular contractions. In the human, this process at term may be protracted, occurring over days to weeks. The final phase, uterine involution, occurs after delivery and is mediated primarily by oxytocin. The first three phases of labor require endocrine, paracrine, and autocrine interaction between the fetus, membranes, placenta, and mother. The fetus has a central role in the initiation of term labor in nonhuman mammals; in humans, the fetal role is not completely understood (Figure 13-2). In sheep, term labor is initiated through activation of the fetal hypothalamicpituitary-adrenal axis, with a resultant increase in fetal adrenocorticotrophic hormone and cortisol. Fetal cortisol increases production of estradiol and decreases production of progesterone by a shift in placental metabolism of cortisol dependent on placental 17α-hydroxylase. The change in the progesterone/estradiol ratio stimulates placental production of oxytocin and PG, particularly PGF2α. If this increase in fetal adrenocorticotrophic hormone and cortisol is blocked, parturition is delayed. In contrast, humans lack placental 17α-hydroxylase and there is no increase in fetal cortisol near term. Rather, in humans, uterine activation may be potentiated in part by increased fetal adrenal production of dehydroepiandrostenedione, which is converted in the placenta to estradiol and estriol. Placental estriol stimulates an increase in maternal (likely decidual) PGF2α, PG receptors, oxytocin receptors, and gap junctions. In humans, there is no documented decrease in progesterone near term and a fall in progesterone is not necessary for labor initiation. However, some research suggests the possibility of a “functional progesterone withdrawal” in humans: Labor is accompanied by a decrease in the concentration of progesterone receptors, as well as a change in the ratio of progesterone receptor isoforms A and B in both the myometrium and membranes. More research is needed to elucidate the precise mechanism through which the human parturition cascade is activated. Fetal maturation may play an important role, as well as maternal Labor: Definition and Physiology 267 Mechanics of Labor 268 Uterine Activity (Powers) 270 The Fetus (Passenger) 270 The Maternal Pelvis (Passage) 272 Cardinal Movements in Labor 275 Engagement 275 Descent 277 Flexion 277 Internal Rotation 277 Extension 277 External Rotation 277 Expulsion 277 Normal Progress of Labor 277 Interventions Affecting Normal Labor Outcomes 279 Active Management of Labor 279 Second Stage of Labor 280 Spontaneous Vaginal Delivery 280 Delivery of the Placenta and Fetal Membranes 281 Episiotomy, Perineal Injury, and Perineal Repair 281

Patterning in placental 11-B hydroxysteroid dehydrogenase methylation according to prenatal socioeconomic adversity.

Abstract: Background Prenatal socioeconomic adversity as an intrauterine exposure is associated with a range of perinatal outcomes although the explanatory mechanisms are not well understood. The development of the fetus can be shaped by the intrauterine environment through alterations in the function of the placenta. In the placenta, the HSD11B2 gene encodes the 11-beta hydroxysteroid dehydrogenase enzyme, which is responsible for the inactivation of maternal cortisol thereby protecting the developing fetus from this exposure. This gene is regulated by DNA methylation, and this methylation and the expression it controls has been shown to be susceptible to a variety of stressors from the maternal environment. The association of prenatal socioeconomic adversity and placental HSD11B2 methylation has not been examined. Following a developmental origins of disease framework, prenatal socioeconomic adversity may alter fetal response to the postnatal environment through functional epigenetic alterations in the placenta. Therefore, we hypothesized that prenatal socioeconomic adversity would be associated with less HSD11B2 methylation. Methods and Findings We examined the association between DNA methylation of the HSD11B2 promoter region in the placenta of 444 healthy term newborn infants and several markers of prenatal socioeconomic adversity: maternal education, poverty, dwelling crowding, tobacco use and cumulative risk. We also examined whether such associations were sex-specific. We found that infants whose mothers experienced the greatest levels of socioeconomic adversity during pregnancy had the lowest extent of placental HSD11B2 methylation, particularly for males. Associations were maintained for maternal education when adjusting for confounders (p<0.05). Conclusions Patterns of HSD11B2 methylation suggest that environmental cues transmitted from the mother during gestation may program the developing fetus’s response to an adverse postnatal environment, potentially via less exposure to cortisol during development. Less methylation of placental HSD11B2 may therefore be adaptive and promote the effective management of stress associated with social adversity in a postnatal environment.

