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Background: We aimed to conduct a systematic review and meta-analysis to evaluate the fetoscopic tracheal occlusion in patients with isolated severe and left-sided diaphragmatic hernia. Methods: Cochrane Library, Embase, and PubMed (Medline) databases were searched from inception to February 2024 with no filters or language restrictions. We included studies evaluating the outcomes of fetoscopic intervention compared to expectant management among patients with severe congenital diaphragmatic hernia exclusively on the left side. A random-effects pairwise meta-analysis was performed using RStudio version 4.3.1. Results: In this study, we included 540 patients from three randomized trials and five cohorts. We found an increased likelihood of neonatal survival associated with fetoscopic tracheal occlusion (Odds Ratio, 5.07; 95% Confidence Intervals, 1.91 to 13.44; p < 0.01) across general and subgroup analyses. Nevertheless, there were higher rates of preterm birth (OR, 5.62; 95% CI, 3.47–9.11; p < 0.01) and preterm premature rupture of membranes (OR, 7.13; 95% CI, 3.76–13.54; p < 0.01) in fetal endoscopic tracheal occlusion group compared to the expectant management. Conclusions: Our systematic review and meta-analysis demonstrated the benefit of fetoscopic tracheal occlusion in improving neonatal and six-month postnatal survival in fetuses with severe left-sided CDH. Further studies are still necessary to evaluate the efficacy of tracheal occlusion for isolated right-sided CDH, as well as the optimal timing to perform the intervention. [ABSTRACT FROM AUTHOR]

Abstract Background Neonatal respiratory distress syndrome (RDS) is a leading cause of neonatal respiratory failure and neonatal mortality. It is frequent in preterm infants, because deficient surfactant needed to keep the airways (alveoli) open to assist infants breathe after birth. Nonetheless, it was also seen in full-term pregnancies. Noninvasive approaches for predicting the development of neonatal respiratory distress (RD) in preterm newborns include comparing the prenatal clinical outcome with the pulmonary artery resistance index (PA-RI) and fetal lung capacity as assessed by the virtual organ computer-aided analysis (VOCAL). Our study aimed to estimate optimal cutoff values and compare measurements of fetal pulmonary artery resistance index (PA-RI) and fetal lung volume (LV) assessed by VOCAL as noninvasive measures to predict neonatal RD development in preterm pregnancies to show which is more accurate. Results Out of the examined 147 women who delivered 147 living newborns, 59 of newborn (40.1%) developed neonatal RD. PA-RI has a higher value in 45 (76.27%), while fetal lung volume (FLV) was significantly lower in 43 (72.88%) of neonates who developed RD. Combining both measurements of PA-RI and FLV could predict all cases of RDS 59 (100%). Thirty of RDS neonates had mechanical ventilation and died (50.85%). Cutoff values of PA-RI ≥ 0.75 with 76.27% sensitivity, 82.95% specificity and 81.5% accuracy, whereas a cutoff of FLV ≤ 28 cm3 with sensitivity of 72.88%, specificity of 65.91% and accuracy of 74.8%, for prediction of RDS. Combining both cutoffs generated a more accurate detection 100%, specificity of 65.91% and 66.3% positive predictive value (PPV) and 100% negative predictive value (NPV) and 83% accuracy. Conclusions Both PA-RI and FLV are promising noninvasive tools which help in predicting RD fetuses with high sensitivity and specificity. PA-RI is more accurate than FLV cm3 in prediction of neonatal RDS. Combining these parameters increases the predictive value.

Background: Neonatal respiratory distress syndrome (RDS) is a leading cause of neonatal respiratory failure and neonatal mortality. It is frequent in preterm infants, because deficient surfactant needed to keep the airways (alveoli) open to assist infants breathe after birth. Nonetheless, it was also seen in full-term pregnancies. Noninvasive approaches for predicting the development of neonatal respiratory distress (RD) in preterm newborns include comparing the prenatal clinical outcome with the pulmonary artery resistance index (PA-RI) and fetal lung capacity as assessed by the virtual organ computer-aided analysis (VOCAL). Our study aimed to estimate optimal cutoff values and compare measurements of fetal pulmonary artery resistance index (PA-RI) and fetal lung volume (LV) assessed by VOCAL as noninvasive measures to predict neonatal RD development in preterm pregnancies to show which is more accurate. Results: Out of the examined 147 women who delivered 147 living newborns, 59 of newborn (40.1%) developed neonatal RD. PA-RI has a higher value in 45 (76.27%), while fetal lung volume (FLV) was significantly lower in 43 (72.88%) of neonates who developed RD. Combining both measurements of PA-RI and FLV could predict all cases of RDS 59 (100%). Thirty of RDS neonates had mechanical ventilation and died (50.85%). Cutoff values of PA-RI ≥ 0.75 with 76.27% sensitivity, 82.95% specificity and 81.5% accuracy, whereas a cutoff of FLV ≤ 28 cm3 with sensitivity of 72.88%, specificity of 65.91% and accuracy of 74.8%, for prediction of RDS. Combining both cutoffs generated a more accurate detection 100%, specificity of 65.91% and 66.3% positive predictive value (PPV) and 100% negative predictive value (NPV) and 83% accuracy. Conclusions: Both PA-RI and FLV are promising noninvasive tools which help in predicting RD fetuses with high sensitivity and specificity. PA-RI is more accurate than FLV cm3 in prediction of neonatal RDS. Combining these parameters increases the predictive value. [ABSTRACT FROM AUTHOR]

