Perinatal results following the prenatal ultrasound diagnosis of single umbilical artery

A case report of single umbilical artery combined with fetal bladder exstrophy in singleton pregnancy and related literature review

BACKGROUND

According to prenatal ultrasonographic studies, single umbilical artery may be present alone or in association with other fetal abnormalities. So far, the exact pathogenesis of bladder exstrophy is unclear. Some scholars believe that bladder exstrophy and cloacal exstrophy should be regarded as a disease spectrum to explore their pathogenesis. If bladder exstrophy and cloacal exstrophy are regarded as the same disease spectrum, then we can speculate that the single umbilical artery should have the probability of being accompanied by bladder exstrophy at the same time.

CASE PRESENTATION

For the first time, we report a rare case of fetal bladder exstrophy with single umbilical artery in single pregnancy. This patient underwent targeted color Doppler ultrasound at 26 weeks of pregnancy which first suspected bladder exstrophy with single umbilical artery and fetal MRI for diagnosis at 38 + 3 weeks of pregnancy which confirmed the suspicion. After the diagnosis was confirmed, the patient was scheduled for a multidisciplinary discussion. Ultimately the patient opted for induced fetal demise at 38 + 5 weeks of pregnancy and the physical appearance of the fetal demise affirmed previous ultrasound and MRI examination results.

CONCLUSIONS

Our report is the first finding of single umbilical artery combined with bladder exstrophy in a singleton pregnancy. Accordingly, our case enhances the evidence that cloacal exstrophy and bladder exstrophy should be treated as the same disease spectrum. In addition, we conducted a literature review on the diagnostic progress of single umbilical artery combined with bladder exstrophy, hoping to provide useful references for the diagnosis of this disease.

Prevalence of single umbilical artery, clinical outcomes and its risk factors: A cross-sectional study

Background

Single umbilical artery (SUA) is found in 0.5–6% of all pregnancies worldwide. Although the association of SUA with some congenital malformations is mainly accepted, its effect on pregnancy/neonatal outcomes is still controversial.

Objective

This is the first study aimed to approximate the SUA prevalence in southern part of Iran. SUA epidemiologic features accompanied by some of its effects on pregnancy/neonatal outcomes are investigated as well.

Materials and Methods

In this cross-sectional study, data from two referral centers in Southern Iran were analyzed. In total, 1,469 pregnancies, fetuses, and neonates were examined for epidemiological features associated with SUA. SUA was confirmed by pathological examination, while congenital anomalies were diagnosed by clinical, ultrasound, and echocardiographical examinations. Data on pregnancy outcome were recorded based on the patients' medical records.

Results

The prevalence of SUA was 3.47% (95% CI: 2.6–4.6%). Fetal anomalies including renal, cardiac, and other congenital anomalies, intrauterine fetal death, early neonatal death, low birth weight, low placental weight, and preterm birth were significantly higher in the SUA group (OR = 68.02, 31.04, 16.03, 3.85, 11.31, 3.22, 2.70, and 2.47, respectively). However, the maternal multiparity was lower in the SUA group (OR = 0.65; 95% CI: 0.44–0.98).

Conclusion

A significant association was observed between SUA and increased risk of intrauterine fetal death and early neonatal death, as well as low birth weight and preterm birth. Obstetrical history of the mother like parity was identified as an important predictor of SUA. Further investigations are suggested on risk stratification of neonates in this regard.

Correlation between ductus venosus spectrum and right ventricular diastolic function in isolated single-umbilical-artery foetus and normal foetus in third trimester

BACKGROUND

Single umbilical artery (SUA) is the most common umbilical cord malformation in prenatal diagnosis. The presence of an SUA can cause blood circulation disorder in the foetus and functional changes of the foetal heart, affecting foetal circulation. The right ventricular diastolic functions in foetuses with isolated SUA and in normal foetuses in the third trimester were evaluated using the spectral Doppler of blood flow in the foetal ductus venosus (DV).

AIM

To evaluate the right ventricular diastolic functions in foetuses with isolated SUA and in normal foetuses in the third trimester.

