RESUMO
Stress response signals can propagate between cells damaged by targeted effects (TE) of ionizing radiation (e.g. energy depositions and ionizations in the nucleus) and undamaged "bystander" cells, sometimes over long distances. Their consequences, called non-targeted effects (NTE), can substantially contribute to radiation-induced damage (e.g. cell death, genomic instability, carcinogenesis), particularly at low doses/dose rates (e.g. space exploration, some occupational and accidental exposures). In addition to controlled laboratory experiments, analysis of observational data on wild animal and plant populations from areas contaminated by radionuclides can enhance our understanding of radiation responses because such data span wide ranges of dose rates applied over many generations. Here we used a mechanistically-motivated mathematical model of TE and NTE to analyze published embryonic mortality data for plants (Arabidopsis thaliana) and rodents (Clethrionomys glareolus) from the Chernobyl nuclear power plant accident region. Although these species differed strongly in intrinsic radiosensitivities and post-accident radiation exposure magnitudes, model-based analysis suggested that NTE rather than TE dominated the responses of both organisms to protracted low-dose-rate irradiation. TE were predicted to become dominant only above the highest dose rates in the data. These results support the concept of NTE involvement in radiation-induced health risks from chronic radiation exposures.
Assuntos
Arabidopsis/embriologia , Arabidopsis/efeitos da radiação , Arvicolinae/embriologia , Acidente Nuclear de Chernobyl , Animais , Perda do Embrião/etiologia , Modelos Biológicos , Doses de Radiação , Radiação IonizanteRESUMO
Both hyperthyroidism and hypothyroidism can have adverse effects in pregnancy. The most common causes of thyrotoxicosis in pregnancy are gestational transient thyrotoxicosis and Graves' disease. It is important to distinguish between these entities as treatment options differ. Women of reproductive age who are diagnosed with Graves' disease should be counseled regarding the impact of treatment options on a potential pregnancy. Although the absolute risk is small, antithyroid medications can have teratogenic effects. Propylthiouracil appears to have less severe teratogenicity compared to methimazole and is therefore favored during the first trimester if a medication is needed. Women should be advised to delay pregnancy for at least 6 months following radioactive iodine to minimize potential adverse effects from radiation and ensure normal thyroid hormone levels prior to conception. As thyroid hormone is critical for normal fetal development, hypothyroidism is associated with adverse obstetric and child neurodevelopmental outcomes. Women with overt hypothyroidism should be treated with levothyroxine (LT4) to a thyrotropin (thyroid-stimulating hormone; TSH) goal of <2.5 mIU/L. There is mounting evidence for associations of maternal hypothyroxinemia and subclinical hypothyroidism with pregnancy loss, preterm labor, and lower scores on child cognitive assessment. Although there is minimal risk of LT4 treatment to keep TSH within the pregnancy-specific reference range, treatment of mild maternal thyroid hypofunction remains controversial, given the lack of clinical trials showing improved outcomes with LT4 treatment.
Assuntos
Complicações na Gravidez , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/terapia , Adulto , Perda do Embrião/etiologia , Feminino , Doença de Graves/complicações , Doença de Graves/diagnóstico , Doença de Graves/terapia , Humanos , Recém-Nascido , Testes para Triagem do Soro Materno/métodos , Testes para Triagem do Soro Materno/normas , Monitorização Fisiológica/métodos , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/terapia , Cuidado Pré-Natal/métodos , Taquicardia/diagnóstico , Taquicardia/etiologia , Taquicardia/terapia , Doenças da Glândula Tireoide/complicações , Testes de Função Tireóidea/métodos , Testes de Função Tireóidea/normas , Tireotoxicose/complicações , Tireotoxicose/diagnóstico , Tireotoxicose/terapia , Redução de Peso/fisiologiaRESUMO
Proteus syndrome is a progressive overgrowth disorder with vascular malformations caused by mosaic expression of the AKT1 c.49G > A, p.(E17K) activating variant which was predicted to cause lethality if expressed ubiquitously. To test that hypothesis, we used the ACTB-Cre gene to activate a conditional Akt1 p.(E17K) allele in the mouse. No offspring that was heterozygous for both Cre and the conditional allele (ßA-Akt1WT/flx) was viable. Fewer than expected numbers of ßA-Akt1WT/flx embryos were seen beginning at E11.5, but a few survived until E17.5. The phenotype ranged from mild to severe, but generally ßA-Akt1WT/flx embryos had fewer visible blood vessels and more hemorrhages than their wild-type littermates, which was suggestive of a vascular abnormality. Examination of E13.5 limb skin showed a primitive capillary network with increased branching complexity and abnormal patterning compared with wild-type skin. By E15.5, wild-type skin had undergone angiogenesis and formed a hierarchical network of remodeled vessels, whereas in ßA-Akt1WT/flx embryos, the capillary network failed to remodel. Mural cell coverage of the blood vessels was also reduced in ßA-Akt1WT/flx skin compared with that of wild type. Restricting expression of Akt1E17K to endothelial, cardiac or smooth muscle cells resulted in viable offspring and remodeled vasculature and did not recapitulate the ßA-Akt1WT/flx phenotype. We conclude that ubiquitous expression of Akt1E17K suppresses remodeling and inhibits the formation of a normal skin vasculature. We postulate that this failure prevents proper circulation necessary to support the growing embryo and that it is the result of interactions of multiple cell types with increased AKT signaling.