The associations between bronchopulmonary dysplasia (BPD) and the gestational pathologies of chorioamnionitis (CA) and hypertensive disorders of pregnancy (HDP) have become increasingly well recognized. However, the mechanisms through which these antenatal conditions cause increased risk of BPD remain less well characterized. The objective of this review is to discuss the role of the placenta in BPD predisposition as a primary driver of intrauterine alterations adversely impacting fetal lung development. We hypothesize that due to similarities in structure and function, placental disorders during pregnancy can uniquely impact the developing fetal lung, creating a unique placental-pulmonary connection. In the current review, we explore this hypothesis through analysis of clinical literature and preclinical model systems evaluating BPD predisposition, discussion of BPD phenotypes, and an overview on strategies to incorporate placental investigation into research on fetal lung development. We also discuss important concepts learned from research on antenatal steroids as a modulator fetal lung development. Finally, we propose that the appropriate selection of animal models and establishment of in vitro lung developmental model systems incorporating primary human placental components are key in continuing to understand and address antenatal predisposition to BPD. [ABSTRACT FROM AUTHOR]

Many preterm infants require mechanical ventilation as life-saving therapy. However, ventilation-induced overpressure can result in lung diseases. Considering the lung as a viscoelastic material, positive pressure inside the lung results in increased hydrostatic pressure and tissue compression. To elucidate the effect of positive pressure on lung tissue mechanics and cell behavior, we mimic the effect of overpressure by employing an uniaxial load onto fetal and adult rat lungs with different deformation rates. Additionally, tissue expansion during tidal breathing due to a negative intrathoracic pressure was addressed by uniaxial tension. We found a hyperelastic deformation behavior of fetal tissues under compression and tension with a remarkable strain stiffening. In contrast, adult lungs exhibited a similar response only during compression. Young’s moduli were always larger during tension compared to compression, while only during compression a strong deformation-rate dependency was found. In fact, fetal lung tissue under compression showed clear viscoelastic features even for small strains. Thus, we propose that the fetal lung is much more vulnerable during inflation by mechanical ventilation compared to normal inspiration. Electrophysiological experiments with different hydrostatic pressure gradients acting on primary fetal distal lung epithelial cells revealed that the activity of the epithelial sodium channel (ENaC) and the sodium-potassium pump (Na,K-ATPase) dropped during pressures of 30 cmH2O. Thus, pressures used during mechanical ventilation might impair alveolar fluid clearance important for normal lung function.

The mechanism of parturition is still unclear. Evidence has shown that delivery is associated with cellular senescence of the amniotic membrane. We isolated fetal lung-associated exosomes from the amniotic fluid from term labor (TL-exos) and verified that the exosomes can cause primary human amniotic epithelial cell (hAEC) senescence and apoptosis and can release higher levels of senescence-associated secretory phenotype (SASP)-related molecules and proinflammatory damage-associated molecular patterns (DAMPs) than exosomes isolated from the amniotic fluid from term not in labor (TNIL-exos). The human lung carcinoma cell lines (A549) can be used as an alternative to alveolar type 2 epithelial cells producing pulmonary surfactant. Therefore, we isolated A549 cell-derived exosomes (A549-exos) and found that they can trigger hAEC to undergo the same aging process. Finally, the animal experiments suggested that A549-exos induced vaginal bleeding and preterm labor in pregnant mice. Therefore, we conclude that exosomes derived from fetal lungs in term labor amniotic fluid induce amniotic membrane senescence, which may provide new insight into the mechanism of delivery.

Abstract Background In this study, we combined ultrasound and Doppler parameters to conclude the most accurate and applicable method for fetal lung maturity assessment. The purpose is to reduce risk of neonatal respiratory distress by assessment of fetal lung maturity through ultrasound and Doppler instead of amniocentesis. Results A total of 120 women were included. The ultrasound examination was performed at a gestational age ranging between 30 and 37 weeks and delivery occurred within 72 h from ultrasound. After birth, 19 fetuses were diagnosed with RDS. The ultrasound parameters assessed for fetal lung maturity showed varying sensitivity and specificity but presence of proximal tibial epiphyses showed the highest sensitivity (91%) and specificity (95%) followed by the presence of distal femoral epiphyses with 90% sensitivity and 84% specificity. The placental grade III maturity showed a sensitivity of 81% and 74% specificity followed by the presence of the amniotic fluid free-floating particles with an 83% sensitivity and 63% specificity, while echogenic fetal thalamus showed 77% and 79% for sensitivity and specificity, respectively, for prediction of fetal lung maturity. By using the fetal biometry, we could report that a BPD between 82.8 and 93.5 mm, AC between 295 and 322 mm, and FL (62.7-72.1 mm) correlated with mature fetal lungs. Regarding Doppler indices, increased resistive index of umbilical artery > 0.69 and of pulmonary artery > 0.78 correlated with neonatal RDS while fetuses with UtA RI values between 0.43 and 0.66 noticed in RDS vs (0.42-0.57) in the non-RDS. MCA RI values are also higher in RDS 0.77–0.88 vs 0.74–0.79 in non-RDS. On the other hand, analysis of colon grading and fetal lung echogenicity in relation to liver showed no significant value in the assessment of fetal lung maturity. Conclusion Ultrasound and Doppler showed good predictive value and accuracy and is considered a valuable non-invasive procedure in assessment of fetal lung maturity. However, no single parameter alone could show a definitive sign

