Transient Neonatal Myasthenia Gravis as a Common Complication of a Rare Disease: A Systematic Review.

Myasthenia gravis (MG) is a rare autoimmune disease. Transient neonatal myasthenia gravis (TNMG) is caused by pathogenic maternal autoantibodies that cross the placenta and disrupt signaling at the neuromuscular junction. This is a systematic review of this transient immunoglobulin G (IgG)-mediated disease. TNMG affects 10-20% of children born to mothers with MG. The severity of symptoms ranges from minor feeding difficulties to life-threatening respiratory weakness. Minor symptoms might go unnoticed but can still interfere with breastfeeding. Acetylcholine-esterase inhibitors and antibody-clearing therapies such as immunoglobulins can be used to treat TNMG, but most children do well with observation only. TNMG is self-limiting within weeks as circulating antibodies are naturally cleared from the blood. In rare cases, TNMG is associated with permanent skeletal malformations or permanent myopathy. The mother's antibodies can also lead to spontaneous abortions. All healthcare professionals meeting pregnant or birthing women with MG or their neonates should be aware of TNMG. TNMG is hard to predict. Reoccurrence is common among siblings. Pre-pregnancy thymectomy and intravenous immunoglobulins during pregnancy reduce the risk. Neonatal fragment crystallizable receptor (FcRn) blocking drugs for MG might reduce TNMG risk.

Synthesis of phospholipids in human placenta.

INTRODUCTION: Placental phospholipid synthesis is critical for the expansion of the placental exchange surface area and for production of signaling molecules. Despite their importance, it is not yet established which enzymes involved in the de novo synthesis and remodeling of placental phospholipids are expressed and active in the human placenta. METHODS: We identified phospholipid synthesis enzymes by immunoblotting in placental homogenates and immunofluorescence in placenta tissue sections. Primary human trophoblast (PHT) cells from term healthy placentas (n = 10) were cultured and exposed to 13C labeled fatty acids (16:0, 18:1 and 18:2 n-6, 22:6 n-3) for 2 and 24 h. Three phospholipid classes; phosphatidic acid, phosphatidylcholine, and lysophosphatidylcholine containing 13C fatty acids were quantified by Liquid Chromatography with tandem mass spectrometry (LC/MS-MS). RESULTS: Acyl transferase and phospholipase enzymes were detected in human placenta homogenate and primarily expressed in the syncytiotrophoblast. Three representative 13C fatty acids (16:0, 18:1 and 18:2 n-6) were incorporated rapidly into phosphatidic acid in trophoblasts, but 13C labeled docosahexaenoic acid (DHA; 22:6 n-3) incorporation was not detected. 13C DHA was incorporated into phosphatidylcholine. Lysophosphatidylcholine containing all four 13C labeled fatty acids were found in high abundance. CONCLUSIONS: Phospholipid synthesis and remodeling enzymes are present in the syncytiotrophoblast. 13C labeled fatty acids were rapidly incorporated into cellular phospholipids. 13C DHA was incorporated into phospholipids through the remodeling pathway rather than by de novo synthesis. These understudied pathways are highly active and critical for structure and function of the placenta.

Oleic acid stimulation of amino acid uptake in primary human trophoblast cells is mediated by phosphatidic acid and mTOR signaling.

Normal fetal development is critically dependent on optimal nutrient supply by the placenta, and placental amino acid transport has been demonstrated to be positively associated with fetal growth. Mechanistic target of rapamycin (mTOR) is a positive regulator of placental amino acid transporters, such as System A. Oleic acid (OA) has been previously shown to have a stimulatory role on placental mTOR signaling and System A amino acid uptake in primary human trophoblast (PHT) cells. We investigated the mechanistic link between OA and System A activity in PHT. We found that inhibition of mTOR complex 1 or 2, using small interfering RNA to knock down raptor or rictor, prevented OA-stimulated System A amino acid transport indicating the interaction of OA with mTOR. Phosphatidic acid (PA) is a key intermediary for phospholipid biosynthesis and a known regulator of the mTOR pathway; however, phospholipid biosynthetic pathways have not been extensively studied in placenta. We identified placental isoforms of acyl transferase enzymes involved in de novo phospholipid synthesis. Silencing of 1-acylglycerol-3-phosphate-O-acyltransferase-4, an enzyme in this pathway, prevented OA mediated stimulation of mTOR and System A amino acid transport. These data indicate that OA stimulates mTOR and amino acid transport in PHT cells mediated through de novo synthesis of PA. We speculate that fatty acids in the maternal circulation, such as OA, regulate placental functions critical for fetal growth by interaction with mTOR and that late pregnancy hyperlipidemia may be critical for increasing nutrient transfer to the fetus.

