The fetal circulation

Perioperative Incidence of Acute Renal Failure in Aortic Arch Reconstruction Using Retrograde Selective Lower Body Perfusion in Neonates and Infants

OBJECTIVE

Examination of the impact of retrograde selective lower body perfusion (SLP) via a femoral arterial catheter on urine output and the incidence of acute kidney injury (AKI) during pediatric aortic arch reconstructions. The secondary objective was if the cannulation of the superficial femoral artery was associated with complications in the perfusion area.

DESIGN

A retrospective study over an 8-year period (January 2015 to December 2023).

SETTING

Pediatric heart center of a tertiary care hospital.

PARTICIPANTS

Neonates and infants (N = 104) undergoing elective aortic arch reconstruction with cardiopulmonary bypass, of whom 45 received retrograde SLP.

INTERVENTIONS

Retrograde SLP via ultrasound-guided, weight-adapted femoral artery catheters for retrograde perfusion during clamping of the descending aorta under surgery, compared to a control group with identical surgical, perfusion, and anesthesiologic management but without SLP.

MEASUREMENTS AND MAIN RESULTS

Perioperative AKI incidence was analyzed using KDIGO criteria at multiple predetermined time points, along with urinary output. The SLP group showed a significantly lower AKI incidence immediately and 6 hours postsurgery (p = 0.001). Higher urine output postoperatively until day 3 (p ≤ 0.045) in the SLP group. No vascular complications were observed until hospital discharge.

CONCLUSIONS

Retrograde SLP is associated with a reduced AKI incidence and increased postoperative urine output, without vascular complications. Further studies are needed to investigate the long-term effects of retrograde SLP on renal function.

Aberrant Subclavian Artery in Interrupted Aortic Arch with Severe Aortic Outlet Obstruction: Cerebral Blood Flow as a Possible Determinant of Embryonic Cardiovascular Development?

Aberrant subclavian artery (ASCA) is frequently observed in interrupted aortic arch (IAA) with aortic/subaortic obstruction. Developmental significance of ASCA in IAA in utero remains elusive. Newborns with prenatally diagnosed isolated IAA under continuous prostaglandin E1 infusion were studied. Cross-sectional areas of aortic valve opening (AVOCSA) and patent ductus arteriosus (PDACSA) were represented by echocardiographic measurement of (diameter)2 indexed by body surface area (m2). Types of IAA and presence of ASCA were examined in relation to sizes of AVOCSA and PDACSA. Twenty-four newborns with IAA (six type A and 18 type B) were reviewed. Male dominance was seen in type B (male 72%). Twenty-three patients had left aortic arch. No type A patients had ASCA, but 50% of type B had ASCA; AVOCSA was significantly smaller in type B than in type A (p = 0.003). In type B, PDACSA was significantly larger in those with ASCA than without (p = 0.003), but AVOCSA exhibited no significant size difference between these two subgroups. Chromosome 22q11 deletion was only seen in type B (56%) and showed no significant correlation with the presence of ASCA. In type B IAA, the presence of ASCA was associated with larger PDACSA, suggesting an adaptive enlargement of the ductus arteriosus and ASCA in response to reduced antegrade flow across small AVOCSA, which may be augmenting cerebral blood flow. Preservation of cerebral blood flow may be another important determinant affecting embryonic cardiovascular development.

A Multiscale Mathematical Model for the Fetal Blood Circulation of the Second Half of Pregnancy

Doppler ultrasound is a commonly used method to assess hemodynamics of the fetal cardiovascular system and to monitor the well-being of the fetus. Indices based on the velocity profile are often used for diagnosis. However, precisely linking these indices to specific underlying physiology factors is challenging. Several influences, including wave reflections, fetal growth, vessel stiffness, and resistance distal to the vessel, contribute to these indices. Understanding these data is essential for making informed clinical decisions. Mathematical models can be used to investigate the relation between velocity profiles and physiological properties. This study presents a mathematical model designed to simulate velocity wave propagation throughout the fetal cardiovascular system, facilitating the assessment of factors influencing velocity-based indices. The model combines a one-fiber model of the heart with a 1D wave propagation model describing the larger vessels of the circulatory system and a lumped parameter model for the microcirculation. Fetal growth from 20 to 40 weeks of gestational age is incorporated by adjusting cardiac and circulatory parameter settings according to scaling laws. The model's results, including cardiac function, cardiac output distribution, and volume distribution, show a good agreement with literature studies for a growing healthy fetus from 20 to 40 weeks. In addition, Doppler indices are simulated in various vessels and agree with literature as well. In conclusion, this study introduces a novel closed-loop 0D-1D mathematical model that has been verified against literature studies. This model offers a valuable platform for analyzing factors influencing velocity-based indices in the fetal cardiovascular system.

Adaptive Growth of the Ductus Arteriosus and Aortic Isthmus in Various Ductus-Dependent Complex Congenital Heart Diseases

BACKGROUND

The ductus arteriosus (DA) is critical in maintaining postnatal circulation in neonates with obstructed systemic circulation (OSC) and pulmonary circulation (OPC). We hypothesized that the size of the DA and aortic isthmus (AoI) undergoes adaptive growth in utero to counteract the hemodynamic challenges in these congenital heart diseases (CHD).

METHODS

Postnatal echocardiograms of neonates diagnosed prenatally with ductal-dependent CHD who were started on prostaglandins within 24 h of birth were reviewed. We assessed the cross-sectional area of the aortic valve opening, pulmonary valve opening, AoI, and DA by calculating (diameter)2/body surface area. Neonates were classified into OSC or OPC then subgrouped depending upon the patency of semilunar valves: OSC with and without aortic atresia (OSC-AA and OSC-nAA, respectively) and OPC with and without pulmonary atresia (OPC-PA and OPC-nPA, respectively).

RESULTS

Ninety-four cases were studied. The DA in OSC was significantly larger than OPC, and the DA in OSC-AA was significantly larger than OSC-nAA. The size of the AoI was significantly larger in OPC than OSC and larger in OSC-AA than OSC-nAA. Within the OSC-nAA group, there was no significant difference in the size of the DA, AoI, or pulmonary valve opening between those with retrograde flow (RF) at the AoI and without (nRF) except the aortic valve opening was significantly larger in nRF. All groups had comparable cross-sectional areas of systemic output.

CONCLUSIONS

Our findings suggest that DA and AoI show compensatory growth to maintain critical blood flow to vital organs against primary anatomical abnormalities in ductus-dependent CHD. (249 words).

Ductus Venosus Agenesis in Monochorionic Twin Pregnancies Complicated by Fetal Growth Restriction: When to Deliver?

Introduction: The prevalence of ductus venosus agenesis (ADV) in singleton pregnancies ranges from 0.04% to 0.15%, while its prevalence in twins remains largely unknown. To our knowledge, in the literature, there is only a single case report of a monochorionic diamniotic (MCDA) pregnancy complicated by ADV. Fetuses with ADV are at increased risk for congenital cardiac disease, heart failure, and fetal growth restriction (FGR). Consequently, these pregnancies have a heightened risk of experiencing an adverse outcome, like stillbirth and neonatal or infant death. Closer antenatal monitoring is warranted when ADV is suspected. Currently, there are no guidelines regarding the standard of care in cases of ADV and no recommendations for the timing of delivery in either singleton or twin pregnancies. Cases: This study aims to provide a comprehensive overview of the management of twin pregnancies complicated by ADV, featuring two cases of MC twins with concurrent sFGR and ADV in one twin. Discussion: These pregnancies experienced completely different outcomes, underscoring the necessity for personalized management tailored to the specific risk factors present in each pregnancy. Typically, in MCDA pregnancies with severe sFGR (type II and III), delivery represents the most reasonable option when venous Doppler abnormalities are identified. However, the absence of the DV complicates the management and the process of decision-making regarding the timing of delivery in cases of sFGR and ADV. We emphasize that effective decision-making should be guided by the presence of additional risk factors, including velamentous insertion, significant estimated fetal weight discordance, and progressive deterioration of the Doppler over time. Conclusions: Our experience suggests that these factors are strongly correlated with poorer outcomes. Given this context, could it be acceptable, in the case of MC pregnancy complicated by severe sFGR and ADV, with worsening findings and additional risk factors (e.g., velamentous insertion, severe birth weight discrepancy), to anticipate the time of delivery starting from 30 weeks of gestational age?