Objectives: To analyze and compare, using ultrasound-based radiomics technology, fetal-lung texture in pregnancies affected by gestational diabetes mellitus (GDM) and/or pre-eclampsia (PE) and in normal pregnancies, overall and at different gestational ages.Methods: In this retrospective study, 430 high-throughput features per fetal-lung image were extracted from 548 fetal-lung ultrasound images (obtained at the level of the four-chamber view of the heart) in 548 pregnant women who delivered between July 2018 and August 2019 at the Obstetrics and Gynecology Hospital of Fudan University. Images had been obtained during ultrasound examinations between 28 and 41 weeks of gestation. The data were divided randomly into training set (80% of fetal-lung images) and independent test set (20% of images), and 20% of the images in the training set were then selected as the validation set. A standard machine-learning model based on ultrasound-based radiomics technology was created using features of fetal-lung texture extracted from the images, and a regression model was used to evaluate the relationship between lung-texture features, GDM and/or PE and gestational age.Results: Of the 548 pregnancies included, 108 were affected by GDM alone, 71 by PE alone and 25 by both GDM and PE, and 344 were normal. The overall performance of the GDM and PE prediction model was superior to that of the gestational-age prediction model, with an area under the receiver-operating-characteristics curve of 0.95-0.99, sensitivity of 78.8-97.1% in the validation set and 74.5-91.3% in the independent test set, specificity of 79.8-94.3% in the validation set and 75.7-88.4% in the independent test set and accuracy of 81.0-95.3% in the validation set and 80.6-86.4% in the independent test set.Conclusions: Using ultrasound-based radiomics technology, fetal lungs from pregnancies grouped according to whether they were affected by GDM and/or PE could be distinguished from each other and from fetal lungs of normal pregnancies, and lungs from pregnancies at different gestational ages could be distinguished. These findings support further research to explore the use of this non-invasive technology to predict neonatal respiratory complications in women with PE, GDM or their combination. © 2020 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Background: In this study, we combined ultrasound and Doppler parameters to conclude the most accurate and applicable method for fetal lung maturity assessment. Thepurpose is to reduce risk of neonatal respiratory distress by assessment of fetal lung maturity through ultrasound and Doppler instead of amniocentesis. Results: A total of 120 women were included. The ultrasound examination was performed at a gestational age ranging between 30 and 37 weeks and delivery occurred within 72 h from ultrasound. After birth, 19 fetuses were diagnosed with RDS. The ultrasound parameters assessed for fetal lung maturity showed varying sensitivity and specificity but presence of proximal tibial epiphyses showed the highest sensitivity (91%) and specificity (95%) followed by the presence of distal femoral epiphyses with 90% sensitivity and 84% specificity. The placental grade III maturity showed a sensitivity of 81% and 74% specificity followed by the presence of the amniotic fluid free-floating particles with an 83% sensitivity and 63% specificity, while echogenic fetal thalamus showed 77% and 79% for sensitivity and specificity, respectively, for prediction of fetal lung maturity. By using the fetal biometry, we could report that a BPD between 82.8 and 93.5 mm, AC between 295 and 322 mm, and FL (62.7-72.1 mm) correlated with mature fetal lungs. Regarding Doppler indices, increased resistive index of umbilical artery > 0.69 and of pulmonary artery > 0.78 correlated with neonatal RDS while fetuses with UtA RI values between 0.43 and 0.66 noticed in RDS vs (0.42-0.57) in the non-RDS. MCA RI values are also higher in RDS 0.77–0.88 vs 0.74–0.79 in non-RDS. On the other hand, analysis of colon grading and fetal lung echogenicity in relation to liver showed no significant value in the assessment of fetal lung maturity. Conclusion: Ultrasound and Doppler showed good predictive value and accuracy and is considered a valuable non-invasive procedure in assessment of fetal lung maturity. However, no single parameter alone could show a definitive sign [ABSTRACT FROM AUTHOR]

Chorioamnionitis, a potentially serious inflammatory complication of pregnancy, is associated with the development of an inflammatory milieu within the amniotic fluid surrounding the developing fetus. When chorioamnionitis occurs, the fetal lung finds itself in the unique position of being constantly exposed to the consequent inflammatory meditators and/or microbial products found in the amniotic fluid. This exposure results in significant changes to the fetal lung, such as increased leukocyte infiltration, altered cytokine, and surfactant production, and diminished alveolarization. These alterations can have potentially lasting impacts on lung development and function. However, studies to date have only begun to elucidate the association between such inflammatory exposures and lifelong consequences such as lung dysfunction. In this review, we discuss the pathogenesis of and fetal immune response to chorioamnionitis, detail the consequences of chorioamnionitis exposure on the developing fetal lung, highlighting the various animal models that have contributed to our current understanding and discuss the importance of fetal exposures in regard to the development of chronic respiratory disease. Finally, we focus on the clinical, basic, and therapeutic challenges in fetal inflammatory injury to the lung, and propose next steps and future directions to improve our therapeutic understanding of this important perinatal stress.

Chorioamnionitis, a potentially serious inflammatory complication of pregnancy, is associated with the development of an inflammatory milieu within the amniotic fluid surrounding the developing fetus. When chorioamnionitis occurs, the fetal lung finds itself in the unique position of being constantly exposed to the consequent inflammatory meditators and/or microbial products found in the amniotic fluid. This exposure results in significant changes to the fetal lung, such as increased leukocyte infiltration, altered cytokine, and surfactant production, and diminished alveolarization. These alterations can have potentially lasting impacts on lung development and function. However, studies to date have only begun to elucidate the association between such inflammatory exposures and lifelong consequences such as lung dysfunction. In this review, we discuss the pathogenesis of and fetal immune response to chorioamnionitis, detail the consequences of chorioamnionitis exposure on the developing fetal lung, highlighting the various animal models that have contributed to our current understanding and discuss the importance of fetal exposures in regard to the development of chronic respiratory disease. Finally, we focus on the clinical, basic, and therapeutic challenges in fetal inflammatory injury to the lung, and propose next steps and future directions to improve our therapeutic understanding of this important perinatal stress. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the toxic effects of cigarette smoke exposure on lung and the protective role of Omega 3 and Vitamin D against these toxic effects biochemically and histologically. 28 pregnant Wistar Albino rats were divided into four groups. The first group was control group; the second group was exposed to smoke of 10 cigarette by puff device 2 hours/day after pregnancy; the third group was exposed to cigarette smoke together with Omega 3 (0.5 mg/kg/day) and the fourth group was exposed to cigarette smoke together with vitamin D (42 microgram/kg/day). Finally, lung tissue sections of the newborn rats were stained with Hemotoxilen eosine and Masson tricromite. Malondialdehyde (MDA) and Fluorescent Oxidation Products (FOU) levels were measured. Fetal weights and the number of fetuses were significantly lower in the group received only cigarette smoke (both p<0.001). Histopathologically, pulmonary volume, number of developed alveols and parenchyma elasticity decreased significantly, meanwhile interstitial tissue increased, elastin and collagen did not develop adequately. Histopathologic changes significantly decreased in the group given Omega 3 and Vitamin D. Statistically, MDA and FOU levels were found to be higher in the group exposed to cigarette smoke compared to the control group, and MDA and FOU levels were lower in the group given Omega 3 along with cigarette smoke (p<0.001). Cigarette smoke caused histologically significant damage to fetal lung tissue, oxidative stress and increased MDA and FOU levels. This damage was significantly reduced with Omega 3 and Vitamine D supplementation. Omega 3 is an important antioxidant; vitamin D has no significant antioxidant effect. [ABSTRACT FROM AUTHOR]