Assuntos
Perda do Embrião/patologia , Embrião de Mamíferos/patologia , Neovascularização Patológica/patologia , Doenças Vasculares Periféricas/patologia , Síndrome de Proteu/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Perda do Embrião/etiologia , Perda do Embrião/metabolismo , Embrião de Mamíferos/metabolismo , Feminino , Camundongos , Camundongos Transgênicos , Neovascularização Patológica/etiologia , Neovascularização Patológica/metabolismo , Doenças Vasculares Periféricas/etiologia , Doenças Vasculares Periféricas/metabolismo , Síndrome de Proteu/etiologia , Síndrome de Proteu/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de SinaisRESUMO
Determining if reproductive failures in ewes at the semiarid region in the state of Bahia are related to the consumption of the species Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, and this study was developed using pregnant ewes divided into six groups: G1, G2, G3, G4 with six animals each, G5 and G6 with ten animals. Each group received fence leaves in the proportion of 1%, 2%, 0.5%, and 0.25% of live weight (LW) respectively; G5 and G6, with ten animals each, receiving 0.25% and 0.5% of the LW, respectively, and the Control Group, comprising 16 ewes, were grass feeding (Cynodon dactylon). Ewes from G1 to G4 were the same, except for two, and started ingestion of the plant four days after ending of natural mating on the 80th day of gestation, while those regarding from G5 to G6 groups started ingestion on the 26th day of gestation ending on the 98 day. The ultrasonographic test was performed weekly. In G1 ewes (1%), there was an embryonic loss on the 32nd and 39th days of gestation and abortion on the 46th day. In G2 (2%), the embryo loss was earlier (on the 26th day of gestation), and abortion on the 46th day of gestation. In G3 group (0.5%), there was an embryonic loss around the 40th day of gestation. In G4 group (0.25%), it was observed the occurrence of one death lamb with bone malformations. In G6 (0.5%), abortion occurred later (108 days), followed by retained placenta. This was also verified in G5 group (0.25%). The presence of fetal malformation was found in death lambs born in G4 group, born alive from G5 and G6 groups, and one aborted from G6. In G5 and G6 groups, there were also genetic alterations on surviving lambs. In addition to these results, recurrent estrus was observed without gestation in G1, G2, G3, and G4 ewes. From the Control Group, 13 normal lambs were born without genetic alterations; furthermore, concerning a quadruple birth, three lambs were born dead. The results infer that species of C. pyramidale in low doses causes reproductive losses in pregnant ewes, therefore it is not recommended for sheep diet over the first 60 days of gestation.(AU)
Para determinar se falhas reprodutivas em ovelhas na região semiárida da Bahia estão relacionadas ao consumo de Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, foi realizado um estudo utilizando-se ovelhas prenhes divididas em seis grupos e dois Grupos Controle. Os grupos G1, G2, G3 e G4 com seis animais cada. Cada grupo recebeu folhas fenadas na proporção de 1%, 2%, 0,5% e 0,25% do peso vivo (PV) respectivamente; G5 e G6, com 10 animais cada, que receberam 0,25% e 0,5% do PV respectivamente. Os Grupos Controle foram alimentados com ração e capim (Cynodon dactylon). Ovelhas dos grupos 1 a 4 iniciaram ingestão da planta quatro dias após monta natural com término aos 80 dias de gestação, enquanto as dos grupos 5 a 6 iniciaram ingestão no 26º dia de gestação com término aos 98 dias. Avaliação ultrassonográfica foi realizada semanalmente. Nos animais do G1 (1%), verificou-se perda embrionária aos 32 e 39 dias de gestação, e aborto aos 46 dias. Nos do G2 (2%) a perda embrionária foi mais precoce (26 dias), e aborto aos 46 dias. No G3 (0,5%), houve perda embrionária em torno dos 40 dias. No G4 (0,25%), verificou-se ocorrência de natimorto com malformações aos 150 dias de gestação. No G6 (0,5%) o aborto ocorreu mais tardiamente (108 dias), seguido de retenção de placenta. Essa ocorrência também foi verificada no G5 (0,25%). A presença de malformação fetal foi encontrada em fetos natimorto do G4, nascidos vivos do G5 e G6, e um abortado do G6. No G5 e G6 também foram observadas alterações de aprumos em cordeiros sobreviventes. Do Grupo Controle nasceram 13 borregos normais, porém uma ovelha apresentou gestação quádrupla com três natimortos. Os resultados inferem que C. pyramidale fenada em baixas doses causa perdas reprodutivas em ovelhas gestantes, não sendo por isso recomendada para a dieta de ovelhas durante os primeiros 60 dias de gestação.(AU)
Assuntos
Animais , Feminino , Gravidez , Intoxicação por Plantas/veterinária , Teratogênicos , Aborto Animal/etiologia , Carneiro Doméstico/anormalidades , Perda do Embrião/etiologia , Fabaceae/intoxicaçãoRESUMO
STUDY OBJECTIVE: The identification of less invasive methods with acceptable diagnostic value for evaluating intrauterine abnormalities can improve the satisfaction of patients and physicians. Although hysteroscopy plus biopsy has favorable predictive and diagnostic values, limited studies have evaluated its value, and the exact value of this method is not completely understood. The aim of this study was to evaluate the prevalence of chronic endometritis in patients with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL) by hysteroscopy and immunohistochemistry. DESIGN: A cross-sectional study. SETTING: An infertility clinic at Jundishapur University Hospital, Ahvaz, Iran. PATIENTS: Women with RIF after IVF and RPL. INTERVENTIONS: Hysteroscopy on the third to fifth day after finishing the menstruation cycle and then a biopsy for immunohistochemistry by a specific monoclonal antibody against the CD138 marker. MEASUREMENTS AND MAIN RESULTS: In total, 85 patients with a mean age of 36.08 ± 5.76 years underwent hysteroscopy on the third to fifth day after finishing the menstruation cycle. At the end of hysteroscopy, a biopsy was taken and assessed using immunohistochemistry by a specific monoclonal antibody against the CD138 marker. Immunohistochemical staining findings of >5 plasma cells per 20 high-power fields were considered the gold standard. The prevalence of chronic endometritis (CE) in both groups and the diagnostic value of hysteroscopy were evaluated. All data were analyzed using the Fisher exact test and analysis of variance. The prevalence of RIF-related CE was 23.4% (11); 21.3% (10) of the cases were diagnosed by hysteroscopy. The prevalence of RPL-related CE was 36.8% (14) and 31.6% (12) based on hysteroscopy and immunohistochemistry staining, respectively. Subsequently, 10 patients (RIF/RPL-related CE with a positive hysteroscopic outcome) were selected randomly for in vitro fertilization therapy, and 3 (30%) of them eventually became pregnant. The sensitivity, specificity, and positive and negative predictive values of hysteroscopy in diagnosing CE were 86.36%, 87.30%, 70.37%, and 94.82%, respectively. CONCLUSION: Hysteroscopy is a reliable diagnostic technique in patients with RIF after in vitro fertilization and RPL that can reliably diagnose chronic endometritis.
