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: prenatal findings

In 450 patients with pregnancy at high risk for fetal malformation and/or intrauterine growth retardation, the umbilical cord was investigated sonographically for the presence of a single umbilical artery. A single umbilical artery was diagnosed in four fetuses between 23 and 33 weeks of gestation and suspected in two. Three cases were overlooked at sonography. All seven surviving fetuses had growth retardation at delivery and four also showed severe malformations. Whenever a single umbilical artery is found at sonography, further work-up is required to rule out associated anomalies, intrauterine growth retardation, or chromosomal abnormality.     

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.     

Spinal cord injury in newborns from use of umbilical artery catheters: report of two cases and a review of the literature

Umbilical artery catheter use in sick newborns has been associated with infarction of major organs such as the intestine and kidneys; spinal cord infarction has also been reported but is rare. We report two cases of spinal cord infarction and review the six others in the literature for preventable or predisposing conditions. Infusion of blood and hypertonic solutions, shock, and high position of the catheter tip were associated with infarction of the anterior spinal cord in these infants.     

320例新生儿出生时脐动脉血气分析

目的探讨新生儿出生时脐动脉血气分析的临床应用价值。 方法选取2013年10月23日至2014年5月13日在北京大学深圳医院阴道分娩的单胎活产新生儿共320例,对新生儿出生时脐动脉血气分析与Apgar评分、羊水性状和新生儿结局进行分析。 结果(1)Apgar评分1 min 4～7分组的pH值、PaCO₂、PaO₂、HCO₃^－、BE值的水平分别为(7.15±0.11)、(64.21±21.62) mmHg、(9.21±4.69) mmHg、(21.12±6.98) mmol/L、(－9.06±7.07) mmol/L,≥8分组分别为7.28±0.10、(43.16±15.06) mmHg、(20.38±9.21) mmHg、(19.59±5.31) mmol/L、(－6.79±4.92) mmol/L,两组比较,pH值、PaO₂及PCO₂水平,差异有统计学意义,t值分别为2.914,－2.764,2.501(P均<0.05)。(2)清亮羊水组的pH值、PaCO₂、PaO₂、HCO₃^－、BE值的水平分别(7.29±0.10)、(43.64±15.35)mmHg、(20.40±7.85)mmHg、(19.81±5.28)mmol/L、(－6.59±4.85)mmol/L,羊水Ⅰ度粪染组的分别为：(7.29±0.06)、(43.88±15.79)mmHg、(21.41±9.61)mmHg、(20.20±6.92)mmol/L、(－6.24±5.55)mmol/L,羊水Ⅱ度粪染组的分别为：(7.24±0.14)、(40.36±14.70) mmHg、(17.38±4.75) mmHg、(16.55±4.13)mmol/L、(－10.09±4.98) mmol/L。三组间比较,血气分析结果差异无统计学意义。 结论胎儿出生时脐动脉血气分析可作为诊断围产期窒息的客观依据,羊水Ⅰ、Ⅱ度粪染不是胎儿窘迫的征像。     

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.     

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.     

Management strategy of umbilical artery aneurysm complicated by cardiac anomaly: case study and literature review

Objective: Key considerations for managing an umbilical artery aneurysm (UAA) are a timely termination and the prevention of rupture of the UAA during delivery. Herein, we propose a treatment strategy based on our experience of UAA complicated by a fetal cardiac anomaly.

Case: A case of UAA was referred to our hospital at 23 weeks of gestation. The UAA increased its size to 6?cm. The blood reservoir within the UAA was presumed to be equivalent to the circulating blood volume of the fetus. At 28 weeks, small echogenic components suspected to be hematomas appeared in the umbilical vein, and the umbilical interstitial substance became edematous. An improvement in the fetus’ condition could not be expected unless the UAA size was smaller. Thus, a cesarean delivery was performed at 30 weeks during which the UAA ruptured. The baby was anemic, disseminated intravascular coagulation (DIC) and later died.

Conclusion: We present an assessment of a large blood reservoir within an UAA that may indicate the likelihood of high-output cardiac failure of the fetus. Either a classical cesarean section or a transverse uterine fundal incision should be performed when the UAA size is greater than 5?cm to prevent rupture of the UAA.     

Doppler in obstetrics: beyond the umbilical artery

Doppler analysis of the umbilical and uterine arteries has long been performed in perinatal medicine to assess fetal health and maternal risk for preeclampsia. Several other vessels can be interrogated to obtain additional, vital information. Velocimetry in the fetal middle cerebral artery can yield evidence of the presence or absence of anemia and, in cases of delayed growth, of the risk of hypoxic damage. Ductus venosus waveforms are a very good indicator of impeding fetal jeopardy and should be used when umbilical artery waveforms become abnormal. Early pregnancy uterine artery Doppler reflects the status of the placental vasculature and, as such, is an excellent tool for predicting the risk of preeclampsia or intrauterine growth restriction.     

Intrapartum umbilical artery Doppler velocimetry as a predictor of adverse perinatal outcome: a systematic review.