The major surfactant protein, SP-A (a product of the SFTPA gene), serves as a marker of type II pneumocyte differentiation and surfactant synthesis. SFTPA expression in cultured human fetal lung (HFL) epithelial cells is upregulated by hormones that increase cyclic AMP (cAMP) and activate TTF-1/NKX2.1 and NF-κB. To further define mechanisms for type II cell differentiation and induction of SP-A, we investigated roles of microRNAs (miRNAs). Using microarray to identify differentially expressed miRNAs in HFL epithelial cells during type II cell differentiation in culture, we observed that members of the miRNA 199a (miR-199a)/miR-214 cluster were significantly downregulated during differentiation. Validated and predicted targets of miR-199a-3p/miR-199a-5p and miR-214, which serve roles in type II cell differentiation (COX-2, NF-κB p50/p65, and CREB1), and the CREB1 target, C/EBPβ, were coordinately upregulated. Accordingly, overexpression of miR-199a-5p, miR-199a-3p, or miR-214 mimics in cultured HFL epithelial cells decreased COX-2, NF-κB p50/p65, CREB1, and C/EBPβ proteins, with an associated inhibition of SP-A expression. Interestingly, overexpression of the EMT factor, ZEB1, which declines during cAMPinduced type II cell differentiation, increased pri-miR-199a and reduced the expression of the targets NF-κB/p50 and COX-2. Collectively, these findings suggest that the developmental decline in miR-199a/miR-214 in HFL causes increased expression of critical targets that enhance type II cell differentiation and SP-A expression. [ABSTRACT FROM AUTHOR]

• Ultrasonography has been explored to quantitatively examine the fetal lung as a non-invasive means. • We proposed a deep learning model for automated fetal lung segmentation and measurement. • Our model was constructed combined U-Net with Graph model and pre-trained Vgg-16 network. • The correlation between the size of fetal lung/heart as delineated by the model with gestational age was analyzed. • Our research will alleviate the labor of the clinicians in routine measurement of the fetal lung/cardiac. The neonatal respiratory morbidity that was primarily caused by the immaturity of the fetal lung is an important clinical issue in close relation to the morbidity and mortality of the fetus. In clinics, the amniocentesis has been used to evaluate the fetal lung maturity, which is time-consuming, costly and invasive. As a non-invasive means, ultrasonography has been explored to quantitatively examine the fetal lung in the past decades. However, existing studies required the contour of the fetal lung which was delineated manually. This may lead to significant inter- and intra-observer variations. We proposed a deep learning model for automated fetal lung segmentation and measurement, which was constructed combined U-Net with Graph model and pre-trained Vgg-16 network. The graph connection would extract stable feature for final segmentation and pre-trained method could speed up convergence. The model was trained with 3500 datasets augmented from 250 ultrasound images with both the fetal lung and heart delineated manually, and tested on 50 ultrasound images. In addition, the correlation between the size of fetal lung/heart as delineated by the model with gestational age was analyzed. The fetal lung and cardiac area were segmented automatically with the accuracy, average Intersection over Union (IoU), sensitivity and precision being 0.991, 0.818, 0.909 and 0.888, respectively. In addition, the size of fetal lung/heart was well correlated with the gestational age, demonstrating good potentials for assessing the fetal development. This study proposed a new robust method for automatic fetal lung segmentation in ultrasound images using Vgg16-GCN-UNet. Our proposed method could be utilized potentially not only to improve existing research in quantitative analyzing the fetal lung using ultrasound imaging technology, but also to alleviate the labor of the clinicians in routine measurement of the fetal lung/cardiac. [ABSTRACT FROM AUTHOR]

Resumen (español) El objetivo de la investigación fue determinar las modificaciones del Doppler de las arterias pulmonares fetales posterior al uso de betametasona para la maduración pulmonar. Se realizó una investigación de tipo explicativa, prospectiva y longitudinal con un diseño cuasi-experimental y una muestra no probabilística intencional de 106 pacientes que acudieron a la consulta Pre-natal de Alto Riesgo del Hospital Central “Dr. Urquinaona". Una vez seleccionadas las pacientes se les administró inyecciones intramusculares de betametasona (12 mg/día) por dos días consecutivos. Se realizaron las mediciones de índice de pulsatilidad, índice de resistencia y relación sistólico / diastólica de las arterias pulmonares fetales. Se observó disminución significativa de los valores promedio del índice de pulsatilidad en la segunda medición comparado con la medición inicial (p < 0,05). Sin embargo, el promedio de la tercera medición no mostró diferencia significativas con los valores iniciales (p = ns). El índice de resistencia disminuyó en la segunda medición para luego aumentar en la tercera medición comparado con el valor inicial (p < 0,05 para las dos mediciones). El valor promedio de la relación sistólico / diastólica presentó disminución significativa durante la segunda medición para luego presentar un aumento significativo al momento de la tercera medición comparado con el valor inicial (p < 0,05 para las dos mediciones). Se concluye que el uso de betametasona para la inducción de la maduración pulmonar produce modificaciones en las mediciones Doppler de las arterias pulmonares fetales. Abstract (english) The objective of research was to determine Doppler modifications of fetal pulmonary arteries after use of betamethasone for lung maturation. An explicative, prospective and longitudinal research was done with a quasi-experimental design and an intentional non-probabilistic sample of 106 patients who assisted to High Risk Antenatal Consult at Hospital Central “Dr. Urquinaona". Once patients were selected, two intramuscular injections of betamethasone (12 mg/day) were administered for two consecutive days. Measurements of pulsatility index, resistance index and systolic / diastolic ratio of fetal pulmonary arteries were done. There was observed a significant reduction of mean values of pulsatility index after second measurement compared with initial measurement (p < 0.05). However, mean value of third measurement did not show significant difference with initial value (p = ns). Resistance index decreased in second measurement and later increased in third measurement compared with initial measurements (p < 0.05 for both measurements). Mean value of systolic / diastolic ratio showed a significant reduction during second measurements and then presented a significant increase at the moment of third measurements (p < 0.05 for both measurements). It is concluded that the use of betamethasone for induction of lung maturation produces modifications in Doppler measurements of fetal pulmonary arteries.