Assuntos
Aborto Habitual/diagnóstico , Perda do Embrião/diagnóstico , Endometrite/diagnóstico , Histeroscopia , Imuno-Histoquímica , Aborto Habitual/epidemiologia , Aborto Habitual/etiologia , Adulto , Biópsia , Doença Crônica , Estudos Transversais , Perda do Embrião/epidemiologia , Perda do Embrião/etiologia , Endometrite/complicações , Endometrite/epidemiologia , Endométrio/metabolismo , Endométrio/patologia , Endométrio/cirurgia , Feminino , Fertilização in vitro , Humanos , Histeroscopia/métodos , Imuno-Histoquímica/métodos , Gravidez , Prevalência , Sensibilidade e EspecificidadeRESUMO
Endometriosis is currently considered as one of the most common diseases associated with infertility. A controversial issue is whether endometriosis per se exerts a detrimental effect on IVF outcomes. Failure of implantation due to endometriosis-associated infertility is a contradictory and widely discussed burden nowadays. The purpose of the study is to assess the quality of embryos and implantation rate in women with infertility associated with endometriosis. The study included infertile reproductive aged women, between 26 and 40 years who underwent IVF and ICSI procedures. The patients were divided into two groups: group I (n = 70) involved 70 patients with recurrent unilateral endometriomas, II control group (n = 50) with tubal factor infertility. The quality of the retrieved embryos was assessed according to the generally accepted classification of Gardner, indicating the rate of implantation in each group. Embryo transfer was performed in case of high quality embryos. Assessing the ovarian reserve indicators, in the group I patients with recurrent unilateral endometriomas the serum level of AMH was significantly lower (2.1 ± 1.75 vs. 3.2 ± 1.4, p < .005), as well as the number of retrieved oocytes (8.1 ± 3.9 and 10.1 ± 6.8, p < .005). The analysis of the results demonstrated that the duration of stimulation in the group patients with recurrent unilateral endometriomas was significantly higher in comparison with the group II (12.2 ± 1.8 and 10.2 ± 1.6 days, p < .001). Nevertheless, the number of good quality embryos retrieved was comparable in both groups (2.2 ± 1.5 and 2.8 ± 1.8). In the group I patients with recurrent unilateral endometriomas, there was a statistically significant decrease of implantation rate (17.1% vs. 24% p < .005). The results of the study revealed no statistical difference in embryo quality in the study cohort. However, it is important to note that a statistically significant difference in implantation rate in the group of endometriosis-associated infertility compared was obtained 1.5 times lower than in the control group (15.8% vs. 24.0% p < .005). The achieved results demonstrated an adverse IVF outcome in infertile women with recurrent endometrioma compared to the control group.
Assuntos
Aborto Habitual/etiologia , Implantação do Embrião , Perda do Embrião/etiologia , Endometriose/complicações , Infertilidade Feminina/etiologia , Doenças Uterinas/complicações , Aborto Habitual/epidemiologia , Aborto Habitual/patologia , Adulto , Estudos de Casos e Controles , Implantação do Embrião/fisiologia , Perda do Embrião/epidemiologia , Perda do Embrião/patologia , Endometriose/epidemiologia , Endometriose/patologia , Feminino , Fertilização in vitro , Humanos , Infertilidade Feminina/epidemiologia , Infertilidade Feminina/patologia , Recuperação de Oócitos , Reserva Ovariana/fisiologia , Indução da Ovulação , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Injeções de Esperma Intracitoplásmicas , Doenças Uterinas/epidemiologia , Doenças Uterinas/patologiaRESUMO
OBJECTIVE: Direct chromosome preparations of chorionic villus samples (CVS) and cell-free DNA (cfDNA) testing both involve analysis of the trophoblastic cell lineage. The aim of this study was to compare the spectrum of rare autosomal trisomies (RATs) detected by these two approaches and assess the available information on their clinical significance. METHODS: Data from 10 reports on genome-wide cfDNA testing were pooled to determine which chromosomes were most frequently involved in RAT-positive cases, and pregnancy outcome information was reviewed. CVS information was obtained from an updated database of 76 102 consecutive CVS analyses performed over a period of 18 years at TOMA laboratory, in which trophoblastic and mesenchymal layers were analyzed and amniotic fluid cell analysis was recommended for RAT-positive cases. Chromosomes involved and presence of confined placental mosaicism, true fetal mosaicism and uniparental disomy (UPD) for imprinted chromosomes were assessed. Also evaluated were the frequency and types of RATs in products of conception. RESULTS: RATs were present in 634 of 196 662 (0.32%) cfDNA samples and 237 of 57 539 (0.41%) CVS trophoblast samples (P < 0.01). The frequency of RATs varied over 8-fold between the cfDNA reports. Confirmation of abnormality through amniocentesis was more likely when RATs were ascertained through cfDNA (14 of 151; 9.3%) than through CVS trophoblasts (seven of 237; 3.0%) (P < 0.01). In cfDNA-ascertained cases, trisomies 15, 16 and 22, which are associated with fetal loss, were identified proportionately more often. Of 151 cases with RAT identified by cfDNA and outcome information available, 41.1% resulted in normal live birth; 27.2% in fetal loss; 7.3% had phenotypic abnormality detected through ultrasound or other follow-up evaluation; 2.0% had a clinically significant UPD; and 14.6% had fetal growth restriction or low birth weight. All autosomes were involved in trisomies in products of conception; the most common RATs detected were trisomies 16, 22 and 15 with a frequency of > 9% each. CONCLUSIONS: Although there are strong parallels between RATs ascertained through cfDNA analysis and direct chromosome preparation of CVS, caution is needed in applying conclusions from CVS analysis to cfDNA testing, and vice versa. RATs identified through genome-wide cfDNA tests have uncertain risks for fetal loss, growth restriction or fetal abnormality. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Assuntos
Ácidos Nucleicos Livres/genética , Amostra da Vilosidade Coriônica/métodos , Resultado da Gravidez/genética , Trissomia/genética , Dissomia Uniparental/genética , Adulto , Amniocentese/métodos , Líquido Amniótico/citologia , Líquido Amniótico/metabolismo , Vilosidades Coriônicas/metabolismo , Transtornos Cromossômicos/genética , Perda do Embrião/etiologia , Feminino , Retardo do Crescimento Fetal/epidemiologia , Estudo de Associação Genômica Ampla/instrumentação , Humanos , Mosaicismo , Placenta/patologia , Gravidez , Resultado da Gravidez/epidemiologia , Trofoblastos/patologiaRESUMO
