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Biomedical subjects

W Sepulveda

Publications and source records attributed to W Sepulveda.

At least 19 recordsLinked to original sources
PubMed2004

Chromosomal abnormalities in fetuses with open neural tube defects: prenatal identification with ultrasound.

OBJECTIVES: To determine the prevalence of chromosomal abnormalities in fetuses with open neural tube defects (NTD) undergoing prenatal chromosome analysis. The role of prenatal ultrasound in detecting those with an underlying chromosomal abnormality was also investigated. METHODS: Over a 6-year period, 144 fetuses with open NTD underwent prenatal chromosome analysis between 12 and 37 weeks of gestation, as part of a prospective, multicenter prenatal diagnosis and counseling program in Chile. This population included 66 fetuses with spina bifida, 46 with acrania/anencephaly, 21 with cephalocele and 11 with iniencephaly. A confident prenatal diagnosis was made in 143 fetuses (99%) and confirmed postnatally in all cases. RESULTS: An underlying chromosomal abnormality was diagnosed in 10 fetuses (7%), six with spina bifida, three with cephalocele and one with craniorachischisis. The prevalence of chromosomal abnormality varied according to the defect present in the fetus, with a 14% (3/21) prevalence among those with cephalocele, 9% (6/66) among those with spina bifida and 2% (1/57) among those with lethal defects such as acrania, anencephaly or iniencephaly. Karyotype results revealed trisomy 18 in seven cases, trisomy 13 in two and mosaicism for a marker chromosome in one. Prenatal ultrasound before the procedure showed that all chromosomally abnormal fetuses had additional findings. The prevalence of chromosomal abnormality in fetuses with spina bifida and cephalocele was higher when chromosome analysis was performed at or before 24 weeks of gestation in comparison to those performed after 24 weeks (5/31 (16%) vs. 4/56 (7%), respectively). However, this difference did not reach statistical significance, probably due to the small number of cases. CONCLUSIONS: A significant number of fetuses with open NTD are chromosomally abnormal. Although prenatal chromosome analysis should be considered in all cases, prenatal ultrasound seems effective in identifying those fetuses with an underlying chromosomal abnormality.

Adult↗
PubMed2003

Prenatal detection of velamentous insertion of the umbilical cord: a prospective color Doppler ultrasound study.

OBJECTIVE: Velamentous insertion of the umbilical cord, with a reported incidence of 1% in singleton pregnancies, has been associated with several obstetric complications including fetal growth restriction, prematurity, congenital anomalies, low Apgar scores, fetal bleeding and retained placenta. The aim of this study was to determine the feasibility of identifying velamentous insertion of the umbilical cord during routine obstetric ultrasound. DESIGN: This was a prospective, cross-sectional ultrasound study in 832 unselected second- and third-trimester singleton pregnancies. Color Doppler ultrasound was routinely performed to identify the placental cord insertion site. The role of three-dimensional (3D) ultrasound in evaluating the placental cord insertion site was also studied in a subset of 50 pregnancies from this population. RESULTS: The placental cord insertion site was identified in 825/832 (99%) cases. Visualization was not achieved in seven third-trimester pregnancies with a posterior placenta. A velamentous insertion was suspected prenatally in eight cases, seven of which were confirmed after delivery as velamentous and one as markedly eccentric (battledore placenta). 3D ultrasound performed poorly at evaluating placental cord insertion site, being less efficient due to poor-quality resolution and far more time-consuming than the combined use of gray-scale and color Doppler ultrasound. CONCLUSIONS: Velamentous insertion of the umbilical cord can reliably be detected prenatally by gray-scale and color Doppler ultrasound. 3D imaging had limited value in the evaluation of the placental cord insertion site in our subset of patients. Systematic assessment of the placental cord insertion site at routine obstetric ultrasound has the potential of identifying pregnancies with velamentous insertion and, therefore, those at risk for obstetric complications including vasa previa.

Adult↗
PubMed2003

Conjoined twins in a triplet pregnancy: early prenatal diagnosis with three-dimensional ultrasound and review of the literature.

We report two cases of conjoined twins complicating a triplet pregnancy diagnosed by two-dimensional ultrasound in the first trimester and evaluated further by three-dimensional ultrasound. A review of the literature over the last 30 years revealed 11 other cases diagnosed prenatally by ultrasound. Overall, three (23%) of these 13 pregnancies were achieved by assisted reproductive techniques and 10 (77%) were diagnosed before 18 weeks. Four women opted for termination of the whole pregnancy and three were managed expectantly, with two delivering before 32 weeks. Two monochorionic pregnancies underwent selective feticide with intrauterine demise of the non-conjoined fetus in both cases. All four dichorionic pregnancies undergoing selective termination or spontaneous embryo reduction to singleton in the first trimester resulted in term delivery of the non-conjoined fetus. The rare condition of conjoined twins in a triplet pregnancy poses a significant obstetric challenge from both diagnostic and management points of view. Accurate determination of chorionicity in these cases plays a critical role in determining management and outcome.