METHODS

Colour Doppler was used to measure the spectrum of foetal DV and tricuspid orifice in 34 foetuses with isolated SUA aged 28-39 wk and in age-matched healthy controls. The DV flow velocities and velocity ratios were measured. The early passive/late active (E/A) ratio at the tricuspid orifice and tissue Doppler Tei index of the foetal right ventricular in the two groups were also measured.

RESULTS

During the third trimester, the isolated SUA group showed a lower ‘a’-wave peak velocity in the DV than the control group (P < 0.05). The correlations between the velocity ratios and E/A ratio at the tricuspid orifice in the two groups were analysed, and the correlation between the ventricular late diastolic velocity/ventricular diastolic peak flow velocity and E/A ratios was the best (R² of the isolated SUA group: 0.520; R² of the control group: 0.358). The correlations between the velocity ratios and tissue Doppler Tei index of foetal right ventricular in the two groups were analysed, and the correlation between the pulsatility index for veins (PIV) and tissue Doppler Tei index ratios was the best (R² of the isolated SUA group: 0.865; R² of the control group: 0.627).

CONCLUSION

In the isolated SUA group, the atrial systolic peak velocity ‘a’ decreased, and this finding might be related to the changes in foetal cardiac functions. The ratio of ventricular late diastolic velocity to ventricular diastolic peak flow velocity was closely related to the E/A ratio at the tricuspid valve and can be used to identify changes in the right ventricular diastolic functions of isolated SUA and healthy foetuses. PIV was closely related to the tissue Doppler Tei index of the foetal right ventricular and can be used to identify the right ventricular overall functions of isolated SUA and healthy foetuses.

Evaluation of right ventricular function in fetuses with isolated single umbilical artery using spatiotemporal image correlation M-mode

Background

Postnatal outcome of fetuses with isolated single umbilical artery (SUA) is determined mainly by right ventricular function. Our study examined whether there are differences in right ventricular function during the gestation period of fetuses with isolated SUA compared to healthy fetuses.

Methods

A prospective study was conducted on 77 fetuses with isolated SUA and 77 gestational age-matched controls from 22 to 39 weeks. For gestational age grouping, the isolated SUA fetuses and the control fetuses were divided into the second trimester group (22–27 weeks; 43 fetuses) and third trimester group (28–39 weeks; 34 fetuses). The fetal tricuspid annular plane systolic excursion (f-TAPSE) M-mode was applied to the tricuspid annulus, parallel to the ventricular septum, and the amplitude of the resulting wave was assessed using spatiotemporal image correlation (STIC) M-mode. We investigated the possible changes to the STIC M-mode indices during the course of pregnancy in both the isolated SUA and control groups. The relationship between f-TAPSE and gestational age was analyzed. Additionally, the correlations between f-TAPSE and birth weight was analyzed, and the birth weight differences between the isolated SUA and control groups in the third trimester were analyzed according to postpartum results.

Results

There was a significant difference in f-TAPSE between isolated SUA and control group in the third trimester (P < 0.05). There were significant correlations between gestational age (GA) and f-TAPSE among control fetuses (R² = 0.9049; P < 0.01). A significant, positive correlation between GA and f-TAPSE was also found with isolated SUA fetuses (R² = 0.8108; P < 0.01). The prevalence of small-for-gestational-age (SGA) fetuses and of discordant birth weight fetuses was significantly higher in the isolated SUA group than in the control group. In univariate analysis, the presence of an isolated SUA was associated with lower birth weight (2940 g compared with 3260 g) and with higher prevalence of SGA (13.0% compared with 3.9%; P < 0.01). The correlations between the birth weight and f-TAPSE in the two groups were analyzed in the third trimester, and the correlation in the isolated SUA group was better than that of the control group (R² was 0.623 and 0.463 in the isolated SUA group and the control group, respectively).

Conclusions

Right ventricular function in isolated SUA is altered as early as in fetal third trimester. STIC M-mode can measure the right heart function of the fetus and may predict isolated SUA with SGA.