Drug Exposure During Pregnancy: A Case-Control Study from a Primary Care Database.

Objective: Drug exposure during pregnancy is frequent, even more during first trimester as pregnant women might not be aware of their condition. We used available electronic health records (EHRs) to describe the use of medications during the first trimester in pregnant women and to compare drug exposure between those women who had an abortion (either elective or spontaneous) compared to those who had live births. Materials and Methods: Case-control study of abortions, either elective or spontaneous (cases), and live birth pregnancies (controls) in Sistema d'Informació per al Desenvolupament de la Investigació en Atenció Primària (Catalan Primary Health electronic health records) from 2012 to 2020. Exposure to drugs during first trimester of pregnancy was considered to estimate the association with abortion by conditional logistic regression and adjusted by health conditions and other drugs exposure. Results: Sixty thousand three hundred fifty episodes of abortions were matched to 118,085 live birth pregnancy episodes. Cases had higher rates of alcohol intake (9.9% vs. 7.2%, p < 0.001), smoking (4.5% vs. 3.6%, p < 0.001), and previous abortions (9.9% vs. 7.8%, p < 0.001). Anxiety (30.3% and 25.1%, p < 0.001), respiratory diseases (10.6% and 9.2%, p < 0.001), and migraine (8.2% and 7.3%, p < 0.001), for cases and controls, respectively, were the most frequent baseline conditions. Cases had lower rate of drug exposure, 40,148 (66.5%) versus 80,449 (68.1%), p < 0.001. Association with abortion was found for systemic antihistamines (adjusted odds ratio [ORadj] 1.23, 95% confidence interval [CI] 1.19-1.27), antidepressants (ORadj 1.11, 95% CI 1.06-1.17), anxiolytics (ORadj 1.31, 95% CI 1.26-1.73), and nonsteroidal anti-inflammatory drugs (ORadj 1. 63, 95% CI 1.59-1.67). Conclusions: These high rates of drug exposures during the first trimester of pregnancy highlights the relevance of informed prescription to women with childbearing potential.

Pneumatocele-induced pneumothorax after COVID-19 infection in a 45-day-old infant.

Throughout the literature, many pathologic lung lesions and complications following coronavirus disease 2019 (COVID-19) infection have been reported including pneumatocele formation which could potentially lead to pneumothorax development. This case report discusses the clinical course of a 45-day-old male with respiratory distress, whose condition worsened over time. Investigations revealed elevated COVID-19 immunoglobulin G (IgG) antibodies with negative COVID polymerase chain reaction (PCR) accompanied by radiologic evidence of pneumatocele formation, which was further complicated by pneumothorax. The clinical presentation of the patient was consistent with post-COVID infection but he had no history of contact with a sick individual which prompted further investigation of the source of the infection. Upon reviewing the history of the mother, symptoms consistent with COVID-19 around 32 weeks of pregnancy were revealed, which raises the possibility of maternal-fetal exchange of COVID-19 infection. This article presents the youngest reported patient with COVID-19 pneumonia that led to pneumatocele formation.

Knockdown of Placental Major Facilitator Superfamily Domain Containing 2a in Pregnant Mice Reduces Fetal Brain Growth and Phospholipid Docosahexaenoic Acid Content.