Adult↗
PubMed2003

Acardiac twin: a systematic review of minimally invasive treatment modalities.

This review of the literature aimed to determine pregnancy outcomes after minimally invasive treatment for occluding vascular supply to acardiac twins. A MEDLINE search was performed until 2002 using the terms 'acardiac', 'acardius', 'twin reversed arterial perfusion (TRAP) sequence' and 'chorangiopagus parasiticus' and 207 articles published in the English-language literature were identified. These articles and the corresponding cited references in English were reviewed. We identified 32 reports involving 74 cases of acardiac twin treated by minimally invasive techniques. Seventy one cases were included for analysis including 40 treated by cord occlusion and 31 by intrafetal ablation. Cord occlusion was first attempted by embolization (n = 5), cord ligation (n = 15), laser coagulation (n = 10), bipolar diathermy (n = 7) and monopolar diathermy (n = 3). Intrafetal ablation was performed by alcohol (n = 5), monopolar diathermy (n = 9), interstitial laser (n = 4) and radiofrequency (n = 13). The overall median gestational ages at treatment and delivery were 21 (range, 14-28) weeks and 36 (range, 19-42) weeks, respectively, with a median treatment-delivery interval of 13 (range, 0-25) weeks. The overall pump twin survival rate was 76% (n = 54). Intrafetal ablation was associated with later median gestational age at delivery (37 vs. 32 weeks, P = 0.04) and higher median treatment-delivery interval (16 vs. 9.5 weeks, P = 0.02) compared with cord occlusion techniques. It was also associated with a lower technical failure rate (13% vs. 35%, P = 0.03), lower rate of premature delivery or rupture of membranes before 32 weeks (23% vs. 58%, P = 0.003) and higher rate of clinical success (77% vs. 50%, P = 0.02) than cord occlusion techniques. There were no statistically significant differences in terms of outcome between the subgroups of fetoscopic- or ultrasound-guided cord occlusion techniques. This review suggests that intrafetal ablation is the treatment of choice for acardiac twins because it is simpler, safer and more effective when compared with the cord occlusion techniques.

Diseases in Twins↗
PubMed2003

Prenatal ultrasound findings in complete trisomy 9.

OBJECTIVE: To report on the prenatal ultrasound findings associated with complete trisomy 9. METHODS: Cases of complete trisomy 9 diagnosed prenatally were identified by reviewing the reports from two large cytogenetics laboratories serving tertiary referral centers for prenatal diagnosis. Information on prenatal ultrasound findings and outcome was obtained in all cases. RESULTS: Nine cases of complete trisomy 9 were identified. The diagnosis was made in the first trimester in four cases, in the second trimester in three and in the third trimester in two. Two fetuses underwent first-trimester ultrasound screening for aneuploidy and the nuchal translucency thickness was increased in both. All five fetuses detected in the second and third trimesters had several fetal anomalies including Dandy-Walker malformation in four cases, facial dysmorphism in four, genitourinary anomalies in three, congenital heart defects in three, ventriculomegaly in three, abnormal hands in two and megacisterna magna in one. Four fetuses were growth-restricted at the time of ultrasound evaluation. However, the two cases diagnosed in the third trimester had routine second-trimester anomaly scans reported as normal. There were no survivors in this series. CONCLUSION: Fetuses with complete trisomy 9 have multiple anomalies that can be readily detected prenatally by ultrasound. These mainly include, but are not restricted to, craniofacial, cardiovascular, musculoskeletal and genitourinary malformations. However, findings can be subtle and therefore missed at the routine second-trimester scan.

Adult↗
PubMed2003

Umbilical artery aneurysm: prenatal identification in three fetuses with trisomy 18.

Aneurysm of the umbilical artery is an extremely rare anomaly of the umbilical cord, with only two cases being documented in the English language literature. We report three cases diagnosed prenatally by ultrasound in the third trimester, all associated with single umbilical artery and multiple structural fetal anomalies. Prenatal karyotyping revealed trisomy 18 in all three cases. Umbilical cord anomalies, although rare, are associated with significant fetal morbidity and mortality. This report identifies umbilical artery aneurysm as an additional prenatal feature of trisomy 18.

Adolescent↗
PubMed2001

Prenatal diagnosis of 13q- syndrome in a fetus with holoprosencephaly and thumb agenesis.

Partial deletion of the long arm of one of the chromosomes 13 is an exceedingly rare condition. We report such a case in a 32-week fetus presenting with polyhydramnios, growth restriction and multiple structural defects including alobar holoprosencephaly, facial abnormalities, clubfoot, clinodactyly and thumb agenesis. Fetal blood sampling revealed a 46,XY, del(13)(q22 --> qter) abnormal male karyotype. Postmortem examination confirmed the prenatal findings and showed other manifestations of the syndrome. To our knowledge, this case represents the first in which the prenatal ultrasound detection of holoprosencephaly in association with distal limb abnormalities led to the prenatal diagnosis of the 13q- syndrome.

Adult↗
PubMed2001

The value of minor ultrasound markers for fetal aneuploidy.

