RESUMO
A previously unrecognized first-trimester presentation of the acrania-anencephaly sequence is described. Ultrasound features included a constriction ring around the external base of the developing skull and an enlarged globular head, resembling a Turkish turban, with large cystic spaces replacing the brain. This constellation of findings was noted in 3 first-trimester fetuses. In 2 of them, it was possible to identify the amniotic membrane attached to the constriction ring. One case presented with anencephaly and fetal demise at 16 weeks. The other 2 women terminated the pregnancies and aborted anencephalic fetuses. This subtype of the acrania-anencephaly sequence could represent an earlier segmental rupture of the amnion, which subsequently entraps the developing fetal skull.
Assuntos
Anencefalia/diagnóstico por imagem , Anencefalia/embriologia , Primeiro Trimestre da Gravidez , Ultrassonografia Pré-Natal/métodos , Aborto Eugênico , Encéfalo/diagnóstico por imagem , Encéfalo/embriologia , Evolução Fatal , Feminino , Humanos , Gravidez , Crânio/diagnóstico por imagem , Crânio/embriologiaRESUMO
The frequency of fetal arcadia in the world is 1:35,000 to 1:48,000 pregnancies; is currently estimated that 1% of newborns in developed countries are the result of assisted reproduction techniques and the frequency of twin pregnancies is close to 18%, of these, an estimated relative risk for cardiac defect is 1.6. However, the association of acardiac fetus, twin pregnancy and assisted reproductive techniques is not fully established. In this paper, we describe a case of fetal acardia, in a pregnancy resulting from assisted reproduction and its obstetric care.
Assuntos
Doenças em Gêmeos , Fertilização in vitro , Morte Fetal/etiologia , Coração Fetal/anormalidades , Gravidez Múltipla , Anormalidades Múltiplas/embriologia , Adulto , Anencefalia/embriologia , Cesárea , Transferência Embrionária , Feminino , Morte Fetal/diagnóstico por imagem , Humanos , Recém-Nascido , Masculino , Gravidez , Risco , UltrassonografiaRESUMO
La acranea es la anomalía fetal caracterizada por la ausencia de la bóveda craneana, acompañado de un completo tejido cerebral. Su causa es debida a una falla en la migración del mesenquima ectodernal o a una discrupción de las bandas amnióticas. La incidencia no es conocida, muy pocos casos han sido reportados en la literatura mundial. El diagnóstico prenatal se identifica por la ausencia de la bóveda craneana a través de la ultrasonografía. El pronóstico es fatal. Nosotros reportamos nuestra experiencia en un feto diagnosticado por ultrasonografía con acranea a las 12 semanas de edad gestacional.
Assuntos
Humanos , Feminino , Gravidez , Anencefalia/embriologia , Anormalidades Congênitas/diagnóstico , Anormalidades Craniofaciais/diagnóstico , Diagnóstico Pré-Natal , Tubo Neural/anormalidades , Ultrassonografia Pré-Natal/métodos , Primeiro Trimestre da Gravidez , PrognósticoRESUMO
AIMS: Brain tissue nodules are occasionally seen in the lungs of neural tube defect (NTD) cases. We looked for brain tissue fragments in amniotic fluid of rats with NTD as it is the basis for the aspiration hypothesis. METHODS: Eighty-seven pregnant rats were randomly divided into experimental (n=58) and control (n=29) groups. Experimental rats received 100,000 U of vitamin A in 1 mL of corn oil on gestational days 8, 9 and 10, while control rats received corn oil. On gestational days 15, 18, 19, 20 and 21, amniotic fluid was drawn from three control animals and five experimental animals and analysed. RESULTS: NTD was found in 22.75% of experimental fetuses and in no control fetuses. Brain tissue fragment number and volume fraction increased between gestational days 18 and 20, falling on day 21. CONCLUSIONS: Excessive doses of vitamin A induce a high rate of early fetal death and development of NTD. Brain tissue fragments in the amniotic fluid reflect the evolution from exencephaly to anencephaly and could support the aspiration hypothesis. However, as it is a late event in the rat, this model may not reproduce the brain tissue nodules in the lung.
Assuntos
Líquido Amniótico , Anencefalia/patologia , Encéfalo/patologia , Anencefalia/induzido quimicamente , Anencefalia/embriologia , Animais , Encéfalo/embriologia , Modelos Animais de Doenças , Feminino , Idade Gestacional , Gravidez , Ratos , Ratos Wistar , Vitamina A/toxicidadeRESUMO
OBJECTIVES: To determine the prevalence of chromosomal abnormalities in fetuses with open neural tube defects (NTD) undergoing prenatal chromosome analysis. The role of prenatal ultrasound in detecting those with an underlying chromosomal abnormality was also investigated. METHODS: Over a 6-year period, 144 fetuses with open NTD underwent prenatal chromosome analysis between 12 and 37 weeks of gestation, as part of a prospective, multicenter prenatal diagnosis and counseling program in Chile. This population included 66 fetuses with spina bifida, 46 with acrania/anencephaly, 21 with cephalocele and 11 with iniencephaly. A confident prenatal diagnosis was made in 143 fetuses (99%) and confirmed postnatally in all cases. RESULTS: An underlying chromosomal abnormality was diagnosed in 10 fetuses (7%), six with spina bifida, three with cephalocele and one with craniorachischisis. The prevalence of chromosomal abnormality varied according to the defect present in the fetus, with a 14% (3/21) prevalence among those with cephalocele, 9% (6/66) among those with spina bifida and 2% (1/57) among those with lethal defects such as acrania, anencephaly or iniencephaly. Karyotype results revealed trisomy 18 in seven cases, trisomy 13 in two and mosaicism for a marker chromosome in one. Prenatal ultrasound before the procedure showed that all chromosomally abnormal fetuses had additional findings. The prevalence of chromosomal abnormality in fetuses with spina bifida and cephalocele was higher when chromosome analysis was performed at or before 24 weeks of gestation in comparison to those performed after 24 weeks (5/31 (16%) vs. 4/56 (7%), respectively). However, this difference did not reach statistical significance, probably due to the small number of cases. CONCLUSIONS: A significant number of fetuses with open NTD are chromosomally abnormal. Although prenatal chromosome analysis should be considered in all cases, prenatal ultrasound seems effective in identifying those fetuses with an underlying chromosomal abnormality.