Comparison of Fetal Cerebellum and Cisterna Magna Length by 2D and 3D Ultrasonography between 18 and 24 Weeks of Pregnancy.

To compare the fetal cerebellum and cisterna magna length measurements by means of two- (2DUS) and three-dimensional (3DUS) ultrasonography using the three-dimensional extended imaging (3D XI), a cross-sectional study with 69 healthy pregnant women between 18 and 24 weeks was performed. For the measurements by 2DUS, the axial planes were used and for the 3DUS a sequence of adjacent axial slices (multislice view). To evaluate the difference between the two techniques, we used the Wilcoxon test. To evaluate the correlation between the cerebellum and cisterna magna length measurements and the gestational age, we used the Spearman correlation coefficient (r). For the calculation of reproducibility, we used the intraclass correlation coefficient (ICC). The mean of the transverse and anterior-posterior diameter of cerebellum and cisterna magna by 3DUS was 9.23 and 6.62 mm, respectively. It was observed that the average of the measurements obtained by 3DUS was significantly higher, 0.76 and 1.02 mm for the length of the cerebellum and cisterna magna, respectively (P < 0.001). There was a high correlation between the length measurement of the cerebellum 3D (r = 0.940, P < 0.001), but low correlation of cisterna magna 3D (r = 0.462, P = 0.080) with the gestational age. There was good intra- and interobserver reproducibility for the cerebellum and cisterna magna 3D with ICC = 0.792 , 0.668, 0.691, and 0.287, respectively. The measurements of the fetal cerebellum and cisterna magna length by 3DUS using the software 3D XI were significantly higher than those obtained by 2DUS.

[Analysis of the combined first trimester screening for chromosomal abnormalities]. / Análise do rastreamento combinado no primero trimestre da gestação para detecção de anomalias cromossômicas.

PURPOSE: to evaluate the performance of the combined first trimester screening for chromosomal abnormalities in a group of the Brazilian population. METHODS: a retrospective study including pregnant women with single fetuses referred to a fetal medicine center to perform the first trimester screening that combines maternal age, nuchal translucency measurement and two maternal serum biochemical markers: free B-hCG and PAPP-A. To evaluate the performance of the test, the detection rate, specificity, negative and positive predicted values and false-positive rates were calculated, considering as high risk the cut-off value above 1 in 300. RESULTS: we studied 456 patients submitted to the test. Advanced maternal age above 35 years was observed in 36.2% of cases. The incidence of chromosomal abnormalities in the study population was 2.2%. Twenty-one patients (4.6%) presented a high risk (above 1:300) by the combined test. Using this cut-off level, the detection rate of the test was 70% for all chromosomal abnormalities and 83.3% for trisomy 21, for a false-positive rate of 3.1%. CONCLUSIONS: the combined first trimester screening was effective to detect chromosomal abnormalities, mainly for trisomy 21, with low false-positive rates. The combined test contributed to decreasing the indication of an invasive test if we compare to maternal age alone as a risk factor.

Análise do rastreamento combinado no primero trimestre da gestação para detecção de anomalias cromossômicas / Analysis of the combined first trimester screening for chromosomal abnormalities