As a result of improvements in ultrasound image quality and scanning technique, an increasing number of subtle morphological changes in fetal anatomy have been identified in the second trimester. Most of these ultrasound features were originally described as normal variants of development with no clinical significance. However, subsequent studies in high-risk populations showed that some of these variants were more prevalent in fetuses with chromosomal defects and therefore proposed as prenatal markers for the detection of aneuploidy. The implications for pregnancy management when one of these so-called minor ultrasound markers is detected have been a matter of continuous controversy in the field of prenatal diagnosis and yet the definitive answer on their clinical significance in the low-risk population is still debated.

Aneuploidy↗
PubMed2001

Fused umbilical arteries: prenatal sonographic diagnosis and clinical significance.

This report describes a series of 5 fetuses with fused umbilical arteries that had the prenatal feature of a single umbilical artery near the placental insertion and the normal 2 umbilical arteries at the fetal end of the cord. In 1 case this vascular anomaly was associated with unilateral renal agenesis in a fetus with a subsequent diagnosis of Hallermann-Streiff syndrome. No perinatal complications were identified in the remaining 4 fetuses. Postpartum examination of the cord revealed that the 2 umbilical arteries fused to form 1 artery for a long segment of the distal portion of the cord. Our findings suggest that the prenatal evaluation of the umbilical cord to document the number of vessels should include multiple views of the cord and demonstration of the 2 intra-abdominal umbilical arteries with color Doppler imaging for a confident diagnosis. Our observation also suggests that, at least in some cases, single umbilical artery may result from incomplete splitting of the single artery normally present in early human embryos.

Adolescent↗
PubMed2001

Nuchal translucency thickness and outcome in chromosome translocation diagnosed in the first trimester.

In order to determine the significance of nuchal translucency thickness on the subsequent natural history of first-trimester fetuses with a chromosome translocation, seven consecutive cases diagnosed between 11 and 13 weeks of gestation were reviewed. Nuchal translucency measurements were successfully obtained before chorionic villus sampling (CVS) in all cases. Three fetuses had an unbalanced translocation and all were associated with increased nuchal translucency and multiple anomalies at the detailed second-trimester scan. There were no survivors in this group. The remaining four fetuses had a balanced translocation; all had normal nuchal translucency thickness and no structural anomalies were detected in the second trimester. Three of these fetuses were born at > or =35 weeks of gestation and were phenotypically normal. However, an unexpected single fetal demise occurred in a dichorionic twin pregnancy at 28 weeks of gestation. It is concluded that nuchal translucency measurements provide important prognostic information on pregnancy outcome in first-trimester fetuses with a chromosome translocation. In parents with a known balanced translocation, the detection of increased nuchal translucency at 11-14 weeks of gestation is associated with unbalanced translocations, structural anomalies and poor pregnancy outcome.

Adult↗
PubMed2000

Risks of funipuncture in fetuses with single umbilical arteries.

OBJECTIVE: To estimate procedure-related risks of funipuncture in fetuses with single umbilical arteries (UAs). METHODS: We identified fetuses that had blood samples collected by funipuncture and in which single UAs were detected, prenatally or postnatally. We also recorded maternal demographics, prenatal sonographic findings, gestational age at the time of the procedure, procedure-related complications, and perinatal outcomes. RESULTS: Over 2 years, 14 fetuses identified as having single UAs had funipuncture for prenatal karyotyping at a median gestational age of 29 weeks (range 20-34 weeks). Each had additional abnormal prenatal sonographic findings. The approach to the cord was transplacental in six cases and transamniotic in eight. There were no failed procedures, and 13 of 14 funipunctures were successful on the first attempt. Three fetuses (21%) had complications (bradycardia in two cases and bleeding in one case), a complication rate not greater than that reported in large series of fetuses that had fetal blood sampling. All three complications were associated with the transamniotic approach. There were no procedure-related pregnancy losses within 2 weeks of the procedure in this series. CONCLUSION: Funipuncture does not seem to be associated with increased risk of procedure-related complications or pregnancy losses in fetuses with single UAs, although the risk could be greater with transamniotic than with transplacental sampling.

Adolescent↗
PubMed2000

Severe polyhydramnios in twin reversed arterial perfusion sequence: successful management with intrafetal alcohol ablation of acardiac twin and amniodrainage.

We present two cases of twin reversed arterial perfusion (TRAP) sequence complicated by severe polyhydramnios during the second trimester. Both cases were successfully managed at 27 and 26 weeks with ultrasound-guided intrafetal alcohol ablation of the acardiac twin and amniodrainage. The pump twins were delivered at 35 and 37 weeks, respectively, and both had uneventful postnatal courses. These cases suggest that, in the setting of severe polyhydramnios, prenatal intervention in TRAP sequence could certainly improve the otherwise poor prognosis of the pump twin. Targeting the main intra-abdominal vessel of the acardiac twin rather than its umbilical cord seems to be a good alternative in the prenatal treatment of these cases. The option of percutaneous intrafetal alcohol injection is widely available and less invasive, simpler and easier to perform than recently advocated endoscopic techniques.

Adult↗