OBJECTIVE: To estimate the procedure-related risk of miscarriage after amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and an updated meta-analysis. METHODS: A search of MEDLINE, EMBASE and The Cochrane Library was carried out to identify studies reporting complications following CVS or amniocentesis. Eligible for inclusion were large controlled studies reporting data for pregnancy loss prior to 24 weeks' gestation. Study authors were contacted when required to identify additional necessary data. Data for cases that had an invasive procedure and controls were inputted into contingency tables and the risk of miscarriage was estimated for each study. Summary statistics based on a random-effects model were calculated after taking into account the weighting for each study included in the systematic review. Procedure-related risk of miscarriage was estimated as a weighted risk difference from the summary statistics for cases and controls. Subgroup analyses were performed according to the similarity in risk levels for chromosomal abnormality between the invasive-testing and control groups. Heterogeneity was assessed using the I2 statistic. Egger's bias was estimated to assess reporting bias in published studies. RESULTS: The electronic search yielded 2943 potential citations, from which 12 controlled studies for amniocentesis and seven for CVS were selected for inclusion in the systematic review. A total of 580 miscarriages occurred following 63 723 amniocentesis procedures, resulting in a weighted risk of pregnancy loss of 0.91% (95% CI, 0.73-1.09%). In the control group, there were 1726 miscarriages in 330 469 pregnancies with a loss rate of 0.58% (95% CI, 0.47-0.70%). The weighted procedure-related risk of miscarriage following amniocentesis was 0.30% (95% CI, 0.11-0.49%; I2 = 70.1%). A total of 163 miscarriages occurred following 13 011 CVS procedures, resulting in a risk of pregnancy loss of 1.39% (95% CI, 0.76-2.02%). In the control group, there were 1946 miscarriages in 232 680 pregnancies with a loss rate of 1.23% (95% CI, 0.86-1.59%). The weighted procedure-related risk of miscarriage following CVS was 0.20% (95% CI, -0.13 to 0.52%; I2 = 52.7%). However, when studies including only women with similar risk profiles for chromosomal abnormality in the intervention and control groups were considered, the procedure-related risk for amniocentesis was 0.12% (95% CI, -0.05 to 0.30%; I2 = 44.1%) and for CVS it was -0.11% (95% CI, -0.29 to 0.08%; I2 = 0%). CONCLUSIONS: The procedure-related risks of miscarriage following amniocentesis and CVS are lower than currently quoted to women. The risk appears to be negligible when these interventions were compared to control groups of the same risk profile. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Riesgo de aborto después de una amniocentesis o una biopsia de vellosidades coriónicas: revisión sistemática de bibliografía y metaanálisis actualizado OBJETIVO: Estimar el riesgo de aborto relacionado con el procedimiento de la amniocentesis o la biopsia de vellosidades coriónicas (BVC) mediante una revisión sistemática de bibliografía y un metaanálisis actualizado. MÉTODOS: Se realizó una búsqueda en MEDLINE, EMBASE y The Cochrane Library para identificar estudios que reportaron sobre complicaciones después de una BVC o amniocentesis. Se consideraron elegibles para su inclusión los estudios controlados de gran tamaño que reportaron datos sobre la pérdida del embarazo antes de las 24 semanas de gestación. Se estableció contacto con los autores de los estudios cuando fue necesario para identificar datos adicionales necesarios. Se introdujeron en tablas de contingencia los datos de los casos que se sometieron a un procedimiento invasivo y controles y se estimó el riesgo de aborto para cada estudio. Las estadísticas resumen basadas en un modelo de efectos aleatorios se calcularon después de tener en cuenta la ponderación para cada estudio incluido en la revisión sistemática. El riesgo de aborto relacionado con cada procedimiento se estimó como una diferencia de riesgo ponderada de las estadísticas resumen para los casos y controles. Los análisis de subgrupos se realizaron de acuerdo con la similitud en los niveles de riesgo de anomalías cromosómicas entre los grupos de prueba invasiva y de control. La heterogeneidad se evaluó mediante el test estadístico I2 . Se estimó el sesgo de Egger para evaluar el sesgo de información reportada en los estudios publicados. RESULTADOS: La búsqueda electrónica arrojó 2943 citas potenciales, de las cuales se seleccionaron para su inclusión en la revisión sistemática 12 estudios controlados para la amniocentesis y siete para la BVC. Después de los 63723 procedimientos de amniocentesis sucedieron un total de 580 abortos, lo que resultó en un riesgo ponderado de pérdida de embarazo del 0,91% (IC 95%, 0,73-1,09%). En el grupo de control hubo 1726 abortos en 330469 embarazos, con una tasa de pérdida del 0,58% (IC 95%, 0,47-0,70%). El riesgo ponderado de aborto relacionado con el procedimiento de amniocentesis fue del 0,30% (IC 95%, 0,11-0,49%; I2 = 70,1%). Después de 13011 procedimientos de BVC se produjeron un total de 163 abortos, lo que resultó en un riesgo de pérdida de embarazo del 1,39% (IC 95%, 0,76-2,02%). En el grupo de control hubo 1946 abortos en 232680 embarazos, lo que supuso una tasa de pérdida del 1,23% (IC 95%, 0,86-1,59%). El riesgo ponderado de aborto relacionado con el procedimiento de BVC fue de 0,20% (IC 95%, -0,13-0,52%; I2 = 52,7%). Sin embargo, cuando se consideraron los estudios que incluyeron sólo mujeres con perfiles de riesgo similares para la anomalía cromosómica en los grupos de intervención y control, el riesgo relacionado con el procedimiento de la amniocentesis fue de 0,12% (IC 95%, -0,05-0,30%; I2 = 44.1%) y para el MVC fue de -0,11% (IC 95%, -0,29-0,08%; I2 = 0%). CONCLUSIONES: Los riesgos de aborto relacionados con el procedimiento de la amniocentesis y la BVC son menores que los actualmente mencionados a las mujeres. El riesgo parece ser insignificante cuando estas intervenciones se compararon con grupos de control del mismo perfil de riesgo.