Unveiling the human fetal-maternal interface during the first trimester: biophysical knowledge and gaps

The intricate interplay between the developing placenta and fetal-maternal interactions is critical for pregnancy outcomes. Despite advancements, gaps persist in understanding biomechanics, transport processes, and blood circulation parameters, all of which are crucial for safe pregnancies. Moreover, the complexity of fetal-maternal interactions led to conflicting data and methodological variations. This review presents a comprehensive overview of current knowledge on fetal-maternal interface structures, with a particular focus on the first trimester. More in detail, the embryological development, structural characteristics, and physiological functions of placental chorionic plate and villi, fetal membranes and umbilical cord are discussed. Furthermore, a description of the main structures and features of maternal and fetal fluid dynamic exchanges is provided. However, ethical constraints and technological limitations pose still challenges to studying early placental development directly, which calls for sophisticated in vitro, microfluidic organotypic models for advancing our understanding. For this, knowledge about key in vivo parameters are necessary for their design. In this scenario, the integration of data from later gestational stages and mathematical/computational simulations have proven to be useful tools. Notwithstanding, further research into cellular and molecular mechanisms at the fetal-maternal interface is essential for enhancing prenatal care and improving maternal and fetal health outcomes.

Changes in Internal Cerebral Vein Pulsation and Intraventricular Hemorrhage in Extremely Preterm Infants

OBJECTIVES

This study aimed to investigate the relationship between internal cerebral vein (ICV) pulsation and intraventricular hemorrhage (IVH) and to identify the cut-off values that predict IVH. We hypothesized that the severity of ICV flow pulsations was related to IVH severity.

STUDY DESIGN

In this prospective observational study, ICV flow was measured in 61 extremely preterm infants using ultrasonography at every 12 hours until 96 hours after birth and on days 7, 14, and 28. The ICV pulsation index (ICVPI = minimum/maximum ICV speed) was calculated and compared among the groups determined by Papile's IVH classification. The ICVPI cut-off values for IVH were determined by receiver operating characteristic curve analysis.

RESULTS

Compared with those in the no IVH (NIVH) group (n = 51), the ICVPI median values in the severe IVH (SIVH; grades 3 and 4) group (n = 5) were lower at 25 to 96 hours and on day 7, whereas those in the mild IVH (MIVH; grades 1 and 2) group (n = 5) were lower at 37 to 60 hours. All SIVH events were initially detected within 60 hours after birth. The ICVPI cut-off values for SIVH were 0.92 at 13 to 24 hours, 0.42 at 25 to 36 hours, 0.58 at 37 to 48 hours, and 0.55 at 49 to 60 hours. Infants whose ICVPI values were below the cut-off value ≥3 times between 13 and 60 hours had a significantly higher SIVH incidence than those whose ICVPI values were below the cut-off value ≤2 times (57.1 vs. 1.9%, p < 0.001).

CONCLUSION

Our results indicate that SIVH had sustained pronounced internal cerebral vein pulsations and that the ICVPI values may help predict SIVH. Further research on strategies to decrease venous pressure for IVH prevention is needed.

KEY POINTS

· IVH preterm infants had sustained ICV pulsations.. · ICV flow in SIVH pulsated stronger.. · ICVPI fluctuation implies postnatal adaptation.. · We newly defined ICVPI to predict SIVH..

Ductus Arteriosus in Fetal and Perinatal Life

The ductus arteriosus represents an essential vascular structure connecting the pulmonary artery and the aorta. Over the past decades, there has been substantial advancement in our understanding of both the fundamental and clinical aspects of the ductus arteriosus. In particular, the clarification of the regulatory mechanisms governing ductal patency in critical stages such as the fetal and the perinatal period has enabled optimal management of both physiological and pathological conditions in which the ductus arteriosus plays a crucial role. Furthermore, a more in-depth understanding of the regulatory mechanisms controlling this fundamental structure has facilitated the development of advanced therapeutic strategies and personalized interventions. In the present review, we provide a comprehensive overview of the ductus arteriosus during fetal and perinatal life, encompassing its physiological functions, pathological conditions, and clinical implications. Through this examination, we aim to contribute to a broader understanding of the ductus arteriosus' role in these critical developmental stages and its significance in clinical practice.

A pneumonectomy model to study flow-induced pulmonary hypertension and compensatory lung growth

In newborns, developmental disorders such as congenital diaphragmatic hernia (CDH) and specific types of congenital heart disease (CHD) can lead to defective alveolarization, pulmonary hypoplasia, and pulmonary arterial hypertension (PAH). Therapeutic options for these patients are limited, emphasizing the need for new animal models representative of disease conditions. In most adult mammals, compensatory lung growth (CLG) occurs after pneumonectomy; however, the underlying relationship between CLG and flow-induced pulmonary hypertension (PH) is not fully understood. We propose a murine model that involves the simultaneous removal of the left lung and right caval lobe (extended pneumonectomy), which results in reduced CLG and exacerbated reproducible PH. Extended pneumonectomy in mice is a promising animal model to study the cellular response and molecular mechanisms contributing to flow-induced PH, with the potential to identify new treatments for patients with CDH or PAH-CHD.

Fetal Aortic and Umbilical Doppler Flow Velocity Waveforms in Pregnancy: The Concept of Aortoumbilical Column

Low impedance within the uteroplacental circulation is crucial for fetal development. Flow velocity waveforms (FVW) have been established for the aortic and umbilical arteries in low-risk pregnancies during the second half of pregnancy, but data regarding early gestation is limited. Both vascular territories exhibit higher impedance patterns in pregnancies complicated by fetal growth restriction (FGR), hypertensive disorders, fetal anemia, and chromosomal abnormalities. Early identification of these complications is critical in obstetric practice, to reduce perinatal morbidity and mortality through prevention and close antenatal surveillance. Available data suggest that aortic and umbilical impedances follow the same variation pattern as pregnancy progresses. This observation implies that both vessels may be considered as a single artery, referred to as the "aortoumbilical column". Our hypothesis posits that changes in the hemodynamic pattern of this column could identify high-risk pregnancies, particularly those complicated by preeclampsia, FGR, intrauterine fetal demise, fetal aneuploidies, and fetal anemia. Understanding vascular embryogenesis and the FVWs of the aortic and umbilical arteries enables comprehension of impedance changes throughout normal pregnancies. The continuous variation in impedance along a single vessel supports our concept of the aortoumbilical column. Deviations from the regular pattern could assist in identifying compromised fetuses during early pregnancy. Further research on normal aortoumbilical column FVW and the development of reference charts is necessary to consider this arterial column as a screening tool in clinical practice.

Fetal echocardiography changes of the right ventricle of well-controlled gestational diabetes mellitus

BACKGROUND

There is few evidence of right ventricular (RV) function in fetuses with gestational diabetes mellitus (GDM). Therefore, the aim of this study was to assess the RV function of fetuses using routine and two-dimensional speckle-tracking echocardiography (2D STE) to determine the effects of well-controlled GDM in the third trimester.

METHODS

We used a Philips Epiq7C ultrasound instrument to obtain RV data sets from 63 subjects from July 2019 to February 2022. We compared the free wall thickness (FWT), fractional area change (FAC), Tei index (TEI), tricuspid annular plane systolic excursion (TAPSE) and free wall longitudinal strain(FWLS)of the RV in mothers with well-controlled GDM and normal gestational age-matched fetuses.

RESULTS

63 third trimester fetuses (32 GDM; 31 healthy controls) met the enrolment criteria. Significant differences in fetal RV were detected between the GDM and control groups for the FAC (36.35 ± 6.19 vs. 41.59 ± 9.11; P = 0.008) and the FWLS (-18.28 ± 4.23 vs. -20.98 ± 5.49; P = 0.021). There was a significant difference among the segmental strains of the base, middle and apex of the RV free wall in the healthy controls (P = 0.003), but in the GDM group, there was no statistical difference (p = 0.076). RV FWLS had a strong correlation with FAC (r = 0.467; P = 0.0002).

CONCLUSIONS

In well-controlled GDM, there was measurable fetal RV hypertrophy and significant systolic function decline, indicating the presence of ventricular remodeling and dysfunction. 2D-STE can evaluate the RV free wall contraction in a more comprehensive way.

Recasting Current Knowledge of Human Fetal Circulation: The Importance of Computational Models

Computational hemodynamic simulations are becoming increasingly important for cardiovascular research and clinical practice, yet incorporating numerical simulations of human fetal circulation is relatively underutilized and underdeveloped. The fetus possesses unique vascular shunts to appropriately distribute oxygen and nutrients acquired from the placenta, adding complexity and adaptability to blood flow patterns within the fetal vascular network. Perturbations to fetal circulation compromise fetal growth and trigger the abnormal cardiovascular remodeling that underlies congenital heart defects. Computational modeling can be used to elucidate complex blood flow patterns in the fetal circulatory system for normal versus abnormal development. We present an overview of fetal cardiovascular physiology and its evolution from being investigated with invasive experiments and primitive imaging techniques to advanced imaging (4D MRI and ultrasound) and computational modeling. We introduce the theoretical backgrounds of both lumped-parameter networks and three-dimensional computational fluid dynamic simulations of the cardiovascular system. We subsequently summarize existing modeling studies of human fetal circulation along with their limitations and challenges. Finally, we highlight opportunities for improved fetal circulation models.

