Single umbilical artery--consequences of prenatal diagnosis]

The authors report about the prenatal diagnosis of 34 cases of fetuses with a single umbilical artery (SUA) observed at the Perinatal Center of Charité. Between January 1989 and June 1991 the SUA has been associated with some adverse perinatal events, such as low birth weight (35%), congenital malformations (35%), perinatal mortality (11%) and placental alterations (76%). The incidence was not higher in girls than in boys. We did not find any chromosomal anomalies in our cases. An accurate ultrasonographic examination of the SUA in the 16th to 20th week is very important. The prognosis of the newborn could be improved by efficient diagnosis and optimum management of pregnancy and of delivery at a perinatal center.     

Single umbilical artery: review of 12 cases

The umbilical cord normally consists of three vessels, two arteries and one vein. The absence of one umbilical artery or single umbilical artery (SUA) has been associated with some adverse perinatal events, such as low birth weight, prematurity, congenital malformations and perinatal mortality. The authors present 12 cases of SUA confirmed by histologic examination and the principal maternal and perinatal features of these cases are analyzed. In our study there were a prematurity rate of 58%, a low birth weight rate of 66% and a perinatal mortality rate of 580/1000. Among our patients, 42% of the infants with SUA had major congenital malformations. An accurate examination of the umbilical cord at delivery is suggested, mainly because SUA is an important index to detect associated congenital malformations.     

Perinatal results following the prenatal ultrasound diagnosis of single umbilical artery

OBJECTIVE. To study the perinatal results in our population, following the prenatal ultrasound diagnosis of a single umbilical artery (SUA), as this alteration is associated with fetal malformations, chromosomal abnormality, and poor perinatal results. MATERIALS AND METHODS. A retrospective review of all obstetric ultrasounds carried out between October 2000 and December 2003 in our service, obtaining the postnatal results of the fetuses diagnosed with an SUA. RESULTS. From a total of 5,987 pregnant patients examined by ultrasound scan at 20th week, an SUA was found in 40 cases, representing an incidence of 0.7%. Of these, 84.6% were normal pregnancies at birth and 15.4% presented other malformations and/or chromosomal abnormalities. No aneuploidy was found in pregnancies where there were no other associated findings in the ultrasound scan at 20 weeks. All cases with serious congenital malformations accompanying the SUA were diagnosed prenatally. There was a 5% of perinatal mortality rate among our fetuses with SUA, which represents a mortality rate 10 times greater than the overall rate among our patients. CONCLUSIONS. The ultrasound discovery of an SUA implies the meticulous search for other associated malformations, and in the absence of these, the risk of a chromosomal abnormality is very low, unless it is a high-risk patient. However, the growth and wellbeing of the fetus must be carefully monitored in the last 3 months, although the ultrasound scan does not show any other associated alterations.     

Single umbilical artery and associated hydronephrosis: a report of 2 cases

BACKGROUND: A single umbilical artery (SUA) in a fetus may be associated with hydronephrosis. CASES: We describe 2 cases of SUA, one of which had severe hydronephrosis with ascites and was stillborn. The other case was born alive with a unilateral hydroureter and is being managed with close monitoring. CONCLUSION: Detection of SUA on antenatal ultrasound should prompt a careful search for urinary tract abnormalities, as associated severe hydronephrosis may lead to a poor outcome.     

Single umbilical artery stenosis associated with intrauterine fetal death post-transfusion

Single umbilical artery is among the most common funicular vascular anomalies. In contrast, umbilical artery stenosis is rare, and has only been reported in three-vessel cords. We describe a case of single umbilical artery stenosis in a fetus with no associated malformations. Intrauterine fetal death occurred at 28 weeks' gestation following cordocentesis and intravascular transfusion for Rhesus alloimmunization. Single umbilical artery stenosis may place the fetus at increased risk, particularly in cases requiring interventions involving cord manipulation.     

Single umbilical artery and umbilical cord torsion leading to fetal death. A case report

BACKGROUND: Intrauterine fetal death is a complication that cannot often be predicted by standard obstetric management. Cord accident may be responsible for about 5% of cases. Umbilical cord torsion is an extremely rare cause of intrauterine fetal death. CASE: An 18-year-old, nulliparous woman presented with a complaint of decreased fetal movement at 38 weeks' gestation. Intrauterine fetal death was diagnosed on ultrasound. The pathologic examination revealed umbilical cord torsion and confirmed a single umbilical artery that was diagnosed on ultrasound. CONCLUSION: Umbilical cord torsion that leads to intrauterine fetal death is extremely rare. A pregnancy with a single umbilical artery may need fetal monitoring during the third trimester.     

