Risk of adverse pregnancy outcome in isolated single umbilical artery diagnosed at the mid-trimester anomaly scan: a large Danish retrospective cohort study.

OBJECTIVE: To examine the association of isolated single umbilical artery (iSUA) confirmed at the mid-trimester anomaly scan and adverse pregnancy outcome and congenital malformations with up to 10 years postnatal follow up. METHODS: This retrospective cohort study included 116,501 singleton pregnancies consecutively enrolled in first trimester screening for aneuploidies and mid-trimester anomaly scan at three University Hospitals in the Capital Region of Copenhagen, Denmark.Data from the Danish Fetal Medicine Database (2008-2017) were verified by manually scrutinizing pre- and postnatal records. The main outcomes of interest were intrauterine fetal demise (IUFD), small for gestational age (SGA), preterm delivery, cesarean section and unrecognized pre- and postnatal congenital malformations. RESULTS: In total, 775 pregnancies with iSUA were identified. Isolated SUA were associated with a significantly increased risk of IUFD (OR 4.16, 95% CI 2.06-8.44), SGA < 3rd centile (aOR 2.41, 95% 1.85-3.14) and SGA < 10th centile (aOR 1.84, 95% CI 1.53-2.21), but not with preterm delivery or cesarean section. The laterality of the missing artery was not associated with SGA. In total, 4.3% of pregnancies with iSUA had unrecognized congenital malformations. 1.5% with iSUA had congenital cardiovascular malformations, which were considered minor. CONCLUSION: Isolated SUA is associated with IUFD and SGA, supporting surveillance during third trimester. If, during the mid-trimester scan, the sonographer achieves thorough, extended cardiac views and finds no additional malformation other than SUA, fetal echocardiography seems not to be needed.

Prenatal Diagnosis of Isolated Single Umbilical Artery: Incidence, Risk Factors and Impact on Pregnancy Outcomes.

Objectives: To assess the incidence of prenatally diagnosed isolated single umbilical artery (iSUA) and its impact on major pregnancy outcomes, as well as to investigate potential risk factors. Materials and methods: A prospective study of singleton pregnancies, undergoing routine anomaly scans at 20+0-24+0 weeks of gestation, was carried out from 2018 to 2022. The effect of sonographically detected iSUA on small-for-gestational-age neonates (SGA) and preterm delivery (PTD) was evaluated using parameterized Student's t-test, nonparametric Mann-Whitney U test and the chi-square test. Multivariable logistic regression models were implemented to assess the independent association between iSUA and the main outcomes, as well as with potential risk factors, while adjusting for specific confounders. Results: The study population included 6528 singleton pregnancies and the incidence of prenatally diagnosed iSUA was 1.3%. Prenatally diagnosed iSUA had a statistically significant association with both SGA neonates (aOR: 1.909; 95% CI: 1.152-3.163) and PTD (aOR: 1.903; 95% CI: 1.035-3.498), while no association was identified between this sonographic finding and preeclampsia. With regard to risk factors, conception via assisted reproductive technology (ART) was associated with increased risk of iSUA (aOR: 2.234; 95% CI: 1.104-4.523), while no other independent predictor for the development of this anatomical variation was identified. Conclusions: Prenatally diagnosed iSUA seems to be associated with a higher incidence of SGA and PTD and is more common in pregnancies following ART, which constitutes a novel finding.

Fetal growth restriction and a single umbilical artery are independent predictors of hypospadias during pregnancy.

INTRODUCTION: Little is known about the association between hypospadias and small fetuses, as well as the pathological implications of fetal growth restriction (FGR). Thus, we aimed to investigate the association between hypospadias and small fetuses using a database of fetal ultrasound and obstetric events. METHODS: A cohort of male singleton infants delivered after 22 weeks of gestation at Keio University Hospital between 2013 and 2019 was retrospectively reviewed. FGR was defined according to the Delphi criteria. Logistic regression analysis was performed to identify the significant predictors of hypospadias. Placental pathology was reviewed in cases with hypospadias. RESULTS: Of the 2,040 male infants included in the present study, 23 had hypospadias. The prevalences of a single umbilical artery (SUA), small for gestational age, maternal hypertensive disorders of pregnancy, and a small placenta, were significantly higher in infants with hypospadias. Multiple logistic regression analysis revealed that FGR (odds ratio [OR] = 9.39; 95% confidence interval [CI], 2.50-35.3) and the presence of a SUA (OR = 33.4; 95% CI, 8.00-139.5) were independently and significantly associated with hypospadias. When FGR was stratified by the time of onset, its association with hypospadias was significant regardless of the time of onset. Moreover, placental histological findings suggested that fetal vascular malperfusion might play a role in hypospadias. DISCUSSION: FGR and SUAs are independent prenatal predictors of the development of hypospadias, and fetal vascular malperfusion of the placenta may be involved in the etiology of hypospadias.