OBJETIVO: avaliar o desempenho do rastreamento combinado do primeiro trimestre da gestação na detecção de anomalias cromossômicas em um grupo da população brasileira. MÉTODO: estudo retrospectivo envolvendo gestantes com feto único, referidas ao setor de medicina fetal para a realização do teste de rastreamento do primeiro trimestre da gestação pela combinação da idade materna, a medida da translucência nucal e dois marcadores bioquímicos do soro materno: free B-hCG e PAPP-A. Para avaliar o desempenho do teste foram calculados a sensibilidade, especificidade, valores preditivos positivos e negativos e as taxas de falso positivo, considerando como risco elevado valores superiores a 1:300. RESULTADOS: foram incluídas 456 gestantes submetidas ao teste. A idade materna avançada, acima de 35 anos, ocorreu em 36,2 por cento dos casos. A incidência de cromossomopatia na população estudada foi de 2,2 por cento. Vinte e uma das gestantes (4,6 por cento) apresentou risco elevado ao teste (superior a 1:300). Usando-se este ponto de corte, a sensibilidade do teste foi de 70 por cento para as cromossomopatias em geral e 83,3 por cento para os casos de trissomia do cromossomo 21, com taxa de falso positivo de 3,1 por cento. CONCLUSÃO: o rastreamento combinado do primeiro trimestre foi eficaz na detecção das anomalias cromossômicas, principalmente em relação aos casos de trissomia 21, com baixas taxas de falso positivo. Observou-se importante contribuição do teste em reduzir a indicação do exame invasivo comparado ao uso da idade materna como fator de risco.

PURPOSE: to evaluate the performance of the combined first trimester screening for chromosomal abnormalities in a group of the Brazilian population. METHODS: a retrospective study including pregnant women with single fetuses referred to a fetal medicine center to perform the first trimester screening that combines maternal age, nuchal translucency measurement and two maternal serum biochemical markers: free B-hCG and PAPP-A. To evaluate the performance of the test, the detection rate, specificity, negative and positive predicted values and false-positive rates were calculated, considering as high risk the cut-off value above 1 in 300. RESULTS: we studied 456 patients submitted to the test. Advanced maternal age above 35 years was observed in 36.2 percent of cases. The incidence of chromosomal abnormalities in the study population was 2.2 percent. Twenty-one patients (4.6 percent) presented a high risk (above 1:300) by the combined test. Using this cut-off level, the detection rate of the test was 70 percent for all chromosomal abnormalities and 83.3 percent for trisomy 21, for a false-positive rate of 3.1 percent. CONCLUSIONS: the combined first trimester screening was effective to detect chromosomal abnormalities, mainly for trisomy 21, with low false-positive rates. The combined test contributed to decreasing the indication of an invasive test if we compare to maternal age alone as a risk factor.

Reference range of fetal renal volume by three-dimensional ultrasonography using the VOCAL method.

OBJECTIVE: To establish reference values for fetal renal volume by three-dimensional sonography using the VOCAL (Virtual Organ Computer-Aided Analysis) method. METHODS: This prospective longitudinal study involved 57 healthy pregnant women who were examined between 24 and 34 weeks of pregnancy. Each fetal kidney was evaluated separately using the VOCAL method with a 30 degree rotation angle. For each gestational age, the following measures were obtained for the right and left kidneys: mean, standard deviation, minimum and maximum values, and the 5th, 10th, 25th, 50th, 75th and 90th percentiles. Polynomial regression models were constructed to assess the relationship between renal volume and gestational age, adjusted by the determination coefficient (R(2)). The Wilcoxon test was used to evaluate the concordance between the right and left renal volumes. Bland-Altman graphs were used to assess intra- and inter-observer variability. RESULTS: The right renal volume increased from 4.5 +/- 1.3 cm(3) at 24 weeks to 12.1 +/- 1.5 cm(3) at 34 weeks. The left renal volume increased from 4.6 +/- 0.8 cm(3) at 24 weeks to 11.9 +/- 1.1 cm(3) at 34 weeks. There was a strong correlation between both the right and left renal volumes and gestational age (R(2) = 0.975 and 0.970, respectively). There were no significant differences between the right and left renal volumes. The mean difference between repeated measures by the same examiner was -0.07 cm(3) (-0.88 to 0.75) for the right kidney and -0.21 cm(3) (-0.95 to 0.75) for the left kidney. The mean difference between repeated measures obtained by two different examiners was -0.07 cm(3) (-1.25 to 1.12) for the right kidney and 0 cm(3) (-1.53 to 1.53) for the left kidney. CONCLUSION: Reference values were generated for fetal renal volume assessed by three-dimensional ultrasonography using the VOCAL method.

