RESUMO
OBJECTIVES: The objectives of this study were to establish gestational age-specific reference ranges for cross-sectional area of the umbilical cord, and its components, in twin pregnancies and to compare them with previously reported singleton reference ranges. METHODS: This was a prospective longitudinal study involving uncomplicated dichorionic twin pregnancies. Sonographic measurements of the cross-sectional area of the umbilical cord, umbilical vein and arteries and Wharton's jelly were obtained in a plane adjacent to the fetal abdomen, every 3 weeks, between 18 and 32 weeks of gestations. Multilevel regression analysis was used to determine gestational age-specific reference ranges for each parameter, and these were plotted against singleton pregnancy references. RESULTS: Three hundred and thirty four ultrasound scans were performed in 44 twin pregnancies, between 18 and 32.9 weeks (mean: 3.8 ± 0.7 scans/pregnancy and mean interval between scans: 3.3 ± 0.9 weeks). All umbilical cord cross-sectional areas (total, vein, artery and Wharton's jelly) showed a significant increase with gestational age. Compared with singleton pregnancy ranges, mean values were considerably lower in twin pregnancies and resemble the lower limits observed in singletons. CONCLUSION: In twin pregnancies, cross-sectional area of the umbilical cord, and its components, increases between 18 and 32 weeks, and mean values are substantially lower compared with singleton pregnancies.
Assuntos
Idade Gestacional , Gravidez de Gêmeos , Artérias Umbilicais/diagnóstico por imagem , Veias Umbilicais/diagnóstico por imagem , Geleia de Wharton/diagnóstico por imagem , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Análise Multinível , Tamanho do Órgão , Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Estudos Prospectivos , Valores de Referência , Análise de Regressão , Ultrassonografia Pré-Natal , Artérias Umbilicais/anatomia & histologia , Cordão Umbilical/anatomia & histologia , Cordão Umbilical/diagnóstico por imagem , Veias Umbilicais/anatomia & histologia , Geleia de Wharton/anatomia & histologiaRESUMO
Group B Streptococcus (GBS), Klebsiella spp. and Pseudomonas spp. are important aetiological agents of neonatal infections in Brazil. There is a lack of data in the literature regarding the specific transport of immunoglobulin G (IgG) against these pathogens in multiple pregnancies. Maternal (n = 55) and umbilical cord (n = 110) blood samples were prospectively collected at birth from 55 twin pregnancies. The factors associated with cord levels and transfer ratios of IgG against GBS, Klebsiella and Pseudomonas were examined. The IgG umbilical cord serum levels specific to GBS, Klebsiella LPS and Pseudomonas LPS were significantly associated with maternal-specific IgG concentrations and the presence of diabetes. The anti-Klebsiella IgG cord serum concentrations were also related to birthweight and the presence of hypertension. The transfer ratios against GBS and Pseudomonas LPS were associated with maternal-specific IgG concentrations. The transfer ratios for GBS and Pseudomonas LPS were associated with gestational age at delivery and the presence of diabetes, respectively. None of the examined parameters were related to Klebsiella LPS transfer ratios. We conclude that in twin pregnancies, specific maternal IgG serum concentrations and diabetes were the parameters associated with umbilical cord serum IgG concentrations reactive with the three pathogens investigated. All the other parameters investigated showed different associations with neonatal-specific IgG levels according to the antigen studied. There was no uniformity of the investigated parameters regarding association with placental IgG transfer ratios against the GBS, Pseudomonas LPS and Klebsiella LPS.
