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N Montenegro

Publications and source records attributed to N Montenegro.

At least 19 recordsLinked to original sources
PubMed2006

Renal tubular dysgenesis: report of two cases in a non-consanguineous couple and review of the literature.

Renal tubular dysgenesis is a rare congenital abnormality of renal development characterized by short and poorly developed proximal convoluted tubules. It is associated to late-appearing oligohydramnios, Potter's sequence, pulmonary hypoplasia and calvarial bone hypoplasia with enlarged fontanels. The onset of oligohydramnios is delayed and variable, normally later than 22 weeks of gestation, conditioning variation in the expression of the other deformities. We report 2 cases of renal tubular dysgenesis occurring in a non-consanguineous couple.

Adult↗
PubMed2005

How should success be defined when attempting medical resolution of first-trimester missed abortion?

OBJECTIVES: There is currently no consensus on how success should be defined after medical management of first-trimester missed abortion. The aim of this study was to determine the transvaginal ultrasound criterion associated with highest success rate and, at the same time, lowest long-term complications. DESIGN: Prospective observational study of consecutively enrolled patients. SETTING: A tertiary care university hospital in northern Portugal. PARTICIPANTS: Forty-four women submitted to medical management of first-trimester missed abortion using a regimen of vaginal misoprostol, with histologically confirmed conception products passed vaginally. A transvaginal ultrasound scan was performed by an experienced sonographer in the morning after treatment, to characterise uterine content. Patients were provided with a chart for daily registration of axillary temperature, vaginal bleeding and lower abdominal pain. Transvaginal ultrasound was repeated 2-3 weeks later, and again after the following menses. MAIN OUTCOME MEASURES: Success rates of medical management when post-treatment transvaginal ultrasound criteria for subsequent expectant management were: absence of intra-uterine sac, largest anteroposterior diameter of hyperechogenic content, and maximum area of hyperechogenic intra-uterine content in a sagittal view. Self-reported duration of vaginal bleeding and abdominal pain after medical treatment. RESULTS: Success rate was 86% (38/44) when absence of gestational sac on the 12 h transvaginal ultrasound was used as the main criterion for subsequent expectant management and there was no need for further intervention. The success rate using the ultrasound criterion anteroposterior diameter < or = 15 mm was 51% (22/43), and with maximum sagittal plane area under 7.5 cm(2), 72% (31/43). Mean duration of vaginal haemorrhage was 9 days (minimum 2 days, maximum 14 days) and of lower abdominal pain 6 days (minimum 0 days, maximum 14 days). No patient recorded an axillary temperature exceeding 37 degrees C. No apparent relationship between the size of ultrasound-estimated intra-uterine content and duration of symptoms was observed. CONCLUSIONS: Absence of gestational sac on transvaginal ultrasound should be the criterion used to document success after medical management of first-trimester missed abortion, as it is associated with the highest short and long-term success rates, as well as mild and self-limited symptoms in the days following treatment.

Abdominal Pain↗
PubMed2001

Ductus venosus blood flow in chromosomally abnormal fetuses at 11 to 14 weeks of gestation.

This article reviews the role of ductus venosus (DV) Doppler evaluation in the screening for aneuploidies at 11 to 14 weeks of gestation. Ductus venosus flow velocity waveforms were obtained immediately before fetal karyotyping in 515 consecutive singleton pregnancies at 11 to 14 weeks. We found 446 normal and 69 abnormal karyotypes. Abnormal flow in the DV was the only significant difference between both groups. Sensitivity of the test was 80% and false positive rate < 1%. Normal karyotype but abnormal flow in the DV was recorded in 17 of 446 cases, 7 presenting a cardiac defect. Increased nuchal translucency seems to be related, in most cases, to early cardiac dysfunction. Chromosomal abnormalities and/or cardiac defects were often found in cases with increased nuchal translucency and abnormal flow in the DV. We suggest that the evaluation of ductal flow between 11 to 14 weeks of gestation should be adopted as a second level screening test to reduce invasive test rate derived from the exclusive measurement of nuchal translucency.

Adolescent↗
PubMed2000

Anticipating twin-twin transfusion syndrome in monochorionic twin pregnancy. Is there a role for nuchal translucency and ductus venosus blood flow evaluation at 11-14 weeks?