INTRODUCTION: Docosahexaenoic acid (DHA) is an n-3 long chain polyunsaturated fatty acid critical for fetal brain development that is transported to the fetus from the mother by the placenta. The lysophosphatidylcholine (LPC) transporter, Major Facilitator Superfamily Domain Containing 2a (MFSD2a), is localized in the basal plasma membrane of the syncytiotrophoblast of the human placenta, and MFSD2a expression correlates with umbilical cord blood LPC-DHA levels in human pregnancy. We hypothesized that placenta-specific knockdown of MFSD2a in pregnant mice reduces phospholipid DHA accumulation in the fetal brain. METHODS: Mouse blastocysts (E3.5) were transduced with an EGFP-expressing lentivirus containing either an shRNA targeting MFSD2a or a non-coding sequence (SCR), then transferred to pseudopregnant females. At E18.5, fetuses were weighed and their placenta, brain, liver and plasma were collected. MFSD2a mRNA expression was determined by qPCR in the brain, liver and placenta and phospholipid DHA was quantified by LC-MS/MS. RESULTS: MFSD2a-targeting shRNA reduced placental mRNA MFSD2a expression by 38% at E18.5 (n = 45, p < 0.008) compared with SCR controls. MFSD2a expression in the fetal brain and liver were unchanged. Fetal brain weight was reduced by 13% (p = 0.006). Body weight, placenta and liver weights were unaffected. Fetal brain phosphatidyl choline and phosphatidyl ethanolamine DHA content was lower in fetuses with placenta-specific MFSD2a knockdown. CONCLUSIONS: Placenta-specific reduction in expression of the LPC-DHA transporter MFSD2a resulted in reduced fetal brain weight and lower phospholipid DHA content in the fetal brain. These data provide mechanistic evidence that placental MFSD2a mediates maternal-fetal transfer of LPC-DHA, which is critical for brain growth.

Overexpression of the LAT1 in primary human trophoblast cells increases the uptake of essential amino acids and activates mTOR signaling.

The System L amino acid transporter, particularly the isoform Large Neutral Amino Acid Transporter Small Subunit 1 (LAT1) encoded by SLC7A5, is believed to mediate the transfer of essential amino acids in the human placenta. Placental System L amino acid transporter expression and activity is decreased in pregnancies complicated by IUGR and increased in fetal overgrowth. However, it remains unknown if changes in the expression of LAT1 are mechanistically linked to System L amino acid transport activity. Here, we combined overexpression approaches with protein analysis and functional studies in cultured primary human trophoblast (PHT) cells to test the hypothesis that SLC7A5 overexpression increases the uptake of essential amino acids and activates mTOR signaling in PHT cells. Overexpression of SLC7A5 resulted in a marked increase in protein expression of LAT1 in the PHT cells microvillous plasma membrane and System L amino acid transporter activity. Moreover, mTOR signaling was activated, and System A amino acid transporter activity increased following SLC7A5 overexpression, suggesting coordination of trophoblast amino transporter expression and activity to ensure balanced nutrient flux to the fetus. This is the first report showing that overexpression of LAT1 is sufficient to increase the uptake of essential amino acids in PHT cells, which activates mTOR, a master regulator of placental function. The decreased placental System L activity in human IUGR and the increased placental activity of this transporter system in some cases of fetal overgrowth may directly contribute to changes in fetal amino acid availability and altered fetal growth in these pregnancy complications.

Maternal-fetal cross-talk via the placenta: influence on offspring development and metabolism.

Compelling epidemiological and animal experimental data demonstrate that cardiometabolic and neuropsychiatric diseases originate in a suboptimal intrauterine environment. Here, we review evidence suggesting that altered placental function may, at least in part, mediate the link between the maternal environment and changes in fetal growth and development. Emerging evidence indicates that the placenta controls the development and function of several fetal tissues through nutrient sensing, modulation of trophoblast nutrient transporters and by altering the number and cargo of released extracellular vesicles. In this Review, we discuss the development and functions of the maternal-placental-fetal interface (in humans and mice) and how cross-talk between these compartments may be a mechanism for in utero programming, focusing on mechanistic target of rapamycin (mTOR), adiponectin and O-GlcNac transferase (OGT) signaling. We also discuss how maternal diet and stress influences fetal development and metabolism and how fetal growth restriction can result in susceptibility to developing chronic disease later in life. Finally, we speculate how interventions targeting placental function may offer unprecedented opportunities to prevent cardiometabolic disease in future generations.

Lipid Profile Variations in Pregnancies with and without Cardiovascular Risk: Consequences for Both Mother and Newborn.

