Trophoblast-specific overexpression of the LAT1 increases transplacental transport of essential amino acids and fetal growth in mice.

Placental System L amino acid transporter activity is decreased in pregnancies complicated by intrauterine growth restriction (IUGR) and increased in fetal overgrowth. However, it is unknown if changes in the expression/activity of placental Large Neutral Amino Acid Transporter Small Subunit 1 (Slc7a5/LAT1) are mechanistically linked to placental function and fetal growth. We hypothesized that trophoblast-specific Slc7a5 overexpression increases placental transport of essential amino acids, activates the placental mechanistic target of rapamycin (mTOR) signaling, and promotes fetal growth in mice. Using lentiviral transduction of blastocysts with a Slc7a5 transgene, we achieved trophoblast-specific overexpression of Slc7a5 (Slc7a5 OX) with increased fetal (+27%) and placental weights (+10%). Trophoblast-specific Slc7a5 overexpression increased trophoblast plasma membrane (TPM) LAT1 protein abundance and TPM System L transporter (+53%) and System A transporter activity (+ 21%). Slc7a5 overexpression also increased transplacental transport of leucine (+ 85%) but not of the System A tracer, 14C-methylamino isobutyric acid, in vivo. Trophoblast-specific overexpression of Slc7a5 activated placental mTORC1, as assessed by increased (+44%) phosphorylation of S6 ribosomal protein (Ser 235/236), and mTORC2 as indicated by phosphorylation of PKCα-Tyr-657 (+47%) and Akt-Ser 473 (+96%). This is the first demonstration that placental transport of essential amino acids is mechanistically linked to fetal growth. The decreased placental System L activity in human IUGR and the increased placental activity of this transporter in some cases of fetal overgrowth may directly contribute to the development of these pregnancy complications.

Regulation of placental amino acid transport in health and disease.

Abnormal fetal growth, i.e., intrauterine growth restriction (IUGR) or fetal growth restriction (FGR) and fetal overgrowth, is associated with increased perinatal morbidity and mortality and is strongly linked to the development of metabolic and cardiovascular disease in childhood and later in life. Emerging evidence suggests that changes in placental amino acid transport may contribute to abnormal fetal growth. This review is focused on amino acid transport in the human placenta, however, relevant animal models will be discussed to add mechanistic insights. At least 25 distinct amino acid transporters with different characteristics and substrate preferences have been identified in the human placenta. Of these, System A, transporting neutral nonessential amino acids, and System L, mediating the transport of essential amino acids, have been studied in some detail. Importantly, decreased placental Systems A and L transporter activity is strongly associated with IUGR and increased placental activity of these two amino acid transporters has been linked to fetal overgrowth in human pregnancy. An array of factors in the maternal circulation, including insulin, IGF-1, and adiponectin, and placental signaling pathways such as mTOR, have been identified as key regulators of placental Systems A and L. Studies using trophoblast-specific gene targeting in mice have provided compelling evidence that changes in placental Systems A and L are mechanistically linked to altered fetal growth. It is possible that targeting specific placental amino acid transporters or their upstream regulators represents a novel intervention to alleviate the short- and long-term consequences of abnormal fetal growth in the future.

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.

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.

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.

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.

Neonatal infection and passive acquisition of serum total IgG and reactive with Streptococcus B, anti-LPS of Klebsiella spp and Pseudomonas spp antibodies in twins

SUMMARY OBJECTIVE To describe the concentration of total and specific IgG antibodies anti-Streptococcus B, anti-lipopolysaccharide of Klebsiella spp, and anti-lipopolysaccharide of Pseudomonas spp in the umbilical cord of newborn(NB) twins and to analyze the association between neonatal infection and antibody concentration in the umbilical cord blood. METHODS A prospective cross-sectional study of a cohort of NB twins admitted during the period of 20 months. Patients with malformations and mothers with infection were excluded. Variables analyzed: gestational age(GA); birth weight(BW); antibody concentrations in umbilical cord blood; infection episodes. We used the paired Student t-test, Spearman correlation, and generalized estimation equation. RESULTS 57 pairs of twins were included, 4 excluded, making the sample of 110 newborns. GA=36±1.65weeks and BW=2304.8±460g(mean±SD). Antibody concentrations in twins(mean±SD): total IgG=835.71±190.73mg/dL, anti-StreptococcusB IgG=250.66±295.1 AU/mL, anti-lipopolysaccharide of Pseudomonas spp IgG=280.04±498.66 AU/mL and anti-lipopolysaccharide of Klebsiella spp IgG=504.75±933.93 AU/mL. There was a positive correlation between maternal antibody levels and those observed in newborns(p <0.005). The transplacental transfer of maternal total IgG and anti-LPS Pseudomonas IgG antibodies was significantly lower at NB GA <34 weeks(p <0.05). Five newborns were diagnosed with an infection. Infants with infection had significantly lower total IgG concentration(p <0.05). CONCLUSION This study showed a positive correlation between maternal and newborn antibodies levels. In infants younger than 34 weeks there is less transfer of total IgG and anti-LPS Pseudomonas IgG. The highest incidence of infection in the newborn group who had significantly lower total IgG serum antibodies reinforces the importance of anti-infectious protection afforded by passive immunity transferred from the mother.