Assuntos
Anticorpos Antibacterianos/imunologia , Imunoglobulina G/imunologia , Klebsiella/imunologia , Lipopolissacarídeos/imunologia , Gravidez de Gêmeos/imunologia , Pseudomonas/imunologia , Streptococcus agalactiae/imunologia , Anticorpos Antibacterianos/sangue , Peso ao Nascer/imunologia , Feminino , Sangue Fetal/imunologia , Sangue Fetal/metabolismo , Idade Gestacional , Humanos , Imunidade Materno-Adquirida/imunologia , Imunoglobulina G/sangue , Recém-Nascido , Masculino , Troca Materno-Fetal/imunologia , Análise Multivariada , Placenta/imunologia , Placenta/metabolismo , Gravidez , Gravidez de Gêmeos/sangue , Estudos ProspectivosRESUMO
OBJECTIVE: To review a single center's experience in the management of twin pregnancies with conjoined fetuses. METHODS: Retrospective study describing prenatal findings, delivery details, surgical treatment and perinatal outcome. RESULTS: The study included 36 twin pregnancies with conjoined twins seen over a period of 12 years in a single tertiary hospital: 69.4% were thoracopagus, 13.9% parapagus, 8.3% omphaloischiopagus 5.6% omphalopagus and 2.8% cephalopagus. Cardiac defects were present in 91.6% of twin pairs and associated malformations were present in 61.8% of the cases: limb abnormalities in 36.1%, abdominal wall defects in 25.0%, cleft lip and/or palate in 13.9% and congenital diaphragmatic hernia in 5.5%. Surgical separation was considered not feasible and prognosis lethal in 30 (83.3%) cases. Termination of pregnancy was performed in 12 pregnancies of poor prognosis. Cesarean section was performed in all remaining cases. Five sets of twins underwent surgical separation and six children survived. Overall survival in our series was 8.3% and, among the livebirths, 13.6%. CONCLUSION: Conjoined twin pregnancies should be referred to tertiary centers for detailed fetal anomaly and echocardiographic assessment to evaluate prognosis and determine the possibility of postnatal surgical separation.
Assuntos
Gêmeos Unidos/patologia , Adulto , Brasil , Parto Obstétrico , Feminino , Humanos , Masculino , Gravidez , Estudos Retrospectivos , Gêmeos Unidos/cirurgia , Adulto JovemRESUMO
We report two cases of exencephaly diagnosed by transvaginal ultrasonography at 8 weeks 4 days and at 9 weeks 3 days of gestation. Both cases presented an irregular cephalic pole, and, in the case seen at 8 weeks 4 days, brain vesicles were also absent, whereas in the case seen at 9 weeks 3 days, the midline echo was indistinguishable with disorganized choroid plexuses. In both cases, anencephaly was evident at 11 and 12 weeks' gestation and the postmortem confirmed the diagnosis.
Assuntos
Anencefalia/diagnóstico por imagem , Primeiro Trimestre da Gravidez , Ultrassonografia Pré-Natal , Aborto Eugênico , Adulto , Feminino , Aconselhamento Genético , Humanos , GravidezRESUMO
OBJECTIVE: To evaluate the association between abnormal ductus venosus (DV) at 11-14 weeks' gestation and chromosomal abnormalities, structural defects and fetal outcome. METHODS: DV flow-velocity waveform (DV-FVW) and nuchal translucency thickness (NT) were prospectively evaluated in 1217 singleton pregnancies. RESULTS: The DV-FVW was abnormal in 84 fetuses, NT was above the 95th centile in 160 fetuses and both markers were observed in 41 fetuses. Chromosomal defects were diagnosed in 22 fetuses. The sensitivity, specificity and positive and negative predictive values for an abnormal karyotype were 86.4%, 86.9%, 11.9% and 99.7%, respectively, for an increased NT. These values were 68.2%, 96.9%, 31.3% and 99.3%, respectively, for DV-FVW abnormalities and 68.2%, 97.6%, 36.6% and 99.3%, respectively, when both markers were found simultaneously. Regarding structural defects, these values were 43.8%, 92.9%, 8.3% and 99.1% for an abnormal NT, 25.0%, 92.6%, 4.8% and 98.8% for DV-FVW abnormalities and 25.0%, 97.9%, 15.4% and 98.9% for both together. Considering those cases of unexplained fetal demise, the values were 44.4%, 85.9%, 5.0% and 98.9% for NT abnormalities, 22.2%, 92.6%, 4.8% and 98.6% for an abnormal DV-FVW and 22.2%, 98%, 15.4% and 98.7% for both. In cases with increased NT, the percentage of live births with normal karyotype and no major fetal structural defects decreased from 93.8% in normal DV-FVW fetuses to 77.3% in abnormal ones. CONCLUSION: DV assessment at 11-14 weeks' gestation is useful in screening for fetal chromosomal abnormalities and may help to reduce the false-positive rate when combined with NT measurement. Abnormal DV-FVW is also associated with an increase in adverse perinatal outcome in fetuses with enlarged NT. However, the value of DV-FVW assessment in cases with normal NT is unclear.