Change over time in internal cerebral vein pulsation in premature infants at risk of intraventricular hemorrhage

BACKGROUND

Prolonged continuation of augmented internal cerebral vein (ICV) pulsation may be related to the development of premature intraventricular hemorrhage (IVH). However, the characteristics of ICV flow patterns in premature infants are unclear.

AIM

To investigate the changes over time in ICV pulsation in premature infants at risk of IVH.

STUDY DESIGN

A 5-year retrospective observational study of a single-center trial.

SUBJECTS

In total, 112 very-low-birth-weight infants with gestational age of ≤32 weeks.

OUTCOME MEASURES

ICV flow was measured every 12 h until 96 h after birth and thereafter on days 7, 14, and 28. The ICV pulsation index (ICVPI), which is a ratio of the minimum/maximum speed of ICV flow, was calculated. We recorded longitudinal ICVPI change and compared ICVPI among three groups classified according to gestational age.

RESULTS

ICVPI started declining after day 1 and reached the minimum median value in 49-60 h after birth (1.0 during 0-36 h, 0.9 during 37-72 h, and 1.0 after 73-84 h). ICVPI was significantly lower during 25-96 h than during 0-24 h and on days 7, 14, and 28. ICVPI in the 23-25-week group was significantly lower between 13-24 h and day 14 than that in the 29-32-week group, and the same was observed for the 26-28-week group between 13-24 h and 49-60 h.

CONCLUSIONS

ICV pulsation was affected by time after birth and gestational age, and this ICVPI fluctuation may reflect a postnatal circulatory adaptation.

Umbilical vein blood flow: State-of-the-art

Placental blood supply to the fetus can be measured by evaluating the umbilical vein blood flow. Despite its potential application in healthcare, the umbilical vein blood flow volume is still used only in research setting. One of the reasons is a concern regarding its reproducibility, partly due to technology issues. Nowadays, technology improvements make this evaluation accurate and reproducible. The aim of this review is to refresh basic elements of the physiology of umbilical vein blood flow and its analysis. Its evaluation in normal and abnormal fetal growth is also discussed.

Cardiac remodeling from the fetus to adulthood

Prenatal cardiac remodeling refers to in utero changes in the fetal heart that occur as a response to an adverse intrauterine environment. In this article, we will review the main mechanisms leading to cardiac remodeling and dysfunction, summarizing and describing the major pathological conditions that have been reported to be related to this in utero plastic adaptive process. We will also recap the current evidence regarding the persistence of fetal cardiac remodeling and dysfunction, both in infancy and later in adult life. Moreover, we will discuss primary, secondary, and tertiary preventive measures and future clinical and research aspects.

T2* weighted fetal MRI and the correlation with placental dysfunction

INTRODUCTION

Transverse relaxation time (T2*) is related to tissue oxygenation and morphology. We aimed to describe T2* weighted MRI in selected fetal organs in normal pregnancies, and to investigate the correlation between fetal organ T2* and placental T2*, birthweight (BW) deviation, and redistribution of fetal blood flow.

METHODS

T2*-weighted MRI was performed in 126 singleton pregnancies between 23+6- and 41+3-weeks' gestation. The T2* value was obtained from the placenta and fetal organs (brain, lungs, heart, liver, kidneys, and spleen). In normal BW pregnancies (BW > 10th centile), the correlation between the T2* value and gestational age (GA) at MRI was estimated by linear regression. The correlation between fetal organ Z-score and BW group was demonstrated by boxplots and investigated by analysis of variance (ANOVA) for each organ.

RESULTS

In normal BW pregnancies fetal organ T2* was negatively correlated with GA. We found a significant correlation between BW group and fetal organ T2* z-score in the fetal heart, kidney, lung and spleen. A positive linear correlation was demonstrated between fetal organ T2* and outcomes related to placental function such as BW deviation and placenta T2* in all investigated fetal organs except for the fetal liver. In the fetal heart, kidneys, and spleen the T2* value showed a significant correlation with fetal redistribution of blood flow (Middle cerebral artery Pulsatility Index) before delivery.

DISCUSSION

Fetal T2* is correlated with BW, placental function, and redistribution of fetal blood flow, suggesting that fetal organ T2* reflects fetal oxygenation and morphological changes related to placental dysfunction.

Umbilical cord management strategies for improving outcomes in preterm infants: a network meta‐analysis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To evaluate the efficacy and safety of different umbilical cord management strategies in preterm infants (before 37 weeks’ gestation), and to provide rankings of the available methods according to their effectiveness and safety profile using a network meta‐analysis.

The Incidence of the Agenesis of Fetal Ductus Venosus at the 11-13 Weeks' Ultrasound Examination

OBJECTIVE

The objective is to examine the incidence of agenesis of fetal ductus venosus (DV) at the routine ultrasound examination at 11-13 weeks.

MATERIALS AND METHODS

This is a retrospective study on women presenting for screening for chromosomal abnormalities. The fetal DV was routinely examined by color Doppler in the sagittal view.

RESULTS

Out of 8,304 fetuses examined, there were 13 cases of DV agenesis (0.15%). The umbilical vein drainage was intra-hepatic in two-thirds of the cases, and all resulted in normal live births. In the remaining one-third of cases, the umbilical vein drained to the inferior vena cava and all had a poor outcome because of aneuploidies, cardiac defects, and Noonan syndrome.

CONCLUSION

Fetal DV agenesis occurs in about one in 650 fetuses and the majority of cases have a benign course and a favorable outcome. Failure to identify the DV should prompt a detailed ultrasound examination, identification of the drainage site of the umbilical vein, and genetic testing.

The SOCE Machinery: An Unbalanced Knowledge between Left and Right Ventricular Pathophysiology

Right ventricular failure (RVF) is the most important prognostic factor for morbidity and mortality in pulmonary arterial hypertension (PAH) or pulmonary hypertension (PH) caused by left heart diseases. However, right ventricle (RV) remodeling is understudied and not targeted by specific therapies. This can be partly explained by the lack of basic knowledge of RV remodeling. Since the physiology and hemodynamic function of the RV differ from those of the left ventricle (LV), the mechanisms of LV dysfunction cannot be generalized to that of the RV, albeit a knowledge of these being helpful to understanding RV remodeling and dysfunction. Store-operated Ca²⁺ entry (SOCE) has recently emerged to participate in the LV cardiomyocyte Ca²⁺ homeostasis and as a critical player in Ca²⁺ mishandling in a pathological context. In this paper, we highlight the current knowledge on the SOCE contribution to the LV and RV dysfunctions, as SOCE molecules are present in both compartments. he relative lack of studies on RV dysfunction indicates the necessity of further investigations, a significant challenge over the coming years.

Fetoplacental oxygen homeostasis in pregnancies with maternal diabetes mellitus and obesity

Despite improvements in clinical management, pregnancies complicated by pre-existing diabetes mellitus, gestational diabetes mellitus or obesity carry substantial risks for parent and offspring. Some of the endocrine and metabolic changes in parent and fetus in diabetes mellitus and obesity lead to fetal oxygen deficit, mostly due to insulin-induced accelerated fetal metabolism. The human fetus deals with reduced oxygenation through a wide range of adaptive responses that act at various levels in the placenta as well as the fetus. These responses ensure adequate oxygen delivery to the fetus, increase the oxygen transport capacity of fetal blood and redistribute oxygen-rich blood to vital organs such as the brain and heart. The liver has a central role in adapting to reduced oxygenation by increasing its oxygen extraction and stimulating erythropoietin synthesis to increase haematocrit. The type of adaptive response depends on the onset and duration of hypoxia and the severity of the metabolic disturbance. In pregnancies characterized by diabetes mellitus or obesity, these adaptive systems come under additional strain owing to the increased maternal supply of glucose and resultant fetal hyperinsulinaemia, both of which stimulate oxidative metabolism. In the rare situation that the adaptive responses are overwhelmed, stillbirth can ensue.

Is It Time to Redefine Fetal Decelerations in Cardiotocography?