Is echocardiography necessary for all single umbilical artery fetuses? A retrospective study in a selected Chinese population

AIM

Previous evidence on the relationship between single umbilical artery (SUA) and congenital heart disease (CHD) is controversial. We thus conducted a retrospective study to explore the potential risk factors associated with CHD in SUA fetuses, and verify if all these SUA fetuses should be referred for detail fetal echocardiography.

METHODS

We reviewed medical records of SUA fetuses referred to Xinhua Hospital for fetal echocardiography between September 2009 and February 2014. All the pregnancies were divided into two groups of CHD and non-CHD according to the results of fetal echocardiography. The maternal and fetal characteristics were compared via χ² test and Fishers' test. Furthermore, Poisson regression was used to analyze the risk factors associated with CHD in SUA pregnancies.

RESULTS

Nineteen CHD cases (12.5%) were detected among 152 SUA fetuses, all with abnormal cardiac views during obstetric screening ultrasound (P < 0.001). χ² test showed that abnormal cardiac screening findings, extracardiac abnormality and infection or threatened abortion during first trimester were significantly associated with prenatal detection of CHD (P < 0.001). Multivariable Poisson regression after adjustment found that SUA fetuses with extracardiac abnormality had 4.74 (95% confidence interval: 1.89, 11.90) times higher risk of CHD.

CONCLUSION

Incidence of CHD was higher in SUA cases, and CHD fetuses could be screened efficiently by abnormal cardiac screening during obstetric screening ultrasound. SUA fetuses with extracardiac abnormality and maternal risk factors have higher risk of CHD, and should be strongly recommended for fetal echocardiography. In contrast, SUA fetuses without above situations might only need routine obstetric follow-up.

The Risk Factors and Neonatal outcomes of Isolated Single Umbilical Artery in Singleton Pregnancy: A Meta-analysis

The current meta-analysis aims to evaluate the risk factors and neonatal outcomes of isolated Single Umbilical Artery (iSUA) in singleton pregnancy. Standard Mean Difference (SMD) or Weighted Mean Difference (WMD) was pooled for the maternal age, gravidity and parity, neonate birth weight and Apgar score one and five minutes after birth. We also pooled the odds ratios (ORs) at 95% confidence intervals (CIs) for maternal smoking status, the rate of neonate delivery before 37 or 34 weeks, Cesarean section (CS), the rate of being admitted to neonatal intensive care unit (NICU) and the serious adverse neonate outcome. Results show that maternal primigravidity [OR: −0.082, CI (−0.152, −0.011), p = 0.023] and female sex of the neonate [OR: 0.805, CI (0.673, 0.963), p = 0.017] were associated with higher risks of iSUA. As compared to normal neonates, the neonates with iSUA had lower birth weight, worse Apgar score, increased risk of delivery before the normal gestational age, increased rate of CS due to fetal distress, increased rate of admission to NICU and prolonged NICU stay. However, no difference in neonatal mortality was observed. Maternal primigravidity and female neonate might associate with increased risk of iSUA. Identification of iSUA is of great importance for prenatal diagnosis and may improve neonatal outcomes.

Association Between Isolated Single Umbilical Artery and Perinatal Outcomes: A Meta-Analysis

Background

To evaluate the association between the isolated single umbilical artery (iSUA) and perinatal outcomes, including pregnancy outcomes and perinatal complications.

Material/Methods

We performed a meta-analysis of 15 eligible studies regarding the relationship between the iSUA and perinatal outcomes, including gestational age at delivery, nuchal cord, placental weight, small for gestational age (SGA), oligohydramnios, polyhydramnios, pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), preeclampsia, and perinatal mortality. The overall odds ratios (OR) or standardized mean difference (SMD) were calculated.

Results

The occurrence of nuchal cord was not found to be different between an iSUA and a three-vessel cord (TVC) fetus. For perinatal complications, the SGA, oligohydramnios, polyhydramnios, GDM, and perinatal mortality showed dramatic difference between women with an iSUA and women with a TVC fetus, which implied that the presence of iSUA significantly increased the risk of perinatal complications. For other perinatal complications, such as PIH and preeclampsia, no significant association was detected.

