Embriogénese: alterações morfológicas e crescimento desorganizado / Embryogenesis: Morphological Alterations and Disorganized Growth

A ocorrência de abortos espontâneos tem uma taxa de incidência elevada. Cerca de 15 a 20 % das gravidezes clinicamente reconhecidas terminam em aborto espontâneo, sendo a causa mais comum as anomalias cromossómicas. Foi objectivo avaliar as alterações morfológicas que mais frequentemente ocorrem no grupo dos crescimentos desorganizados (CD) (classificação de Poland et al.). Foram estudados 75 casos de abortos espontâneos, classificados histologicamente em crescimento desorganizado; subdividido em 4 tipos: CD1, CD2, CD3 e CD4. Foram consideradas as seguintes características morfológicas–macroscópicas: embrião; cordão umbilical; saco gestacional–intacto, roto e fragmentado; e crescimento (semanas de idade gestacional (IG)); e – microscópicas: córion; aspecto das vilosidades; estroma (edema, vasos, celularidade), trofoblasto vilositário e extravilositário; e desenvolvimento (semanas de IG). Da amostra, 29 casos correspondiam a CD1 —saco gestacional intacto contendo fluido mucóide, 32 a CD2 –embrião sem estruturas externas reconhecíveis, 8 a CD3 –embrião apenas com evidência dos pólos cefálicos e caudal, 6 a CD4— embrião com evidência de pólos cefálico e caudal; e outras estruturas externas reconhecíveis. À semelhança de outros autores, na nossa série, a hipoplasia do córion, a irregularidade do contorno vilositário, o edema e a hipovascularização foram também as alterações mais frequentes. Estes critérios poderão ter valor “preditivo” na classificação morfológica (diagnóstica) podendo orientar no aconselhamento genético de futuras gravidezes

The occurrence of spontaneous abortions has a highincidence rate. About 15 to 20% of the pregnanciesclinically recognized finish in spontaneous abortion,being the most common cause the chromosomalabnormalities.It was aim to evaluate the morphologic alterationsthat more frequently happen in the group of thegrowth disorganized (GD) embryos (classification ofPoland et al.).Seventy-five cases of spontaneous abortion werestudied, classified histologically in disorganized growth; subdivided in 4 types: GD1, GD2, GD3 and GD4. Thefollowing morphologic characteristics were considered -macroscopic: embryo; umbilical cord; gestational sac -intact, ruptured and fragmented; and growth (weeks ofgestational age); and - microscopic: chorion; aspect ofthe villi; stroma (oedema, vessels and cellularity); villous and extravillous trophoblast; and development (weeks of gestational age).Of the studied cases, 29 corresponded to GD1 —emptygestational sac containing mucoid fluid, 32 GD2- embryowithout recognizable external structures, 8 GD3 -embryojust with evidence of the cephalic and caudal poles, 6GD4— embryo with evidences of cephalic and caudalpoles, and others recognizable external structures.Like other authors, in our series, the hipoplasia of thechorion, the irregularity of the villi contour, the oedema and the hipovascularization were also the most frequent alterations.These criteria can have “predictive” value in themorphologic (diagnostic) classification and also couldprove some guide in the genetic consulting of future pregnancies (AU)

Characteristics and outcomes of fetuses with pericardial effusions.

Little is known about the characteristics and outcomes of fetuses with pericardial effusions (PEs); therefore, this study sought to identify factors associated with fetal PEs and the natural histories and outcomes of fetuses with PEs. Large PEs are associated with a greater likelihood of structural heart disease, impaired cardiac function, and chromosomal abnormalities, and PEs with hydrops or extracardiac malformations are associated with death. Most fetal PEs resolve, and fetuses with isolated PEs have a very good prognosis.

[Fetal nephro-/uropathy: a retrospective analysis of 124 cases seen in the period from 1996 to 2002]. / Fetale Nephro-/Uropathien: Retrospektive Analyse von 124 Fällen, erfasst im Zeitraum von 1996 bis 2002.