Twin-twin transfusion syndrome is a major complication of monochorionic twin pregnancies. In foetuses from monochorionic twinning the presence of increased nuchal translucency thickness (NT) has been associated with an increased risk of developing this syndrome. One of the presumed mechanisms of increased NT is early cardiac failure, indirectly indicated by abnormal blood flow in the ductus venosus. We present eleven cases of monochorionic twin pregnancies in which nuchal translucency thickness and ductus venosus blood flow evaluation was performed at 11-14 weeks. In the two cases presenting with nuchal translucency discrepancy between the two foetuses along with anomalous ductus venosus blood flow in the foetus with increased nuchal translucency, twin-twin transfusion syndrome (TTTS) eventually developed. In none of the twins displaying no inter-twin difference in NT measurements and in those with discrepant NT but normal flow in both ductus venosus, was the progression to TTTS observed. In the two cases which developed TTTS, foetoscopic laser coagulation of the vascular anastomosis was successfully carried out at 18 weeks and normalisation of the venous return was registered. These findings suggest that the association of increased NT and abnormal flow in the ductus venosus in monochorionic twins may be an early manifestation of haemodynamic imbalance between the donor and the recipient eventually manifested as twin-twin transfusion syndrome. Further studies, however, are necessary to establish the potential role of the combination of NT and ductus venosus blood flow assessment as a screening method for TTTS.

Adult↗
PubMed2000

Prenatal diagnosis of congenital heart disease. Critical evaluation of a twelve-month experience.

INTRODUCTION: A retrospective study of fetal echocardiographies performed in the Ultrasound Unit of the Department of Obstetrics and Gynecology between January and December 1998 was carried out. MATERIAL AND METHODS: We performed 271 fetal echocardiographies (236 fetuses; 230 pregnant women). A triplex ultrasound machine was used with a 5 or 3.5 MHz transabdominal probe. RESULTS: The median maternal age was 31 years (17-44) and the median gestational age at the time of the first examination was 27 weeks (15-38). A hundred and thirty-two pregnant women (57.4%) were internal referrals and (98) 42.6% were referred by other hospitals. The most common indications for referral were maternal age > or = 35 years old (n = 48), gestational diabetes (n = 38), family history of congenital heart disease (n = 24) and insulin-dependent diabetes (n = 23). Accuracy of 32 echocardiographies was limited by technical difficulties. Out of 236 fetuses, 205 (86.9%) presented a normal scan, whereas 31 (13.1%) showed some abnormality: 22 structural cardiac defects; 5 rhythm anomalies and one with a mixed abnormality. In three cases a pericardial effusion was detected in the absence of any structural or rhythm anomaly and regressed spontaneously after birth. Three fetuses were referred prenatally for treatment to another center. Eight out of fifteen patients followed in the Pediatric Cardiology outpatient clinic were submitted to surgical treatment. In four cases the parents opted for termination of pregnancy and two neonatal deaths occurred. Four patients were lost for follow-up. DISCUSSION: Our study suggests that strict criteria for a referral of pregnant women to specialized fetal echocardiography are still missing. The median gestational age of 27 weeks at the time of the first examination was clearly out of the generally accepted recommended period (18-24 weeks). It is time to improve the collaboration between the different health professionals involved in the care of pregnant women in order to increase the sensitivity of screening for congenital heart disease.

Adult↗
PubMed1999

Cardiac defects in chromosomally normal fetuses with abnormal ductus venosus blood flow at 10-14 weeks.

OBJECTIVE: To assess a possible relationship between ductus venosus blood flow abnormalities and cardiac defects in chromosomally normal fetuses with increased nuchal translucency thickness at 10-14 weeks of gestation. METHODS: Ductus venosus Doppler ultrasound blood flow velocity waveforms were obtained at 10-14 weeks' gestation immediately before fetal karyotyping in 200 consecutive singleton pregnancies with increased nuchal translucency. Fetal echocardiography was subsequently carried out in those with normal fetal karyotype. RESULTS: Reverse or absent flow during atrial contraction was observed in 11 of the 142 chromosomally normal fetuses with increased nuchal translucency. Major defects of the heart and/or great arteries were present in seven of the 11 with abnormal ductal flow and increased nuchal translucency, but in none of the 131 with normal flow. CONCLUSION: These preliminary results suggest that abnormal ductus venosus blood flow in chromosomally normal fetuses with increased nuchal translucency identifies those with an underlying major cardiac defect.

Blood Flow Velocity↗
PubMed1999

Neonatal cerebral Doppler: arterial and venous flow velocity measurements using color and pulsed Doppler system.

