RESUMO
Se realizó el Tap test y la prueba de Clements para evaluar madurez pulmonar fetal en 260 muestras de líquido amniótico obtenidas por amniocentesis transabdominal. El Tap test informó madurez en todas las muestras con prueba de Clements positiva (n = 156) e inmadurez en 20 de las 104 (19,2%) muestras con prueba de Clements intermedia y negativa. Ocurrieron 54 nacimientos dentro de las 72 horas de realizada la amniocentesis. Ninguno de los RN del grupo con prueba de Clements positiva (n = 50) o intermedia (n = 3) y Tap test inmaduro y presentó SDR. Nuestros resultados demuestran que el Tap test en un examen confiable y al parecer de mayor especificidad que la prueba de Clements para evaluar en forma rápida la madurez pulmonar fetal
Assuntos
Gravidez , Humanos , Feminino , Maturidade dos Órgãos Fetais , Líquido Amniótico/análise , Pulmão/crescimento & desenvolvimento , AmniocenteseRESUMO
Estudiamos 582 pacientes no diabéticos mediante las pruebas de tiempo de permanencia del anillo de burbujas (T.P.A.B.) y Clements y col. Se analizaron 665 muestras de líquidos amnióticos. La utilidad de las pruebas se determinó sobre 357 mujeres que parieron dentro de la semana de su realización. La sensibilidad, especificidad y exactitud para el T.P.A.B. fue 100,92,90 y 96,64%, respectivamente, con sólo 3,4% de falsos positivos, mientras que para la de Clements y col. estos valores fueron 100,86,69 y 86,83% con 13,31% de falsos positivos. Hubo 3 muertes perinatales por síndrome de dificultad respiratoria. se concluye que el T.P.A.B. aventaja a la prueba de Clements y col. en el manejo del embarazo de alto riesgo
Assuntos
Gravidez , Humanos , Feminino , Síndrome do Desconforto Respiratório do Recém-Nascido/diagnóstico , Líquido Amniótico/análiseRESUMO
Se estudió la correlación entre la detección ultrasonográfica de vérnix y el aspecto macroscópico del líquido amniótico (LA) y la madurez pulmonar fetal (MPF) en 73 pacientes de la Unidad de Alto Riesgo del Servicio de Obstetricia y Ginecología del Hospital "Guillermo Grant Benavente" de Concepción. La concordancia entre el aspecto macroscópico del LA obtenido por amniocentesis y la ultrasonografía fue correcta en 59 de los 73 casos (80,8%). En 4 casos (5,5%) la ultrasonografía informó un tipo menor y en 10 casos (13,7%) informó un tipo mayor al que correspondía según el aspecto macroscópico. La ultrasonografía detectó correctamente el 95%de los LA macroscópicamente tipo III (38 de 40) y el 64%de los LA tipo II o tipo I (14 de 22 y 7 de 11, respectivamente). En todos los casos de tipo I por ultrasonografía la prueba de Clements fue negativa (n = 9; MPF = 0%), en cambio fue positiva en 8 de los 20 casos de LA tipo II (MPF = 40%) y en 38 de los 44 casos de LA tipo III (MPF = 86,4%). Nuestro estudio permite concluir que la detección ultrasonográfica de vérnix abundante (LA tipo III) permite asegurar MPF y la ausencia o la presencia de escaso vérnix (LA tipo I) permite suponer inmadurez pulmonar, con lo cual pareciera innecesario realizar estudio de LA para MPF, lo que permite evitar el empleo de amniocentesis, procedimiento invasivo que no está exento de complicaciones tanto maternas como fetales
Assuntos
Maturidade dos Órgãos Fetais , Líquido Amniótico/análise , Verniz Caseoso/análise , Diagnóstico Pré-Natal , UltrassonografiaRESUMO
Se estudió el valor de la lectura de la densidad óptica a 650 mm (DO650) para predecir la presencia o ausencia de fosfatidilglicerol (PG) en 52 muestras de LA no contaminadas con sangre ni meconio, obtenidas por amniocentesis transabdominal, en las cuales la prueba de Clements (PC) fue informada como negativa. La totalidad de las muestras excepto una tuvieron lectura de DO650 * 0,050, detectándose la presencia de PG en 22 de ellas (42,3%), no observándose diferencias significativas en ningún rango de lectura. Nuestros resultados demuestran que la DO650 no permite discriminar la presencia o ausencia de PG en muestras de LA con PC negativa, lo puede ser debido a que las bajas concentraciones necesarias para detectar PG en LA son incapaces de modificar significativamente la DO650. Se concluye que cuando la PC es negativa, la lectura de la DO650 es un paso innecesario en la evaluación de la inmadurez pulmonar fetal