Correlation between biomagnetic and Doppler findings of umbilical artery in fetal growth restriction

OBJECTIVE: To assess the value of biomagnetic recordings of the umbilical artery over Doppler ultrasound screening in order to predict complications of impaired uteroplacental blood flow in fetuses with intrauterine growth restriction (IUGR). METHODS: Our study population included 11 IUGR preeclamptic (34-37-weeks gestation; birth weight 1969 +/- 129 g) and 19 normal pregnancies (34-37-weeks gestation; birth weight 3195 +/- 229 g). Umbilical artery Doppler ultrasound waveform measurements were expressed in terms of pulsatility index (PI). Biomagnetic signals (waveforms) recorded from the IUGR umbilical artery were expressed in terms of magnetic power spectral amplitudes. RESULTS: In all cases, the frequency band considered was 2 to 7 Hz. The spectral amplitudes were low (mean: 117+/-24 fT/ radical Hz) in most (90.9%) IUGR pregnancies and high (mean: 224+/-37 fT/ radical Hz) in most normal pregnancies (89.5%). There was a statistically significant difference between normal and IUGR pregnancies with respect to spectral amplitudes (p < 0.0001), Doppler PI (p < 0.0005), pH (p < 0.0005) and Apgar score (p < 0.0005). Multiple linear regression analysis revealed an influence of PI, pH and Apgar scores on the biomagnetic values (ANOVA: p < 0.0005). CONCLUSION: Our data imply that biomagnetic values of the umbilical artery flow could prove to be a helpful method for the evaluation of fetal well being especially in pregnancies complicated with preeclampsia and growth restriction.     

A case of single umbilical artery with various fetal anomalies: correlations between prenatal ultrasonographic diagnosis and autopsy

We report a case of a single umbilical artery with various fetal anomalies, and a comparative study between prenatal ultrasonographic diagnosis and autopsy was done. The prenatal ultrasonographic diagnosis included, atrial septal defect (ASD), ventricular septal defect (VSD), mitral atresia or stenosis and a single great vessel. At autopsy, ASD, VSD, mitral atresia, overriding aorta and pulmonary atresia were evident. In case of other anomalies, the findings in the prenatal diagnosis and at autopsy were encephalocele, adrenal hypoplasia and a single umbilical artery. The ultrasonic detection of these anomalies is discussed and the limitations of this diagnostic method are given attention.     

Single umbilical artery and its siding in the second trimester of pregnancy: relation to chromosomal defects

OBJECTIVES: To determine the possible association between single umbilical artery (SUA) in the second trimester of pregnancy and the incidence of chromosomal abnormalities. To determine whether the presence of chromosomal defects in fetuses with SUA is related to the side of the missing artery. METHODS: Color flow imaging of the fetal pelvis was used to determine the number of umbilical arteries in 2147 fetuses immediately before amniocentesis for karyotyping in the second trimester of pregnancy. RESULTS: SUA was diagnosed in 102/2147 (4.8%) cases. The left umbilical artery was absent in 60/102 (58.8%) fetuses, compared with the 42/102 (41.2%) for the right artery. The rate of chromosome abnormalities was significantly higher among fetuses with SUA than among those with 2 umbilical arteries (19/102 or 18.6% versus 109/2045 or 5.3%; OR = 4.1, 95% CI 2.3-7.1, p < 0.0001). Among fetuses with SUA, there was no significant difference in the rate of chromosome abnormalities between those with absence of the left versus the right artery (11/60 or 18.3% versus 8/42 or 19.0%, p = 0.93). There was an SUA in 5/39 (12.8%) cases with trisomy 21, 8/16 (50%) with trisomy 18, 1/4 (25%) with trisomy 13 and 5/69 (7.2%) with other chromosomal defects. There were no chromosome abnormalities in fetuses where a single umbilical artery was an isolated sonographic finding. All fetuses with SUA and chromosomal defects had associated abnormalities detected by ultrasound. CONCLUSION: A single umbilical artery (SUA) in the second trimester of pregnancy has a high association with trisomy 18, 13, 21 and other chromosomal defects, but all chromosomally abnormal fetuses had associated malformations detected by ultrasound. The absence of the left artery is more frequent than the absence of the right artery. The association with chromosomal abnormalities seems to be equal on each side.     