OBJECTIVE: To contribute to the establishment of reference values of blood flow velocity assessed by cerebral Doppler in healthy infants related to gestational age and birth weight during the first week of life. METHODS: Five arteries and three veins were evaluated respectively in 120 (74 premature) newborns and in 100 (70 preterm) infants. In a quarter of the latter three recordings at 5-minute intervals were made to assess reproducibility. The relation between flow measurements and gestational age was assessed by linear regression, means by analysis of variance (or Kruskall-Wallis test) and paired samples by Student's t test. RESULTS: There was a significant increase of arterial velocities with increasing gestational age and birth weight, but not for venous velocities. Significant higher values were found in the internal carotid artery followed by the medium cerebral artery. The venous velocities were highly reproducible and the main patterns observed were bandlike and sinusoid type. CONCLUSION: The knowledge of normal cerebrovascular physiology is essential to understand the pathogenesis of neonatal brain damage and can help pediatricians in an accurate interpretation of the flow profile in neurological pathology.

Arteries↗
PubMed1998

Comparison of three ELISA tests for seroepidemiology of bovine fascioliosis.

The aim of the present study was to compare the sensitivity, specificity and usefulness of the DIG-ELISA, DOT-ELISA and Indirect ELISA tests for determining the seroprevalence of fasciolosis in cattle under tropical conditions in Mexico. To standardize the tests, positive and negative sera to F. hepatica from 88 Holstein Freisian adult cows located in an enzootic area of fascioliosis and 88 crossbred adult cattle from a fluke-free area were used. For the epidemiological study, 85 crossbred cattle between 1 to 7 years of age were used. Animals were bled every two months, from March 1995 to September 1996 and the sera obtained were stored at -70 degrees C, until used. Indirect ELISA showed a sensitivity of 96.5% and a specificity of 98.8%, DIG-ELISA 97.5% and 80.0% and DOT-ELISA 93.1% and 95.4%, respectively. During 1995, Indirect ELISA yielded the highest levels of IgG anti-F. hepatica antibodies. However, in 1996, after animal treatment with triclabendazole, DIG-ELISA tended to show higher percentages of antibody-positive animals, but it was not significantly different (p>0.05) from the other tests. Comparisons made in parallel to the faecal sedimentation test demonstrated that all serological tests detected higher percentages of positive animals. Only one serum out of ten (10%) of Paramphistomum spp. cross-reacted with the DOT-ELISA test, but no cross-reaction was observed with sera from animals with other parasites. All ELISA tests were highly sensitive and specific; they may be recommended for use in seroepidemiological surveys for F. hepatica.

Animals↗
PubMed1998

Outcome of 88 pregnancies with absent or reversed end-diastolic blood flow (ARED flow) in the umbilical arteries.

OBJECTIVES: To investigate both perinatal and postneonatal morbidity and mortality in fetuses with absent or reversed end-diastolic flow (ARED flow) in the umbilical artery. STUDY DESIGN: A 5 year prospective follow-up of 88 fetuses with ARED flow. RESULTS: Sixteen stillbirths, 16 neonatal deaths, six postneonatal deaths and one death at 2 years of age were noted. Out of the 42 fetuses born alive, 36 showed a normal neurological development whereas six were mentally handicapped. Adverse prognosis was more frequently found in the group with absent end-diastolic flow at first examination and then reversed flow until delivery, compared to the groups of always absent or always reversed end-diastolic flows. CONCLUSIONS: Prompt delivery is recommended in these high-risk pregnancies in order to prevent long-term sequelae, obviously depending on the local limits of viability. Further studies appropriately designed for assessing long-term neurodevelopment of fetuses with ARED flow, although demanding, are mandatory.

Female↗
PubMed1998

Semiautomated ultrasonographic measurement of fetal nuchal translucency using a computer software tool.

Nuchal translucency (NT) thickness measurement has been recently proposed as a part of routine ultrasound scanning during the late first trimester of pregnancy, for the early screening of chromosomal abnormalities. Manual determination of NT is currently performed using electronic calipers placed by the operator in the middle of two echogenic lines displayed on the screen. Therefore, intraobserver and interobserver repeatability can be questioned. This paper presents a software tool that has been developed for achieving this goal in a semiautomatic way, improving the reproducibility of the method.

Chromosome Aberrations↗
PubMed1998

Anomalous fetal venous return associated with major chromosomopathies in the late first trimester of pregnancy.

We report three cases of increased nuchal translucency at 12-13 weeks of gestation in three fetuses with trisomies 13, 18 and 21. All three fetuses were associated with anomalous venous return evaluated by Doppler ultrasonography. Complete pathological examination was performed following termination in each case. We suggest that alterations in the venous compartment can be an early sign of poor outcome and should prompt a detailed search for cardiac defects early in gestation.

Adult↗
PubMed1998

Variation of embryonic/fetal heart rate at 6-13 weeks' gestation.