Background: Maternal cardiovascular risk and its implications can have significant repercussions for both the mother and the child. This study compares the lipid profiles of two distinct groups of pregnant women, those with and without cardiovascular risk, to shed light on its effects on maternal and outcomes for newborns. Materials and Methods: This study enrolled 86 pregnant women, dividing them into two groups: Group 1 (n = 46, healthy pregnancies) and Group 2 (n = 40, pregnancies with cardiovascular risk factors). The data collected included maternal demographics, smoking history, pre-existing pathologies, and a range of laboratory measures. Neonatal outcomes were also recorded. Results: Group 2 showed a significant increase in the percentage of newborns with abnormal APGAR scores (p-value < 0.0001), congenital abnormalities (p-value < 0.0001), severe prematurity (p-value < 0.0001), and neonatal mortality rates (p-value < 0.0001), as well as differences in birth weight (p-value = 0.0392) and therapy usage (surfactant: p-value < 0.001, steroids p-value = 0.004, and antibiotics p-value < 0.001). Regarding laboratory measures, Group 2 exhibited significantly elevated levels of total cholesterol, LDL-C (p-value < 0.0001), ApoB (p-value < 0.0001), Lp(A) (p-value = 0.0486), triglycerides (p-value < 0.0001), and hs-CRP (p-value = 0.0300). Discussion: These results underscore the elevated risk associated with pregnancies complicated by cardiovascular risk factors. Group 2 demonstrated a more concerning clinical profile, with a higher prevalence of detrimental neonatal outcomes and different lipid and inflammatory profiles, signifying a potential pathophysiological link. Conclusions: The differential lipid profiles and adverse neonatal outcomes in pregnancies with cardiovascular risks highlight the urgency of effective risk stratification and management strategies in this population.

Maternal obesity alters the placental transcriptome in a fetal sex-dependent manner.

Infants born to obese mothers have an increased risk of developing obesity and metabolic diseases in childhood and adulthood. Although the molecular mechanisms linking maternal obesity during pregnancy to the development of metabolic diseases in offspring are poorly understood, evidence suggests that changes in the placental function may play a role. Using a mouse model of diet-induced obesity with fetal overgrowth, we performed RNA-seq analysis at embryonic day 18.5 to identify genes differentially expressed in the placentas of obese and normal-weight dams (controls). In male placentas, 511 genes were upregulated and 791 genes were downregulated in response to maternal obesity. In female placentas, 722 genes were downregulated and 474 genes were upregulated in response to maternal obesity. The top canonical pathway downregulated in maternal obesity in male placentas was oxidative phosphorylation. In contrast, sirtuin signaling, NF-kB signaling, phosphatidylinositol, and fatty acid degradation were upregulated. In female placentas, the top canonical pathways downregulated in maternal obesity were triacylglycerol biosynthesis, glycerophospholipid metabolism, and endocytosis. In contrast, bone morphogenetic protein, TNF, and MAPK signaling were upregulated in the female placentas of the obese group. In agreement with RNA-seq data, the expression of proteins associated with oxidative phosphorylation was downregulated in male but not female placentas of obese mice. Similarly, sex-specific changes in the protein expression of mitochondrial complexes were found in placentas collected from obese women delivering large-for-gestational-age (LGA) babies. In conclusion, maternal obesity with fetal overgrowth differentially regulates the placental transcriptome in male and female placentas, including genes involved in oxidative phosphorylation.

Spontaneous massive fetomaternal hemorrhage: two case reports and a literature review of placental pathology.

BACKGROUND: Massive fetomaternal hemorrhage (FMH) is a rare event during pregnancy that may cause severe fetal anemia or death. CASE PRESENTATION: This paper reports two cases of fetomaternal hemorrhage with unexplained reasons. Both cases required emergency caesarean sections for non-reassuring fetal status and were treated with neonatal blood transfusion. Fetomaternal hemorrhage was confirmed via maternal Kleihauer-Betke test. CONCLUSION: We found parenchymal pallor, increased nucleated red blood cells (nRBCs), and syncytial knots (SKs) in the placentas, which are compatible with fetal anemia. Immunohistochemical staining indicated VEGF, CD34, and CD31 expression in the endothelial cells of the capillaries, characteristic of massive FMH placenta. This article also reviews the particular histopathological changes in FHM placenta according to the placental lesion classification system.

Placental transport of Erythromycin and its effect on placental inflammatory factors.