Conclusions

Our meta-analysis suggests that the presence of iSUA would increase the risk of perinatal complications such as SGA, oligohydramnios, polyhydramnios, GDM, and perinatal mortality. Therefore, pregnant women with an iSUA fetus have poorer perinatal outcomes and more attention should be given to the management of their pregnancy compared to women with a TVC fetus.

A practical approach to fetal growth restriction

Fetal growth restriction is one of the most complex problems encountered by obstetricians. Ultrasound-estimated fetal weight less than the 10th percentile for the gestational age is the most widely accepted diagnostic criterion. Management protocols vary from institution to institution. Doppler velocimetry provides valuable information about fetal status. We offer a practical approach to management and timing of delivery based on available data in the literature.

Detection of single umbilical artery in the first trimester ultrasound: its value as a marker of fetal malformation

Introduction. The value of a single umbilical artery (SUA) in first trimester ultrasound is not well established. The aim of our study was to determinate the relevance of diagnosis of single umbilical artery in first trimester ultrasound as an early marker suggesting the presence of malformations or associated chromosomopathies. Material and Methods. Retrospective study of clinical cases of SUA diagnosed at the University Hospital Puerta de Hierro in Madrid (Spain) during the first trimester ultrasound between September 2008 and September 2012. Results. Prevalence of SUA was 1.1% in single pregnancies and 3.3% in twin pregnancies. Sensitivity, specificity, false positive rate, and false negative rate for the finding in the first trimester were 84.2, 99.8, 0.2, and 15.7%, respectively. 17.6% of cases had associated malformations. With an ultrasound in the 16th week most of the cases with significant fetal malformation were diagnosed. Discussion. SUA is a useful marker in the first trimester for fetal malformation pathology, as it will allow detecting a large number of cases with malformations before 20 weeks of gestation.

Prenatal detection of cardiac anomalies in fetuses with single umbilical artery: diagnostic accuracy comparison of maternal-fetal-medicine and pediatric cardiologist

AIM

To determine agreement of cardiac anomalies between maternal fetal medicine (MFM) physicians and pediatric cardiologists (PC) in fetuses with single umbilical artery (SUA).

METHODS

A retrospective review of all fetuses with SUA between 1999 and 2008. Subjects were studied by MFM and PC, delivered at our institution, and had confirmation of SUA and cardiac anomaly by antenatal and neonatal PC follow-up. Subjects were divided into four groups: isolated SUA, SUA and isolated cardiac anomaly, SUA and multiple anomalies without heart anomalies, and SUA and multiple malformations including cardiac anomaly.

RESULTS

39,942 cases were studied between 1999 and 2008. In 376 of 39,942 cases (0.94%), SUA was diagnosed. Only 182 (48.4%) met inclusion criteria. Cardiac anomalies were found in 21% (38/182). Agreement between MFM physicians and PC in all groups combined was 94% (171/182) (95% CI [89.2, 96.8]). MFM physicians overdiagnosed cardiac anomalies in 4.4% (8/182). MFM physicians and PC failed to antenatally diagnose cardiac anomaly in the same two cases.

CONCLUSIONS

Good agreement was noted between MFM physicians and PC in our institution. Studies performed antenatally by MFM physicians and PC are less likely to uncover the entire spectrum of cardiac abnormalities and thus neonatal follow-up is suggested.

Relationship of isolated single umbilical artery to fetal growth, aneuploidy and perinatal mortality: systematic review and meta-analysis

OBJECTIVE

To review the available literature on outcome of pregnancy when an isolated single umbilical artery (iSUA) is diagnosed at the time of the mid-trimester anomaly scan.

METHODS

We searched MEDLINE (1948-2012), EMBASE (1980-2012) and the Cochrane Library (until 2012) for relevant citations reporting on outcome of pregnancy with iSUA seen on ultrasound. Data were extracted by two reviewers. Where appropriate, we pooled odds ratios (ORs) for the dichotomous outcome measures: small for gestational age (SGA), perinatal mortality and aneuploidy. For birth weight we determined the mean difference with 95% CI.