Assuntos
Densitometria , Maturidade dos Órgãos Fetais , Líquido Amniótico/análise , Fosfatidilgliceróis/metabolismo , Pulmão/embriologia , AmniocenteseRESUMO
Se trata de un estudio prospectivo y longitudinal, orientado a la obtención de valores normales para el índice de líquido amniótico (ILA) obtenido mediante ultrasonografía, sumando los diámetros de las cuatro lagunas mayores de líquido amniótico obtenidas en cada cuadrante uterino. La muestra estuvo constituida por 394 pacientes cuya gestación evolucionó sin ningún contratiempo y las medidas del ILA fueron obtenidas a partir de las 18 semanas hasta el término con intervalo de 7 días, calculándose para cada edad gestacional sus respectivas medidas de tendencia central y de dispersión. Los resultados obtenidos muestran que los valores del ILA a lo largo de la gestación están representados en un cinturon o banda de bordes bastante regulares y amplios, en el cual sobresalen dos picos, el primero a las 26 semanas y el segundo a las 33 semanas. Entre la 18 y 25 semanas el valor promedio para el ILA fue de 10,67 con una DE de 3,27. Entre las 26 y 35 semanas el valor del ILA fue de 13 con una DE de 4,1 y, finalmente, para el grupo comprendido entre las 30 y 41 semanas, el valor medio del ILA fue de 13,3 con una DE de 4,4..
Assuntos
Humanos , Feminino , Ultrassonografia , Líquido Amniótico/análiseRESUMO
La anencefalia es una malformación del sistema nervioso central que resulta de un defecto en el proceso de embriogénesis. La sobrevida del recién nacido es de pocas horas o de pocos días. El ultrasonido es un exámen complementario que permite hacer el diagnóstico precoz en 100% de los casos. La falta de donantes renales para el transplante ha provocado que varias entidades busquen maneras alternas para atender la creciente demanda de estos órganos. Por este motivo, desde la década del 60 se han intentado usar recién nacidos anencefálos como donantes potenciales. Se relata un caso de transplante renal a partir de un anencéfalo a un receptor adolescente; hubo rechazo del injerto despues de algunas semanas. Discutimos los problemas suscitados a partir de la revisión de la literatura, los cuales se relacionan con la ética, técnica operatoiria y función del órgano transplantado.
Assuntos
Adolescente , Humanos , Masculino , Feminino , Acetilcolinesterase/diagnóstico , Transplante/métodos , Anencefalia/congênito , Líquido Amniótico/análise , Rim/transplanteRESUMO
Se estudió la madurez pulmonar neonatal mediante la prueba rápida de Clements para surfactante en 52 muestras de contenido gástrico de recién nacidos por intervención cesárea, obtenidas en los primeros minutos de vida. El aspecto físico, el grado de acidez, la citología y la prueba de Clements dieron resultados similares en estas muestras que en otras de líquido amniótico tomadas precozmente durante la cesárea. En el período neonatal ninguno de los 47 recién nacidos con prueba de Clements positiva en el contenido gástrico sufrió síndrome de dificultad respiratoria en contraste con 4 de 5, con resultados intermedios o negativos
Assuntos
Gravidez , Recém-Nascido , Humanos , Masculino , Feminino , Líquido Amniótico/química , Conteúdo Gastrointestinal/análise , Conteúdo Gastrointestinal/química , Líquido Amniótico/análise , Pulmão/embriologia , Cesárea , Maturidade dos Órgãos Fetais , Síndrome do Desconforto Respiratório do Recém-Nascido/diagnóstico , Tensoativos/análise , Fatores de TempoRESUMO
En 102 embarazos patológicos se estudió amniótico que se obtuvo por punción suprapúbica practicada con aguja 40/8-50/8 sin anestesia local. Se realizaron los test de Clements abreviado (TCLE), el de coagulación acelerada (TCA) y la determinación de las células naranjas (CN). Los datos obtenidos se introdujeron a una computadora personal IBM, PS50 para su ordenamiento habiéndose confeccionado un programa previo a tal efecto. La inmadurez, madurez pulmonar, madurez completa y término fueron establecidos por el resultado de las pruebas comparados tetrospectivamente con el examen neonatológico. La inmadurez y la madurez fue establecida con resultados satisfactorios especialmente con TCLE y TCA comparándolos con los de otros autores. Los valores del conteo de CN no arrojaron las conclusiones esperadas por lo que se recomienda la revisión del procedimiento