Norman-Roberts syndrome: prenatal diagnosis and autopsy findings

We report on the autopsy findings of a male fetus in the 27th week of gestation with Norman-Roberts syndrome. The unaffected parents are first cousins and have a five-year-old child with a low, sloping forehead, broad and prominent nasal bridge, widely set eyes, severe psychomotor retardation, and an agyric cortex. Prenatal diagnosis showed a small head at the 25th week of gestation. At this time, a slowing-down of the growth of the sonographic measurements of the biparietal diameter and head circumference was found. Both the biparietal diameter (57 mm, <5th percentile) and the head circumference (207 mm, <5th percentile) showed a delay of at least two weeks in comparison with other non-cephalic somatometric parameters, that were normal for the gestational age (femur length: 46 mm=median value). After termination of pregnancy, post-mortem examination showed a normotrophic fetus with microcrania and marked microcephaly (brain weight: 50 g), low, sloping forehead, broad and prominent nasal bridge, and widely set eyes. The cerebral hemispheres displayed an almost completely smooth surface with poorly defined sylvian fissures and failure of operculization of the insula. Microscopic examination showed a predominantly four-layered cortex (lissencephaly type I). Karyotype was normal and in situ hybridization did not show any deletion in the Miller-Dieker/isolated lissencephaly critical region on 17p13.3. The syndromes with lissencephaly are reviewed.     

Volumetric umbilical artery blood flow: comparison of the normal versus the single umbilical artery cord

OBJECTIVE: This was a study of the volumetric blood flow in single umbilical artery (SUA) cords as compared to three-vessel cords. Hypothesis: SUA flow will be twice that of an artery in a normal cord. METHODS: We studied 276 patients (24 SUA, 252 normal cord) at 18-40 weeks' gestation utilizing gray-scale and color Doppler. Flow, flow/kg, velocity, artery diameter, Doppler velocimetry indices, estimated fetal weight (EFW) and amniotic fluid index (AFI) were compared. All fetuses were anatomically and cytogenetically normal. RESULTS: Blood flow increased with advancing gestation and the SUA volume was twice that in the normal cord artery. Flow/kg decreased for both cords, with the SUA values twice those of normal cords. Arterial diameter and velocity increased, but to a greater degree in SUA. Velocimetry, although in the normal range, decreased progressively with the resistance indices always lower in the SUA cord. EFW and AFI were the same for both groups. CONCLUSION: Volumetric blood and its components were measured indirectly with ultrasound. The SUA cord artery carried twice the blood volume of an artery in a three-vessel cord. Other flow parameters changed appropriately to explain the increased flow. For the anatomically normal fetus with SUA there was no increase in intrauterine growth restriction.     

Volumetric umbilical artery blood flow: comparison of the normal versus the single umbilical artery cord

Objective : This was a study of the volumetric blood flow in single umbilical artery (SUA) cords as compared to three-vessel cords. Hypothesis: SUA flow will be twice that of an artery in a normal cord. Methods : We studied 276 patients (24 SUA, 252 normal cord) at 18-40 weeks' gestation utilizing gray-scale and color Doppler. Flow, flow/kg, velocity, artery diameter, Doppler velocimetry indices, estimated fetal weight (EFW) and amniotic fluid index (AFI) were compared. All fetuses were anatomically and cytogenetically normal. Results : Blood flow increased with advancing gestation and the SUA volume was twice that in the normal cord artery. Flow/kg decreased for both cords, with the SUA values twice those of normal cords. Arterial diameter and velocity increased, but to a greater degree in SUA. Velocimetry, although in the normal range, decreased progressively with the resistance indices always lower in the SUA cord. EFW and AFI were the same for both groups. Conclusion : Volumetric blood and its components were measured indirectly with ultrasound. The SUA cord artery carried twice the blood volume of an artery in a three-vessel cord. Other flow parameters changed appropriately to explain the increased flow. For the anatomically normal fetus with SUA there was no increase in intrauterine growth restriction.     

Parathyroid agenesis: prenatal ultrasonographic features and pathological findings

We report a girl with parathyroid agenesis. The gross anomaly of the long bones was diagnosed prenatally by ultrasound. Pregnancy was terminated at 24 weeks of gestation. There were no other apparent system anomalies except parathyroid gland agenesis and long bone abnormalities. This case is the first reported case of parathyroid agenesis with normal thyroid glands and other systems.     

Congenital malignant extrarenal rhabdoid tumor: prenatal ultrasound findings

BACKGROUND:Congenital cancer is rare, and metastatic cancer of the infant at birth is even more unusual. Pregnancy management may be altered if fetal tumors are detected by prenatal ultrasound.CASE:We present a 29-week gestation with polyhydramnios and a fetus with a congenital malignant extrarenal rhabdoid tumor on the left neck and chest with generalized metastases. Cytogenetic analysis of the tumor cells revealed a trisomy 7.CONCLUSION:Prenatal ultrasound permits in utero detection of fetal tumors and identification of complications.