Chromosomal abnormalities Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 1999;21(7):371-376
DOI 10.1590/S0100-72031999000700002
Purpose: to evaluate the possible value of pulsed and color Doppler of ductus venosus blood flow in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Methods: the ductus venosus flow velocity waveforms and the nuchal translucency (NT) thickness were obtained immediately before the chorionic villus sample in 26 pregnancies. We employed the following criteria for the suspicion of chromosomal defects: reverse or absent flow during atrial contraction and NT greater or equal to 3 mm. We calculated the sensitivity, the specificity, the negative and positive predictive value for each of the above items. Results: there were 9 chromosomal abnormalities (3 cases of trisomy 21, 2 cases of trisomy 13, 1 case of trisomy 9, 1 case of trisomy 22, 1 triploidy and 1 monosomy X). Abnormal ductus venosus flow was observed in all cases (sensitivity of 100%). In the normal fetuses (17 cases) only 1 had abnormal flow (specificity of 94%). Concerning NT, the sensitivity and the specificity were 88% and 76%, respectively. Conclusion: our preliminary results suggest that the presence of chromosomal abnormalities may be strongly suspected when an increased NT thickness is associated with an absent or reverse flow in the ductus venosus. We speculated that both methods are valid in the screening of chromosomal defects.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 1999;21(7):371-376
DOI 10.1590/S0100-72031999000700002
Purpose: to evaluate the possible value of pulsed and color Doppler of ductus venosus blood flow in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Methods: the ductus venosus flow velocity waveforms and the nuchal translucency (NT) thickness were obtained immediately before the chorionic villus sample in 26 pregnancies. We employed the following criteria for the suspicion of chromosomal defects: reverse or absent flow during atrial contraction and NT greater or equal to 3 mm. We calculated the sensitivity, the specificity, the negative and positive predictive value for each of the above items. Results: there were 9 chromosomal abnormalities (3 cases of trisomy 21, 2 cases of trisomy 13, 1 case of trisomy 9, 1 case of trisomy 22, 1 triploidy and 1 monosomy X). Abnormal ductus venosus flow was observed in all cases (sensitivity of 100%). In the normal fetuses (17 cases) only 1 had abnormal flow (specificity of 94%). Concerning NT, the sensitivity and the specificity were 88% and 76%, respectively. Conclusion: our preliminary results suggest that the presence of chromosomal abnormalities may be strongly suspected when an increased NT thickness is associated with an absent or reverse flow in the ductus venosus. We speculated that both methods are valid in the screening of chromosomal defects.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(4):243-246
DOI 10.1590/S0100-72032001000400007
Purpose: to evaluate the possibility and accuracy of fetal karyotyping in pleural effusions. Methods: we studied fifteen fetuses with unilateral or bilateral pleural effusions. All of these fetuses underwent intrauterine thoracocentesis guided by ultrasound examinations. The gestational age varied from 19 to 34 weeks. A morphogenetic ultrasound examination was performed in each case by the authors in order to identify associated structural anomalies. When the cellular cultures of pleural effusion samples were negative, an alternative karyotype was obtained by cordocentesis. A fetal lymphocyte culture was made of pleural effusion samples for karyotype in a similar technique as for fetal blood. Results: the fetal karyotype was successful in 12 cases. There were 4 abnormal results, all of them were Down syndromes, and in the other 8 cases the chromosomal analyses were normal. The fetal karyotype was confirmed and compared by newborn blood chromosomal analysis, genetic evaluation or necropsy. There were no maternal or fetal side effects related to the procedure. Conclusions: the fetal karyotyping performed in pleural effusions obtained by intrauterine thoracocentesis proved to be highly efficient and safe. It must be the method of choice for rapid karyotyping in fetuses with pleural edema.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(4):243-246
DOI 10.1590/S0100-72032001000400007
Purpose: to evaluate the possibility and accuracy of fetal karyotyping in pleural effusions. Methods: we studied fifteen fetuses with unilateral or bilateral pleural effusions. All of these fetuses underwent intrauterine thoracocentesis guided by ultrasound examinations. The gestational age varied from 19 to 34 weeks. A morphogenetic ultrasound examination was performed in each case by the authors in order to identify associated structural anomalies. When the cellular cultures of pleural effusion samples were negative, an alternative karyotype was obtained by cordocentesis. A fetal lymphocyte culture was made of pleural effusion samples for karyotype in a similar technique as for fetal blood. Results: the fetal karyotype was successful in 12 cases. There were 4 abnormal results, all of them were Down syndromes, and in the other 8 cases the chromosomal analyses were normal. The fetal karyotype was confirmed and compared by newborn blood chromosomal analysis, genetic evaluation or necropsy. There were no maternal or fetal side effects related to the procedure. Conclusions: the fetal karyotyping performed in pleural effusions obtained by intrauterine thoracocentesis proved to be highly efficient and safe. It must be the method of choice for rapid karyotyping in fetuses with pleural edema.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(5):291-298
DOI 10.1590/S0100-72032001000500004