Assuntos
Adulto , Humanos , Feminino , Idade Gestacional , Líquido Amniótico/análiseRESUMO
A total of 153 patients' charts were reviewed over a 6-year period to assess the results of the practice of amniocentesis for diabetic mothers at term (greater than or equal to 37 weeks' gestation) before elective induction/delivery. The number of cases with absent phosphatidylglycerol were determined at each specific gestational age at or near term. Phosphatidylglycerol was present in 130, and phosphatidylglycerol was absent in 23 at first amniocentesis sampling. A significant proportion (approximately 21%) of those with gestational diabetes were phosphatidylglycerol-negative as late as 38 weeks' gestation. A similar proportion of overt diabetic patients were phosphatidylglycerol-negative as late as 39 weeks' gestation. These figures give the clinician some estimate of the likelihood of the absence of phosphatidylglycerol at or near term if amniocentesis is used before elective delivery in these patients.
Assuntos
Amniocentese , Maturidade dos Órgãos Fetais , Pulmão/embriologia , Gravidez em Diabéticas/fisiopatologia , Líquido Amniótico/análise , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Fosfatidilgliceróis/análise , Gravidez , Síndrome do Desconforto Respiratório do Recém-Nascido/etiologiaRESUMO
We studied longitudinal ultrasonographic growth patterns (abdominal circumference, biparietal diameter) initiated early in gestation in 52 pregnancies complicated by pregestational diabetes mellitus and 19 controls. Three predominant patterns of growth were ascertained including a heretofore unrecognized pattern characterized by accelerated abdominal circumference growth (greater than 90th percentile) before 24 weeks' gestational age. Maternal and neonatal anthropometric and metabolic parameters were contrasted for the three patterns. The findings suggest that in some cases of diabetic macrosomia that can be recognized before 24 weeks' gestation, augmented growth may be influenced by factors other than fetal hyperinsulinism.
Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Macrossomia Fetal/diagnóstico , Gravidez em Diabéticas/fisiopatologia , Ultrassonografia , Líquido Amniótico/análise , Glicemia/análise , Diabetes Mellitus Tipo 1/metabolismo , Desenvolvimento Embrionário e Fetal , Feminino , Macrossomia Fetal/metabolismo , Macrossomia Fetal/fisiopatologia , Humanos , Insulina/análise , Gravidez , Gravidez em Diabéticas/metabolismo , Diagnóstico Pré-NatalRESUMO
Newborn screening programs for the detection of congenital hypothyroidism have dramatically shortened the time before treatment is begun. However, concern still exists about central nervous system sequelae which may persist due to a period of untreated intrauterine hypothyroidism. Presence of polyhydramnios led to the ultrasound diagnosis of a fetal goiter. Hypothyroidism was confirmed at 34 weeks gestation by percutaneous fetal blood sampling, which revealed an elevated TSH (186 mU/L) and a low T4 (19.3 nmol/L). Intraamniotic fluid injections of 500 micrograms levothyroxine sodium (T4) every 10-14 days increased fetal serum T4 (59.2 nmol/L), decreased fetal serum TSH (14 mU/L), decreased amniotic fluid TSH, and decreased the size of the fetal goiter. The infant was born at term without perinatal complications. Thyroid function studies on cord blood were normal (T4, 109.4 nmol/L; TSH, 1.3 mU/L), and the infant was discharged on oral T4. Follow-up examination at age 6 weeks revealed that the infant was developmentally normal and clinically and chemically euthyroid. Intrauterine T4 therapy can suppress fetal TSH and treat fetal hypothyroidism despite hypothyroid levels of serum T3. Highly sensitive TSH assays may allow the use of amniotic fluid TSH as a marker for fetal hypothyroidism.