Historically, fetal heart rate (FHR) decelerations were classified into "early", "late", and "variable" based on their relationship with uterine contractions. So far, three different putative etiologies were taken for granted. Recently, this belief, passed down through generations of birth attendants, has been questioned by physiologists. This narrative review aimed to assess the evidence on pathophysiology behind intrapartum FHR decelerations. This narrative review is based on information sourced from online peer-reviewed articles databases and recommendations from the major scientific societies in the field of obstetrics. Searches were performed in MEDLINE/PubMed, EMBASE, and Scopus and selection criteria included studies in animals and humans, where the physiology behind FHR decelerations was explored. The greater affinity for oxygen of fetal hemoglobin than the maternal, the unicity of fetal circulation, and the high anaerobic reserve of the myocardium, ensure adequate oxygenation to the fetus, under basal conditions. During acute hypoxic stress the efficiency of these mechanisms are increased because of the peripheral chemoreflex. This reflex, activated at each uterine contraction, is characterized by the simultaneous activation of two neural arms: the parasympathetic arm, which reduces the myocardial consumption of oxygen by decreasing the FHR and the sympathetic component, which promotes an intense peripheric vasoconstriction, thus centralizing the fetal blood volume. This review summarizes the evidence supporting the hypoxic origin of FHR decelerations, therefore archiving the historical belief that FHR decelerations have different etiologies, according to their shape and relationship with uterine contractions. The present review suggests that it is time to welcome the new scientific evidence and to update the CTG classification systems.

Impact of the Addition of a Centrifugal Pump in a Preterm Miniature Pig Model of the Artificial Placenta

The recent demonstration of normal development of preterm sheep in an artificial extrauterine environment has renewed interest in artificial placenta (AP) systems as a potential treatment strategy for extremely preterm human infants. However, the feasibility of translating this technology to the human preterm infant remains unknown. Here we report the support of 13 preterm fetal pigs delivered at 102 ± 4 days (d) gestation, weighing 616 ± 139 g with a circuit consisting of an oxygenator and a centrifugal pump, comparing these results with our previously reported pumpless circuit (n = 12; 98 ± 4 days; 743 ± 350 g). The umbilical vessels were cannulated, and fetuses were supported for 46.4 ± 46.8 h using the pumped AP versus 11 ± 13 h on the pumpless AP circuit. Upon initiation of AP support on the pumped system, we observed supraphysiologic circuit flows, tachycardia, and hypertension, while animals maintained on a pumpless AP circuit exhibited subphysiologic flows. On the pumped AP circuit, there was a progressive decline in umbilical vein (UV) flow and oxygen delivery. We conclude that the addition of a centrifugal pump to the AP circuit improves survival of preterm pigs by augmenting UV flow through the reduction of right ventricular afterload. However, we continued to observe the development of heart failure within a matter of days.

Clinical Opinion: The diagnosis and management of suspected fetal growth restriction: an evidence-based approach

This study reviewed the literature about the diagnosis, antepartum surveillance, and time of delivery of fetuses suspected to be small for gestational age or growth restricted. Several guidelines have been issued by major professional organizations, including the International Society of Ultrasound in Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine. The differences in recommendations, in particular about Doppler velocimetry of the ductus venosus and middle cerebral artery, have created confusion among clinicians, and this review has intended to clarify and highlight the available evidence that is pertinent to clinical management. A fetus who is small for gestational age is frequently defined as one with an estimated fetal weight of <10th percentile. This condition has been considered syndromic and has been frequently attributed to fetal growth restriction, a constitutionally small fetus, congenital infections, chromosomal abnormalities, or genetic conditions. Small for gestational age is not synonymous with fetal growth restriction, which is defined by deceleration of fetal growth determined by a change in fetal growth velocity. An abnormal umbilical artery Doppler pulsatility index reflects an increased impedance to flow in the umbilical circulation and is considered to be an indicator of placental disease. The combined finding of an estimated fetal weight of <10th percentile and abnormal umbilical artery Doppler velocimetry has been widely accepted as indicative of fetal growth restriction. Clinical studies have shown that the gestational age at diagnosis can be used to subclassify suspected fetal growth restriction into early and late, depending on whether the condition is diagnosed before or after 32 weeks of gestation. The early type is associated with umbilical artery Doppler abnormalities, whereas the late type is often associated with a low pulsatility index in the middle cerebral artery. A large randomized clinical trial indicated that in the context of early suspected fetal growth restriction, the combination of computerized cardiotocography and fetal ductus venosus Doppler improves outcomes, such that 95% of surviving infants have a normal neurodevelopmental outcome at 2 years of age. A low middle cerebral artery pulsatility index is associated with an adverse perinatal outcome in late fetal growth restriction; however, there is no evidence supporting its use to determine the time of delivery. Nonetheless, an abnormality in middle cerebral artery Doppler could be valuable to increase the surveillance of the fetus at risk. We propose that fetal size, growth rate, uteroplacental Doppler indices, cardiotocography, and maternal conditions (ie, hypertension) according to gestational age are important factors in optimizing the outcome of suspected fetal growth restriction.

Vitamin E and preterm infants

In evaluating vitamin E (VE) nutritional status of preterm infants, it is essential that any data should be compared with those of healthy term infants, and never with those of adults. Moreover, it should be evaluated in terms of gestational age (GA), not birth weight (BW), because placental transfer of most nutrients from mother to fetus is dependent on GA, not BW. Judging from the limited data during the last 75 years, there was no significant correlation between GA and VE concentrations in circulation or in the red blood cells (RBCs), leukocytes, and buccal mucosal cells. In addition, the oxidizability of polyunsaturated fatty acids (PUFAs) in plasma or RBCs, as targets for protection by VE chain-breaking ability, was lower in preterm infants. However, because of the minimal information available about hepatic VE levels, which is considered a key determinant of whole body VE status, the decision on whether VE status of preterm infants is comparable with that of term infants should be postponed. Clinical trials of VE supplementation in preterm infants were repeatedly undertaken to investigate whether VE reduces severity or inhibits development of several diseases specific to preterm infants, namely retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), and germinal matrix hemorrhage - intraventricular hemorrhage (GMH-IVH). Most of these trials resulted in a misfire, with a few exceptions for IVH prevention. However, almost all these studies were performed from 1980s to early 1990s, in the pre-surfactant era, and the study populations were composed of mid-preterm infants with GAs of approximately 30 weeks (wks). There is considerable difference in 'preterm infants' between the pre- and post-surfactant eras; modern neonatal medicine mainly treats preterm infants of 28 wks GA or less. Therefore, these results are difficult to apply in modern neonatal care. Before considering new trials of VE supplementation, we should fully understand modern neonatal medicine, especially the recent method of oxygen supplementation. Additionally, a deeper understanding of recent progress in pathophysiology and therapies for possible target diseases is necessary to decide whether VE administration is still worth re-challenging in modern neonatal intensive care units (NICUs). In this review, we present recent concepts and therapeutic trends in ROP, BPD, and GMH-IVH for those unfamiliar with neonatal medicine. Numerous studies have reported the possible involvement of reactive oxygen species (ROS)-induced damage in relation to supplemental oxygen use, inflammation, and immature antioxidant defense in the development of both BPD and ROP. Various antioxidants effectively prevented the exacerbation of BPD and ROP in animal models. In the future, VE should be re-attempted as a complementary factor in combination with various therapies for BPD, ROP, and GMH-IVH. Because VE is a natural and safe supplement, we are certain that it will attract attention again in preterm medicine.

Retrograde flow in aortic isthmus in normal and fetal heart disease by principal component analysis and computational fluid dynamics

OBJECTIVES

Reverse flow Retrograde flow (RF) of blood in the aortic isthmus can be observed in different types of fetal heart disease (FHD), including abnormalities in heart structure and function. This study sought to investigate the relationship between RF and blood flow parameters, and develop a computational fluid dynamics (CFD) model to understand the mechanisms underlying this observation.

MATERIAL AND METHODS

A total of 281 fetuses (gestational age [GA] 26.6±.3 weeks) with FHD and 2803 normal fetuses (GA: 26.1±.1 weeks) by fetal echocardiography collected from May 2016 to December 2018. Principal component analysis (PCA) was performed to find the relationship and the CFD model reconstructed from 3D/4D spatio-temporal image correlation (STIC) images to simulate hemodynamics.

RESULTS

There was a significant difference in the percentages of RF between the study (80/201 (39%)) and control (29/2803 (1%)) groups (p < 0.05). The RF occur when the aorta flow rate (left heart) is reduced to 60% by CFD stimulation. Pearson correlation analysis showed significant correlations between flow rate and wall shear stress(WSS) (r = .883, p = 0.047) variables at the AI.

CONCLUSION

Volumetric flow rate of AO or left heart was the main component of the cause of RF. The hemodynamics of the cardiovascular system have highly complex behavior hinge on the turbulent nature of circulating blood flow.

Dynamics of skin microvascular blood flow in 4-6-year-old children in association with pre- and postnatal black carbon and particulate air pollution exposure

BACKGROUND

A growing body of evidence indicates that cardiovascular health in adulthood, particularly that of the microcirculation, could find its roots during prenatal development. In this study, we investigated the association between pre- and postnatal air pollution exposure on heat-induced skin hyperemia as a dynamic marker of the microvasculature.