Assuntos
Aberrações Cromossômicas/embriologia , Feto/irrigação sanguínea , Resultado da Gravidez , Ultrassonografia Pré-Natal/métodos , Aborto Espontâneo/diagnóstico por imagem , Aborto Espontâneo/fisiopatologia , Velocidade do Fluxo Sanguíneo/fisiologia , Feminino , Feto/anormalidades , Feto/fisiopatologia , Idade Gestacional , Humanos , Cariotipagem , Idade Materna , Gravidez , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To determine the accuracy and practicality of fetal echocardiography in the identification of structural and functional cardiac abnormalities prior to 16 weeks' gestation in fetuses with increased nuchal translucency thickness (NT). METHODS: Between January 1996 and June 2002 early fetal echocardiography using the transvaginal route was performed at 12-16 weeks' gestation on 275 fetuses with increased NT. The abnormal cardiac findings were classified as either structural (congenital heart defects) or functional, defined as transient phenomena which might later disappear, such as isolated tricuspid regurgitation and an enlarged ascending aorta. The abnormal findings were related to pregnancy outcome, including autopsy results, karyotyping results, and late fetal and neonatal echocardiography. RESULTS: Cardiac abnormalities were present in 61 fetuses overall (22.2%); including structural cardiac defects in 37 fetuses (13.5%) and functional abnormalities in 24 fetuses (8.7%). Structural cardiac abnormalities were associated with abnormal karyotype in 24 fetuses and normal karyotype in 13 fetuses. Of the 24 fetuses with functional cardiac abnormalities, 2 (8.3%) had isolated tricuspid regurgitation and 22 (91.7%) had enlarged ascending aorta. Abnormal karyotype was present in this group in 4 cases (16.7%). CONCLUSION: Increased NT can be used to define a high-risk group that should receive specialized early fetal echocardiography. This is a reliable technique with great potential for the diagnosis of both structural and functional cardiac abnormalities.
Assuntos
Cardiopatias Congênitas/diagnóstico por imagem , Pescoço/embriologia , Ultrassonografia Pré-Natal/métodos , Adolescente , Adulto , Aorta/anormalidades , Autopsia , Velocidade do Fluxo Sanguíneo/fisiologia , Ecocardiografia , Feminino , Idade Gestacional , Cardiopatias Congênitas/fisiopatologia , Humanos , Cariotipagem , Pessoa de Meia-Idade , Pescoço/diagnóstico por imagem , Gravidez , Resultado da Gravidez , Segundo Trimestre da Gravidez , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/fisiopatologia , TrissomiaRESUMO
OBJECTIVE: To compare cervical length measurements obtained at 11 to 14 weeks and 22 to 24 weeks of gestation in an unselected group of pregnant women and to correlate the measurements with time of delivery. METHODS: This was a prospective study involving 529 pregnant women attending for routine antenatal care who underwent transvaginal scans at 11-14 weeks and 22-24 weeks for evaluation of cervical length. The mean cervical length was calculated at both stages of gestation and lengths were compared between groups which delivered at term or prematurely, this being defined as delivery before 37 completed weeks of gestation. RESULTS: The mean cervical lengths at 11-14 and 22-24 weeks were, respectively, 42.4 mm and 38.6 mm. Cervical length at 11-14 weeks was not significantly different between the groups which delivered at term (42.7 mm) and preterm (40.6 mm). However, at the 22-24-week evaluation, cervical length was significantly shorter in the group which had a preterm delivery than in that which had a term delivery (26.7 mm and 39.3 mm, respectively; P = 0.0001). In the group of women with a previous history of one or more preterm deliveries, there was a greater shortening in cervical length from the first to the second evaluation than there was in the group of women with no previous history of preterm delivery. This shortening was also more pronounced in the group which delivered prematurely (from 40.6 mm to 26.7 mm) than in that which delivered at term (from 42.7 mm to 39.3 mm). CONCLUSION: There is a spontaneous shortening in the pregnant cervix from the first to the second trimester of pregnancy. The shortening is more rapid in pregnant women who deliver prematurely and who have a history of previous preterm delivery.