Assuntos
Doenças Fetais/diagnóstico , Bócio Nodular/diagnóstico , Hipotireoidismo/diagnóstico , Poli-Hidrâmnios/complicações , Diagnóstico Pré-Natal , Tireotropina/análise , Ultrassonografia , Adulto , Líquido Amniótico/análise , Feminino , Sangue Fetal/análise , Bócio Nodular/complicações , Bócio Nodular/tratamento farmacológico , Humanos , Hipotireoidismo/complicações , Hipotireoidismo/tratamento farmacológico , Gravidez , Testes de Função Tireóidea , Tireotropina/sangue , Tiroxina/uso terapêuticoRESUMO
alpha-Fetoprotein levels were measured on 148 paired samples from the maternal serum and amniotic fluid in women greater than or equal to age 35, who were undergoing early amniocentesis (12 to 14 weeks) for chromosomal analysis. These 148 women were white, weighed less than 200 pounds, had no serious medical problems, and did not have a fetal abnormality detected by ultrasonography or karyotype analysis. There was a significant rise in the maternal serum alpha-fetoprotein concentration from 12 to 14 weeks' gestation. Amniotic fluid alpha-fetoprotein peaked at 13 weeks and then significantly declined by 14 weeks' gestation. Similar to reports from normal pregnancies at 16 and 17 weeks, we found no correlation between the maternal serum and amniotic fluid alpha-fetoprotein levels between 12 and 14 weeks. Amniotic fluid alpha-fetoprotein levels cannot be predicted by levels in the maternal serum in pregnancies between 12 and 14 weeks' gestation.
Assuntos
Amniocentese , Líquido Amniótico/análise , Doenças Fetais/diagnóstico , Defeitos do Tubo Neural/diagnóstico , alfa-Fetoproteínas/análise , Adulto , Feminino , Idade Gestacional , Humanos , Recém-Nascido , GravidezRESUMO
The purpose of this study was to determine whether amniotic fluid glucose concentrations is of value in the rapid diagnosis of intraamniotic infection. Amniocenteses were performed in 168 patients with preterm labor and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as Mycoplasma species. The prevalence of positive amniotic fluid cultures was 13.6% (23/168). Patients with positive amniotic fluid cultures for microorganisms had significantly lower median amniotic fluid glucose concentrations than patients with negative amniotic fluid cultures (median 11 mg/dl, range 2 to 30 mg/dl vs median 28 mg/dl, range 3 to 74, respectively; p less than 0.001). Amniotic fluid glucose concentrations below 14 mg/dl had a sensitivity of 86.9% (20/23), a specificity of 91.7% (133/145), a positive predictive value of 62.5% (20/32), and a negative predictive value of 97.8% (133/136) in the detection of a positive amniotic fluid culture. Amniotic fluid glucose determination is a rapid, sensitive, inexpensive, and simple test for the detection of intraamniotic infection in women with preterm labor and intact membranes.
Assuntos
Líquido Amniótico/análise , Infecções Bacterianas/diagnóstico , Corioamnionite/diagnóstico , Glucose/análise , Trabalho de Parto Prematuro/etiologia , Líquido Amniótico/microbiologia , Bactérias/citologia , Contagem de Colônia Microbiana , Feminino , Violeta Genciana , Humanos , Recém-Nascido , Fenazinas , Gravidez , Coloração e RotulagemRESUMO
Insulin-like growth factor (IGF) binding proteins (IGFBP) were purified from conditioned media of cultured bovine endothelial cells (ECBP) and from human amniotic fluid (IGFBP-1), and then labeled by radioiodination. 125I-ECBP and 125I-IGFBP-1 were perfused through isolated beating rat hearts for 1 and 5 min, and the hearts fixed and analyzed for 125I-BP content and distribution. One to 4% of the perfused 125I-ECBP and 125I-IGFBP-1 crossed the capillary boundary. The ECBPs predominantly localized as intact 125I-BP in connective tissue elements of the heart with less 125I-BP in cardiac muscle. The ratio of 125I-ECBP in connective tissue: muscle (normalized to percent vol of these compartments) was greater than or equal to 10:1. In contrast, the IGFBP-1 had a greater affinity for cardiac muscle with ratios of 125I-IGFBP-1 in connective tissue:muscle of approximately 1:2. When 125I-IGF-I, in the absence of any BPs, was perfused through the hearts approximately 3-5% left the microcirculation and was found in subendothelial tissues. 125I-IGF-I localized primarily to cardiac muscle with a distribution of connective tissue:cardiac muscle of about 1:3. The findings in the isolated perfused heart were confirmed in intact animals. After 125I-IGFBP-1 was injected into anesthetized rats and allowed to circulate for 5 min, substantial radioactivity was associated with the heart. As in the isolated heart, the IGFBP-1 preferentially localized to cardiac muscle with a connective tissue:cardiac muscle ratio of 1:3. We conclude that IGFBPs produced by endothelial cells and the IGFBP-1 contained in amniotic fluid can cross the capillary boundaries of the rat heart, and that the ECBPs preferentially localize in connective tissue elements of the myocardium, whereas IGFBP-1 predominantly localizes in cardiac muscle.