RESUMO OBJETIVOS Descrever o título de anticorpos IgG total e específico anti-Streptococcus B, anti-lipopolissacarídeos(LPS) de Klebsiella e Pseudomonas no cordão umbilical em gêmeos e analisar a possível associação entre os títulos desses anticorpos e a ocorrência de infecção. MÉTODOS Estudo prospectivo transversal de uma coorte de recém-nascidos (RN) gemelares em 20 meses. Excluídos: malformação, infecção congênita ou materna. Variáveis estudadas: idade gestacional(IG); peso de nascimento(PN); título de anticorpos e episódios de infecção. Foram utilizados testes t-Student pareado, correlação de Spearman e equações de estimação generalizadas. RESULTADOS Elegíveis 59 pares de gêmeos, excluídos 4 e incluídos 55 pares (n=110RN). A IG foi 36±1,65semanas e o PN foi 2304,8±460g (média±DP). Concentrações de anticorpos dos RN(média±DP): IgG total=835,71±190,73 mg/dL, IgG anti-Streptococcus B=295,1±250,66 UA/mL, IgG anti-LPS Pseudomonas=280,04±498,66 UA/mL e IgG anti-LPS Klebsiella=504,75± 933,93UA/mL. Houve correlação positiva entre níveis de anticorpos maternos e aqueles observados nos RN (p<0,005). A transferência transplacentária de anticorpos maternos IgG total e IgG anti-LPS Pseudomonas foi significativamente menor em RN IG < 34semanas (p<0,05). Foram diagnosticados 5 RN com infecção. Os RN que apresentaram infecção tinham concentração de IgG total significativamente menor (p<0,05). CONCLUSÕES Na população estudada existe correlação entre os anticorpos maternos e os níveis de anticorpos no RN. Nos gêmeos menores que 34 semanas há menor transferência de IgG total e IgG anti-LPS Pseudomonas. Nos RN com infecção a concentração de IgG total é significativamente menor, o que demonstra a maior vulnerabilidade e risco de infecção dessa população e a importância da imunidade passiva transferida pela placenta.

Hypertriglyceridemia and adverse outcomes during pregnancy / Hipertrigliceridemia y consecuencias adversas en el embarazo

Abstract Introduction: During pregnancy, levels of maternal serum triglycerides increase as a physiological adaptation mechanism to meet the needs of the developing fetus. However, although an excessive increase has been associated with preeclampsia, macrosomia and preterm delivery, the levels from which measurements should be taken in each trimester to prevent complications have not been established conclusively. Objective: To review the physiopathology, effects on mother and child, expected values in each trimester and therapeutic interventions in maternal hypertriglyceridemia. Materials and methods: A review was made based on a search of articles in the ScienceDirect, Pubmed, Scopus, LILACS, Cochrane and SciELO databases, with the terms: Pregnancy; Hypertriglyceridemia; Maternal-Fetal Exchange; Fetal Development; Pregnancy Complications in English and its equivalents in Spanish. Results: 59 articles met the search criteria and responded to the objectives. Conclusions: The limited amount and the great variability of the data indicate the need to carry out further research to establish the normal triglycerides ranges during the three trimesters of pregnancy and to determine risks and effective interventions before pregnancy in order to reduce maternal and child morbidity and mortality.

Resumen Introducción. Durante el embarazo, los niveles séricos de triglicéridos maternos aumentan como un mecanismo de adaptación fisiológica para suplir las necesidades del feto en desarrollo. Pese a que el incremento excesivo se ha asociado a preeclampsia, macrosomía y parto pretérmino, no se han establecido de manera contundente los niveles a partir de los cuales se deben tomar medidas en cada trimestre para prevenir complicaciones. Objetivo. Hacer una revisión sobre fisiopatología, efectos en madre e hijo, valores esperados en cada trimestre e intervenciones terapéuticas en hipertrigliceridemia gestacional. Materiales y métodos. Se realizó una revisión con la búsqueda de artículos en las bases de datos ScienceDirect, PubMed, Scopus, LILACS, Cochrane y SciELO con los términos: Pregnancy; Hypertriglyceridemia; Maternal-Fetal Exchange; Fetal Development; Pregnancy Complications y sus equivalentes en español. Resultados. Se encontraron 59 artículos que cumplieron los criterios de búsqueda y daban respuesta a los objetivos. Conclusiones. El número limitado y la gran variabilidad de los datos indican la necesidad de realizar más investigaciones que establezcan los rangos de normalidad de los triglicéridos durante los tres trimestres del embarazo y así determinar riesgos e intervenciones eficaces antes de la gestación y reducir la morbimortalidad materno-infantil.