Objective: Erythromycin is used for prevention and control of infectious perinatal morbidity. It has been hypothesised that erythromycin crosses the placenta and has an effect on the production of placental inflammatory factors. We evaluated the transport of erythromycin in an ex-vivo closed perfusion system of the placenta and determined its effect on the production of placenta inflammatory markers. Methods: In 2013, a prospective basic science study was conducted at the placental laboratory of College of Medicine and Health Sciences, United Arab Emirates. Six term placentas from uncomplicated pregnancies were studied using the ex-vivo dual closed-loop human placental cotyledon perfusion technique. Erythromycin was added to the perfusate in the maternal compartment. Samples were obtained from the maternal and fetal up to 240 minutes. Results: The reference antipyrine was detected in the fetal circulation in the first 15 minutes after addition of the drug. At this point the mean antipyrine was 49.90±2.10µg/ml in the maternal perfusate and 7.1±1.56µg/ml in fetal perfusate. The fetal and maternal concentration became similar at 120 minutes. The transfer of antipyrine from maternal to fetal compartment was 98.66%. The differences between perfusion groups were non-significant that indicates the perfusion of placentas was comparable. After media exchange in both sides, erythromycin was added to the maternal perfusate. The experimental period of four hours was continued with medium circulation on both maternal and fetal circulation. The concentration of erythromycin decreased in the maternal circuit by 36.4% and increased in the fetal circuit by 65%. The concentration of IL-6 in the maternal circuit was normal. Conclusion: Erythromycin crossed the placenta and did not inhibit the production of IL-6. Future studies are needed concerning neonatal adverse effects and the development of antibiotic resistance.

Origins of abnormal placentation: why maternal veins must not be forgotten.

The importance of uterine microvascular adaptations during placentation in pregnancy has been well established for decades. Inadequate dilatation of spiral arteries is associated with gestational complications, such as preeclampsia and/or intrauterine growth restriction. More recently, it has become clear that trophoblast cells invade and adapt decidual veins and lymphatic vessels 1 month before spiral arteries become patent and before intervillous space perfusion starts. Normal intervillous space hemodynamics is characterized by high volume flow at low velocity and pressure in the interseptal compartments surrounding the chorionic villi, hereby facilitating efficient maternal-fetal exchange. In case of shallow decidual vein dilatation, intervillous arterial supply exceeds venous drainage. This will cause congestion in the interseptal compartments with subsequently reduced perfusion and increased pressure. An efficient mechanism to counteract venous congestion and safeguard the viability of the conceptus is by reducing arterial inflow via shallow dilatation of the spiral arteries. This review made the case for intervillous space congestion as an unexplored trigger for inadequate spiral artery dilatation during the placentation process, eventually leading to abnormal systemic circulatory dysfunctions. An abnormal maternal venous function can result from an abnormal maternal immune response to paternal antigens with an imbalanced release of vasoactive mediators or can exist before conception. To get the full picture of abnormal placentation, maternal veins must not be forgotten.

Human placental lipid content and lipid metabolic enzyme abundance in obesity and across gestation.

Changes in placental lipid metabolism influence the delivery of lipids critical for fetal development and fetal requirements for lipids change across gestation. We hypothesized that placental lipid content and metabolic enzyme protein levels increase across gestation and are elevated in obesity. Placentas (4-40 weeks' gestation) were collected from control (body mass index, BMI = 18.5-24.9, n=37) and obese (BMI > 30, n=19) pregnant women. Trophoblast villous tissue was homogenized and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) for phospholipid and triacylglycerol (TAG) analysis and western blot for protein quantification. The placental content of TAG species and nine of 35 identified phosphatidylcholines (PC) were significantly higher (P<0.05) in first trimester (28-79%, 10-47%, respectively). Furthermore, two TAG and three PC differed by maternal BMI and were significantly increased (P<0.05) in the obese group in first trimester (72-87%, 88-119%, respectively). Placental protein abundance of glycerol-2-phosphate (GPAT3) and 1-acyl-sn-glycerol-3-phosphate acyltransferase 2 (AGPAT2), involved in de novo synthesis of PC and TAG, were higher (P<0.05) in the first trimester (66 and 74%, respectively). The protein abundance of the PC-remodeling enzyme PLA2G4c was also higher (63%) in first trimester (P<0.05). In conclusion, the placental content of many phospholipid and TAG species and the protein level of associated synthesis enzymes are higher in first-trimester human placenta. The high PC content may be related to the rapid membrane expansion in early pregnancy and the low placental oxygen tension may promote the accumulation of tissue TAGs in first trimester. Maternal obesity had only limited impact on placental lipid content and metabolic enzyme protein abundance.

Recruitment and Retention of Urban Pregnant Women to a Clinical Study Administering an Oral Isotope Dietary Tracer.