Maternal Plasma Cell-Free Fetal and Maternal DNA at 11-13 Weeks' Gestation: Relation to Fetal and Maternal Characteristics and Pregnancy Outcomes

Abstract: Objective: To examine the possible relationship between maternal and fetal characteristics and pregnancy outcomes on fetal and maternal cell-free (cf) DNA in mate

Gestational diabetes induces chronic hypoxia stress and excessive inflammatory response in murine placenta

Abstract: Metabolic impairments in maternal obesity and gestational diabetes mellitus (GDM) induce an abnormal environment in peripheral blood and cause vascular structure alterations which affect the placental development and function. A GDM model was developed using C57BL/6J female mice fed with high fat food (HF) (40% energy from fat) and a control group with control food (CF) (14% energy from fat) for 14 weeks before mating and throughout the gestation period. A subset of dams was sacrificed at gestational day (GD) 18.5 to evaluate the fetal and placental development. HF-fed dams exhibited significant increase in the maternal weight gain and homeostasis model assessment for insulin resistance index (HOMA-IR), impaired insulin secretion of glucose stimulus and glucose clearance of insulin stimulus before pregnancy; in addition, they also had the increase in the fetal and placental weight. HF-fed dams at GD 18.5 showed the high level of circulating maternal inflammation factors and were associated with increased oxidative stress and hypoxia in the labyrinth, abnormal vascular development with a high level of hypoxia inducible factor-1α (HIF-1α) and VEGF-A expression, but without a parallel increase in CD31 level; were induced an exaggerated inflammatory response in placental vascular endothelial cell. Our findings show that GDM induces more maternal weight gain and fetus weight, with abnormal maternal circulating metabolic and inflammation factors, and forms a placental hypoxia environment and impacts the placental vascular development. Our findings indicate that gestational diabetes induce excessive chronic hypoxia stress and inflammatory response in placentas which may contribute mechanisms to the high risks of perinatal complications of obesity and GDM mothers.

Preeclampsia-Like Symptoms Induced in Mice by Fetoplacental Expression of STOX1 Are Reversed by Aspirin Treatment

Abstract: Preeclampsia (PE) is a common human-specific pregnancy disorder defined by hypertension and proteinuria during gestation and responsible for maternal and fetal morbimortality. STOX1, encoding a transcription factor, was the first gene associated with PE as identified by positional cloning approaches. Its overexpression in choriocarcinoma cells mimics the transcriptional consequences of PE in the human placenta. Here, we created transgenic mouse strains overexpressing human STOX1. Wild-type female mice crossed with transgenic male mice reproduce accurately the symptoms of severe PE: gestational hypertension, proteinuria, and elevated plasma levels of soluble fms-like tyrosine kinase 1 and soluble endoglin. Placental and kidney histology were altered. Symptoms were prevented or alleviated by aspirin treatment. STOX1-overexpressing mice constitute a unique model for studying PE, allow testing therapeutic approaches, and assessing the long-term effects of the preeclamptic syndrome.

Arginine nutrition and fetal brown adipose tissue development in nutrient-restricted sheep

Abstract: Intrauterine growth restriction is a significant problem worldwide, resulting in increased rates of neonatal morbidity and mortality, as well as increased risks for metabolic and cardiovascular disease. The present study investigated the role of maternal undernutrition and l-arginine administration on fetal growth and development. Embryo transfer was utilized to generate genetically similar singleton pregnancies. On Day 35 of gestation, ewes were assigned to receive either 50 or 100% of their nutritional requirements. Ewes received i.v. injections of either saline or l-arginine three times daily from Day 100 to Day 125. Fetal growth was assessed at necropsy on Day 125. Maternal dietary manipulation altered circulating concentrations of leptin, progesterone, and amino acids in maternal plasma. Fetal weight was reduced in nutrient-restricted ewes on Day 125 compared with 100% fed ewes. Compared with saline-treated underfed ewes, maternal l-arginine administration did not affect fetal weight but increased weight of the fetal pancreas by 32% and fetal peri-renal brown adipose tissue mass by 48%. These results indicate that l-arginine administration enhanced fetal pancreatic and brown adipose tissue development. The postnatal effects of increased pancreatic and brown adipose tissue growth warrant further study.