BACKGROUND: The embryological development of the kidneys and the urinary tract follows a complex choreography. Disorders are quite common. The incidence of disorders amounts to 0.3 - 0.8 % of live-born infants. In addition, several chromosomal anomalies are combined with renal malformations. The poor prognosis of some of these diseases is reflected in a perinatal mortality of 6.3 %. PATIENTS AND METHODS: Retrospectively 124 cases with fetal nephro-/uropathy detected by prenatal ultrasonography between 1996 and 2002 were analyzed. Features of hypo-dysplastic kidneys (uni- or bilateral) were seen in 21 cases. Multicystic kidney disease (uni- or bilateral) existed in 40 fetuses. In some cases of multicystic or dysplastic kidney diseases, extrarenal malformations were combined. 21 fetuses suffered from autosomal recessive polycystic kidney disease. 18 male unborns showed the typical picture of intravesical obstruction due to posterior uretheral valves. The prune belly syndrome was seen 4 times. Hydronephrotic kidneys with more than 5 mm pelvic dilatation were detected in 13 cases. Renal agenesis led to a lethal outcome perinatally in 5 cases. One child died of bilateral thrombosis of renal artery and venous system. RESULTS: The high incidence of diseases with a poor prognosis accounts for the high mortality of 50.8 % (intrauterine or postnatal death, induced abortion). Such a fatal outcome was observed in autosomal recessive polycystic kidney disease, bilateral multicystic dysplastic kidney disease, bilateral renal dysplasia combined with severe extrarenal malformations, intravesical obstruction, renal agenesis and bilateral thrombosis of the renal vessels. Only 60 children survived. Of these 26 needed urological surgery. 15 suffered from progressive renal insufficiency. During a follow-up of 8 - 58 months only 44 exhibited a normal renal function. CONCLUSIONS: Such complex renal and urological diseases in the fetus require an interdisciplinary management of the pregnancy.

Cardioprotective stress response in the human fetal heart.

OBJECTIVE: We propose that the fetal heart is highly resilient to hypoxic stress. Our objective was to elucidate the human fetal gene expression profile in response to simulated ischemia and reperfusion to identify molecular targets that account for the innate cardioprotection exhibited by the fetal phenotype. METHODS: Primary cultures of human fetal cardiac myocytes (gestational age, 15-20 weeks) were exposed to simulated ischemia and reperfusion in vitro by using a simulated ischemic buffer under anoxic conditions. Total RNA from treated and baseline cells were isolated, reverse transcribed, and labeled with Cy3 or Cy5 and hybridized to a human cDNA microarray for expression analysis. This analysis revealed a highly significant (false discovery rate, <3%) suppression of interleukin 6 transcript levels during the reperfusion phase confirmed by means of quantitative polymerase chain reaction (0.25 +/- 0.11-fold). Interleukin 6 signaling during ischemia and reperfusion was assessed at the protein expression level by means of Western measurements of interleukin 6 receptor, the signaling subunit of the interleukin 6 receptor complex (gp130), and signal transducer of activated transcription 3. Posttranslational changes in the protein kinase B signaling pathway were determined on the basis of the phosphorylation status of protein kinase B, mitogen-activated protein kinase, and glycogen synthase kinase 3beta. The effect of suppression of a prohypertrophic kinase, integrin-linked kinase, with short-interfering RNA was determined in an ischemia and reperfusion-stressed neonatal rat cardiac myocyte model. Endogenous secretion of interleukin 6 protein in culture supernatants was measured by enzyme-linked immunosorbent assay. RESULTS: Human fetal cardiac myocytes exhibited a significantly lower rate of apoptosis induction during ischemia and reperfusion and after exposure to staurosporine and recombinant interleukin 6 compared with that observed in neonatal rat cardiac myocytes ( P < .05 for all comparisons, analysis of variance). Exposure to exogenously added recombinant interleukin 6 increased the apoptotic rate in both rat and human fetal cardiac myocytes ( P < .05). Short-interfering RNA-mediated suppression of integrin-linked kinase, a prohypertrophy upstream kinase regulating protein kinase B and glycogen synthase kinase 3beta phosphorylation, was cytoprotective against ischemia and reperfusion-induced apoptosis in neonatal rat cardiac myocytes ( P < .05). CONCLUSIONS: Human fetal cardiac myocytes exhibit a uniquely adaptive transcriptional response to ischemia and reperfusion that is associated with an apoptosis-resistant phenotype. The stress-inducible fetal cardiac myocyte gene repertoire is a useful platform for identification of targets relevant to the mitigation of cardiac ischemic injury and highlights a novel avenue involving interleukin 6 modulation for preventing the cardiac myocyte injury associated with ischemia and reperfusion.