Comparative study of umbilical cord cross-sectional area in foetuses with isolated single umbilical artery and normal umbilical artery.

Single umbilical artery (SUA) is one of the most common prenatal diagnoses in cases of foetal abnormality. This prospective study evaluated 77 foetuses with isolated SUAs and 77 healthy foetuses, both at 22-39 gestational weeks. We categorised gestational age into the second and third trimesters, measured the umbilical arterial blood flow parameters and calculated the umbilical vein (UV) area, umbilical artery (UA) area and UV area/UA area ratio. In the second and third trimesters, a higher UA area was obtained in the isolated SUA group than in the control group (p < .01). Furthermore, the isolated SUA group had a lower UV area/UA area ratio than the control group (p < .01), and a positive linear correlation was found between gestational age and UV area in both groups (p < .01). The presence of isolated SUAs was associated with low birth weight and a high prevalence of small for gestational age.IMPACT STATEMENTWhat is already known on this subject? Single umbilical artery (SUA) is one of the most common prenatally diagnosed foetal abnormalities and approximately 80% foetuses with SUA have isolated SUA, which is a soft indicator of chromosome abnormalities, congenital malformations and premature birth. Umbilical cord cross-sectional area can be evaluated prenatally by ultrasound imaging. Normal values increase with gestational age and foetal size in single pregnancies. Changes in umbilical cord thickness have been associated with complications during pregnancy.What do the results of this study add? The correlation between gestational age and umbilical vein area in the isolated single umbilical artery (SUA) group and control group was better than that between gestational age and umbilical artery area. UA area increased significantly in both groups before 28 weeks but not after 28 weeks, particularly in the isolated SUA group.What are the implications of these findings for clinical practice and/or further research? The study provides a reliable basis for maternal foetal monitoring during pregnancy in the isolated SUA and control groups. Objective assessment of the occurrence and development of foetuses with isolated single umbilical artery was performed.

Society for Maternal-Fetal Medicine Consult Series #57: Evaluation and management of isolated soft ultrasound markers for aneuploidy in the second trimester: (Replaces Consults #10, Single umbilical artery, October 2010; #16, Isolated echogenic bowel diagnosed on second-trimester ultrasound, August 2011; #17, Evaluation and management of isolated renal pelviectasis on second-trimester ultrasound, December 2011; #25, Isolated fetal choroid plexus cysts, April 2013; #27, Isolated echogenic intracardiac focus, August 2013).