The aim of this study was to investigate changes in heart rate, namely the intraindividual variation, in normal embryos/fetuses between 6 and 13 weeks' gestation. A prospective study was performed of 41 singleton pregnancies undergoing routine ultrasound examination during the first trimester of pregnancy. For each case, the embryonic/fetal heart rate was measured on three consecutive occasions with a mean interval of 4 min. The difference in heart rate values between the serial measurements varied from 0 to 18 beats/min and was significantly associated with gestational age (Spearman r = 0.26, p < 0.01). In the group of 15 fetuses (examined before 10 weeks' gestation), the difference between measurements (median = 0 beats/min, range 0-8 beats/min) was significantly lower (z = 2.48, p < 0.05) than in fetuses assessed after 10 weeks of gestation (median = 3, range 0-18 beats/min). Reliable and reproducible information concerning embryonic/fetal heart rate may be obtained from a single measurement, especially when pregnancies are examined before 10 weeks of gestation.

Female↗
PubMed1998

Screening for chromosomal abnormalities at 10-14 weeks: the role of ductus venosus blood flow.

OBJECTIVE: To assess the possible role of Doppler ultrasound assessment of ductus venosus blood flow in screening for chromosomal abnormalities at 10-14 weeks of gestation. METHODS: Ductus venosus flow velocity waveforms were obtained immediately before fetal karyotyping in 486 consecutive singleton pregnancies at 10-14 weeks of gestation. All cases were screened for chromosomal defects by a combination of maternal age and fetal nuchal translucency thickness. The peak systolic and diastolic velocities, the velocity during atrial contraction and the pulsatility index were measured. RESULTS: There were 63 chromosomal defects (38 cases of trisomy 21, 12 cases of trisomy 18, seven cases of trisomy 13, three cases of Turner's syndrome and three cases of triploidy). In 57 (90.5%) cases there was reverse or absent flow during atrial contraction. Abnormal ductus venosus flow was also observed in 13 (3.1%) of the 423 chromosomally normal fetuses. In the chromosomally abnormal group, compared to the normal group, the median heights of the S and D waves were significantly lower and the pulsatility index was significantly higher. However, multivariate regression analysis demonstrated that only the height of the A wave provided a significant independent contribution in distinguishing between the chromosomally normal and abnormal groups. CONCLUSION: These preliminary results suggest that assessment of ductus venous blood flow in pregnancies considered to be at high risk for chromosomal defects may result in a major reduction in the need for invasive testing, with only a small decrease in sensitivity.

Adolescent↗
PubMed1998

Venous return and right ventricular diastolic function in ARED flow fetuses.

The absence or reversal of end-diastolic flow in the umbilical artery (UA) is widely accepted as an ominous sign of fetal compromise. However, in these high-risk pregnancies, the significance of sequentially appearing changes of the venous return is poorly established. Doppler blood flow waveforms were longitudinally assessed in the inferior vena cava (IVC), ductus venosus (DV), umbilical vein (UV) and tricuspid valve, along with the UA, middle cerebral artery and descending aorta. Thirty-two serial Doppler studies were performed in six fetuses with intrauterine growth-retardation (IUGR). In the cases of absent or reversed UA endodiastolic flow, changes in the venous return were found following the same sequence: presence of dicrote pulsations in the UV, increase of retrograde flow in the IVC and reduction or inversion of DV velocity during atrial contraction. Transtricuspid flow patterns changed from normal to a restrictive pattern of ventricular filling. There were two intrauterine deaths and one early neonatal death. Our preliminary results suggest that the evaluation of the venous compartment of hemodynamically disturbed preterms fetuses along with right ventricular filling appears to be a useful model for investigating the physiopathology of fetal deterioration and, therefore, may yield indirect discriminatory signs of severe compromise.

Adult↗
PubMed1997

Prenatal diagnosis of partial trisomy 2q. Case report.

A case of partial trisomy 2(q21q33) detected by cordocentesis at 27 weeks' gestation in a polymalformed fetus is described. This is the second case of a prenatally detected de novo duplication of 2q and the first involving the region referred to above.

Adult↗
PubMed1997

Dyssegmental dysplasia: a case report of a Rolland-Desbuquois type.

Two different forms of dyssegmental dysplasia, mild and severe, can be distinguished on clinical, radiographic and chondro-osseous morphologic grounds. The milder Rolland-Desbuquois type is frequently characterised by survival beyond the newborn period. The lethal Silverman-Handmaker type has distinctive and more severe findings. In this paper, a rare case of the Rolland-Desbuquois type is presented. The case is unusual because although it was the milder form, the child died on the 10th day of life.

Abnormalities, Multiple↗