Assuntos
Líquido Amniótico/análise , Permeabilidade Capilar , Proteínas de Transporte/metabolismo , Endotélio Vascular/metabolismo , Miocárdio/metabolismo , Animais , Bovinos , Tecido Conjuntivo/metabolismo , Vasos Coronários/metabolismo , Humanos , Imuno-Histoquímica , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina , Radioisótopos do Iodo , Masculino , RatosRESUMO
There is a paucity of data regarding the concentration of prostaglandins (PGs) in the amniotic fluid of women with preterm labor. The purpose of this study was to determine if preterm labor is associated with changes in amniotic fluid concentration of prostaglandins E2 and F2 alpha. Amniotic fluid was retrieved by transabdominal amniocentesis from women with preterm labor and intact membranes. Patients were classified into three groups according to the response to tocolysis and the presence or absence of intra-amniotic infection. PGE2 and PGF2 alpha were measured using specific and sensitive RIA kits. Amniotic fluid concentrations of PGE2 and PGF2 alpha were significantly higher in women with preterm labor and intra-amniotic infection than in women without infection, regardless of the response to tocolysis. These data suggest that both PGs are involved in the mechanism of preterm labor and may have prognostic value.
Assuntos
Líquido Amniótico/análise , Dinoprosta/análise , Dinoprostona/análise , Trabalho de Parto Prematuro/metabolismo , Infecções Bacterianas/metabolismo , Estudos Transversais , Feminino , Humanos , Gravidez , Complicações na Gravidez/metabolismoRESUMO
BACKGROUND AND METHODS: Fetal macrosomia occurs despite nearly normal maternal blood glucose levels in women with diabetes treated with insulin. We examined the hypothesis that it may be caused by insulin transferred as an insulin-antibody complex from the mother to her fetus. We adapted and validated a method based on high-performance liquid chromatography and used it to quantitate insulin in small volumes (0.5 to 1.0 ml) of cord serum from 51 infants born to mothers with insulin-dependent diabetes mellitus. RESULTS: In mothers receiving only human insulin (n = 6), only human insulin was detected in cord serum. Of the remaining 45 infants, whose mothers received animal insulin during pregnancy, 28 (group 1) had levels of animal (bovine or porcine) insulin (mean [+/- SE], 707 +/- 163 pmol per liter) that constituted 27.4 +/- 2.5 percent of the total insulin concentration (2393 +/- 500 pmol per liter) measured in the cord serum. The cord-serum insulin concentration in the remaining 17 infants (group 2), in whom only human insulin was detected (381 +/- 56 pmol per liter), was only 15 percent of that in group 1 (P less than 0.001). There was a significant correlation between the maternal and the cord-serum concentrations of anti-insulin antibody and the concentration of animal insulin in the baby (r = 0.77, P less than 0.01, and r = 0.76, P less than 0.001, respectively), suggesting that the animal insulin was transferred as an insulin-antibody complex. In group 1 the mean concentration of animal insulin in cord serum was higher in the 12 infants with macrosomia than in the 16 infants without the condition (1113 +/- 321 vs. 402 +/- 110 pmol per liter; P less than 0.05), and the concentration of animal insulin in cord serum correlated with birth weight (r = 0.39, P less than 0.05). The maternal glycosylated hemoglobin values and the incidence of respiratory distress syndrome were similar in groups 1 and 2. CONCLUSIONS: Considerable amounts of antibody-bound insulin are transferred from mother to fetus during pregnancy in some women with insulin-dependent diabetes mellitus; the extent of transfer correlates with the maternal concentration of anti-insulin antibody. The correlation between macrosomia and the concentrations of animal insulin in cord serum indicates that the transferred insulin has biologic activity and suggests that the formation of antibody to insulin in the mother is a determinant of fetal outcome independent of maternal blood glucose levels.
Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Macrossomia Fetal/etiologia , Insulina/metabolismo , Troca Materno-Fetal , Gravidez em Diabéticas/metabolismo , Adulto , Líquido Amniótico/análise , Formação de Anticorpos , Complexo Antígeno-Anticorpo/análise , Glicemia/análise , Cromatografia Líquida de Alta Pressão , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/imunologia , Feminino , Sangue Fetal/análise , Humanos , Recém-Nascido , Insulina/efeitos adversos , Anticorpos Anti-Insulina/análise , Gravidez , Gravidez em Diabéticas/tratamento farmacológico , Gravidez em Diabéticas/imunologiaRESUMO
Eleven hundred thirty-four pregnant women with reliable dates underwent ultrasound evaluation for amniotic fluid index (AFI) measurement with the modified four-quadrant technique. We found that from 13 weeks' gestation the AFI rose progressively until 26 weeks. From then to 38 weeks the AFI measurements demonstrated little variation. After 38 weeks the AFI appeared to decline gradually. In the third trimester the mean AFI was 16.0 +/- 4.8 cm; 5% of cases had an AFI less than or equal to 8 cm, and 5% had an AFI greater than or equal to 24 cm. These results confirm the reproducibility of the semiquantitative technique and suggest that in estimating amniotic fluid volume, AFI measurement may be a more appropriate means than measurement of the single largest pocket or subjective assessment. Serial AFI measurement would be an effective way of assessing fetal status throughout pregnancy.
Assuntos
Líquido Amniótico/análise , Retardo do Crescimento Fetal/diagnóstico , Idade Gestacional , Ultrassonografia/normas , Feminino , Humanos , Gravidez , Reprodutibilidade dos Testes , Ultrassonografia/instrumentação , Ultrassonografia/métodosRESUMO
The amniotic fluid index (AFI), a semiquantitative technique for assessing amniotic fluid volume, has been shown to be a useful adjunct in antepartum surveillance. We evaluated the usefulness of the AFI in the early intrapartum period as it relates to subsequent fetal morbidity and fetal heart rate patterns. Two hundred term gravidas presenting in the latent phase of labor with vertex-presenting fetuses were studied. An intrapartum AFI less than or equal to 5.0 cm was associated with a significant increase in the risk of cesarean section for fetal distress and of an Apgar score of less than 7 at one minute as well as abnormal fetal heart rate patterns in late labor. The majority (71.4%) of the patients with an intrapartum AFI less than or equal to 5.0 cm had ruptured membranes on entry; however, there was no significant difference in outcome when they were compared to patients with intact membranes and oligohydramnios. Variable decelerations on entry were associated with oligohydramnios in 43.8% of the patients. An AFI less than or equal to 5.0 cm in the early intrapartum period is a risk factor for perinatal morbidity and abnormal fetal heart rate patterns in subsequent labor, and ruptured membranes in early labor are a risk factor for oligohydramnios.
Assuntos
Líquido Amniótico/análise , Sofrimento Fetal/diagnóstico , Diagnóstico Pré-Natal/métodos , Adulto , Cardiotocografia , Estudos de Avaliação como Assunto , Feminino , Sofrimento Fetal/epidemiologia , Sofrimento Fetal/fisiopatologia , Frequência Cardíaca Fetal , Maternidades , Humanos , Los Angeles , Gravidez , Resultado da Gravidez , Diagnóstico Pré-Natal/normas , Fatores de Risco , UltrassonografiaRESUMO
Appropriate counselling and clinical management of the pregnant woman with a mosaic amniotic fluid cell karyotype are difficult. The majority of the data on mosaicism and pseudomosaicism are derived from studies employing the flask technique for the analysis of amniotic fluid cell cultures. Since the majority of laboratories now utilize the in-situ technique, such data may not be relevant when analyzing results from the in-situ colony technique. We reviewed the incidence of mosaicism in 6339 amniotic fluid samples using the in-situ technique. Data are presented on the types of aberrations and clinical outcomes. A classification of mosaicism is presented that distinguishes mosaicism of clinical importance from that which is obviously of extrafetal origin or artifactual. This approach clarifies the significance of mosaic states detected by the in-situ colony technique and provides a rational foundation for genetic counselling and for planning clinical interventions.