[Reliability of fetal pulse oximetry for the detection of fetal acidosis]. / Die Zuverlässigkeit der fetalen Pulsoxymetrie bei der Detektion einer fetalen Azidose.

Fetal pulse oximetry is a continuous method to exclude the lack of oxygen in cases of non-reassuring fetal heart rate. This study aims at the evaluation of the predictive value of this method concerning the development of fetal acidosis. 136 fetuses with non-reassuring heart rate were monitored by fetal pulse oximetry. In all cases fetal blood pH and base excess were determined repeatedly by fetal blood analysis (FBA). The pH value and base excess in the umbilical artery and scalp blood as well as the changes of pH and base excess were correlated to the duration of low, medium and high fetal oxygen saturation (FSpO (2)). Sensitivity, specificity, positive and negative predictive values were calculated for the assumption that "FSpO (2) < or = 30 % for at least 10 or 15 minutes" predicts a pH or base excess in the umbilical artery and in FBA of < 7.1/7.15/7.2 or < or = -4/8/12 mmol/L and a decline of pH (base excess) by more than 0.05 (0.1) pH units (4 mmol/L). A highly significant negative correlation was found between umbilical artery and FBA pH and base excess as well as the change of both and the duration of low oxygen saturation. Additionally the change of FBA pH depends on the duration of medium FSpO (2). A pH below 7.15 in FBA as well as base excess < or = -12 mmol/L were safely detected by a cut-off of "FSpO (2) < or = 30 % for at least 10 minutes" and pH < 7.1 and base excess < or = -12 mmol/l in FBA in 100 % and 75 %, respectively. A decline of pH by more than 0.1 pH units and of base excess by more than 4 mmol/L were excluded by a negative predictive value of 98 %. In conclusion, medium and progressive acidosis can be reliably excluded by fetal pulse oximetry.

Perinatal hyperoxia for 14 days increases nerve conduction time and the acute unitary response to hypoxia of rat carotid body chemoreceptors.

Hyperoxia in the immediate perinatal period, but not in adult life, is associated with a life-long impairment of the ventilatory response to acute hypoxia. This effect is attributed to a functional impairment of peripheral chemoreceptors, including a reduction in the number of chemoreceptor afferent fibers and a reduction in "whole nerve" afferent activity. The purpose of the present study was to assess the activity levels of single chemoreceptor units in the immediate posthyperoxic period to determine whether functional impairment extended to single chemoreceptor units and whether the impairment was only induced by hyperoxia exposure in the immediate postnatal period. Two groups of rat pups were exposed to 60% inspired O2 fraction for 2 wk at ages 0-14 days and 14-28 days, at which time single-unit activities were isolated and recorded in vitro. Compared with control pups, hyperoxia-treated pups had a 10-fold reduction in baseline (normoxia) spiking activity. Peak unit responses to 12, 5, and 0% O2 were reduced and nerve conduction time was significantly slower in both hyperoxia-treated groups compared with control groups. We conclude that 1) hyperoxia greatly reduces single-unit chemoreceptor activities during normoxia and acute hypoxia, 2) the treatment effect is not limited to the immediate newborn period, and 3) at least part of the impairment may be due to changes in the afferent axonal excitability.

In utero gene therapy: prospect and future.

Many genetic disorders are reported to cause irreversible damage to the fetus before birth. In utero gene therapy may be an effective tool for correction of genetic disorders by replacing defective gene with normal one. There are many reasons for moving forward with in utero gene therapy. The most important reason is to provide early intervention as to prevent or slow dysfunction and morbidity. This approach may prove to be advantageous in rapidly replicating fetal cells, and less sensitive to immune response to vector or transgene product due to underdeveloped immune system. In addition, the developing fetus may be a better candidate for gene therapy than the adult because gene engraftment may be more feasible in early fetal life, where stem cells or pleuripotent progenitor cells are more accessible to vectors. Some reports are available on successful in utero gene transfer in animal models but many questions remain to be answered before in utero gene therapy can be considered a viable solution to human. The real moral challenge facing in utero gene therapy is finding ways to insure that the review of protocols is adequate, and that those undertaking trials are competent to do so. Present review article analyzes the overall progress of the field, and the research that still needs to be performed before it can be considered to human clinical trials.

[Lymphangioma--prenatal and perinatal aspects--Part one]. / Naczyniak limfatyczny--aspekty prenatalne i perinatalne--czesc pierwsza.