Glucocorticoid Programming of the Fetal Male Hippocampal Epigenome

Abstract: The late-gestation surge in fetal plasma cortisol is critical for maturation of fetal organ systems. As a result, synthetic glucocorticoids (sGCs) are administered to pregnant women at risk of delivering preterm. However, animal studies have shown that fetal exposure to sGC results in increased risk of behavioral, endocrine, and metabolic abnormalities in offspring. Here, we test the hypothesis that prenatal GC exposure resulting from the fetal cortisol surge or after sGC exposure results in promoter-specific epigenetic changes in the hippocampus. Fetal guinea pig hippocampi were collected before (gestational day [GD52]) and after (GD65) the fetal plasma cortisol surge (Term∼GD67) and 24 hours after (GD52) and 14 days after (GD65) two repeat courses of maternal sGC (betamethasone) treatment (n = 3–4/gp). We identified extensive genome-wide alterations in promoter methylation in late fetal development (coincident with the fetal cortisol surge), whereby the majority of the affected promoters exhibited hypom...

Preeclampsia: a link between trophoblast dysregulation and an antiangiogenic state

Abstract: A 24-year-old nulliparous woman developed mildly elevated blood pressure (140–150/90–100 mmHg) without proteinuria (20 mg protein in a 24-hour urine collection) at 306/7 weeks of gestation. The fetus was small for gestational age (estimated fetal weight under the fifth percentile). At 325/7 weeks of gestation, the patient complained of epigastric pain, blood pressure was 180/110 mmHg, proteinuria was documented (780 mg protein in a 24-hour urine collection), schistocytes were detected in the peripheral smear, platelet count was 60,000 cells per mm3, and serum glutamic oxaloacetic transaminase was 234 U/l. The patient was diagnosed with severe preeclampsia/HELLP syndrome. Antenatal steroids were administered to induce fetal lung maturity. She and her family want to know the causes of this condition, what treatment is available, and whether there are any long-term implications of this diagnosis.

Placental DNA methylation alterations associated with maternal tobacco smoking at the RUNX3 gene are also associated with gestational age.

Abstract: Aims: The developmental origins of health and disease hypothesis states that later-life disease may be influenced by the quality of the in utero environment. Environmental toxicants can have detrimental effects on fetal development, potentially through effects on placental development and function. Maternal smoking during pregnancy is associated with low birth weight, preterm birth and other complications, and exposure to cigarette smoke in utero has been linked to gross pathologic and molecular changes to the placenta, including differential DNA methylation in placental tissue. The aim of this study was to investigate the relationship between maternal smoking during pregnancy, methylation changes in the placenta and gestational age. Materials & methods: We used Illumina®’s (CA, USA) Human Methylation27 BeadChip technology platform to investigate the methylation status of 21,551 autosomal, non-SNP-associated CpG loci in DNA extracted from 206 human placentas and examined loci whose variation in methylatio...

Endocrinology of parturition

Abstract: The myometrium must remain relatively quiescent during pregnancy to accommodate growth and development of the feto-placental unit, and then must transform into a highly coordinated, strongly contracting organ at the time of labour for successful expulsion of the new born. The control of timing of labour is complex involving interactions between mother, fetus and the placenta. The timely onset of labour and delivery is an important determinant of perinatal outcome. Both preterm birth (delivery before 37 week of gestation) and post term pregnancy (pregnancy continuing beyond 42 weeks) are both associated with a significant increase in perinatal morbidity and mortality. There are multiple paracrine/autocrine events, fetal hormonal changes and overlapping maternal/fetal control mechanisms for the triggering of parturition in women. Our current article reviews the mechanisms for uterine distension and reduced contractions during pregnancy and the parturition cascade responsible for the timely and spontaneous onset of labour at term. It also discusses the mechanisms of preterm labour and post term pregnancy and the clinical implications thereof.