RESULTS

We identified three cohort studies and four case-control studies reporting on 928 pregnancies with iSUA. There was significant heterogeneity between cohort and case-control studies. Compared to fetuses with a three-vessel cord, fetuses with an iSUA were more likely to be SGA (OR 1.6 (95% CI, 0.97-2.6); n = 489) or suffer perinatal mortality (OR 2.0 (95% CI, 0.9-4.2); n = 686), although for neither of the outcomes was statistical significance reached. The difference in mean birth weight was 51 g (95% CI, -154.7 to 52.6 g): n = 407), but again this difference was not statistically significant. We found no evidence that fetuses with iSUA have an increased risk for aneuploidy.

CONCLUSION

In view of the non-significant association between iSUA and fetal growth and perinatal mortality, and in view of the heterogeneity in studies on aneuploidy, we feel that large-scale, prospective cohort studies are needed to reach definitive conclusions on the appropriate work-up in iSUA pregnancies. At present, targeted growth assessment after diagnosis of iSUA should not be routine practice.

Single umbilical artery: Does side matter?

INTRODUCTION

The aim of this study was to determine if laterality of an absent umbilical artery (AUA) is associated with specific sonographic findings, chromosomal defects or postpartum birth defects.

MATERIALS AND METHODS

In this retrospective cohort study, ultrasound reports and medical records of patients who received an obstetric ultrasound at the University of Iowa Hospitals and Clinics with an identified laterality of the AUA from 1989 to 2007 (n = 405) were reviewed. Rates of sonographic abnormalities between fetuses with a right versus left AUA were compared using Fisher's exact test. Adjustments for confounding were made using logistic regression modeling. The significance level was set at 0.05.

RESULTS

Right AUAs on ultrasound demonstrate higher unadjusted rates of ultrasound abnormalities with a higher percentage of fetuses with >1 additional abnormality (51.1 vs. 37.0%; p = 0.0043). The left AUA group had a significantly higher percentage of isolated AUA (63.0 vs. 48.8%; p = 0.004). In a multivariate analysis, a sonographic right AUA was significantly associated with gastrointestinal (GI) and genitourinary (GU) abnormalities. No other ultrasonographic and umbilical artery Doppler abnormalities, chromosomal defects or postpartum birth defects were significantly associated with a specific laterality of the AUA.

DISCUSSION

Our study identified a significant association between a right AUA and concomitant fetal GI and GU abnormalities. Contrary to previous reports, we conclude that laterality of the AUA may prove to be an easily identified early marker of fetal abnormalities.

Single umbilical artery in twin pregnancies

OBJECTIVE

Our purpose was to evaluate the antenatal incidence of single umbilical artery (SUA) in twin pregnancies according to chorionicity and to assess its relationship with outcome.

METHODS

Consecutive twin pregnancies undergoing ultrasound evaluation at our institutions were included. A targeted sonographic evaluation of the umbilical cord and vessels was performed in all cases. Chorionicity was determined according to standard ultrasound criteria.

RESULTS

A total of 174 twin pregnancies, 100 dichorionic (DC) and 74 monochorionic (MC), were included in the study. An SUA was identified in 17 (9.8%) pregnancies, and in 18 (5.2%) fetuses. No difference was found in the incidence of SUA in DC and MC twins. Among affected pregnancies, all but one DC twin pregnancy were discordant for SUA. Structural and/or chromosomal abnormalities were present in 27.8% of fetuses with SUA. The prevalence of small-for-gestational-age fetuses and of discordant birth weight (> 20% discordance) was higher in the SUA group than in the rest of the population, although these differences were not statistically significant. Twin pairs discordant for SUA had significantly higher weight discordance than those with normal umbilical cords. The sonographic cross-sectional area of the SUA did not appear to show the typical adaptive dilatation usually seen in singleton pregnancies with SUA.