Introduction: Pregnant women are a vulnerable population that are difficult to engage in clinical research. We report successful recruitment and retention strategies used in a longitudinal pilot study of urban racially/ethnically diverse pregnant women that involved administration of an orally ingested isotope tracer, multiple venipunctures, biopsy of placenta after delivery, and cord or placental blood collection. Materials and Methods: We used direct strategies to recruit English-speaking obese and nonobese pregnant women aged 17-45 years, who were in the third trimester of pregnancy. The study required data collection at 32-34 and 34-36 gestational weeks and delivery. Strategies included frequent personal engagement with participants and staff to build relationships and trust, tangible appreciation, and the study team being present at delivery. In addition, leveraging hospital information technology (IT) services was critical to ensure retention through labor and delivery (LD). Results: A racially (52% Black, 23% White, and 10% other) and ethnically (15% Hispanic or Latinx) diverse sample of pregnant women was enrolled. Of the 52 women enrolled, 85% of women completed all procedures. Conclusions: This is the first report of successful strategies for recruitment and retention of racially/ethnically diverse pregnant women in a longitudinal study requiring oral administration of an isotope tracer. Personal engagement with multiple touch points, starting with recruitment and continuing regularly throughout the third trimester, was the most successful strategy. Creating and maintaining relationships with the LD providers and staff and utilizing hospital IT, including targeted electronic medical record alerts, ensured successful retention for the duration of the study. Trial Registration: Not applicable.

Serum concentrations of selected perfluoroalkyl substances for US females compared to males as they age.

Gender-age specific linear statistical models were fitted to analyze gender-based differences in serum concentrations of PFOA, PFNA, PFHxS, and PFOS for US adults and adolescents (N = 17,932) and children age < 12 years (N = 637) using nationally representative data for US for 2003-2018. Around the age of about 11-12 years for PFOS, PFNA, and PFNA, and around 15 years for PFOA, females begin to have reliably lower serum PFAS than males. This divergence is maximized around the ages of about 35 to 40 years for the alkylate compounds PFOA and PFNA, and from around 24-52 years for the sulfonate compounds PFOS and PFHxS. For example, for PFOS, gender divergence was 1.15 ng/mL at age 15, compared to 5.6 ng/mL at the age of 37 years. Uniquely, PFOS remained lower in females in most years after age 56, a contrast to the convergence in other PFAS studied. For males, increasing patterns were followed by somewhat decreasing patterns of concentration for most PFAS, the reverse was observed for females. The findings have implications for study design. Based on the results provided in detailed tables and figures for this study, we recommend separate analyses of male and female data. In addition, female serum concentration data should be considered for stratified analysis for pre- and post-menopausal time periods. From a mechanistic perspective, the data add support to existing questions about influences on gender differences in serum PFAS that may be attributed to causes other than menstruation, pregnancy, and lactation. These are amenable to further study.

Mechanistic Target of Rapamycin Complex 2 Regulation of the Primary Human Trophoblast Cell Transcriptome.

Mechanistic Target of Rapamycin Complex 2 (mTORC2) regulates placental amino acid and folate transport. However, the role of mTORC2 in modulating other placental functions is largely unexplored. We used a gene array following the silencing of rictor to identify genes regulated by mTORC2 in primary human trophoblast (PHT) cells. Four hundred and nine genes were differentially expressed; 102 genes were down-regulated and 307 up-regulated. Pathway analyses demonstrated that inhibition of mTORC2 resulted in increased expression of genes encoding for pro-inflammatory IL-6, VEGF-A, leptin, and inflammatory signaling (SAPK/JNK). Furthermore, down-regulated genes were functionally enriched in genes involved in angiogenesis (Osteopontin) and multivitamin transport (SLC5A6). In addition, the protein expression of leptin, VEGFA, IL-6 was increased and negatively correlated to mTORC2 signaling in human placentas collected from pregnancies complicated by intrauterine growth restriction (IUGR). In contrast, the protein expression of Osteopontin and SLC5A6 was decreased and positively correlated to mTORC2 signaling in human IUGR placentas. In conclusion, mTORC2 signaling regulates trophoblast expression of genes involved in inflammation, micronutrient transport, and angiogenesis, representing novel links between mTOR signaling and multiple placental functions necessary for fetal growth and development.

Characterization of the Primary Human Trophoblast Cell Secretome Using Stable Isotope Labeling With Amino Acids in Cell Culture.