Soft markers were originally introduced to prenatal ultrasonography to improve the detection of trisomy 21 over that achievable with age-based and serum screening strategies. As prenatal genetic screening strategies have greatly evolved in the last 2 decades, the relative importance of soft markers has shifted. The purpose of this document is to discuss the recommended evaluation and management of isolated soft markers in the context of current maternal serum screening and cell-free DNA screening options. In this document, "isolated" is used to describe a soft marker that has been identified in the absence of any fetal structural anomaly, growth restriction, or additional soft marker following a detailed obstetrical ultrasound examination. In this document, "serum screening methods" refers to all maternal screening strategies, including first-trimester screen, integrated screen, sequential screen, contingent screen, or quad screen. The Society for Maternal-Fetal Medicine recommends the following approach to the evaluation and management of isolated soft markers: (1) we do not recommend diagnostic testing for aneuploidy solely for the evaluation of an isolated soft marker following a negative serum or cell-free DNA screening result (GRADE 1B); (2) for pregnant people with no previous aneuploidy screening and isolated echogenic intracardiac focus, echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1B); (3) for pregnant people with no previous aneuploidy screening and isolated thickened nuchal fold or isolated absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening through cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (4) for pregnant people with no previous aneuploidy screening and isolated choroid plexus cysts, we recommend counseling to estimate the probability of trisomy 18 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1C); (5) for pregnant people with negative serum or cell-free DNA screening results and an isolated echogenic intracardiac focus, we recommend no further evaluation as this finding is a normal variant of no clinical importance with no indication for fetal echocardiography, follow-up ultrasound imaging, or postnatal evaluation (GRADE 1B); (6) for pregnant people with negative serum or cell-free DNA screening results and isolated fetal echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend no further aneuploidy evaluation (GRADE 1B); (7) for pregnant people with negative serum screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and discussion of options for no further aneuploidy evaluation, noninvasive aneuploidy screening through cell-free DNA, or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (8) for pregnant people with negative cell-free DNA screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend no further aneuploidy evaluation (GRADE 1B); (9) for pregnant people with negative serum or cell-free DNA screening results and isolated choroid plexus cysts, we recommend no further aneuploidy evaluation, as this finding is a normal variant of no clinical importance with no indication for follow-up ultrasound imaging or postnatal evaluation (GRADE 1C); (10) for fetuses with isolated echogenic bowel, we recommend an evaluation for cystic fibrosis and fetal cytomegalovirus infection and a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C); (11) for fetuses with an isolated single umbilical artery, we recommend no additional evaluation for aneuploidy, regardless of whether results of previous aneuploidy screening were low risk or testing was declined. We recommend a third-trimester ultrasound examination to evaluate growth and consideration of weekly antenatal fetal surveillance beginning at 36 0/7 weeks of gestation (GRADE 1C); (12) for fetuses with isolated urinary tract dilation A1, we recommend an ultrasound examination at ≥32 weeks of gestation to determine if postnatal pediatric urology or nephrology follow-up is needed. For fetuses with urinary tract dilation A2-3, we recommend an individualized follow-up ultrasound assessment with planned postnatal follow-up (GRADE 1C); (13) for fetuses with isolated shortened humerus, femur, or both, we recommend a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C).

Prenatal diagnosis of single umbilical artery and postpartum outcome.

OBJECTIVES: To investigate the incidence of the single umbilical artery (SUA) malformation and postpartum outcomes in a retrospective analysis of 781 fetuses. MATERIALS AND METHODS: This retrospective analysis included 781 pregnant women carrying singleton fetuses diagnosed with SUA at Gansu Provincial Maternal and Child-care Hospital between 2013 and 2019. Detailed data on maternal and fetal characteristics and postpartum outcomes were obtained. RESULTS: In total, 624 (79.9 %) fetuses were diagnosed with isolated SUA and 157 (20.1 %) fetuses had SUA together with other structural and/or chromosome abnormalities. The highest incidence of malformation was found in the urinary system, followed by the cardiovascular system and digestive system. The incidence of SUA was 59.1 % on the right side and 40.9 % on the left side. Fetuses with SUA and other abnormalities tended to have a lower mean birth weight (3061 g vs 3201 g, p < 0.01), but no difference in the rate of preterm delivery was noted. CONCLUSIONS: After a diagnosis of SUA, structural observation of the fetus is required. The urinary, cardiovascular and digestive systems should be the focus of observation. If relevant malformations are found, then genetic testing must be performed. With isolated SUA, dynamic monitoring of biological indicators is recommended for lower birth weight, but genetic testing is not recommended.

First-trimester sonographic diagnosis of sirenomelia: A multicenter series of 12 cases and review of the literature.

OBJECTIVE: To determine the key sonographic features for the diagnosis of sirenomelia in the first trimester of pregnancy. METHODS: Cases of sirenomelia from several prenatal diagnosis centers were retrospectively identified and reviewed. The diagnosis was established through the detection of fused lower limbs. Additional sonographic findings were also noted. RESULTS: A total of 12 cases were collected. The most striking sonographic finding was the detection of malformed lower limbs, which appeared to be fused and in an atypical position. Nuchal translucency thickness was mildly increased in three cases (25%). An abdominal cyst, representing the dilated blind-ending bowel, was noted in seven cases (58%). Color flow imaging detected a single umbilical artery in six cases (50%) and the associated intra-abdominal vascular anomalies in three cases (25%). No cases of aneuploidy were detected. The pregnancy was terminated in nine cases (75%) and intrauterine demise occurred in the remaining three cases (25%). CONCLUSIONS: The sonographic detection of abnormal lower limbs or an intra-abdominal cyst located laterally during the first-trimester scan may be warning signs of sirenomelia. This should prompt a detailed examination of the fetal lower body and intra-abdominal anatomy, including the main abdominal vessels, in order to look for additional confirmatory findings.