CONCLUSIONS

The incidence of SUA in twins is higher than in singletons, with no difference between MC and DC twins. Intrapair discordance for SUA in identical twins provides evidence against an exclusively genetic origin of this anomaly. The apparent failure of compensatory dilatation of the umbilical artery in twins with SUA may explain in part the higher risk for fetal growth restriction in these cases.

Long-term physical and neurologic development in newborn infants with isolated single umbilical artery

OBJECTIVE

This study compared birth parameters and the longitudinal course in physical and neurologic development between children with 2 and 3 vessel umbilical cords.

STUDY DESIGN

Our study of the Collaborative Perinatal Project included singletons of at least 24 weeks' gestation with single umbilical artery at birth and no identifiable congenital anomalies. Demographics that were collected included maternal age, race, smoking status, and socioeconomic index. Delivery data included gestational age, birthweight, Apgar scores, placental weight, and umbilical cord insertion and length. Growth and neurodevelopmental parameters were collected at various intervals from birth to 7 years.

RESULTS

There were 263 infants with isolated single umbilical artery and 41,415 infants with 3 vessel cords. A random effect model that controlled for potential confounders did not show clinically significant differences in the physical and neurodevelopment measures between these groups.

CONCLUSION

Our study shows no evidence of differential longitudinal physical growth or neurologic outcomes between infants with 2 or 3 vessel cords.

Single umbilical artery and congenital heart disease in selected and unselected populations

OBJECTIVE

A variable association between single umbilical artery (SUA) and congenital heart disease (CHD) has been reported previously. Discrepancies in the results may be related to the populations studied. In this study we assessed the relationship between SUA and CHD in two well-defined selected and unselected populations.

METHODS

This was a retrospective review of all cases of SUA detected antenatally in a tertiary referral center between 1997 and 2003. Umbilical arteries were routinely identified around the fetal bladder by color-flow Doppler ultrasonography. The unselected population included pregnancies from a well-defined geographical area, delivering in the same hospital. The selected group was referred from other hospitals because of suspected abnormalities or other risk factors. Major CHD was defined as CHD needing postnatal treatment or long-term follow-up.

RESULTS

There were 10 fetuses with major CHD in the selected group: four cases among 25 with extracardiac defects (16%; 95% CI, 4.5-36.1%) and six cases out of 22 with no other abnormalities (27%; 95% CI, 10.7-50.2%; P = 0.35). In the unselected group there were two cases of major CHD, both among the 13 fetuses with extracardiac abnormalities (15%; 95% CI, 2-45%), while there were no major cardiac defects in the 85 fetuses with SUA and no extracardiac abnormalities (0%; 95% CI, 0-4%; P = 0.03).

CONCLUSIONS

The association between SUA and CHD varies dramatically with population selection criteria. The risk for CHD after the detection of SUA in an otherwise apparently normal fetus from an unselected population seems small and may not warrant specialist fetal echocardiography.

Reducing stillbirths: screening and monitoring during pregnancy and labour

BACKGROUND

Screening and monitoring in pregnancy are strategies used by healthcare providers to identify high-risk pregnancies so that they can provide more targeted and appropriate treatment and follow-up care, and to monitor fetal well-being in both low- and high-risk pregnancies. The use of many of these techniques is controversial and their ability to detect fetal compromise often unknown. Theoretically, appropriate management of maternal and fetal risk factors and complications that are detected in pregnancy and labour could prevent a large proportion of the world's 3.2 million estimated annual stillbirths, as well as minimise maternal and neonatal morbidity and mortality.

METHODS

The fourth in a series of papers assessing the evidence base for prevention of stillbirths, this paper reviews available published evidence for the impact of 14 screening and monitoring interventions in pregnancy on stillbirth, including identification and management of high-risk pregnancies, advanced monitoring techniques, and monitoring of labour. Using broad and specific strategies to search PubMed and the Cochrane Library, we identified 221 relevant reviews and studies testing screening and monitoring interventions during the antenatal and intrapartum periods and reporting stillbirth or perinatal mortality as an outcome.