The Human Placental Sexome Differs between Trophoblast Epithelium and Villous Vessel Endothelium

Abstract: Molecular mechanisms underlying sexual dimorphism in mammals, fetal sex influences on intrauterine development, and the sex-biased susceptibility for selected diseases in adulthood are novel areas of current research. As importantly, two decades of multifaceted research has established that susceptibility to many adult disorders originates in utero, commonly secondary to the effects of placental dysfunction. We hypothesized that fetal sex influences gene expression and produces functional differences in human placentas. We thus extended previous studies on sexual dimorphism in mammals, which used RNA isolated from whole tissues, to investigate the effects of sex on four cell-phenotypes within a single key tissue, human placental villi. The cells studied included cytotrophoblasts, syncytiotrophoblast, arterial and venous endothelial cells. The cells were isolated from placentas of male or female fetuses and subjected to microarray analysis. We found that fetal sex differentially affected gene expression in a cell-phenotype dependent manner among all four cell-phenotypes. The markedly enriched pathways in males were identified to be signaling pathways for graft-versus-host disease as well as the immune and inflammatory systems that parallel the reported poorer outcome of male fetuses. Our study is the first to compare global gene expression by microarray analysis in purified, characterized, somatic cells from a single human tissue, i.e. placental villi. Importantly, our findings demonstrate that there are cell-phenotype specific, and tissue-specific, sex-biased responses in the human placenta, suggesting fetal sex should be considered as an independent variable in gene expression analysis of human placental villi.

Gestational alloimmune liver disease and neonatal hemochromatosis.

Abstract: Neonatal hemochromatosis (NH) is a clinical syndrome consisting of liver disease and pathologic siderosis of various extrahepatic tissues. NH is a form of secondary hemochromatosis in which severe fetal liver injury causes iron overload due to poor regulation of maternofetal iron flux. Gestational alloimmune liver disease (GALD) has been established as the cause of fetal liver injury resulting in nearly all cases of NH. In GALD, sensitization of some women to a fetal liver antigen results in development of specific antifetal liver IgG antibodies. When delivered to the fetal circulation these antibodies bind to the antigen and activate the terminal complement cascade resulting in hepatocyte injury and death. GALD may produce subacute and chronic fetal liver injury (congenital cirrhosis) typical of NH. It may also produce acute injury and acute liver failure of the fetus and newborn, often with no iron overload or siderosis.

Maternal smoking during pregnancy and fetal organ growth: a magnetic resonance imaging study

Abstract: Objective: To study whether maternal cigarette smoking during pregnancy is associated with alterations in the growth of fetal lungs, kidneys, liver, brain, and placenta. Design: A case-control study, with operators performing the image analysis blinded. Setting: Study performed on a research-dedicated magnetic resonance imaging (MRI) scanner (1.5 T) with participants recruited from a large teaching hospital in the United Kingdom. Participants: A total of 26 pregnant women (13 current smokers, 13 non smokers) were recruited; 18 women (10 current smokers, 8 nonsmokers) returned for the second scan later in their pregnancy. Methods: Each fetus was scanned with MRI at 22–27 weeks and 33–38 weeks gestational age (GA). Main outcome measures: Images obtained with MRI were used to measure volumes of the fetal brain, kidneys, lungs, liver and overall fetal size, as well as placental volumes. Results: Exposed fetuses showed lower brain volumes, kidney volumes, and total fetal volumes, with this effect being greater at visit 2 than at visit 1 for brain and kidney volumes, and greater at visit 1 than at visit 2 for total fetal volume. Exposed fetuses also demonstrated lower lung volume and placental volume, and this effect was similar at both visits. No difference was found between the exposed and nonexposed fetuses with regards to liver volume. Conclusion: Magnetic resonance imaging has been used to show that maternal smoking is associated with reduced growth of fetal brain, lung and kidney; this effect persists even when the volumes are corrected for maternal education, gestational age, and fetal sex. As expected, the fetuses exposed to maternal smoking are smaller in size. Similarly, placental volumes are smaller in smoking versus nonsmoking pregnant women.

Circulating MicroRNAs in maternal blood as potential biomarkers for fetal hypoxia in-utero.