Lymphangioma or cystic hygroma is a congenital malformation of the lymphatic system which has been commonly associated with fetal aneuploidy, hydrops, structural malformations and intrauterine death. In this paper we would like to report two cases of lymphangioma diagnosed prenatally in the third trimester in the fetuses with normal karyotype, normal NT in the first trimester and without other structural anomalies and with good perinatal outcome.

Reproductive outcomes after pregnancy complicated by maternal-fetal surgery.

OBJECTIVE: The reproductive outcomes for women after the pregnancy complicated by maternal-fetal surgery were evaluated to obtain evidence-based information for prenatal risk counseling. STUDY DESIGN: The retrospective review identified 83 women with maternal-fetal surgery from a single institution (1996-2002). These women were sent a consent form and a questionnaire to document postoperative problems, fertility, obstetric outcomes, and psychosocial concerns in pregnancy after the index fetal therapy. Institutional Review Board approval was obtained from Committee for Protection of Human Subjects. RESULTS: The total return rate was 55 (66%). The pregnancy rate was 62% (18% spontaneous abortion, 24% preterm delivery, and 58% term delivery). Complications were reported in 12 of 34 pregnancies (35%), including uterine dehiscence/rupture (12%/6%), cesarean hysterectomy (3%), and antepartum hemorrhage requiring transfusion (9%). CONCLUSION: The reproductive outcome of uterine dehiscence, rupture, and hysterectomy was 12%, 6%, and 3%, respectively, after a pregnancy complicated by maternal-fetal surgery. The uterine rupture rate is similar to the rupture rate after "classical" cesarean section (4%-9%).

Contingent screening for Down syndrome is an efficient alternative to non-disclosure sequential screening.

OBJECTIVE: To present a first and second trimester Down syndrome screening strategy, whereby second-trimester marker determination is contingent on the first-trimester results. Unlike non-disclosure sequential screening ('the Integrated test'), which requires all women to have markers in both trimesters, this allows a large proportion of the women to complete screening in the first trimester. METHODS: Two first-trimester risk cut-offs defined three types of results: positive and referred for early diagnosis; negative with screening complete; and intermediate, needing second-trimester markers. Multivariate Gaussian modelling with Monte Carlo simulation was used to estimate the false-positive rate for a fixed 85% detection rate. The false-positive rate was evaluated for various early detection rates and early test completion rates. Model parameters were taken from the SURUSS trial. RESULTS: Completion of screening in the first trimester for 75% of women resulted in a 30% early detection rate and a 55% second trimester detected rate (net 85%) with a false-positive rate only 0.1% above that achievable by the Integrated test. The screen-positive rate was 0.1% in the first trimester and 4.7% for those continuing to be tested in the second trimester. If the early detection rate were to be increased to 45% or the early completion rate were to be increased to 80%, there would be a further 0.1% increase in the false-positive rate. CONCLUSION: Contingent screening can achieve results comparable with the Integrated test but with earlier completion of screening for most women. Both strategies need to be evaluated in large-scale prospective studies particularly in relation to psychological impact and practicability.

First prenatal diagnosis for Wolfram syndrome by molecular analysis of the WFS1 gene.

Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by early onset diabetes mellitus and progressive optic atrophy in the first decade of life. Other clinical features such as diabetes insipidus, deafness, renal tract abnormalities or psychiatric illnesses are often present. The sequence of the Wolfram syndrome gene (WFS1) was described in 1998, and mutations in the gene have been reported in many populations. To date, the function of the putative protein remains unknown. Here we report prenatal diagnosis by analysing the WFS1 gene, in a foetus belonging to a family with a child diagnosed for Wolfram syndrome. The parents are carriers of the c.2206G > C (G736R) mutation. To our knowledge this is the first description of prenatal diagnosis for Wolfram syndrome, based on the molecular analysis of the WFS1 gene.

Evolution of heart disease in utero.

Cardiac embyogenesis occurs in the first 6 to 7 weeks of human development. Although it is during this time that many of the major cardiovascular defects develop, many of these lesions continue to evolve and others develop in the latter half of gestation. There may be development or progression of ventricular inflow or outflow tract and arch obstruction, and ventricular or great artery hypoplasia. There may be progressive antrioventricular or semi-lunar valve regurgitation which can compromise the fetal circulation. There may be development of dysrhythmias, primary myocardial disease and heart failure. The fetal shunts, the foramen ovale and ductus arteriosus, may change in form and function. Finally, cardiac tumors may develop, grow, or regress. Knowledge of the mechanisms of and potential for progression in fetal heart disease is critical for counseling regarding prognosis and for planning of prenatal and neonatal management.