The article compares the haemodynamics of DCC against ICC, using a non-asphyxial ~40 s interval between clamping and ventilation in preterm lambs (Smolich & Kenna, 2022). The findings from Smolich and Kenna suggest that the haemodynamic benefits of DCC, compared with this current ventilation time delay following ICC, may be minor in uncomplicated preterm deliveries. Keywords: birth transition; delayed cord clamping; fetal heart; fetal lung; neonatal resuscitation; neonate; ventilation EN birth transition delayed cord clamping fetal heart fetal lung neonatal resuscitation neonate ventilation 3641 3642 2 08/17/22 20220815 NES 220815 The transition of the fetus to newborn life involves a number of physiological changes, specifically to the respiratory and cardiovascular systems. [Extracted from the article]

Key points Chronic fetal hypoxaemia is a common pregnancy complication associated with intrauterine growth restriction that may influence respiratory outcome at birth., We investigated the effect of maternal chronic hypoxia for a month in late gestation on signalling pathways regulating fetal lung maturation and the transition to air-breathing at birth using isobaric hypoxic chambers without alterations to maternal food intake., Maternal chronic hypoxia in late gestation increases fetal lung expression of genes regulating hypoxia signalling, lung liquid reabsorption and surfactant maturation, which may be an adaptive response in preparation for the successful transition to air-breathing at birth., In contrast to other models of chronic fetal hypoxaemia, late gestation onset fetal hypoxaemia promotes molecular regulation of fetal lung maturation. This suggests a differential effect of timing and duration of fetal chronic hypoxaemia on fetal lung maturation, which supports the heterogeneity observed in respiratory outcomes in newborns following exposure to chronic hypoxaemia in utero., Abstract Chronic fetal hypoxaemia is a common pregnancy complication that may arise from maternal, placental and/or fetal factors. Respiratory outcome of the infant at birth likely depends on the duration, timing and severity of the hypoxaemic insult. We have isolated the effect of maternal chronic hypoxia (MCH) for a month in late gestation on fetal lung development. Pregnant ewes were exposed to normoxia (21% O2) or hypoxia (10% O2) from 105 to 138 days of gestation (term ∼145 days). At 138 days, gene expression in fetal lung tissue was determined by quantitative RT-PCR. Cortisol concentrations were determined in fetal plasma and lung tissue. Numerical density of surfactant protein positive cells was determined by immunohistochemistry. MCH reduced maternal [ABSTRACT FROM AUTHOR]

Although lung disease is the primary clinical outcome in COVID-19 patients, how SARS-CoV-2 induces lung pathology remains elusive. Here we describe a high-throughput platform to generate self-organizing and commensurate human lung buds derived from hESCs cultured on micropatterned substrates. Lung buds resemble human fetal lungs and display proximodistal patterning of alveolar and airway tissue directed by KGF. These lung buds are susceptible to infection by SARS-CoV-2 and endemic coronaviruses and can be used to track cell type-specific cytopathic effects in hundreds of lung buds in parallel. Transcriptomic comparisons of infected lung buds and postmortem tissue of COVID-19 patients identified an induction of BMP signaling pathway. BMP activity renders lung cells more susceptible to SARS-CoV-2 infection and its pharmacological inhibition impairs infection by this virus. These data highlight the rapid and scalable access to disease-relevant tissue using lung buds that recapitulate key features of human lung morphogenesis and viral infection biology., Competing Interests: Conflict of interests A.H.B. is a co-founder of startup companies RUMI Viro Inc., RUMI Scientific Inc., and OvaNova Laboratories, LLC, and serves on their scientific advisory boards. Both A.H.B. and E.A.R. are shareholders of RUMI Viro Inc. and RUMI Scientific Inc. C.M.R. is a founder of Apath LLC; a Scientific Advisory Board member of Imvaq Therapeutics, Vir Biotechnology, and Arbutus Biopharma; and an advisor for Regulus Therapeutics and Pfizer., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Congenital cystic adenomatoid malformation accounts for the vast majority of congenital cystic lung pathologies. The clinical spectrum of congenital cystic adenomatoid malformation is wide and ranges from silent incidental lesions to severe congenital respiratory distress or stillbirths. Management of clinically silent lesions is still a matter of debate, with conservative follow-up being a popular approach during the last decade. However, an optimal methodology of follow-up is yet to be determined. In this study, ultrasound is proposed as a follow-up tool for clinically silent lesions based on the findings in a case with known congenital cystic adenomatoid malformation from the antenatal period, which has been followed up for four years. [ABSTRACT FROM AUTHOR]