Abstract: Stillbirth affects 1 in 200 pregnancies and commonly arises due to a lack of oxygen supply to the fetus. Current tests to detect fetal hypoxia in-utero lack the sensitivity to identify many babies at risk. Emerging evidence suggests that microRNAs derived from the placenta circulate in the maternal blood during pregnancy and may serve as non-invasive biomarkers for pregnancy complications. In this study, we examined the expression of miRs known to be regulated by hypoxia in two clinical settings of significant fetal hypoxia: 1) labour and 2) fetal growth restriction. Six miRs (miR 210, miR 21, miR 424, miR 199a, miR 20b, and miR 373) were differentially expressed in pregnancies complicated by fetal hypoxia. In healthy term pregnancies there was a 4.2 fold increase in miR 210 (p<0.01), 2.7 fold increase in miR 424 (p<0.05), 2.6 fold increase in miR 199a (p<0.01) and 2.3 fold increase in miR 20b (p<0.05) from prior to labour to delivery of the fetus. Furthermore, the combined expression of miR 21 and miR 20b correlated with the degree of fetal hypoxia at birth determined by umbilical cord lactate delivery (r = 0.79, p = 0.03). In pregnancies complicated by severe preterm fetal growth restriction there was upregulation of the hypoxia-regulated miRs compared to gestation-matched controls: 3.6 fold in miR 210 (p<0.01), 3.6 fold in miR 424 (p<0.05), 5.9 fold in miR 21 (p<0.01), 3.8 fold in miR 199a (p<0.01) and 3.7 fold in miR 20b (p<0.01). Interestingly, the expression of miR 373 in gestation matched controls was very low, but was very highly expressed in FGR (p<0.0001). Furthermore, the expression increased in keeping with the degree of in-utero hypoxia estimated by fetal Doppler velocimetry. We conclude quantifying hypoxia-regulated miRs in the maternal blood may identify pregnancies at risk of fetal hypoxia, enabling early intervention to improve perinatal outcomes.

Adaptations of placental and cord blood ABCA1 DNA methylation profile to maternal metabolic status.

Abstract: In utero environmental perturbations have been associated with epigenetic changes in the offspring and a lifelong susceptibility to cardiovascular diseases (CVD). DNA methylation at the ATP-binding cassette transporter A1 (ABCA1) gene was previously associated with CVD, but whether these epigenetic marks respond to changes in the maternal environment is unknown. This study was undertaken to assess the associations between the maternal metabolic profile and ABCA1 DNA methylation levels in placenta and cord blood. Placenta and cord blood samples were obtained at delivery from 100 women including 26 with impaired glucose tolerance (IGT) diagnosed following a 75 g-oral glucose tolerance test (OGTT) between week 24 and 28 of gestation. ABCA1 DNA methylation and mRNA levels were measured using bisulfite pyrosequencing and quantitative real-time PCR, respectively. We report that ABCA1 DNA methylation levels on the maternal side of the placenta are correlated with maternal high density lipoprotein cholesterol (HDL-C) levels (r < –0.21; P < 0.04) and glucose levels 2 h post-OGTT (r = 0.25; P = 0.02). On the fetal side of the placenta, ABCA1 DNA methylation levels are associated with cord blood triglyceride levels (r = –0.28; P = 0.01). ABCA1 DNA methylation variability on both sides of the placenta are also associated with ABCA1 mRNA levels (r < –0.35; P = 0.05). As opposed to placenta, cord blood DNA methylation levels are negatively correlated with maternal glucose 2 h post-OGTT (r = –0.26; P = 0.02). In conclusion, the epivariations observed in placenta and cord blood likely contribute to an optimal materno–fetal cholesterol transfer. These in utero epigenetics adaptations may also potentially trigger the long-term susceptibility of the newborn to dyslipidemia and CVD.

Neutrophil and endothelial adhesive function during human fetal ontogeny

Abstract: Attenuation of the immune response contributes to the high rate of neonatal infections, particularly in premature infants. Whereas our knowledge of innate immune functions in mature neonates is growing, little is known about the ontogeny of neutrophil recruitment. We investigated neutrophils and ECs in the course of gestation with respect to rolling and adhesive functions. With the use of microflow chambers, we demonstrate that the neutrophil's ability to roll and adhere directly correlates with gestational age. These adhesion-related abilities are very rare in extremely premature infants (<30 weeks of gestation), which may correlate with our observation of markedly reduced expression of PSGL-1 and Mac-1 on neutrophils in preterm infants. In parallel, the capacity of HUVECs to mediate neutrophil adhesion under flow increases with gestational age. In addition, HUVECs from extremely premature infants exerting the lowest ability to recruit adult neutrophils show a diminished up-regulation of E-selectin and ICAM-1. Finally, by following neutrophil function postnatally, we show that maturation of PMN recruitment proceeds equivalently during extra- and intrauterine development. Thus, PMN recruitment and EC adhesion-related functions are ontogenetically regulated in the fetus, which might contribute significantly to the high risk of life-threatening infections in premature infants.