Assuntos
Colo do Útero/diagnóstico por imagem , Trabalho de Parto Prematuro/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Adolescente , Adulto , Colo do Útero/anatomia & histologia , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Estudos Prospectivos , Análise de Regressão , Sensibilidade e EspecificidadeRESUMO
OBJECTIVES: To determine the extent of overlapping of the internal cervical os by the lower placental edge at 11-14 weeks' gestation which best predicts placenta previa at term. PATIENTS AND METHODS: This was a prospective study initially involving 381 singleton pregnancies with a live fetus at 11-14 weeks attending for routine antenatal care. The distance between the lower placental edge and the internal cervical os was longitudinally evaluated by transvaginal ultrasound examination at 11-14 weeks', 20-24 weeks', and 30-34 weeks' gestation. The first 203 cases were selected at random (first phase) and after this period only cases with the lower placental edge reaching and/or overlapping the internal cervical os were followed up (n = 170, second phase). Thus a total of 373 cases were analyzed, 351 of whom were examined in all three trimesters. Multiple regression analysis was used to estimate the probability of predicting placenta previa at term using the overlap of the lower placental edge over the internal cervical os in the first trimester of pregnancy. RESULTS: A change in the relative position of the placenta (placental migration) was observed in all 351 cases examined in the three trimesters of pregnancy. In the general population, represented by the 203 cases (first phase), the incidence of placenta previa at 11-14 weeks' gestation was 42.3% (86/203), at 20-24 weeks' 3.9% (8/203) and at term 1.9% (4/203). A total of 18 cases of placenta previa and 17 cases of marginal placenta were observed at term. It was estimated that when the lower placental edge overlaps the internal cervical os by 23 mm at 11-14 weeks the probability of placenta previa at term is 8% with a sensitivity of 83.3% and specificity of 86.1%. CONCLUSION: The present study establishes the probability of placenta previa at term depending on the relationship of the lower placental edge to the internal cervical os at 11-14 weeks.
Assuntos
Placenta Prévia/diagnóstico por imagem , Ultrassonografia Pré-Natal , Adolescente , Adulto , Feminino , Humanos , Valor Preditivo dos Testes , Gravidez , Primeiro Trimestre da Gravidez , Estudos Prospectivos , Análise de Regressão , Vagina/diagnóstico por imagemRESUMO
OBJECTIVE: To compare cervical length measurements in twin pregnancies obtained from patients in the recumbent and standing positions. METHODS: Fifty women with uncomplicated twin pregnancies underwent monthly transvaginal ultrasound examinations for cervical length measurement in the recumbent and standing positions. The correlation between cervical length measurements obtained in the recumbent and standing positions, and between these measurements and gestational age, were examined. The significance of the differences between measurements obtained in the recumbent and standing positions was also analyzed. RESULTS: Based on data obtained at the first ultrasound examination, there was a significant correlation between cervical length measurements in the recumbent and standing positions (r = 0.77; t = 8.25; P < 0.0001) and both measurements showed a significant inverse correlation with gestational age (recumbent position: r = -0.60, P < 0.0001; standing position: r = -0.46; P = 0.0008). The mean of the differences (standing - recumbent) was -1.8 mm (95% confidence interval = -3.7-0.04; t = -1.96; P = 0.06) and the mean of percentage differences ((standing - recumbent)/recumbent x 100) was -2.9% (95% confidence interval = -8.6-2.7; t = -1.04; P = 0.3). When the data obtained at all examinations were examined by multiple regression analysis, cervical length measurement in the recumbent position was the only parameter that correlated significantly with the percentage difference between cervical length measurements (P < 0.0001). CONCLUSIONS: Cervical length in twin pregnancies decreases with gestation and there is a good correlation between measurements obtained from women in the recumbent and standing positions. No significant changes in cervical length were observed comparing measurements obtained in the two maternal positions.
Assuntos
Colo do Útero/diagnóstico por imagem , Postura , Gravidez Múltipla , Ultrassonografia Pré-Natal , Adulto , Colo do Útero/anatomia & histologia , Feminino , Idade Gestacional , Humanos , Gravidez , Análise de Regressão , GêmeosRESUMO
The aim of this study was to evaluate the detection of fetal structural abnormalities by the 11-14 week scan. 2853 pregnant women were submitted to a routine ultrasound scan between the 11th and 14th week and the fetal skull, brain, spine, abdominal wall, limbs, stomach and bladder were examined. Following the scans the patients were examined in the second or third trimester of pregnancy. An isolated increased nuchal translucency was not considered an abnormality. However, these patients had an early echocardiography assessment. Fetal structural abnormalities were classified as major or minor and of early or late onset. A total of 130 (4.6%) defects were identified and 29 (22.3%) of these were diagnosed at the 11-14 week scan, including nine cardiac defects associated with increased nuchal translucency. The antenatal ultrasound detection rate was 71.5%, and 31.2% were detected in the first-trimester assessment. 78.8% of the major defects were diagnosed by the prenatal scan and 37.8% by the 11-14 week scan. Fetal structural abnormalities at the 11-14 week scan were detected in approximately 22.3% of the cases, therefore, a second-trimester anomaly scan is important in routine antenatal care to increase the prenatal detection of fetal defects.