Intrauterine growth restriction induced by placental restriction (PR) in sheep leads to chronic hypoxemia and reduced surfactant maturation. The underlying molecular mechanism involves altered regulation of hypoxia signaling by increased prolyl hydroxylase domain (PHD) expression. Here, we evaluated the effect of intratracheal administration of the PHD inhibitor dimethyloxalylglycine (DMOG) on functional, molecular, and structural determinants of lung maturation in the control and PR sheep fetus. There was no effect of DMOG on fetal blood pressure or fetal breathing movements. DMOG reduced lung expression of genes regulating hypoxia signaling (HIF-3α, ACE1), antioxidant defense (CAT), lung liquid reabsorption (SCNN1-A, ATP1-A1, AQP-1, AQP-5), and surfactant maturation (SFTP-A, SFTP-B, SFTP-C, PCYT1A, LPCAT, ABCA3, LAMP3) in control fetuses. There were very few effects of DMOG on gene expression in the PR fetal lung (reduced lung expression of angiogenic factor ADM, water channel AQP-5, and increased expression of glucose transporter SLC2A1). DMOG administration in controls reduced total lung lavage phosphatidylcholine to the same degree as in PR fetuses. These changes appear to be regulated at the molecular level as there was no effect of DMOG on the percent tissue, air space, or numerical density of SFTP-B positive cells in the control and PR lung. Hence, DMOG administration mimics the effects of PR in reducing surfactant maturation in the lung of control fetuses. The limited responsiveness of the PR fetal lung suggests a potential biochemical limit or reduced plasticity to respond to changes in regulation of hypoxia signaling following exposure to chronic hypoxemia in utero. [ABSTRACT FROM AUTHOR]

An increase in oxygen tension at birth is one of the key signals that initiate pulmonary vasodilation in the fetal lung. We investigated the hypothesis that targeting endothelial nitric oxide synthase (eNOS) to the mitochondrial outer membrane regulates reactive oxygen species (ROS) formation in the fetal pulmonary artery endothelial cells (PAEC) during this transition. We isolated PAEC and pulmonary arteries from 137-day gestation fetal lambs (term = 144 days). We exposed PAEC to a simulated transition from fetal to (3% O2) to normoxic (21%) or hyperoxic (95% O2) postnatal PO2 or to the nitric oxide synthase (NOS) agonist ATP. We assessed the effect of O2 and ATP on eNOS interactions with the mitochondrial outer membrane protein porin and with the chaperone hsp90. We also investigated the effect of decoy peptides that blocked eNOS interactions with porin or hsp90 on PAEC angiogenesis and vasodilator function of pulmonary arteries. Transition of fetal PAEC from 3 to 21% O2 but not to 95% O2 or exposure to ATP increased eNOS association with hsp90 and porin. Decoy peptides that blocked eNOS interactions decreased NO release, increased O2 consumption and mitochondrial ROS levels, and impaired PAEC angiogenesis. Decoy peptides also inhibited the relaxation responses of pulmonary artery rings and dilation of resistance size pulmonary arteries to ATP. The mitochondrial-antioxidant mito-ubiquinone restored the response to ATP in decoy peptide-treated pulmonary arteries. These data indicate that targeting eNOS to mitochondria decreases endothelial oxidative stress and facilitates vasodilation in fetal pulmonary circulation at birth. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective To evaluate lung growth in healthy fetuses and those with congenital diaphragmatic hernia ( CDH) using two-dimensional ( 2D) ultrasound. Methods Fetal right lung measurements obtained by 2D ultrasound between 19 and 37 weeks' gestation were evaluated longitudinally in 66 healthy fetuses and 52 fetuses with isolated left-sided CDH. Right lung areas were determined by the 'tracing' and 'longest-diameters' methods and, subsequently, lung area-to-head circumference ratios ( LHRs) were calculated. Functions fitted to these size parameters with respect to gestational age were evaluated for three sets of group-wise comparisons: (1) healthy vs CDH fetuses; (2) different degrees of severity of CDH; and (3) CDH fetuses that survived vs those that died by 6 months postpartum. Results There was a significantly slower increase in right lung areas and LHRs with advancing gestational age in CDH fetuses than in healthy individuals ( P < 0.05). Compared to those with milder forms of CDH, lung areas and LHRs of fetuses with more severe forms displayed a smaller increase ( P < 0.05) and LHRs of fetuses with severe CDH did not increase during pregnancy ( P > 0.05). Individuals who died postpartum did not show any increase in LHR ( P > 0.05) throughout gestation. Conclusions The right lung area and LHR, calculated using either the longest-diameters or tracing method, display reduced growth rates during gestation in cases of isolated left-sided CDH as compared with healthy fetuses. The growth curve characteristics of fetal lung areas and LHRs may be useful for predicting neonatal mortality. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Many preterm infants require mechanical ventilation as life-saving therapy. However, ventilation-induced overpressure can result in lung diseases. Considering the lung as a viscoelastic material, positive pressure inside the lung results in increased hydrostatic pressure and tissue compression. To elucidate the effect of positive pressure on lung tissue mechanics and cell behavior, we mimic the effect of overpressure by employing an uniaxial load onto fetal and adult rat lungs with different deformation rates. Additionally, tissue expansion during tidal breathing due to a negative intrathoracic pressure was addressed by uniaxial tension. We found a hyperelastic deformation behavior of fetal tissues under compression and tension with a remarkable strain stiffening. In contrast, adult lungs exhibited a similar response only during compression. Young's moduli were always larger during tension compared to compression, while only during compression a strong deformation-rate dependency was found. In fact, fetal lung tissue under compression showed clear viscoelastic features even for small strains. Thus, we propose that the fetal lung is much more vulnerable during inflation by mechanical ventilation compared to normal inspiration. Electrophysiological experiments with different hydrostatic pressure gradients acting on primary fetal distal lung epithelial cells revealed that the activity of the epithelial sodium channel (ENaC) and the sodium-potassium pump (Na,K-ATPase) dropped during pressures of 30 cmH 2 O. Thus, pressures used during mechanical ventilation might impair alveolar fluid clearance important for normal lung function., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Naumann, Koppe, Thome, Laube and Zink.)