Objective: to study the value of Doppler velocimetry of the ductus venosus and of the umbilical artery and vein, in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Patients and Methods: a total of 314 fetuses were studied consecutively. In 112 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 202 cases the postnatal phenotype was used as a basis for the result. In addition to the routine ultrasonographic examination, all the fetuses were submitted to measurement of the nuchal translucency thickness and to Doppler velocimetry of the umbilical artery and vein, particularly of the ductus venosus. For statistical analysis the Fisher exact test and the Mann-Whitney test were used. Results: twenty-three cases of chromosomal abnormalities occurred. Of these abnormal cases, the ductus venosus blood flow during atrial contraction was absent (1 case) and reverse (22 cases), sensitivity was 92%. In the group of normal fetuses (289 cases), 6 evaluations demonstrated alterations in the Doppler of the ductus venosus (specificity of 97.6%, positive and negative predictive values of 76.7% and 93.3%, respectively); the false-positive rate was 2.4%. In reference to the umbilical vein and umbilical artery, there was no statistically significant difference between the abnormal and the normal group. Conclusion: The only parameter of Doppler velocimetry of the umbilical artery and vein which contributed to the detection of aneuploidies was the accidental discovery of the reverse blood flow in both vessels. Although our favorable results demonstrated that the Doppler velocimetry of the ductus venosus is effective in detecting aneuploidies, this conclusion, however, is preliminary and needs further investigation.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(5):291-298
DOI 10.1590/S0100-72032001000500004
Objective: to study the value of Doppler velocimetry of the ductus venosus and of the umbilical artery and vein, in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Patients and Methods: a total of 314 fetuses were studied consecutively. In 112 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 202 cases the postnatal phenotype was used as a basis for the result. In addition to the routine ultrasonographic examination, all the fetuses were submitted to measurement of the nuchal translucency thickness and to Doppler velocimetry of the umbilical artery and vein, particularly of the ductus venosus. For statistical analysis the Fisher exact test and the Mann-Whitney test were used. Results: twenty-three cases of chromosomal abnormalities occurred. Of these abnormal cases, the ductus venosus blood flow during atrial contraction was absent (1 case) and reverse (22 cases), sensitivity was 92%. In the group of normal fetuses (289 cases), 6 evaluations demonstrated alterations in the Doppler of the ductus venosus (specificity of 97.6%, positive and negative predictive values of 76.7% and 93.3%, respectively); the false-positive rate was 2.4%. In reference to the umbilical vein and umbilical artery, there was no statistically significant difference between the abnormal and the normal group. Conclusion: The only parameter of Doppler velocimetry of the umbilical artery and vein which contributed to the detection of aneuploidies was the accidental discovery of the reverse blood flow in both vessels. Although our favorable results demonstrated that the Doppler velocimetry of the ductus venosus is effective in detecting aneuploidies, this conclusion, however, is preliminary and needs further investigation.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2002;24(3):167-173
DOI 10.1590/S0100-72032002000300004
Purpose: to study the value of nuchal translucency (NT) measurement in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Methods: a total of 1152 fetuses were studied consecutively. In 124 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 1028 cases the result was based on the postnatal phenotype. In addition to the routine ultrasonographic examination, all fetuses were submitted to measurement of the NT thickness. For statistical analysis Student's t test and ANOVA were used. Sensitivity, specificity, positive and negative predictive values, false-positive rate and likelihood ratio were calculated. Results: twenty-three cases of chromosomal abnormalities occurred. Of these abnormal cases, NT measurement was above the 95th percentile in 16 (sensitivity of 69.5%). In the group of normal fetuses (1129 cases), NT measurement was above the 95th percentile in 41 (specificity of 96.3%, positive and negative predictive values of 28.0% and 99.3%, respectively, false-positive rate of 3.7% and likelihood ratio of 19.1). Conclusion: our results suggest that the presence of chromosomal abnormalities may be strongly suspected when there is an increased NT thickness. One can infer that the quantitative NT analysis is sufficient to classify the risk of chromosomal anomalies in the first trimester of the pregnancy. Although the ultrasound operator's training and skill is still necessary, it is a method of clinical applicability.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2002;24(3):167-173
DOI 10.1590/S0100-72032002000300004
Purpose: to study the value of nuchal translucency (NT) measurement in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Methods: a total of 1152 fetuses were studied consecutively. In 124 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 1028 cases the result was based on the postnatal phenotype. In addition to the routine ultrasonographic examination, all fetuses were submitted to measurement of the NT thickness. For statistical analysis Student's t test and ANOVA were used. Sensitivity, specificity, positive and negative predictive values, false-positive rate and likelihood ratio were calculated. Results: twenty-three cases of chromosomal abnormalities occurred. Of these abnormal cases, NT measurement was above the 95th percentile in 16 (sensitivity of 69.5%). In the group of normal fetuses (1129 cases), NT measurement was above the 95th percentile in 41 (specificity of 96.3%, positive and negative predictive values of 28.0% and 99.3%, respectively, false-positive rate of 3.7% and likelihood ratio of 19.1). Conclusion: our results suggest that the presence of chromosomal abnormalities may be strongly suspected when there is an increased NT thickness. One can infer that the quantitative NT analysis is sufficient to classify the risk of chromosomal anomalies in the first trimester of the pregnancy. Although the ultrasound operator's training and skill is still necessary, it is a method of clinical applicability.