Vacinação contra o vírus influenza em gestantes: cobertura da vacinação e fatores associados / Influenza vaccine in pregnant women: immunization coverage and associated factors

OBJETIVO: Descrever a cobertura vacinal de gestantes para influenza e fatores associados à recusa ou à aceitação da vacina. MÉTODOS: Estudo descritivo, prospectivo, que incluiu 300 puérperas atendidas no Hospital e Maternidade Santa Joana (SP). Os dados foram coletados em outubro de 2010, por meio de questionário pré-testado, aplicado por profissional treinado. RESULTADOS: A média de idade das mães foi 30,5 anos; 231 (77%) eram casadas; 164 (54,7%) primigestas; 192 (64%) tinham nível superior de escolaridade; e 240 (80%) estavam empregadas. Durante o pré-natal, 234 (78%) receberam informação sobre a vacina contra influenza e 287 (95,7%) foram imunizadas; 210 (73,2%) mulheres tinham conhecimento sobre a proteção neonatal pela vacinação materna. Fatores associados à aceitação foram: campanha do governo (133; 44,3%) e recomendação médica durante o pré-natal (163; 54,3%). Entre as 13 grávidas que recusaram a vacinação, as razões foram: negligência (4), falta de tempo (4), falta de indicação médica (3) ou contraindicação pelo médico (2), mas 69,2% teriam sido vacinadas se tivessem sido informadas sobre a proteção neonatal. CONCLUSÃO: O receio da pandemia e a campanha pública tiveram importante impacto na elevada cobertura vacinal para influenza em gestantes. Recomendação médica e campanha do governo foram os principais motivos de aceitação da vacina.

OBJECTIVES: To describe the immunization coverage of the influenza vaccine for pregnant women, and factors associated to vaccination compliance. METHODS: This is a prospective, descriptive study including 300 women who had just given birth at Hospital and Maternity Santa Joana in Sao Paulo, Brazil. Data were collected through a pre-tested questionnaire applied by a trained evaluator during October 2010. RESULTS: The mean age of mothers was 30.5 years; 231 (77%) were married; 164 (54.7%) were primigravidas; 192 (64%) had higher education; and 240 (80%) were employed. During the prenatal period, 234 (78%) received information about the influenza vaccine and 287 (95.7%) were immunized; 210 (73.2%) women knew about neonatal protection achieved through maternal vaccination. The factors associated with maternal acceptance of the vaccine were government campaign (133; 44.3%), and medical recommendation during prenatal visits (163; 54.3%). A total of 13 pregnant women refused vaccination for the following reasons: neglect (4), lack of time (4), lack of recommendation from their physician (3) or contraindication by physician (2), but 69.2% of them would have accepted immunization had they been informed about neonatal protection. CONCLUSIONS: The fear of a pandemic and the public vaccination campaign had an important impact on the high immunization coverage for influenza on pregnant women. Medical recommendation and the government campaign were the main reasons for vaccine compliance.

Diagnóstico de enfermedad de Chagas en maternas y recién nacidos de Moniquirá y Miraflores, Boyacá, Colombia / Diagnosis of Chagas disease in Pregnant Women and Newborns in Moniquirá and Mira-Florez, Boyacá, Colombia

Objetivo: Se estudia la infección por Trypanosoma cruzi en mujeres embarazadas en Moniquirá y Miraflores, en Boyacá, Colombia, y la transmisión transplacentaria. Materiales y métodos: Se programó el tamizaje de 826 maternas (600 a 950) en los 2 municipios, se logró un total de 702 participantes de las cuales se procesaron 659 muestras (358 de Moniquirá y 301 de Miraflores), mediante técnicas de ELISA en papel de filtro y se confirmaron las positivas con ELISA en suero, inmunofluorescencia indirecta, hemocultivo y reacción en cadena de la polimerasa. Resultados: La prevalencia actual de enfermedad de Chagas en maternas es de 3,34% (22/659), 3,99% (12/301) en Miraflores y 2,79% (10/358) en Moniquirá. De 22 maternas en seguimiento, se logró obtener datos de 18 de los recién nacidos (RN), de los cuales 6 fueron positivos para las pruebas de hemocultivo. Se consideró el hemocultivo como la técnica confirmatoria de parasitemia en RN antes de 8 meses, por lo tanto, la incidencia transplacentaria global sería de 27,27% RN positivos/año (6/22). Luego del seguimiento del entorno hogar y peridomicilio, búsqueda de triatomíneos y fumigación de la vivienda, se inició tratamiento de RN con benzonidazole a razón de 5-8 mg/kg/día durante 60 días. Conclusiones: La prevalencia en maternas obtenida es superior a los reportes en Chile y Brasil; pero inferiores a Bolivia, Argentina y Uruguay. La incidencia transplacentaria encontrada en un año de seguimiento es similar a la reportada en Chile (16 al 28%), superior a la de Brasil (1%), Uruguay (0,5 a 3%) y Bolivia y Paraguay (7%).