OBJECTIVE: To evaluate the diagnostic prediction of intrapartum umbilical artery Doppler velocimetry for adverse perinatal outcomes using systematic quantitative overview of the available literature. DESIGN: Online searching of MEDLINE database (January 1966-September 1997), scanning of bibliography of known primary and review articles, review of recent journal issues and that from personal files. Study selection, assessment of study quality and data extraction were all performed in duplicate under masked conditions. PARTICIPANTS: 2700 women (unselected, low, high, and combined low and high obstetric risk populations) included in eight studies selected for meta-analyses. MAIN OUTCOME MEASURES: Likelihood ratios (LRs) for positive and negative test results were generated for the following outcome measures: Apgar scores < 7 at 1 and 5 minute following delivery, small for gestational age fetus; intrapartum fetal heart rate abnormality, umbilical arterial acidosis at delivery; and caesarean section for fetal distress. RESULTS: For Apgar score < 7 at 1 minute following delivery, the pooled LR was 2.5 (95% CI 1.7-3.7) for a positive test and 1.0 (95% CI 0.9-1.1) for a negative test result. A positive test predicted an Apgar score < 7 at 5 minute following delivery with a pooled LR of 1.3 (95% CI 0.4-4.1) while a negative test had a pooled LR of 1.0 (95% CI 0.8-1.2). For the prediction of a small for gestational age fetus, the pooled LR was 3.4 (95% CI 2.3-5.1) for a positive test and 0.9 (95% CI 0.8-1.0) for a negative test. The prediction for fetal heart rate abnormality during labour was similarly disappointing: the pooled LR for a positive test result was 1.4 (95% CI 0.9-1.2) whereas a negative test result generated a pooled LR of 0.9 (95% CI 0.9-1.0). With umbilical acidosis at delivery, the pooled LR was 1.6 (95% CI 1.1-2.5) for a positive test and 1.1 (95% CI 1.0-1.2) for a negative test. The LRs for the prediction of caesarean section for fetal distress were 4.1 (95% CI 2.7-6.2) for a positive test result and 0.9 (95% CI 0.8-1.0) for a negative test result. CONCLUSION: Intrapartum umbilical artery Doppler velocimetry is a poor predictor of adverse perinatal outcomes.     

Pulsed Doppler umbilical artery waveforms: significance of elevated umbilical artery systolic/diastolic ratios in the normally grown fetus

Previous studies have demonstrated a high correlation between elevated resistance in the placental circulation, evidenced by abnormal umbilical artery systolic-to-diastolic (S/D) ratios, and the subsequent birth of a small for gestational age (SGA) infant. However, few data exist on the significance of elevated S/D ratios for pregnancies in which outcome does not involve an SGA infant. Pulsed Doppler spectral recordings and level II ultrasound examinations were performed 373 times in 256 referred high-risk patients. Doppler data were not used for patient management decisions. Thirty-two women with elevated umbilical artery S/D ratios of 4.5 or greater (defined as abnormal regardless of gestational age) gave birth to non-SGA infants. The ultrasound characteristics and outcome for this group were compared with those of 200 patients who were also non-SGA but who exhibited normal waveforms and with 24 SGA infants with predominantly abnormal waveforms. Thirty-one percent of the non-SGA infants with abnormal waveforms had structural malformations, a rate significantly higher (P less than or equal to .03) than the 18% malformation rate in the normal-waveform group. Further, the stillbirth rate and number of terminations of pregnancy for lethal anomalies were five times greater in the non-SGA group with abnormal waveforms than in the non-SGA group with normal waveforms (P less than or equal to .001). A wide variety of structural malformations was observed in the abnormal-waveform group, most frequently involving the central nervous system. Amniotic fluid volume tended to be decreased in the SGA group, whereas increased amniotic fluid volume or hydramnios was seen in 23% of the non-SGA abnormal-waveform group.     

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 is associated with an increased incidence of structural and chromosomal anomalies and growth restriction

The objective to characterize neonatal outcome associated with ultrasonographic identification of a single umbilical artery. Pregnancies diagnosed with single umbilical artery antenatally were identified. All prenatal/antenatal and pediatric records were reviewed for maternal demographics, associated anomalies, karyotypic analysis, pregnancy complications, and neonatal outcome. Twenty-seven pregnancies complicated by fetal single umbilical artery were identified. Of the 27 pregnancies, 5 (18.5%) underwent pregnancy termination and 1 (3.7%) experienced fetal demise. Of the 21 liveborn infants, 4 (19%) died within the first year of life. Sixty-seven percent of fetuses had an associated structural anomaly. Sixteen of the 27 pregnancies underwent amniocentesis and 7 of these were chromosomally abnormal. All of the karyotypically abnormal fetuses had a structural defect in addition to the single umbilical artery. Of the six fetuses without any associated structural or chromosomal anomalies, three (50%) demonstrated growth restriction. Single umbilical artery is relatively rare finding. When a single umbilical artery is identified, a vigilant search for associated anomalies should be undertaken. Pregnancies identified as having fetuses with associated structural anomalies should be offered amniocentesis. Pregnancies with isolated single umbilical artery should be carefully monitored for evidence of fetal growth restriction.