Congenital diaphragmatic hernia: prenatal diagnosis permits immediate intensive care with high survival rate in isolated cases. A population-based study.

OBJECTIVES: To estimate the prognosis of prenatally diagnosed isolated congenital diaphragmatic hernia (PDICDH) treated with 'immediate planned care' (IPC) between 1999 and 2003 in Eastern Brittany. METHODS: The prognosis of PDICDH was compared with the prognosis of the other live-born CDH, either prenatally undiagnosed or not having had IPC. IPC consisted in prenatal lung maturation with corticosteroids, elective caesarean section at 37 weeks, immediate intubation, surfactant, high- frequency ventilation or oscillation, nitric oxide, intravenous prostacyclin, anaesthesia and haemodynamic support. Surgical repair was performed in the NICU 34 h after birth. RESULTS: The incidence of CDH was 0.8 per thousand with a prenatal diagnosis rate of 27/30 (90%), leading to a termination of pregnancy in nine cases. Ten CDH were associated with other malformations. IPC in PDICDH was performed in 12 cases. The survival rate of PDICDH with IPC was 11/12 versus 1/9 in CDH with no IPC or no prenatal diagnosis (p < 0.01). Logistic regression analysis showed that IPC was determinant for survival (p < 0.01). CONCLUSION: Prenatal diagnosis of isolated CDH treated with immediate planned care is associated with a high survival rate. This suggests that prenatal diagnosis associated with specifically adapted postnatal procedure may improve the prognosis of isolated CDH.

Positive maternal serum triple test screening in severe early onset hypophosphatasia.

OBJECTIVES: Hypophosphatasia is a rare heritable inborn error of metabolism characterized by a liver/bone/kidney alkaline phosphatase defective bone mineralization due to mutations in the tissue-non-specific alkaline phosphatase (TNS-ALP) gene. To date 128 mutations are described in the TNS-ALP gene located on the short arm of chromosome 1. The clinical presentation of hypophosphatasia is variable ranging from early onset lethal short-limb dwarfism to a late-onset presentation with fractures in childhood or adulthood. METHODS: We report a pregnancy with a positive maternal serum triple test screening and a post-mortem pathological and molecular diagnosis of perinatal lethal hypophosphatasia. RESULTS: Two heterogeneous missense mutations in the TNS-ALP gene were found, of which one was not previously described. CONCLUSION: This case report adds to the list of fetal malformations found after positive maternal serum triple test screening and reports a previously undescribed mutation in the TNS-ALP gene responsible for hypophosphatasia.

Prenatal rupture of a left ventricular diverticulum: a case report and review of the literature.

Congenital left ventricular diverticulum is a rare malformation. We report a case of a ruptured congenital left ventricular diverticulum in a 24-week-old fetus. The fetus was referred for a large and circumferential pericardial effusion confirmed by cross-sectional echocardiography in our tertiary fetal cardiology unit. Pericardiocentesis removed 25 mL of old hematic fluid. The fetus died 5 days later. The pathological examination showed a ruptured submitral fibrous diverticulum of the posterior wall of the left ventricle. There is no previous report in the literature of prenatal rupture of a cardiac diverticulum. The submitral location and the fibrous wall of the diverticulum is uncommon. As regards this case, we reviewed the diagnostic criteria and the outcome of 11 cases of prenatal cardiac diverticulum reported in the literature.

Diagnosis and outcome of dextrocardia diagnosed in the fetus.

A retrospective review of 5,539 fetal echocardiograms over a 22-year period revealed 85 cases of dextrocardia. In primary dextrocardia (46 cases), the incidence of situs solitus, inversus, and ambiguous, was similar and associated with a high incidence of complex cardiac malformations in situs solitus and situs ambiguous. Secondary dextrocardia (39 cases) was due to intrathoracic displacement and, when caused by diaphragmatic hernia, was associated with cardiac malformations in 31% of cases. Even in complex cases, fetal echocardiography was highly accurate; therefore, specific counseling can be given to parents.