Assuntos
Aborto Espontâneo/etiologia , Amniocentese/efeitos adversos , Amostra da Vilosidade Coriônica/efeitos adversos , Adulto , Aberrações Cromossômicas/estatística & dados numéricos , Perda do Embrião/epidemiologia , Perda do Embrião/etiologia , Feminino , Idade Gestacional , Humanos , Gravidez , Segundo Trimestre da Gravidez , Diagnóstico Pré-Natal , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de RiscoRESUMO
Understanding of the mechanism of embryo loss is critical for successful pregnancy considering an increase in the incidence of infertility. In this study, we focus on the effect of alterations in the expression of the AKT/AMPK/mTOR signalling pathway in mouse uterine tissue after embryo loss induced by harmful environmental exposure to carbon disulfide (CS2). CS2 is a material used in certain production processes, and women are sometimes exposed to it in occupational settings. We created an animal model of gestating mice exposed to CS2 on gestation days 3 (GD3), 4 (GD4), 5 (GD5) and 6 (GD6) with various corresponding endpoints after the exposure. The uterine tissue was collected according to the endpoint time series to detect the expression levels of mTOR, p-mTOR, pAKT, and pAMPK using western blot, RT-PCR, immunohistochemistry staining, and ELISA. Dietary supplementation with N-carbamoyl glutamic acid (NCG) was used to verify the effect of the mTOR signalling pathway on embryo loss caused by CS2. We detected down-regulation of the levels of the mTOR and p-mTOR proteins; the levels of these two proteins were decreased by 49.35% and 51.44% at the GD5 endpoint after GD4 exposure and by 38.55% and 59.51% after GD3 exposure, respectively. The change in the expression level of mTOR mRNA was consistent with the protein expression, and the mRNA level at the GD5 endpoint was decreased by 55.0% after GD4 exposure (Pâ¯<â¯0.05). Additionally, protein expression levels of pAKT were decreased by 49.05%, and the levels of pAMPK were increased by 25.51% at the GD5 endpoint after GD4 exposure (Pâ¯<â¯0.05). A similar trend was observed for pAKT and pAMPK at the GD4 endpoint after GD3 exposure, at the GD6 endpoint after GD5 exposure, and at the GD7 endpoint after GD6 exposure (Pâ¯<â¯0.05). Supplementation with NCG contributed to recovery from the effects of CS2 by increasing the protein expression levels of mTOR and pAKT by 47.54% and 63.79% (Pâ¯<â¯0.05), respectively, while the pAMPK protein level was decreased by 37.15% (Pâ¯<â¯0.05) at the GD5 endpoint after GD4 exposure. It should be noted that the number of implanted embryos was significantly increased after supplementation with NCG. Our results indicate that down-regulation of mTOR at the time of implantation is regulated by pAKT and pAMPK, that may be an important factor for embryo loss induced by CS2.
Assuntos
Dissulfeto de Carbono/farmacologia , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Útero/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Regulação para Baixo/efeitos dos fármacos , Perda do Embrião/etiologia , Perda do Embrião/metabolismo , Feminino , Idade Gestacional , Camundongos , Modelos Animais , Azeite de Oliva/farmacologia , Gravidez , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/metabolismo , Serina-Treonina Quinases TOR/genética , Regulação para Cima/efeitos dos fármacos , Útero/metabolismoRESUMO
Maternal obesity can cause complications for both women and their offspring for generations. Therefore, we intended to verify the repercussions of induction of transgenerational obesity on biochemical parameters, reproductive performance, and congenital anomaly frequency in Wistar rats. Female rats were used from successive generations. The female rats of parental generation (F0, n=10) were mated to obtain their offspring (F1 generation). F1 female rats received a monosodium glutamate (MSG) solution to induce obesity (n=07) or vehicle (control, n=06) during the neonatal period. These adult female rats were classified as normal or obese using the Lee Index, mated, and delivered offspring (F2 generation), which were also evaluated for obesity using the Lee Index in adult life (F2MSG, n=13, born from obese dams) or non-obesity status (F2Control, n=12, born from control dams), and were mated in adulthood. During pregnancy, glycemia and an oral glucose tolerance test (OGTT) were analyzed. At term pregnancy, the females were sacrificed for serum biochemical profile, maternal reproductive outcomes, and fetal development. In F2MSG rats, body weight gain at early pregnancy, glycemia by OGTT, total cholesterol, high-density-lipoprotein, and alanine transaminase activity were higher compared with those of F2Control rats. F2MSG rats also presented a lower implantation number and gravid uterus weight, increased pre-implantation loss and anomaly frequency in their fetuses (F3 generation) compared with those of F2Control rats. Therefore, even without significant changes in body weight gain, obesity was established at the end of pregnancy of Wistar rats using other biomarkers. Additionally, these rats showed multiple adverse reproductive outcomes, confirming the deleterious effects that lead to obesity.
Assuntos
Adiposidade , Fenômenos Fisiológicos da Nutrição Animal , Fenômenos Fisiológicos da Nutrição Materna , Obesidade/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal , Reprodução , Aumento de Peso , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Anormalidades Congênitas/etiologia , Anormalidades Congênitas/fisiopatologia , Implantação do Embrião , Perda do Embrião/etiologia , Perda do Embrião/fisiopatologia , Feminino , Lipídeos/sangue , Tamanho da Ninhada de Vivíparos , Obesidade/sangue , Obesidade/embriologia , Gravidez , Ratos WistarRESUMO
Recurrent pregnancy loss (RPL) is a physical and mental burden for women. In Vietnam, exploring the cause of miscarriages is still a challenge to clinical physicians. We aimed to investigate the etiology of RPL in the National Hospital of Obstetrics and Gynecology in Vietnam from 2012 to 2014. The cross-sectional study included 301 pregnant women with a history of RPL. The patients were examined and offered medical testing to determine the cause(s). Based on the testing, we determined causation for (11.29%) patients who had positive scores on an antiphospholipid antibody test and who were subsequently successfully treated for their problem.