Medida do comprimento do osso nasal entre 11 e 15 semanas de gestação em uma população brasileira: estudo preliminar / Measurement of fetal nasal bone length in the period between 11 and 15 gestational weeks in a Brazilian population: a preliminary study

OBJETIVO: Determinar valores de referência para o comprimento do osso nasal entre 11 e 15 semanas de gestação em uma população brasileira. MATERIAIS E MÉTODOS: Realizou-se estudo de corte transversal com 171 gestantes normais entre 11 e 15 semanas completas. O osso nasal foi medido por via transabdominal em todos os casos. Foram calculados os percentis 5 a 95 para o comprimento do osso nasal pela fórmula: média ± 1,645 desvio-padrão. Para avaliar a correlação do comprimento do osso nasal com parâmetros antropométricos fetais utilizou-se o coeficiente de correlação de Spearman, com intervalo de confiança de 95 por cento. RESULTADOS: O osso nasal foi mensurado em todos os casos, sendo que o comprimento médio variou de 1,69 mm a 2,94 mm. O comprimento do osso nasal mostrou-se fortemente correlacionado com todos os parâmetros antropométricos fetais (p < 0,001) e com a idade gestacional (R² = 0,59). CONCLUSÃO: Apesar de ser um estudo preliminar, a curva de referência do comprimento do osso nasal foi estabelecida.

OBJECTIVE: To establish reference values for fetal nasal bone length measurements between 11 and 15 gestational weeks in a Brazilian population. MATERIALS AND METHODS: A cross-sectional study was developed with 171 normal pregnant women between their 11th and 15th gestational weeks. The fetal nasal bone was measured by means of transabdominal ultrasound in all of the cases. The 5th and 95th percentiles for the nasal bone length were calculated by the formula: mean ± 1.645 standard deviation. The Spearman correlation coefficient with 95 percent confidence interval was utilized to correlate the nasal bone length with fetal anthropometric parameters. RESULTS: The nasal bone could be measured in all of the cases with the mean length ranging between 1.69 mm and 2.94 mm. Nasal bone length demonstrated to be strongly correlated with all of the fetal anthropometric parameters (p < 0.001) and with the gestational age (R² = 0.59). CONCLUSION: Despite the preliminary character of the present study, a reference range of fetal nasal bone length was established.

Diagnóstico ultra-sonográfico de anomalias fetais entre 10, 5 e 14 semanas de gestaçäo / Ultra-sonographic diagnosis of fetal anomalies at 10, 5-14 week's gestation

A translucência nucal (TN) é, no momento, o melhor marcador ultrasonográfico de aneuploidia no 1§ trimestre. Além disso, o ultra-som (US) nesta fase é capaz de identificar uma série de malformações (MF). Buscando conhecer a sensibilidade (S) e a especificidade (ESP) da TN em relação às aneuploidias e do US em relação às MF, estudamos 1.168, fetos entre 10,5 e 14 semanas de idade gestacional. Encontramos 882 fetos normais (75,5 por cento), 237 com TN aumentada (20,3 por cento), 28 com TN aumentada e MF (2,4 por cento) e 21 com MF (l,8 por cento). Foram realizadas 597 biópsias de vilo corial ( 51,1 por cento ), sendo que 51 foram anormais. Mais um caso de alteração cromossômica foi observado após o parto, totalizando 52 aneuploidias (4,5 por cento).Além das 49 MF diagnosticadas no primeiro trimestre, outras 17 foram vistas posteriormente. A S e a ESP da TN em relação à detecção de aneuploidias foi de 80,0 e 80,0 por cento se utilizarmos como critério um risco maior que 11300, e 71,0 e 94,0 por cento se o critério for TN maior ou igual a 2,8 mm. A associação entre MF no primeiro trimestre e aneuploidia foi de 3810 por cento. Em relação à MF, a S e a ESP do US no primeiro trimestre foi de 89,4 por cento e 100,0 por cento