RESULTS

We found a dearth of rigorous evidence of direct impact of any of these screening procedures and interventions on stillbirth incidence. Observational studies testing some interventions, including fetal movement monitoring and Doppler monitoring, showed some evidence of impact on stillbirths in selected high-risk populations, but require larger rigourous trials to confirm impact. Other interventions, such as amniotic fluid assessment for oligohydramnios, appear predictive of stillbirth risk, but studies are lacking which assess the impact on perinatal mortality of subsequent intervention based on test findings. Few rigorous studies of cardiotocography have reported stillbirth outcomes, but steep declines in stillbirth rates have been observed in high-income settings such as the U.S., where cardiotocography is used in conjunction with Caesarean section for fetal distress.

CONCLUSION

There are numerous research gaps and large, adequately controlled trials are still needed for most of the interventions we considered. The impact of monitoring interventions on stillbirth relies on use of effective and timely intervention should problems be detected. Numerous studies indicated that positive tests were associated with increased perinatal mortality, but while some tests had good sensitivity in detecting distress, false-positive rates were high for most tests, and questions remain about optimal timing, frequency, and implications of testing. Few studies included assessments of impact of subsequent intervention needed before recommending particular monitoring strategies as a means to decrease stillbirth incidence. In high-income countries such as the US, observational evidence suggests that widespread use of cardiotocography with Caesarean section for fetal distress has led to significant declines in stillbirth rates. Efforts to increase availability of Caesarean section in low-/middle-income countries should be coupled with intrapartum monitoring technologies where resources and provider skills permit.

The value of single umbilical artery in the prediction of fetal aneuploidy: findings in 12,672 pregnant women

OBJECTIVES

To assess the risk of the association of single umbilical artery and aneuploidies.

METHODS

In a general unselected obstetric population of 12,672 singleton pregnant women from January 1998 to December 2002, we detected 61 fetuses (prevalence, 0.48%) with single umbilical artery (SUA) on prenatal ultrasound at 16 to 23 menstrual weeks.

RESULTS

Among the 61 fetuses with 2-vessel cord, 39 (64%) had SUA as an isolated finding, and 22 (36%) had additional findings, either minor or major. One (2.56%) of the 39 fetuses with SUA as an isolated finding had aneuploidy (trisomy 21 at maternal age of 32 years), whereas 5 (41.6%) of the 12 fetuses with SUA concomitant with major anomalies were aneuploid. None of the 10 fetuses with SUA and minor anomalies had aneuploidy. Among the 12,611 women with 3-vessel cord, we instead found 8 cases of trisomy 21 (0.06%), 1 case of translocation 14-21 (0.007%), 5 cases of trisomy 18 (0.04%), 1 case of trisomy 13 (0.007%), 1 case of 47,XXX (0.007%), and 2 cases of monosomy X (0.01%).

CONCLUSIONS

In an unselected population, second trimester sonographic detection of SUA and major fetal anomalies indicate increased risk for fetal aneuploidy. However, even if this study is based on a large population, the only 1 case of trisomy 21 among the fetuses with SUA as an isolated finding is not sufficient to draw a conclusion, and larger studies are needed to confirm or infirm this single case.

Literature Review and suggested protocol for managing ultrasound soft markers for Down syndrome: Thickened nuchal fold, echogenic bowel, shortened femur, shortened humerus, pyelectasis and absent or hypoplastic nasal bone

Mid-trimester soft markers have been linked with Down syndrome and other aneuploidies. There are many other prenatal screening tests available with better detection rates for Down syndrome than the mid-trimester ultrasound. Many patients confronted with the diagnosis of a soft marker become anxious and may request a diagnostic test (amniocentesis) despite the associated risk of miscarriage. This is also despite the fact that most fetuses with an isolated soft marker are chromosomally normal. The management of a pregnancy with a soft marker must therefore be planned in a manner designed to minimize patient anxiety. Likelihood ratios can be used to modify a patient's 'prior risk' (based on age or prior screening tests) and create a new risk. This calculation may help identify a subset of patients suitable for further investigation. It has been proposed that 'negative' likelihood ratios can be used to reduce a patient's risk if no soft marker is found at a mid-trimester ultrasound. There remain concerns about this approach and further research is required before this approach enters common practice. The published work surrounding the management of thickened nuchal fold, echogenic bowel, shortened femur, shortened humerus, pyelectasis (renal pelvis dilatation) and hypoplastic nasal bone is reviewed. Each soft marker has different associations and individual management plans for each of these soft markers are presented. Although isolated single umbilical artery is not usually considered a soft marker of aneuploidy, a management plan for this common finding is also included.