Assuntos
Aborto Habitual/etiologia , Anticorpos Antifosfolipídeos/sangue , Perda do Embrião/etiologia , Gestantes , Útero/anormalidades , Aborto Habitual/sangue , Aborto Habitual/epidemiologia , Adulto , Anticorpos Anticardiolipina/sangue , Aberrações Cromossômicas/estatística & dados numéricos , Estudos Transversais , Perda do Embrião/epidemiologia , Feminino , Humanos , Idade Materna , Gravidez , Vietnã/epidemiologiaRESUMO
Chronic intervillositis of unknown etiology (CIUE) is a poorly understood, relatively rare condition characterized histologically by the intervillous infiltration of mononuclear cells in the placenta. Clinically, CIUE is associated with poor pregnancy outcome (e.g., impaired fetal growth, preterm birth, fetal death) and high risk of recurrence in subsequent pregnancies. Because CIUE is not defined consistently, it is essential to clearly define this condition. We therefore review the published definitions of CIUE. In addition, we provide an overview of the reviewed histopathological and maternal characteristics, obstetric features, and pregnancy outcomes. Medical publication databases were searched for articles published through February 2017. Eighteen studies were included in our systematic review. The sole inclusion criterion used in all studies was the presence of intervillous infiltrates. Overall, CIUE was characterized by adverse pregnancy outcome. Miscarriage occurred in 24% of cases, with approximately half of these miscarriages defined as late. Impaired growth was commonly observed, 32.4% of pregnancies reached term, and the live birth rate was 54.9%. The high recurrence rate (25.1%) of the intervillous infiltrates in subsequent pregnancies underscores the clinical relevance of CIUE, the need for increased awareness among pathologists and clinicians, and the need for further research. Criteria for the diagnosis of CIUE are proposed and a Delphi study could be used to resolve any controversy regarding these criteria. Future studies should be designed to characterize the full clinical spectrum of CIUE.
Assuntos
Doença Crônica , Doenças Placentárias/diagnóstico , Placenta/imunologia , Diagnóstico Pré-Natal , Aborto Espontâneo/epidemiologia , Aborto Espontâneo/etiologia , Corioamnionite/diagnóstico , Corioamnionite/imunologia , Corioamnionite/patologia , Corioamnionite/fisiopatologia , Vilosidades Coriônicas/imunologia , Vilosidades Coriônicas/patologia , Vilosidades Coriônicas/fisiopatologia , Diagnóstico Diferencial , Perda do Embrião/epidemiologia , Perda do Embrião/etiologia , Feminino , Morte Fetal/etiologia , Retardo do Crescimento Fetal/epidemiologia , Retardo do Crescimento Fetal/etiologia , Humanos , Placenta/patologia , Placenta/fisiopatologia , Doenças Placentárias/imunologia , Doenças Placentárias/patologia , Doenças Placentárias/fisiopatologia , Guias de Prática Clínica como Assunto , Gravidez , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/etiologia , Recidiva , Risco , Índice de Gravidade de Doença , Natimorto/epidemiologiaRESUMO
BACKGROUND: Morphometric and morphokinetic evaluation of in vitro cultured human embryos allows evaluation without time restriction and reduces intra- and inter-observer variability. Even though these technologies have been reported to improve the quality of cleavage stage embryo evaluation during fresh culture, possible advantages in the evaluation of cryopreserved embryos have been scarcely explored. This study aims to compare morphometric and morphokinetic parameters between slow frozen and vitrified embryos and to determine their relationship to embryo survival and implantation rate (IR) after thawing/warming. METHODS: During fresh culture, morphometric characteristics (Total Cell Volume (TCV), symmetry, fragmentation and number of blastomeres) were measured in 286 thawed/warmed embryos. Likewise, after thawing/warming, similar morphometric characteristics were measured in 135 survived embryos. Moreover, morphokinetic parameters (time to mitosis resumption and time to compaction) were measured in 90 embryos after thawing/warming. Then, using linear regression, we investigated the differences between vitrified and slow frozen embryos and the relation of the measured characteristics to embryo survival and IR. Statistical corrections were applied to account for data clustering and for multiple testing. RESULTS: Vitrified embryos resume mitosis and start compaction significantly earlier than slow frozen embryos. Mitosis resumption rate was 82% for vitrified and 63% for slow frozen embryos and median time to mitosis resumption was 7.6 h and 13.1 h (p = 0.02), respectively. Compaction rate was 62% in vitrified and only 23% in slow frozen embryos. Median time to compaction was 18.1 h for vitrified embryos but, for slow frozen could not be computed since less than half of the slow frozen embryos reached compaction (p = 0.0001). Moreover, intact embryos resume mitosis significantly earlier than not intact ones regardless of the freezing method (rate: 79% vs. 66%, median time: 7.6 h vs 14.6 h, respectively, p = 0.03). Regarding morphometrics, slow frozen embryos showed lower TCV and higher blastomere symmetry after thawing than vitrified embryos despite having similar blastomere number. IR was related to blastomere number at cryopreservation in slow frozen embryos, but not in vitrified ones. CONCLUSIONS: Interestingly, vitrified/warmed embryos undergo mitosis resumption and compaction significantly earlier than slow frozen/thawed embryos. However, the clinical use of this morphokinetic parameters still remains to be investigated in larger studies. TRIAL REGISTRATION: Retrospectively registered on December 15, 2015 NCT02639715 .
Assuntos
Forma Celular , Tamanho Celular , Fase de Clivagem do Zigoto/fisiologia , Implantação do Embrião , Perda do Embrião , Embrião de Mamíferos/citologia , Adulto , Blastômeros/citologia , Células Cultivadas , Fase de Clivagem do Zigoto/citologia , Estudos de Coortes , Criopreservação/métodos , Perda do Embrião/etiologia , Perda do Embrião/patologia , Transferência Embrionária/métodos , Feminino , Humanos , Gravidez , Taxa de Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos RetrospectivosRESUMO
Maternal diabetes causes congenital malformations and delays embryonic growth in the offspring. We investigated effects of maternal diabetes on mouse embryos during gastrulation and early organogenesis (ED7.5-11.5). Female mice were made diabetic with streptozotocin, treated with controlled-release insulin implants, and mated. Maternal blood glucose concentrations increased up to embryonic day (ED) 8.5. Maternal hyperglycemia induced severe growth retardation (approx.1 day) in 53% of the embryos on ED8.5, death in most of these embryos on ED9.5, and the termination of pregnancy on ED10.5 in litters with >20% dead embryos. Due to this selection, developmental delays and reduction in litter size were no longer observed thereafter in diabetic pregnancies. Male and female embryos were equally sensitive. High-throughput mRNA sequencing and pathway analysis of differentially expressed genes showed that retarded embryos failed to mount the adaptive suppression of gene expression that characterized non-retarded embryos (cell proliferation, cytoskeletal remodeling, oxidative phosphorylation). We conclude that failure of perigastrulation embryos of diabetic mothers to grow and survive is associated with their failure to shut down pathways that are strongly down-regulated in otherwise similar non-retarded embryos. Embryos that survive the early and generalized adverse effect of maternal diabetes, therefore, appear the subset in which malformations become manifest.