METHODS

In 139 children between the ages of 4 and 6 who are followed longitudinally within the ENVIRONAGE birth cohort, we measured skin perfusion by Laser Doppler probes using the Periflux6000. Residential black carbon (BC), particulate (PM₁₀ and PM_2.5) air pollution, and nitrogen dioxide (NO₂) levels were modelled for each participant's home address using a high-resolution spatiotemporal model for multiple time windows. We assessed the association between skin hyperemia and pre- and postnatal air pollution using multiple regression models while adjusting for relevant covariates.

RESULTS

Residential BC exposure during the whole pregnancy averaged (IQR) 1.42 (1.22-1.58) µg/m³, PM₁₀ 18.88 (16.64 - 21.13) µg/m³, PM_2.5 13.67 (11.5 - 15.56) µg/m³ and NO₂ 18.39 (15.52 - 20.31) µg/m³. An IQR increment in BC exposure during the third trimester of pregnancy was associated with an 11.5 % (95% CI: -20.1 to -1.9; p = 0.020) lower skin hyperemia. Similar effect estimates were retrieved for PM₁₀, PM_2.5 and NO₂ (respectively 13.9 % [95% CI: -21.9 to -3.0; p = 0.003], 17.0 % [95% CI: -26.7 to -6.1; p = 0.004] and 12.7% [95 % CI: -22.2 to -1.9; p = 0.023] lower skin hyperemia). In multipollutant models, PM_2.5 showed the strongest inverse association with skin hyperemia. Postnatal exposure to BC, PM₁₀, PM_2.5 or NO₂, was not associated with skin hyperemia at the age of 4 to 6, and did not alter the previous reported prenatal associations when taken into account.

CONCLUSION

Our findings support that BC, particulate air pollution, and NO₂ exposure, even at low concentrations, during prenatal life, can have long-lasting consequences for the microvasculature. This proposes a role of prenatal air pollution exposures over and beyond postnatal exposure in the microvascular alterations which were persistent into childhood.

Fluctuations in internal cerebral vein and central side veins of preterm infants

BACKGROUND

Studies on the acute management of extremely low birthweight (ELBW) infants reveal a high incidence of intraventricular hemorrhage (IVH) in infants with high-grade internal cerebral vein perfusion waveform fluctuations. In this prospective observational study we investigated the Doppler perfusion waveform fluctuations in the great cerebral vein, straight sinus, and internal cerebral veins of ELBW infants.

METHODS

We evaluated perfusion waveforms after birth every 12 h until 120 h in 73 ELBW infants (<1,000 g) at our hospital. Fluctuations were categorized into four patterns of increasing magnitude, Grades 0-3.

RESULTS

The maximum grades of perfusion waveform fluctuations of the internal cerebral veins were 0, 1, 2, and 3 detected in 12, 38, 13, and 10 infants, respectively; those of the great cerebral vein were 0, 1, 2, and 3 detected in 5, 17, 20, and 31 infants, respectively; and those of the straight sinus were 0, 1, 2, and 3 detected in 1, 5, 17, and 50 infants, respectively. Only one of 803 simultaneous measurements of the Doppler perfusion waveforms showed stronger fluctuations of the peripheral vein than those of the central side veins. Intraventricular hemorrhage was associated with high-grade fluctuations in the internal cerebral veins but not in the great cerebral vein or straight sinus.

CONCLUSIONS

Most infants had high-grade fluctuations in the great cerebral vein and straight sinus, with lower grade fluctuations in the internal cerebral vein, but IVH was not associated with those markers. Intraventricular hemorrhage was correlated with high-grade fluctuations only in the internal cerebral veins.

Peripheral chemoreflex activation and cardiac function during hypoxemia in near-term fetal sheep without placental compromise

A drop in arterial oxygen content activates fetal chemoreflex including an increase in sympathetic activity leading to peripheral vasoconstriction and redistribution of blood flow to protect the brain, myocardium, and adrenal glands. By using a chronically instrumented fetal sheep model with intact placental circulation at near-term gestation, we investigated the relationship between peripheral chemoreflex activation induced by hypoxemia and central hemodynamics. A total of 17 Åland landrace sheep fetuses at 115-128/145 gestational days were instrumented. Carotid artery was catheterized in 10 fetuses and descending aorta in 7 fetuses. After a 4-day recovery, baseline measurements of fetal arterial blood pressures, blood gas values, and fetal cardiovascular hemodynamics by pulsed Doppler ultrasonography were obtained under isoflurane anesthesia. Comparable data to baseline were collected 10 min (acute hypoxemia) and 60 min (prolonged hypoxemia) after maternal hypo-oxygenation to saturation level of 70%-80% was achieved. During prolonged hypoxemia, pH and base excess (BE) were lower and lactate levels were higher in the descending aorta than in the carotid artery. During hypoxemia mean arterial blood pressure (MAP) in the descending aorta increased, whereas in the carotid artery, MAP decreased. In addition, right pulmonary artery pulsatility index values increased, and the diastolic component in the aortic isthmus blood flow velocity waveform became more retrograde, thus decreasing the aortic isthmus antegrade/retrograde blood flow (AoI Net Flow) ratio. Both fetal ventricular cardiac outputs were maintained even during prolonged hypoxemia when significant fetal metabolic acidemia developed. Fetal chemoreflex activation induced by hypoxemia decreased the perfusion pressure in the cerebral circulation. Fetal weight-indexed left ventricular cardiac output (LVCO) or AoI Net Flow ratio did not correlate with a drop in carotid artery blood pressure.NEW & NOTEWORTHY During fetal hypoxemia with intact placental circulation, peripheral chemoreflex was activated, as demonstrated by an increase in the descending aorta blood pressure, pulmonary vasoconstriction, and an increase in retrograde diastolic AoI blood flow, while both ventricular cardiac outputs remained stable. However, perfusion pressure in the cerebral circulation decreased. These changes were seen even during prolonged hypoxemia when significant metabolic acidosis developed. Weight-indexed LVCO or AoI Net Flow ratio did not correlate with a drop in carotid artery blood pressure.

High penetrance of inferior vena cava system atresia in severe thrombophilia caused by homozygous antithrombin Budapest 3 variant: Description of a new syndrome

Atresia of inferior vena cava (IVC) is a rare congenital malformation associated with high risk of venous thrombosis that still has unknown etiology, although intrauterine IVC thrombosis has been suggested to be involved. The identification of IVC atresia in a case with early idiopathic venous thrombosis and antithrombin deficiency caused by the homozygous SERPINC1 c.391C > T variant (p.Leu131Phe; antithrombin Budapest 3) encouraged us to evaluate the role of this severe thrombophilia in this vascular abnormality. We have done a cross-sectional study in previously identified cohorts of patients homozygous for the Budapest 3 variant (N = 61) selected from 1118 patients with congenital antithrombin deficiency identified in two different populations: Spain (N = 692) and Hungary (N = 426). Image analysis included computed tomography and phlebography. Atresia of the IVC system was observed in 17/24 cases (70.8%, 95% confidence interval [CI]: 48.9%-87.3%) homozygous for antithrombin Budapest 3 with available computed tomography (5/8 and 12/16 in the Spanish and Hungarian cohorts, respectively), 16 had an absence of infrarenal IVC and one had atresia of the left common iliac vein. All cases with vascular defects had compensatory mechanisms, azygos-hemiazygos continuation or double IVC, and seven also had other congenital anomalies. Short tandem repeat analysis supported the specific association of the IVC system atresia with SERPINC1. We show the first evidence of the association of a severe thrombophilia with IVC system atresia, supporting the possibility that a thrombosis in the developing fetal vessels is the reason for this anomaly. Our hypothesis-generating results encourage further studies to investigate severe thrombophilic states in patients with atresia of IVC.

Haemodynamic dependence of mechano-genetic evolution of the cardiovascular system in Japanese medaka

The progression of cardiac gene expression-wall shear stress (WSS) interplay is critical to identifying developmental defects during cardiovascular morphogenesis. However, mechano-genetics from the embryonic to larval stages are poorly understood in vertebrates. We quantified peak WSS in the heart and tail vessels of Japanese medaka from 3 days post fertilization (dpf) to 14 dpf using in vivo micro-particle image velocimetry flow measurements, and in parallel analysed the expression of five cardiac genes (fgf8, hoxb6b, bmp4, nkx2.5, smyd1). Here, we report that WSS in the atrioventricular canal (AVC), ventricular outflow tract (OFT), and the caudal vessels in medaka peak with inflection points at 6 dpf and 10-11 dpf instead of a monotonic trend. Retrograde flows are captured at the AVC and OFT of the medaka heart for the first time. In addition, all genes were upregulated at 3 dpf and 7 dpf, indicating a possible correlation between the two, with the cardiac gene upregulation preceding WSS increase in order to facilitate cardiac wall remodelling.