The mechanism of parturition is still unclear. Evidence has shown that delivery is associated with cellular senescence of the amniotic membrane. We isolated fetal lung-associated exosomes from the amniotic fluid from term labor (TL-exos) and verified that the exosomes can cause primary human amniotic epithelial cell (hAEC) senescence and apoptosis and can release higher levels of senescence-associated secretory phenotype (SASP)-related molecules and proinflammatory damage-associated molecular patterns (DAMPs) than exosomes isolated from the amniotic fluid from term not in labor (TNIL-exos). The human lung carcinoma cell lines (A549) can be used as an alternative to alveolar type 2 epithelial cells producing pulmonary surfactant. Therefore, we isolated A549 cell-derived exosomes (A549-exos) and found that they can trigger hAEC to undergo the same aging process. Finally, the animal experiments suggested that A549-exos induced vaginal bleeding and preterm labor in pregnant mice. Therefore, we conclude that exosomes derived from fetal lungs in term labor amniotic fluid induce amniotic membrane senescence, which may provide new insight into the mechanism of delivery., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wan, Chen, Gu, Liu, Zhou, Zhang, Lu, Li and Wang.)

Prenatal identification of lung abnormalities has increased with prenatal surveillance. With the advent of improved antenatal imaging over the past ten years, the diagnosis, assessment and management of congenital cystic lung abnormalities have changed. These were once considered the exclusive domain of the surgeon, who had the authority to operate on all congenital cystic lung abnormalities regardless of size or clinical signs in order to avoid the risk of cancer and improve lung growth in even asymptomatic infants. Clinicians are reconsidering this approach in the light of the spontaneous improvement and possible resolution that occurs over months to years with many of these lesions, thinking about the opportunity to take a more conservative approach in many minimally symptomatic or asymptomatic infants in the early months of life. The risks of subsequent cancer are poorly understood and probably overstated. Many centers advocate surgery only in cases of symptomatic or significant lesions, although there is little consensus as to what constitutes a significant lesion. This article will review current knowledge (classification, pathogenesis, genetics, prenatal evaluation, clinical implications) on congenital cystic adenomatoid malformations (CCAM) and discuss management options for young children with these lung abnormalities. [ABSTRACT FROM AUTHOR]

Abstract: Maturation of pulmonary fetal type II cells to initiate adequate surfactant production is crucial for postnatal respiratory function. Little is known about specific mechanisms of signal transduction controlling type II cell maturation. The ErbB4 receptor and its ligand neuregulin (NRG) are critical for lung development. ErbB4 is cleaved at the cell membrane by the γ-secretase enzyme complex whose active component is either presenilin-1 (PSEN-1) or presenilin-2. ErbB4 cleavage releases the 80kDa intracellular domain (4ICD), which associates with chaperone proteins such as YAP (Yes-associated protein) and translocates to the nucleus to regulate gene expression. We hypothesized that PSEN-1 and YAP have a development-specific expression in fetal type II cells and are important for ErbB4 signaling in surfactant production. In primary fetal mouse E16, E17, and E18 type II cells, PSEN-1 and YAP expression increased at E17 and E18 over E16. Subcellular fractionation showed a strong cytosolic and a weaker membrane location of both PSEN-1 and YAP. This was enhanced by NRG stimulation. Co-immunoprecipitations showed ErbB4 associated separately with PSEN-1 and with YAP. Their association, phosphorylation, and co-localization were induced by NRG. Confocal immunofluorescence and nuclear fractionation confirmed these associations in a time-dependent manner after NRG stimulation. Primary ErbB4-deleted E17 type II cells were transfected with a mutant ErbB4 lacking the γ-secretase binding site. When compared to transfection with wild-type ErbB4, the stimulatory effect of NRG on surfactant protein mRNA expression was lost. We conclude that PSEN-1 and YAP have crucial roles in ErbB4 signal transduction during type II cell maturation. [Copyright &y& Elsevier]

The article presents a study which investigates the potential application of diffusion-weighted (DW) magnetic resonance imaging (MRI) in fetuses with congenital diaphragmatic hernia (CDH). The mothers of 93 fetuses with normal lungs and 14 fetuses with left-sided CDH were scanned using the magnetic resonance imaging (MRI) system. The study found that the DW MRI is a useful predictor of postnatal outcome.

Cigarette smoking, one of the most pervasive habits in society, presents many well established health risks. While lung cancer is probably the most common and well documented disease associated with tobacco exposure, it is becoming clear from recent research that many other diseases are causally related to smoking. Whether from direct smoking or inhaling environmental tobacco smoke (ETS), termed secondhand smoke, the cells of the respiratory tissues and the lining pulmonary surfactant are the first body tissues to be directly exposed to the many thousands of toxic chemicals in tobacco. Considering the vast surface area of the lung and the extreme attenuation of the blood-air barrier, it is not surprising that this organ is the primary route for exposure, not just to smoke but to most environmental contaminants. Recent research has shown that the pulmonary surfactant, a complex mixture of phospholipids and proteins, is the first site of defense against particulates or gas components of smoke. However, it is not clear what effect smoke has on the surfactant. Most studies have demonstrated that smoking reduces bronchoalveolar lavage phospholipid levels. Some components of smoke also appear to have a direct detergent-like effect on the surfactant while others appear to alter cycling or secretion. Ultimately these effects are reflected in changes in the dynamics of the surfactant system and, clinically in changes in lung mechanics. Similarly, exposure of the developing fetal lung through maternal smoking results in postnatal alterations in lung mechanics and higher incidents of wheezing and coughing. Direct exposure of developing lung to nicotine induces changes suggestive of fetal stress. Furthermore, identification of nicotinic receptors in fetal lung airways and corresponding increases in airway connective tissue support a possible involvement of nicotine in postnatal asthma development. Finally, at the level of the alveoli of the lung, colocalization of nicotinic receptors and surfactant-specific protein in alveolar cells is suggestive of a role in surfactant metabolism. Further research is needed to determine the mechanistic effects of smoke and its components on surfactant function and, importantly, the effects of smoke components on the developing pulmonary system.