Prenatal detection and outcome of congenital diaphragmatic hernia (CDH) associated with deletion of chromosome 15q26: Two patients and review of the literature

Congenital diaphragmatic hernia (CDH) is a severe birth defect characterized by a defect in the diaphragm with pulmonary hypoplasia and postnatal pulmonary hypertension. Approximately 50% of CDH cases are associated with other non-pulmonary congenital anomalies (so called non-isolated CDH) and in 5-10% of cases there is a chromosomal etiology. The majority of CDH cases are detected prenatally. In some cases prenatal chromosome analysis reveals a causative chromosomal anomaly, most often aneuploidy. Deletion of 15q26 is the most frequently described structural chromosomal aberration in patients with non-isolated CDH. In this paper we report on two patients with a deletion of 15q26 and phenotypes similar to other patients with CDH caused by 15q26 deletions. This phenotype consists of intra-uterine growth retardation, left-sided CDH, cardiac anomalies and characteristic facial features, similar to those seen in Fryns syndrome. We propose that when this combination of birth defects is identified, either pre- or postnatally, further investigations to confirm or exclude a deletion of 15q26 are indicated, since the diagnosis of this deletion will have major consequences for the prognosis and, therefore, can affect decision making.

Middle cerebral artery blood flow velocimetry among healthy fetuses with a single umbilical artery

OBJECTIVE

A single umbilical artery (SUA) is an independent risk factor for perinatal morbidity and mortality in healthy fetuses. The aims of the study were (1) to determine middle cerebral artery (MCA) blood flow velocimetric values among fetuses without structural or chromosomal anomalies with an SUA and to compare them with nomograms of patients with a 3-vessel cord and (2) to measure the pulsatility index (PI) of the umbilical artery among these patients.

METHODS

The PI values of the MCA and umbilical arteries were determined prospectively among 98 healthy fetuses with an SUA. The PI values were compared with nomograms of patients with a 3-vessel umbilical cord. For the MCA, peak systolic velocity (PSV) was also measured. Patients carrying fetuses with intrauterine growth restriction or congenital anomalies were excluded from the study. Middle cerebral artery PI values below the fifth percentile and PSV values above the 95th percentile adjusted for gestational age were considered abnormal.

RESULTS

Gestational age ranged between 22 and 37.9 weeks (median, 30.3 weeks). After adjusting for gestational age, no alterations in the MCA PI and umbilical PI were found in comparison with the normal range for a 3-vessel cord known in the literature. Middle cerebral artery PSV values were also within the normal range for gestational age in all patients.

CONCLUSIONS

The MCA PI and PSV values among healthy fetuses with an isolated SUA were similar to nomograms for fetuses with a 3-vessel umbilical cord. Therefore, abnormal MCA PI and PSV values among fetuses with an SUA should be treated the same as in patients with a 3-vessel umbilical cord.

Nurses' guide to early detection of umbilical arterial catheter complications in infants

Umbilical arterial catheters (UAC) are routinely used in the care of critically ill newborns. Complications related to UACs include vascular compromise, hemorrhage, complications related to malposition, severance of the catheter itself, and infection. This article is Part II in a series dedicated to assessing infants with an umbilical catheter. Part I focused on infants with umbilical venous catheters; this article will focus on the physical assessment relevant to infants with an UAC. Complications related to UACs can occur during any phase of treatment: insertion, while indwelling, or after discontinuing the catheter. Review of clinical signs of complications along with clinical photographs, will assist caregivers in promptly recognizing UAC-related complications.