The correlation between patent foramen ovale and brain ischemia in plateau residents

Background

It has been suggested that patent foramen ovale (PFO) contributes to the majority of cryptogenic stroke cases in young people, however, the direct link is still undetermined. Here we analyzed the correlation between PFO and brain ischemia lesions in a cohort of cases that were long-term residents in the plateau to provide solid evidence to support the causal relation between PFO and brain ischemia lesion or cryptogenic stroke.

Methods

Long-term residents with young age from Qinghai Plateau were recruited and separated by PFO positivity. Brain MRI was used to image 100 PFO positive cases and 100 healthy controls. The diameter of PFO was measured by echocardiography. The location, number and anterior/posterior circulation of ischemia lesions were also evaluated. The correlation between PFO (including positivity and diameter) and brain ischemia lesion (including positivity and other characteristics) was analyzed by chi-square test. Further, the chi-square test for the trend test was used to analyze the linear correlation between these groups.

Results

We found a strong correlation between the positivity of PFO and brain ischemia lesion, with 71% of PFO cases showing the presence of brain ischemia lesions, and only 19% for healthy controls (p < 0.001). The diameter of PFO is strongly and linearly correlated with the incidence rate of brain ischemia lesion (RR = 3.737 (95%CI 2.496 to 5.767).

Conclusion

We found a convincing correlation between the positivity of PFO and brain ischemia lesion in residents of the plateau. Our findings provide another solid evidence of the direct causal relation between PFO and brain ischemia lesion.

Ethanol's disruptive effects upon early breathing plasticity and blood parameters associated with hypoxia and hypercapnia

Early ethanol exposure affects respiratory neuroplasticity; a risk factor associated with the Sudden Infant Death Syndrome. High and chronic ethanol doses exert long-lasting effects upon respiratory rates, apneic episodes and ventilatory processes triggered by hypoxia. The present study was performed in 3-9-day-old rat pups. Respiratory processes under normoxic and hypoxic conditions were analyzed in pups intoxicated with different ethanol doses which were pre-exposed or not to the drug. A second major goal was to examine if acute and/or chronic early ethanol exposure affects blood parameters related with hypercapnic or hypoxic states. In Experiment 1, at postnatal day 9, animals previously treated with ethanol (2.0 g/kg) or vehicle (0.0 g/kg) were tested sober or intoxicated with 0.75, 1.37 or 2.00 g/kg ethanol. The test involved sequential air conditions defined as initial normoxia, hypoxia and recovery normoxia. Motor activity was also evaluated. In Experiment 2, blood parameters indicative of possible hypoxic and hypercapnic states were assessed as a function of early chronic or acute experiences with the drug. The main results of Experiment 1 were as follows: i) ethanol's depressant effects upon respiratory rates increased as a function of sequential treatment with the drug (sensitization); ii) ethanol inhibited apneic episodes even when employing the lowest dose at test (0.75 g/kg); iii) the hyperventilatory response caused by hypoxia negatively correlated with the ethanol dose administered at test; iv) ventilatory long-term facilitation (LTF) during recovery normoxia was observed in pups pre-exposed to the drug and in pups that received the different ethanol doses at test; v) self-grooming increased in pups treated with either 1.37 or 2.00 g/kg ethanol. The main result of Experiment 2 indicated that acute as well as chronic ethanol exposure results in acidosis-hypercapnia. The results indicate that early and brief experiences with ethanol are sufficient to affect different respiratory plasticity processes as well as blood biomarkers indicative of acidosis-hypercapnia. An association between the LTF process and the acidosis-hypercapnic state caused by ethanol seems to exist. The mentioned experiences with the drug are sufficient to result in an anomalous programming of respiratory patterns and metabolic conditions.

Comparative Anatomical Studies on Ductus Venosus in Fetuses of Domestic Ruminants

The study has aimed to investigate and determine the anatomical position, shape, size, and histological features of the ductus venosus, and its role as a shunt in the fetal circulatory system in domestic ruminants. The research was conducted on 19 bovine, 11 sheep and 5 goat fetuses, aborted at the late stage of pregnancy or deceased just after delivery. The general anatomy of the ductus venosus was investigated by in-situ dissection of the corrosive cast obtained by injection of 25% solution of Vinylite mass through the umbilical vein. For histological examination, the fetal tissue samples were stained with Hematoxylin and Eosin, Masson’s trichrome, Verhoeff-Van Gieson and Gomoriꞌs silver stain. The results showed that ruminant fetal ductus venosus is a curved, trumpet-shaped vessel, situated in the central part of the liver, above the porta hepatis. Its ventral part is constricted in the form of an isthmus, having a prominent lip-like thickening at the junction with the portal sinus. Histological examination showed the dominant presence of collagen and elastic fibers in its tunica media, with thin bands of smooth muscle fibers oriented in a longitudinal and circular direction indicating ability for vasoconstriction and vasodilatation.

Achieving sustained extrauterine life: Challenges of an artificial placenta in fetal pigs as a model of the preterm human fetus

Artificial placenta (AP) technology aims to maintain fetal circulation, while promoting the physiologic development of organs. Recent reports of experiments performed in sheep indicate the intrauterine environment can be recreated through the cannulation of umbilical vessels, replacement of the placenta with a low-resistance membrane oxygenator, and incubation of the fetus in fluid. However, it remains to be seen whether animal fetuses similar in size to the extremely preterm human infant that have been proposed as a potential target for this technology can be supported in this way. Preterm Yucatan miniature piglets are similar in size to extremely preterm human infants and share similar umbilical cord anatomy, raising the possibility to serve as a good model to investigate the AP. To characterize fetal cardiovascular physiology, the carotid artery (n = 24) was cannulated in utero and umbilical vein (UV) and umbilical artery were sampled. Fetal UV flow was measured by MRI (n = 16). Piglets were delivered at 98 ± 4 days gestation (term = 115 days), cannulated, and supported on the AP (n = 12) for 684 ± 228 min (range 195-3077 min). UV flow was subphysiologic (p = .002), while heart rate was elevated on the AP compared with in utero controls (p = .0007). We observed an inverse relationship between heart rate and UV flow (r2  = .4527; p < .001) with progressive right ventricular enlargement that was associated with reduced contractility and ultimately hydrops and circulatory collapse. We attribute this to excessive afterload imposed by supraphysiologic circuit resistance and augmented sympathetic activity. We conclude that short-term support of the preterm piglet on the AP is feasible, although we have not been able to attain normal fetal physiology. In the future, we propose to investigate the feasibility of an AP circuit that incorporates a centrifugal pump in our miniature pig model.

The impact of probiotics on gut health via alternation of immune status of monogastric animals

The intestinal immune system is affected by various factors during its development, such as maternal antibodies, host genes, intestinal microbial composition and activity, and various stresses (such as weaning stress). Intestinal microbes may have an important impact on the development of the host immune system. Appropriate interventions such as probiotics may have a positive effect on intestinal immunity by regulating the composition and activity of intestinal microbes. Moreover, probiotics participate in the regulation of host health in many ways; for instance, by improving digestion and the absorption of nutrients, immune response, increasing the content of intestinal-beneficial microorganisms, and inhibiting intestinal-pathogenic bacteria, and they participate in regulating intestinal diseases in various ways. Probiotics are widely used as additives in livestock and the poultry industry and bring health benefits to hosts by improving intestinal microbes and growth performance, which provides more choices for promoting strong and efficient productivity.

Lack of evidence for impaired preload or Bezold-Jarisch activation during brief umbilical cord occlusions in fetal sheep

Impaired cardiac preload secondary to umbilical cord occlusion (UCO) has been hypothesized to contribute to intrapartum decelerations, brief falls in fetal heart rate (FHR), through activation of the Bezold-Jarisch reflex. This cardioprotective reflex increases parasympathetic and inhibits sympathetic outflows triggering hypotension, bradycardia, and peripheral vasodilation, but its potential to contribute to intrapartum decelerations has never been systematically examined. In this study, we performed bilateral cervical vagotomy to remove the afferent arm and the efferent parasympathetic arm of the Bezold-Jarisch reflex. Twenty-two chronically instrumented fetal sheep at 0.85 of gestation received vagotomy (n = 7) or sham vagotomy (control, n = 15), followed by three 1-min complete UCOs separated by 4-min reperfusion periods. UCOs in control fetuses were associated with a rapid fall in FHR and reduced femoral blood flow mediated by intense femoral vasoconstriction, leading to hypertension. Vagotomy abolished the rapid fall in FHR (P < 0.001) and, despite reduced diastolic filling time, increased both carotid (P < 0.001) and femoral (P < 0.05) blood flow during UCOs, secondary to carotid vasodilation (P < 0.01) and delayed femoral vasoconstriction (P < 0.05). Finally, vagotomy was associated with an attenuated rise in cortical impedance during UCOs (P < 0.05), consistent with improved cerebral substrate supply. In conclusion, increased carotid and femoral blood flows after vagotomy are consistent with increased left and right ventricular output, which is incompatible with the hypothesis that labor-like UCOs impair ventricular filling. Overall, the cardiovascular responses to vagotomy do not support the hypothesis that the Bezold-Jarisch reflex is activated by UCO. The Bezold-Jarisch reflex is therefore mechanistically unable to contribute to intrapartum decelerations.