AbstractObjective:To study Trypanosoma cruzi infection in pregnant women and its transplacental transmission in Moniquira and Miraflores, Boyaca, Colombia.Materials and methods: Screening of 862 pregnant women in both municipalities was planned; 689 participants were screened by Elisa technique on blood samples drawn on filter paper from whom 659 samples were processed (358 from Moniquira and 301 from Miraflores). Elisa and IFAT in serum, blood cultures and PCR were carried out in positive pregnant women and their children.Results: The total prevalence of Chagas disease in pregnant women was 3.3% (22/659), 3.9% (12/301) in Miraflores and 2.7% (10/358) in Moniquira. Of the 22 pregnant women who were followed, data was obtained from 18 of their newborns, 6 of whom had positive blood cul-ture tests. Blood cultures were considered as the confirmatory technique for parasitemia in newborns before 8 months of age. Therefore, the overall rate of transmission of congenital infection was 33.3% (6/18). After following-up at the homes and peridomiciles, searching for triatomine bugs and spraying the homes, we began treatment for the infected newborns with benznidazole at a dose of 5-8 mg/kg/day for 60 days.Conclusions: The prevalence found in pregnant women was similar to that reported for Casanare. The rate of transmission of congenital infection was similar to that reported in Chile (16%-28%) and higher than those in Brazil (1%), Argentina (1.5%-4.5%), Uruguay (0.5%-3%), Bolivia (7%) and Paraguay (7%)

El embarazo humano: paradigma biológico de tolerancia y adaptación / Human pregnancy, a biological paradigm of tolerance and adaptation

This review analyses the changes in immunological tolerance, and the systemic and local hemodynamic changes observed along human pregnancy. To underscore the conceptual importance of tolerance and adaptation the background isprovided by the two main advocates ofthese ideas: Gandhi and Darwin. The cognate factors that determine immunological tolerance (IT), systemic (SA) and local adaptation (LA) are múltiple; IT = desensitisation to paternal antigens, absence of HLA-A, roles of HLA-G, natural killer cells and their receptors; SA = decreased vascular resistance, plasma volume expansión, increased cardiac output and plasma renin activity; LA = prostacyclin, nitric oxide, kallikrein-kinin system, vasodilator arm of the renin angiotensin system, vascular endothelial growth factor (VEGF). A possible role of vasodilators in the crucial process of trophoblast invasión and uterine artery transformation is supported. The relevance ofan adequate adaptation to pregnancy is highlighted not only by the intragestational complications derivedfrom a defective process, such as intrauterine growth restriction, preterm birth, and preeclampsia -its foremost expression- but also by the long term cardiovascular complications ofthe mother and her offspring.

Fisiologia e farmacologia da placenta: efeitos da anestesia sobre o útero,placenta e feto / Placental physiology and pharmacology: effects of anesthesiaon the uterus, placenta and fetus

Justificativa e objetivos: o objetivo desta revisão é proporcionar ao leitor informações úteis para a condução adequada da anestesia obstétrica. Conteúdo: inicialmente, discorre-se sobre a fisiologia e as funções da placenta e os principais determinantes do fluxo útero-placentário. Os mecanismos de passagem transplacentária de fármacos são elucidados com destaque para a difusão simples, que se fundamenta na lei de Fick.A correlação de técnicas e drogas anestésicas com a segurança materna, circulação útero-placentária e o bem-estar fetal é pormenorizada nos seguimentos da anestesia regional, relacionada ao uso de anestésicos locais e opioides e da anestesia geral, com o uso de anestésicos venosos, inalatórios e bloqueadores neuromusculares. Conclusão: o progresso e novos conhecimentos sobre as técnicas anestésicas em obstetrícia são de suma importância para a segurança materno-fetal.

Background and objectives: The objective of this review is to provide the reader with useful information for the proper conduct of obstetric anesthesia. Contents: Initially, the authors discuss about the physiology and functions of the placenta and the major determinants of utero-placental flow. The mechanisms of transplacental transfer of drugs are elucidated with emphasis on simple diffusion, which is based in the Fick's law. The correlation of anesthetic drugs and techniques with maternal safety, uteroplacental circulation and fetal well-being is detailed in regional anesthesia, related to the use oflocal anesthetics and opioids, and in general anesthesia, related to the use of inhaled and intravenous anesthetics, and also neuromuscular blockers. Conclusion: Progress and new knowledge about anesthetic techniques in obstetrics are important to provide a good level of security to the mother and fetus.