Expression of the human surfactant protein-A2 (hSP-A2) gene is lung specific, occurs in type II and Clara cells, and is developmentally and hormonally regulated in fetal lung. Using transfected human fetal type II cells, we previously observed that ∼300 bp of 5′-flanking DNA mediated cAMP and interleukin-1 (IL-1) stimulation and dexamethasone (Dex) inhibition of hSP-A2 promoter activity. This region contains response elements for estrogen-related receptor α element (ERRE, –241 bp), thyroid transcription factor (TTF)-1/Nkx2.1 (TTF-binding protein, –171 bp), upstream stimulatory factor 1/2 (E-box, –80 bp), and stimulatory protein (Sp) 1 (G/T-box, –62 bp), which are essential for basal and cAMP induction of hSP-A2 expression. To define genomic regions necessary for developmental, hormonal, and tissue-specific regulation of hSP-A2 expression in vivo, we analyzed transgenic mice carrying hGH reporter genes comprised of 313 bp of hSP-A2 gene 5′-flanking DNA ± mutation in the TBE or 175 bp of 5′-flanking DNA, containing TBE, E-box and G/T-box, but lacking ERRE. Transgenes containing 313 or 175 bp of hSP-A2 5′-flanking DNA were expressed in a lung cell-specific manner and developmentally regulated in concert with the endogenous mouse SP-A gene. In cultured lung explants from hSP-A-313:hGH transgenic fetal mice, cAMP and IL-1 induced and Dex inhibited transgene expression. However, the 175-bp hSP-A2 genomic region was insufficient to mediate hormonal regulation of hSP-A2 promoter activity. The finding that expression of the hSP-A-313TBEmut:hGH transgene was essentially undetectable in fetal lung and was not hormonally regulated in transgenic fetal lung explants underscores the critical importance of the TBE in lung cell-specific, developmental, and hormonal regulation of hSP-A2 gene expression. [ABSTRACT FROM AUTHOR]

The article describes the association between the intrapulmonary circulation and the degree of lung growth in fetuses with congenital diaphragmatic hernia (CDH). Results reveal that peak early-diastolic reversed flow (PEDRF) is quick and easy to calculate, and demonstrated the strongest and most consistent correlation with lung-to-head ratio (LHR) for gestational age. The link between PEDRF and LHR might be an additional parameter that could aid establish prognosis in fetuses with CDH.

Objectives: To determine the precision and accuracy of ultrasound in estimating the fetal lung to body weight ratio (FLB ratio) using two-dimensional (2D) and three-dimensional (3D) ultrasound by comparison with postmortem measurements, and to evaluate its potential to diagnose pulmonary hypoplasia. Methods: Lung volumes were estimated by 3D ultrasound (rotational technique) and fetal weights were measured by 2D ultrasound (Hadlock equation) in 35 fetuses immediately before termination of pregnancy at 15-38 weeks. Sonographic estimates of FLB ratio were compared with postmortem values. Based on the pathological definition of pulmonary hypoplasia, the accuracy of sonographic estimation of the FLB ratio was analyzed. Results: The mean gestational age at termination of pregnancy was 26.7 (range, 15-38) weeks. The mean FLB ratios were 0.018 (SD, 0.006) on ultrasound and 0.019 (SD, 0.007) at autopsy (P = 0.730). Bias and precision of sonographic FLB ratio were - 0.001 and 0.003 (absolute limits, - 0.007 to + 0.006), respectively. Pulmonary hypoplasia was diagnosed in 12 (34.3%) cases at autopsy. The sonographic FLB ratio was significantly lower in fetuses with pulmonary hypoplasia at autopsy (median, 0.011; range, 0.004-0.014) than it was in those without pulmonary hypoplasia (median, 0.022; range, 0.013-0.045, P < 0.001). The sensitivity and specificity of the sonographic FLB ratio for diagnosing pulmonary hypoplasia were 91.7% (11/12) and 91.3% (21/23), respectively, the positive and negative predictive values were 84.6% (11/13) and 95.5% (21/22), and the accuracy was 91.4% (32/35). Conclusion: FLB ratio can be estimated precisely on ultrasound examination, albeit with wide limits of agreement. The sonographically estimated FLB ratio may be useful in the prediction and diagnosis of pulmonary hypoplasia. [ABSTRACT FROM AUTHOR]

Objective: To determine the accuracy and precision of prenatal three-dimensional (3D) ultrasound in estimating fetal lung volume using the rotational multiplanar technique (VOCAL) by comparing it to postmortem volume measurements. Methods: Fetal lung volume was measured during 3D ultrasound examination using a rotational multiplanar technique in eight cases of congenital diaphragmatic hernia (CDH) (six left and two right-sided) and in 25 controls without pulmonary malformation, immediately before termination. Prenatal 3D sonographic estimates of fetal lung volume were compared with postmortem measurement of fetal lung volume achieved by water displacement. Results: The intraclass correlation coefficient of fetal lung volume estimated by 3D ultrasound and measured at postmortem examination was 0.95 in CDH cases and 0.99 in controls. Based on Bland-Altman analysis, the bias, precision and limits of agreement were, respectively, 0.35 cm(3), 1.46 cm(3) and between -2.51 and + 3.21 cm(3) in cases with CDH and 0.08 cm(3), 2.80 cm(3) and between -5.41 and + 5.57 cm(3) in controls. The mean relative error of 3D ultrasound fetal lung volume measurement was -7.19% (from -42.70% to + 18.11%) in CDH cases and -0.72% (from -30.25% to + 19.22%) in controls, while the mean absolute error of 3D ultrasound fetal lung volume measurement was 1.40 (range, 0.71-2.52) cm(3) and 2.12 (range, 0.05-4.98) cm(3), respectively. Accuracy of 3D ultrasound for measuring fetal lung volumes was 84.86 (range, 57.30-99.48)% in cases with CDH and 91.38 (range, 69.75-99.45)% in controls. The mean intraobserver variability for lung volume estimated by 3D ultrasound was 0.28 cm(3) in controls and 0.17 cm(3) in CDH cases. Conclusion: Prenatal 3D ultrasound can estimate accurately fetal lung volume using the rotational multiplanar technique for volume measurements (VOCAL), even in fetuses with very small lungs, such as cases with isolated CDH. [ABSTRACT FROM AUTHOR]