Embryological development of the human cranio-facial arterial system: a pictorial review

The embryological development of the cerebral vasculature is very complex. Historical and also more recent studies based on human embryos, comparative anatomy and cerebral angiographies allowed us to better understand this vasculature development. The knowledge and understanding of such embryological development are important for physicians interested in neurovascular pathologies. Indeed, all vascular variants and almost all vascular pathologies, such as aneurysms, dolichoectasia, atherosclerosis, and neurovascular conflicts could be explained by an alteration during the embryological life. There are also many variants of these vascular structures present in normal developed adults, which are variably associated with pathological entities. Understanding the process which leads to the development of the normal cerebral arterial system in humans is, therefore, very important to have a better knowledge of the possible clinical and surgical implications of these anomalies. In this paper, we review the embryological development of the cranio-facial arterial vasculature from its beginning at approximately days 21–50 of intrauterine life, with pictures illustrating each developmental phase.

The assessment of the fetal heart function using two-dimensional speckle tracking with a high frame rate

BACKGROUND

Two-dimensional (2D) speckle tracking echography (STE) is a new diagnostic modality that allows for the assessment of myocardial deformation. The present study assessed the feasibility of fetal 2D-STE at a high frame rate and determined the reference values for left ventricular (LV)- and right ventricular (RV)- global longitudinal strain (GLS).

METHODS

In this prospective study, 109 fetuses with gestational ages ranging from 18 to 38 weeks underwent 2D echocardiography between August 2018 and December 2019. All recordings were performed using the Aplio i800 (CANON Medical Systems Corporation, Tochigi, Japan) and a convex probe (4 MHz) for fetuses.

RESULTS

Longitudinal peak systolic strain measurements were obtained in 98 of 109 healthy fetuses (90%). All ultrasound videos were recorded with a median frame rate of 172 (range, 100-274) frames/s. The LV-GLS was almost constant, regardless of the number of weeks since the second trimester (r = -0.0087, p = ns). The RV-GLS decreased significantly with gestational age (r = 0.39, p < 0.01).

CONCLUSIONS

STE may be useful for quantifying the systolic myocardial function in a fetus.

Reversal of blood flow in deep cerebral vein in preterm intraventricular hemorrhage: two case reports

BACKGROUND

Intraventricular hemorrhage during the early stage is a major complication in very low birth weight infants. Elevation of venous pressure is one of the contributing factors. The internal cerebral vein receives most of the venous flow from the subependymal germinal matrix, the most common site of origin of intraventricular hemorrhage. Recently, it has been reported that pulsatile or partially interrupted internal cerebral vein waveforms might also be risk factors for intraventricular hemorrhage in extremely low birth weight infants. Here, we report two cases of partially reversed internal cerebral vein flow with intraventricular hemorrhage. There are no published reports documenting this unique flow pattern.

CASE PRESENTATION

Between 2013 and 2020, we had in our neonatal intensive care unit two cases of very low birth weight infants (27 and 25 weeks of gestational age) who showed a partially reversed internal cerebral vein waveform pattern, which was recognized as a new blood flow pattern. Their internal cerebral vein flow patterns were continuously flat early after birth. They showed an intraventricular hemorrhage on the unilateral side with partially interrupted internal cerebral vein flow at 31 and 41 hours after birth (27- and 25-week-old neonates, respectively). Consecutively, their internal cerebral vein flow changed to a partially reversed pattern with intraventricular hemorrhage on the contralateral side at 43 and 87 hours after birth (27- and 25-week-old neonates, respectively). Their flow patterns improved by day 7. These partially reversed patterns were equivalent to triphasic venous flow, and the reverse flow corresponded to A- and V-waves.

CONCLUSION

In the two cases, the internal cerebral vein flow patterns were normal and flat before intraventricular hemorrhage and changed to a severe flow pattern (partially interrupted or reversed flow) at the same time as the detection of intraventricular hemorrhage. After the development of intraventricular hemorrhage, they improved. These cases indicate that a partially reversed or interrupted internal cerebral vein flow pattern may be derived from central venous pressure elevation and related to intraventricular hemorrhage in very low birth weight infants, however, it is difficult to determine when this flow pattern occurs in relation to intraventricular hemorrhage.

Fetal whole heart blood flow imaging using 4D cine MRI

Prenatal detection of congenital heart disease facilitates the opportunity for potentially life-saving care immediately after the baby is born. Echocardiography is routinely used for screening of morphological malformations, but functional measurements of blood flow are scarcely used in fetal echocardiography due to technical assumptions and issues of reliability. Magnetic resonance imaging (MRI) is readily used for quantification of abnormal blood flow in adult hearts, however, existing in utero approaches are compromised by spontaneous fetal motion. Here, we present and validate a novel method of MRI velocity-encoding combined with a motion-robust reconstruction framework for four-dimensional visualization and quantification of blood flow in the human fetal heart and major vessels. We demonstrate simultaneous 4D visualization of the anatomy and circulation, which we use to quantify flow rates through various major vessels. The framework introduced here could enable new clinical opportunities for assessment of the fetal cardiovascular system in both health and disease.

Fetal cardiovascular hemodynamics in type 1 diabetic pregnancies at near-term gestation

INTRODUCTION

Poor glycemic control in maternal type 1 diabetes mellitus during pregnancy can affect fetal cardiac and placental function. However, studies concerning fetal central hemodynamics have revealed conflicting results. We hypothesized that in pregnancies complicated by maternal type 1 diabetes, fetal cardiovascular and placental hemodynamics are comparable to the control fetuses at near-term gestation. In addition, we investigated the relation between newborn serum biomarkers of cardiac function and fetal cardiovascular and placental hemodynamics. Furthermore, we studied whether maternal diabetes is associated with placental inflammation.

MATERIAL AND METHODS

In this prospective case-control study, fetal central and peripheral hemodynamics were assessed by ultrasonography in 33 women with type 1 diabetes and in 67 controls with singleton pregnancies between 34⁺² and 40⁺² gestational weeks. Newborn umbilical cord serum was collected to analyze cardiac natriuretic peptides (atrial and B-type natriuretic peptides) and troponin T concentrations. Placental tissue samples were obtained for cytokine analyses.

RESULTS

Fetal ventricular wall thicknesses were greater and weight-adjusted stroke volumes and cardiac outputs were lower in the type 1 diabetes group than in the control group. Pulsatility in the aortic isthmus and inferior vena cava blood flow velocity waveforms was greater in the type 1 diabetes group fetuses than in the controls. A positive correlation was found between branch pulmonary artery and aortic isthmus pulsatility index values. Umbilical artery pulsatility indices were comparable between the groups. Umbilical cord serum natriuretic peptide and troponin T concentrations were elevated in the type 1 diabetes fetuses. These cardiac biomarkers correlated significantly with cardiovascular hemodynamics. Placental cytokine levels were not different between the groups.

CONCLUSIONS

In maternal type 1 diabetes pregnancies, fetal cardiovascular hemodynamics is impaired. Maternal type 1 diabetes does not seem to alter placental vascular impedance or induce placental inflammation.

Artificial placenta and womb technology: Past, current, and future challenges towards clinical translation

Extreme prematurity remains a major cause of neonatal mortality and severe long-term morbidity. Current neonatal care is associated with significant morbidity due to iatrogenic injury and developmental immaturity of extreme premature infants. A more physiologic approach, replacing placental function and providing a womb-like environment, is the foundational principle of artificial placenta (AP) and womb (AW) technology. The concept has been studied during the past 60 years with limited success. However, recent technological advancements and a greater emphasis on mimicking utero-placental physiology have improved the success of experimental models, bringing the technology closer to clinical translation. Here, we review the rationale for and history of AP and AW technology, discuss the challenges that needed to be overcome, and compare recent successful models. We conclude by outlining some remaining challenges to be addressed on the path towards clinical translation and opportunities for future research.