Assuntos
Deficiências do Desenvolvimento/etiologia , Diabetes Mellitus Experimental/complicações , Perda do Embrião/etiologia , Embrião de Mamíferos/anormalidades , Gravidez em Diabéticas , Animais , Anormalidades Congênitas/etiologia , Diabetes Mellitus Experimental/induzido quimicamente , Feminino , Tamanho da Ninhada de Vivíparos , Camundongos , Gravidez , Somitos/embriologia , EstreptozocinaRESUMO
Metabolic disorders, such as PCOS (polycystic ovarian syndrome) and T2DM (type 2 diabetes mellitus), are associated with menstrual dysfunction, anovulation, infertility, and early pregnancy loss. Ovarian dysfunction is not only related to low pregnancy rates but also to the increased risk of miscarriage. Women with PCOS or T2DM, characterized by hyperinsulinemia, commonly experience ovarian dysfunction. In this study, we first explored whether high insulin levels directly affected ovarian functioning during embryo implantation. Mice in the insulin-treated group were given a subcutaneous injection of human recombinant insulin. After insulin treatment, serum levels of E2 (estrogen), PROG (progesterone), LH (luteinizing hormone), and FSH (follicle-stimulating hormone) were obviously lower, and there was a significant decrement of ovarian GDF9 (growth differentiation factor 9) mRNA. H&E (hematoxylin and eosin) staining showed a greater number of immature follicles and less luteinization in the insulin group. Further autophagy was studied in this process. A significant increase of P62 (SQSTM1/Sequestosome1) and a decrease of Cathepsin B, BECN1 (Beclin 1), and ULK1 (Unc-51-like kinase 1) mRNA in ovary was found in the insulin group. Western blot analysis showed that the expressions of LC3 (microtubule-associated protein 1 light chain 3), BECN1, and Cathepsin B proteins in ovaries from insulin group were obviously reduced, while P62 proteins were significantly increased. All these results illustrated that insulin could directly impair ovarian function during embryo implantation and the imbalance of ovarian autophagy due to insulin. Autophagy could enhance the impaired ovarian function results from insulin.
Assuntos
Anovulação/etiologia , Autofagia , Modelos Animais de Doenças , Perda do Embrião/etiologia , Regulação da Expressão Gênica no Desenvolvimento , Hiperinsulinismo/fisiopatologia , Ovário/fisiopatologia , Animais , Animais não Endogâmicos , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Catepsina B/genética , Catepsina B/metabolismo , Implantação do Embrião , Feminino , Fator 9 de Diferenciação de Crescimento/genética , Fator 9 de Diferenciação de Crescimento/metabolismo , Hiperinsulinismo/metabolismo , Hiperinsulinismo/patologia , Insulina Glargina , Camundongos , Ovário/metabolismo , Ovário/patologia , Gravidez , Distribuição Aleatória , Proteína Sequestossoma-1/genética , Proteína Sequestossoma-1/metabolismoRESUMO
Advancing the age at which puberty and subsequent sexual maturation is attained in cattle is central to the reproductive and economic efficiency of both beef and dairy production systems worldwide. Onset of puberty in both male and female cattle is regulated by a complex network of biochemical processes and involves interaction among many key metabolic, neuroendocrine and reproductive tissues. Although our understanding of the biochemical interplay that conditions and eventually triggers the pubertal process has improved in recent years, much of the intricate mechanistic detail still eludes us. Environmental factors, such as nutritional management, as well as the genetic makeup of the animal undoubtedly affect the timing of puberty in cattle. In particular, there is now overwhelming evidence to support the importance of early life nutrition in regulating the timing of puberty in both bulls and heifers. For both genders, there is significant evidence that an improved metabolic status, early in calfhood, advances maturation of the hypothalamic-pituitary-gonadal axis, therefore facilitating earlier sexual development. Although advancing sexual maturation is a desirable goal, it is important that any strategy used does not impinge upon normal gametogenesis or postpubertal fertility potential. To this end, the aim of this review is to discuss the underlying biology of puberty in cattle with particular emphasis on the role of nutritional management during early calfhood in: (1) advancing the maturity of the hypothalamic-pituitary-gonadal axis; and (2) implications for the quality of gametes and subsequent fertility.
Assuntos
Bovinos , Perda do Embrião/etiologia , Embrião de Mamíferos/citologia , Células Germinativas/citologia , Reprodução/fisiologia , Maturidade Sexual/fisiologia , Animais , Bovinos/embriologia , Sobrevivência Celular , Feminino , Masculino , Controle de QualidadeRESUMO
OBJECTIVE: In the current study we aimed to evaluate the effect of embryo transfer on gene expression during pre-implantation development and its consequences on implantation rate, offspring rate at birth and embryonic and fetal losses in the rabbit model. STUDY DESIGN: The mRNA expressions of 8 candidate genes were compared between 6-day-old in vivo-produced embryos (non-manipulated embryos) to those of 6-day-old embryos previously recovery at the third day of development and transferred into recipient rabbit females (manipulated embryos). Furthermore, we compared between both experimental groups the implantation rate and offspring rate at birth and embryonic and fetal losses. RESULTS: Differences in transcript abundance of OCT4, C1qTNF1, EMP1 and TNFAIP6 were observed in transferred embryos. In addition, lower implantation and offspring rates at birth were obtained in transferred embryos than in the control group. In addition, embryonic losses were significantly higher in the transferred group than in the control. However, fetal losses were similar between groups. CONCLUSION: The findings of the current study show that embryo transfer manipulation influenced mRNA expression of late blastocysts prior to implantation, resulting in higher gestational losses as a consequence of faulty embryonic implantation.