The placental villus syncytiotrophoblast, the nutrient-transporting and hormone-producing epithelium of the human placenta, is a critical regulator of fetal development and maternal physiology. However, the identities of the proteins synthesized and secreted by primary human trophoblast (PHT) cells remain unknown. Stable Isotope Labeling with Amino Acids in Cell Culture followed by mass spectrometry analysis of the conditioned media was used to identify secreted proteins and obtain information about their relative rates of synthesis in syncytialized multinucleated PHT cells isolated from normal term placental villus tissue (n = 4/independent placenta). A total of 1,344 proteins were identified, most of which have not previously been reported to be secreted by the human placenta or trophoblast. The majority of secreted proteins are involved in energy and carbon metabolism, glycolysis, biosynthesis of amino acids, purine metabolism, and fatty acid degradation. Histone family proteins and mitochondrial proteins were among proteins with the slowest synthesis rate whereas proteins associated with signaling and the plasma membrane were synthesized rapidly. There was a significant overlap between the PHT secretome and proteins known be secreted to the fetal circulation by the human placenta in vivo. The generated data will guide future experiments to determine the function of individual secreted proteins and will help us better understand how the placenta controls maternal and fetal physiology.

Trauma and pregnancy: Is flow cytometry detection and quantification of fetal red blood cells useful?

OBJECTIVE: To assess whether positive flow cytometry quantification of fetal red blood cells is associated with adverse maternal and neonatal outcomes in cases of mild trauma during pregnancy. STUDY DESIGN: A retrospective database study was conducted at a single tertiary center between 2013 and 2019. All pregnant women with viable gestation involved in trauma who underwent flow cytometry quantification of fetal red blood cells were included in the study. Flow cytometry was considered positive (≥0.03/≥30 ml). Composite adverse maternal and neonatal outcome was defined as one or more of the following: intrauterine fetal death, placental abruption, pre-term birth <37 weeks of gestation, immediate premature rupture of the membranes, and immediate delivery following trauma. Univariate analysis was performed followed by multivariate logistic regression analysis controlling for potential confounders, to assess the role of flow cytometry in predicting adverse maternal and neonatal outcome. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. RESULTS: During the study period 1023 women met inclusion and exclusion criteria. The mechanisms of injury were motor vehicle accident in 387 women (38%), falls in 367 (36%), direct abdominal injury in 353 (35%) and in 14 women (1%) other mechanism of injury. Flow cytometry was considered positive (≥0.03/≥30 ml) in 119 women (11.6%) with median result of 0.03 [0.03-0.04], and negative in 904 women (88.4%) ((≤0.03/≤30 ml) with median result of 0.01 [0.01-0.02]. Composite adverse outcome occurred in 8% of the women involved in trauma during pregnancy, with no difference between the groups with vs. without positive flow cytometry (4.2% vs. 8.5%; p = 0.1). Positive flow cytometry was not associated with any adverse maternal or neonatal outcome. This was confirmed on multivariate analysis controlling for potential confounders. CONCLUSION: Flow cytometry result is not related to adverse maternal and fetal/neonatal outcome of women involved in minor trauma during pregnancy. We suggest that flow cytometry should not be routinely assessed in pregnant women involved in minor trauma.

Reduction of In Vivo Placental Amino Acid Transport Precedes the Development of Intrauterine Growth Restriction in the Non-Human Primate.

Intrauterine growth restriction (IUGR) is associated with reduced placental amino acid transport (AAT). However, it remains to be established if changes in AAT contribute to restricted fetal growth. We hypothesized that reduced in vivo placental AAT precedes the development of IUGR in baboons with maternal nutrient restriction (MNR). Baboons were fed either a control (ad libitum) or MNR diet (70% of control diet) from gestational day (GD) 30. At GD 140, in vivo transplacental AA transport was measured by infusing nine (13)C- or (2)H-labeled essential amino acids (EAAs) as a bolus into the maternal circulation at cesarean section. A fetal vein-to-maternal artery mole percent excess ratio for each EAA was measured. Microvillous plasma membrane (MVM) system A and system L transport activity were determined. Fetal and placental weights were not significantly different between MNR and control. In vivo, the fetal vein-to-maternal artery mole percent excess ratio was significantly decreased for tryptophan in MNR. MVM system A and system L activity was markedly reduced in MNR. Reduction of in vivo placental amino acid transport precedes fetal growth restriction in the non-human primate, suggesting that reduced placental amino acid transfer may contribute to IUGR.