Role of ductus venosus agenesis in right ventricle development

Ductus venosus agenesis (DVA) results from portal-umbilical and hepatic-systemic venous system connection failure. Despite a large series of DVA was reported, an accurate description of single fetus cardiac trend with hemodynamic consequences is missing. We describe two fetuses with DVA early detection, comparing right ventricle (RV) development in extrahepatic and intrahepatic drainages. In extrahepatic drainage, the RV was larger and slightly hypertrophic. In intrahepatic drainage, the RV showed reduced dimensions. Ventricle dimension differences decreased and became balanced in perinatal period. Detection of non-balanced ventricles in early second trimester should lead to sonographic follow-up. If DVA is hypothesized, it is important to identify other subdiaphragmatic connections that could alter cardiac preload and ventricle development.

Perception of general pediatricians in Riyadh towards vaccination of patients with congenital heart diseases

Background:

Congenital heart defected (CHD) children are often predisposed to numerous conditions ranging from arrythmias, infections, to heart failure. Proper implementation of vaccination plan and multidisciplinary acts are mandatory for maintaining such cases to reduce the mortality and morbidity. Furthermore, CHD are also at risk of vaccine adverse reaction and several blooddisseminated pathogens infections, and at risk of death if such events where to occur. Perception and Interpretation of the knowledge and experience of general pediatricians towards vaccination of patients with congenital heart diseases is a crucial element to understand, and to improve healthcare practice in Riyadh, Saudi Arabia.

Aims:

To clarify, our aim is to investigate views of different pediatricians in vaccination plans, to perceive junior and senior pediatricians, and to identify extra vaccines given to children with a congenital heart defect.

Settings and Design:

This study is a cross-sectional study that includes the distribution of 246 questionnaires through personal interview focusing on pediatric cardiologists and general pediatricians with varying years of practice and degrees. Study was conducted by six medical interns: Mohammed O. Alfakhri, Meshal F. Alhajji, Abdulrahman M. Alyani, Yahya Z. Murad, Abdulrahman E. Alghannam, Alwaleed H. Algahtani, in six different teritiary hospitals, King Abdulaziz Medical City (KAMC), King Fahad Medical City (KFMC), King Faisal Specialist Hospital (KFSH), King Salman Hospital, and Alyamamah Hospital, in Riyadh, Saudi Arabia.

Methods and Material:

Data was collected through a convenient sampling technique and was analyzed using SPSS (version 20) and rearranged to observe the most frequent information obtained from the questionnaire.

Statistical Analysis Used:

Categorical study was described in frequencies and bar charts. Chi-Square test of significance was used after the data entry to assess the significance of the values obtained.

Results and Conclusions:

There was no significant difference between the six hospitals. In the following study, 81.7% of the participants believe that patients with congenital heart diseases are combined immunodeficient, and 84.6% agreed on giving special\extra vaccine with no preference over live and\or killed vaccine. On top of that, participants believe that the extra vaccines given to congenital heart disease patients with combined immunodeficiency are meningococcal and pneumococcal vaccines, and the special vaccine given to them are respiratory syncytial virus (RSV) and influenza vaccine. To conclude, congenitally heart defected children are widespread worldwide. Children suffering from the disease are having a serious problem that affects their lives from its earliest. For that, our research mainly focuses on improving their lives by trying to reduce the effect of several other preventable diseases using vaccines as and when they need. Several other studies believed in giving extra/special vaccines that vary depending on the location of the study. However, in Riyadh, we found that most pediatricians agree on giving extra vaccines as meningococcal and pneumococcal, and RSV and influenza as special vaccines to children with congenital heart defects.

Atrial and Ventricular Deformation Analysis in Normal Fetal Hearts Using Two-Dimensional Speckle Tracking Echocardiography

OBJECTIVE

Two-dimensional speckle tracking echocardiography (2D-STE)-based strain values of the left and the right ventricle have been established; however, less is known about atrial deformation. The aim of our study was to assess both atrial strain and ventricular strain using 2D-STE in a cardiac 4-chamber view and to investigate the effect of possible influencing factors such as gestational age.

METHODS

Fetal echocardiography was performed on a Toshiba Aplio 500 ultrasound system. Based on an apical or basal 4-chamber view of the fetal heart, left and right ventricular longitudinal peak systolic strain (LVLPSS and RVLPSS) as well as left and right atrial longitudinal peak systolic strain (LALPSS and RALPSS) were assessed by 2D-STE.

RESULTS

A total of 101 healthy fetuses were included. The mean gestational age (GA) was 26.0 ± 5.6 weeks. GA was significantly positively correlated (p < 0.05) with LVLPSS and RVLPSS and significantly negatively correlated (p < 0.05) with LALPSS and RALPSS. The mean values for LVLPSS and RVLPSS were -17.44 ± 2.29% and -16.89 ± 1.72%. The mean values for LALPSS and RALPSS were 34.09 ± 4.17% and 35.36 ± 2.90%.

CONCLUSION

Ventricular and atrial deformation analysis in 2D-STE was technically feasible and showed comparable values to current data. For future research on myocardial function (MF) of the fetus, considering GA as an influencing factor for deformation analysis seems to be adequate. Especially, atrial deformation analysis allows the assessment of diastolic myocardial function. Further research needs to clarify the clinical meaning of these myocardial deformation indices in fetuses at risk.

Intrahepatic persistent fetal right umbilical vein: a retrospective study

Introduction: To appraise the incidence and value of intrahepatic persistent right umbilical vein (PRUV).Methods: This was a single-center study. Records of all women with a prenatal diagnosis of intrahepatic PRUV were reviewed. The inclusion criteria were women with gestational age greater than 13 weeks of gestation. Exclusion criteria were fetuses with situs abnormalities, due to the hepatic venous ambiguity, and extrahepatic PRUV. The primary outcome was the incidence of intrahepatic PRUV in our cohort. The secondary outcomes were associated malformations.Results: 219/57,079 cases (0.38%) of intrahepatic PRUV were recorded. The mean gestational age at diagnosis was 21.8 ± 2.9 weeks of gestations. PRUV was isolated in the 76.7%, while in 23.3% was associated with other major or minor abnormalities. The most common associated abnormalities were cardiovascular abnormalities (8.7%), followed by genitourinary abnormalities (6.4%), skeletal abnormalities (4.6%), and central nervous system abnormalities (4.1%). Within the cardiovascular abnormalities, the most common one was ventricular septal defect (six cases).Conclusion: In most cases PRUV is an isolated finding. Associated minor or major malformations are presented in the 23.3% of the cases, so this finding should prompt detailed prenatal assessment of the fetus, with particular regard to cardiovascular system.

Delivery room emergencies in critical congenital heart diseases

Transition from fetal to postnatal life is a complex process. Even in the absence of congenital heart disease, about 4-10% of newborns require some form of assistance in the delivery room. Neonates with complex congenital heart disease should be expected to require significant intervention and thus the resuscitation team must be well prepared for such a delivery. Prenatal assessment including fetal and maternal health in general and detailed information on fetal heart structure, function and hemodynamics in particular are crucial for planning the delivery and resuscitation. In addition, understanding the impact of cardiac structural anomaly and associated altered blood flow on early postnatal transition is essential for success of resuscitation in the delivery room. In this article, we will briefly review transitional circulation focusing on altered hemodynamics of the complex congenital heart diseases and then discuss the process of preparing for these high-risk deliveries. Finally, we will review the pathophysiology resulting from the cardiac structural anomaly with resultant altered fetal circulation and discuss delivery room management of specific critical congenital heart diseases.

Noninvasive determination of the fetal cardiac interatrial pressure gradients by Doppler ultrasonography: preliminary results

Objective: In 2000, Johnson et al. measured the atrial pressures puncturing the atria invasively in 19 fetuses that will be terminated. In this study, it is aimed to define the fetal cardiac interatrial pressure gradient noninvasively. The pressure gradients were calculated using the ductus venosus (DV) and pulmonary vein (PV) blood flow velocities and Bernoulli equation for flowing fluids.Methods: "S," "a," and the time-averaged maximum velocities in both veins of 246 fetuses were used in the simplified Bernoulli equation; Δp=4 ([Formula: see text]). Additionally, the umbilical vein maximum velocity is measured in order to calculate ducto-umbilical pressure gradient.Results: The average interatrial pressure gradient was biggest in the ventricular systole and the least gradient was in the atrial systole of a cardiac cycle. The pressure gradient changes throughout the second and the third trimester have four periods with two increases and two decreases.Conclusions: The interatrial and ducto-umbilical pressure gradients can be measured noninvasively in order to follow the hemodynamic of the fetal circulatory system.