Assuntos
Blastocisto/metabolismo , Ectogênese , Implantação do Embrião , Perda do Embrião/etiologia , Transferência Embrionária/efeitos adversos , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Animais , Biomarcadores/metabolismo , Técnicas de Cultura Embrionária , Feminino , Reabsorção do Feto/etiologia , Inseminação Artificial/efeitos adversos , Tamanho da Ninhada de Vivíparos , Masculino , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Gravidez , RNA Mensageiro/metabolismo , CoelhosRESUMO
An epidemiological study of risk factors for fetal losses was carried out on 62,403 high-yielding Holstein cows in 29 large highly technified dairy herds in northern Mexico (25° N; 23.5 °C mean annual temperature). Multivariate multiple-group response model indicated that fetal losses between 43 and 260 days of pregnancy were 23 %. Heat-stressed cows at conception (temperature-humidity index, THI >82) were 14 times more likely (P < 0.01) to present fetal losses than not heat-stressed cows (27 vs. 18 %). Heat-stressed cows at 60 days of pregnancy (THI >82) were 4.5 times more likely (P < 0.01) to present fetal losses than cows suffering heat stress in early gestation (29.1 vs. 17.7 %). The proportion of cows experiencing fetal loss was lower for multiparous than primiparous cows (odds ratio; OR = 0.7). Cows with twin pregnancies had significantly increased chances of losing their fetuses than cows with a single fetus (33.6 vs. 20.7 %; P < 0.01). Cows with three milkings per day were 30 % more likely (P < 0.01) to lose their fetuses than cows milked twice daily. Cows calving in winter and spring had significantly increased chances of losing their fetuses than cows calving in summer and fall (30-35 vs. 4-5 %; P < 0.01). It was concluded that, in this particular environment, heat stress exert a great influence on fetal losses in high producing Holstein cows.
Assuntos
Doenças dos Bovinos/epidemiologia , Transtornos de Estresse por Calor/veterinária , Complicações na Gravidez/veterinária , Aborto Animal/epidemiologia , Criação de Animais Domésticos , Animais , Bovinos , Doenças dos Bovinos/fisiopatologia , Indústria de Laticínios , Perda do Embrião/etiologia , Perda do Embrião/veterinária , Feminino , Transtornos de Estresse por Calor/epidemiologia , Lactação/fisiologia , México/epidemiologia , Leite/metabolismo , Paridade , Gravidez , Complicações na Gravidez/epidemiologia , Gravidez Múltipla , Fenômenos Reprodutivos Fisiológicos , Fatores de Risco , Estações do Ano , Clima TropicalRESUMO
Toxicological studies have shown that phthalate esters (PAEs), a class of widely used and environmentally prevalent chemicals, can increase the abortion rate in animals, but epidemiological evidence is scarce. This study aimed to explore the relationship between the urinary concentration of phthalate metabolites and the risk of clinical pregnancy loss. A total of 132 women who underwent clinical pregnancy loss (cases) and 172 healthy pregnant women (controls) were recruited from Beijing, China. Eight phthalate metabolites in urine were determined by ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Five phthalate metabolites, monomethyl phthalate (MMP), monoethyl phthalate (MEP), monoisobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono(2-ethlyhexyl) phthalate (MEHP), were detected in at least 95% of the urine samples, with the highest median concentration of 51.0 µg/g of creatinine for MnBP of all participants. The differences in urinary concentrations of phthalate metabolites between cases and controls were evaluated using the Mann-Whitney U test. The concentrations of MEP (median of 18.7 µg/g of creatinine), MiBP (23.3 µg/g of creatinine), and MnBP (58.2 µg/g of creatinine) detected in the cases were significantly higher than those (15.7 µg/g of creatinine for MEP, 19.4 µg/g of creatinine for MiBP, and 43.9 µg/g of creatinine for MnBP) in the controls (p < 0.05). Increasing risks of clinical pregnancy loss were observed from the first to fourth quartiles of the MEP, MiBP, and MnBP concentrations (p < 0.05 for trend). We concluded that exposure to MEP, MiBP, and MnBP was associated with an increased risk of clinical pregnancy loss.
Assuntos
Perda do Embrião/etiologia , Perda do Embrião/urina , Monitoramento Ambiental , Metaboloma , Ácidos Ftálicos/metabolismo , Ácidos Ftálicos/urina , Adulto , Pequim , Estudos de Casos e Controles , Ésteres/urina , Feminino , Humanos , Pessoa de Meia-Idade , Razão de Chances , Gravidez , Fatores de Risco , Adulto JovemRESUMO
To address the role of bacterial infection in hatching failure of wild geese, we monitored embryo development in a breeding population of Greater white-fronted geese (Anser albifrons) on the Arctic Coastal Plain of Alaska. During 2013, we observed mortality of normally developing embryos and collected 36 addled eggs for analysis. We also collected 17 infertile eggs for comparison. Using standard culture methods and gene sequencing to identify bacteria within collected eggs, we identified a potentially novel species of Neisseria in 33 eggs, Macrococcus caseolyticus in 6 eggs, and Streptococcus uberis and Rothia nasimurium in 4 eggs each. We detected seven other bacterial species at lower frequencies. Sequences of the 16S rRNA genes from the Neisseria isolates most closely matched sequences from N. animaloris and N. canis (96 to 97% identity), but phylogenetic analysis suggested substantial genetic differentiation between egg isolates and known Neisseria species. Although definitive sources of the bacteria remain unknown, we detected Neisseria DNA from swabs of eggshells, nest contents, and cloacae of nesting females. To assess the pathogenicity of bacteria identified in contents of addled eggs, we inoculated isolates of Neisseria, Macrococcus, Streptococcus, and Rothia at various concentrations into developing chicken eggs. Seven-day mortality rates varied from 70 to 100%, depending on the bacterial species and inoculation dose. Our results suggest that bacterial infections are a source of embryo mortality in wild geese in the Arctic.