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.

Shear-wave elastography - virtual touch tissue quantification of fetal placentas with a single umbilical artery.

OBJECTIVE: In this study, we aimed to evaluate the elasticities of fetal placentas with a single umbilical artery using the Virtual Touch Tissue Quantification (VTTQ) technique. MATERIALS AND METHODS: Pregnant women with fetuses with a single umbilical artery (SUA) and pregnant women with fetuses having three vessel cord (3VC) at 18-22 weeks of gestation were enrolled in the research. The placentas were evaluated and divided into three equal parts as the inner 1/3 of the placenta (fetal edge), the outer 1/3 of the placenta (maternal edge) and the central 1/3 of the placenta (central part). Shear-wave velocity (SWV) measurements were used in the elastographic evaluation of placentas by VTTQ. RESULTS: Forty pregnant women were included in the study (n = 20 SUA, n = 20 three vessel cord pregnant women). The placental Acoustic Radiation Force Impulse (VTTQ) of the placenta regarding SWV measurement values of the fetal edge of the placenta in the fetuses with SUA and the control group were 0.876 and 0.957 m/sec, respectively. A significant statistical difference was found between the groups regarding the measurement of the stiffness of fetal placenta (p = 0.021). There was no significant difference between the measured stiffness values of the central or outer region of the placentas. CONCLUSIONS: In this study, we found lower SWV scores for the fetal edge of the placenta with SUA. This finding may reflect tissue elasticity level, and we hope that the use of the VTTQ technique may contribute to predicting the pregnancy-related morbidities of fetuses with SUA in the future.

Prenatally Diagnosed Single Umbilical Artery (SUA) - Retrospective Analysis of 1169 Fetuses.

PURPOSE: The incidence of a fetal single umbilical artery (SUA) is about 0.5 % and has been associated with an increased risk of congenital malformations, fetal aneuploidy and intrauterine growth restriction (IUGR). MATERIALS AND METHODS: A retrospective analysis of 1169 women with singleton pregnancies diagnosed with fetal SUA between 1997 and 2014 in a specialized practice for prenatal diagnostics has been performed. Data was obtained on maternal and fetal findings as well as pregnancy outcome. RESULTS: 989 (84.6 %) fetuses showed an isolated SUA (iSUA) while 180 (15.4 %) presented with SUA and additional structural and/or chromosomal abnormalities. Structural malformations were distributed as follows: 9.0 % cardiovascular, 3.5 % urogenital, 2.9 % musculoskeletal, 3.0 % gastrointestinal and 2.1 % cerebral. 2.1 % of the fetuses had chromosomal aberrations. 50.8 % (49.2 %) of the fetuses were female (male) and right vs. left SUA was found in 64.2 % (35.8 %) of the cases. Fetuses with SUA and additional abnormalities showed lower rates of live births (85.0 % vs. 98.5 %, p < 0.001), a lower median birth weight (2825 g vs. 3220 g, p < 0.001), higher rates of preterm delivery before week 34 + 0 (13.7 % vs. 3.8 %, p < 0.001) and weighed less than the 5th growth percentile in 21.6 % vs. 9.3 % (p < 0.001) of the fetuses with iSUA. In 5.1 % (60) of the children, chromosomal or structural abnormalities were detected post-partum. CONCLUSION: Once fetal SUA is diagnosed, intense sonoanatomy of the fetus is required and, if associated malformations are found, genetic testing must be offered. In iSUA intermittent biometry is recommended for the early detection of IUGR but additional genetic testing is not necessarily recommended.

Ultrasound screening: Status of markers and efficacy of screening for structural abnormalities.

Aneuploidy is a major cause of perinatal morbidity and mortality and can have a significant impact on expecting parents and their families. With early screening and diagnosis it is important to be able to educate parents regarding the potential impact of the diagnosis. This knowledge allows parents the opportunity to consider management options early in the pregnancy, permitting more time to mentally and emotionally prepare both for the course of the pregnancy, and after the birth of the child should the pregnancy continue. Prenatal screening provides pregnant women a non-invasive risk assessment for the most common aneuploidies. Those who are considered "high-risk" then have the option for additional diagnostic (invasive) testing. Prior to the 1980s, prenatal screening consisted of risk assessment through maternal age; however, with the advent of maternal serum biochemical analysis and ultrasound, the field of prenatal screening developed significantly. As biochemical and sonographic advances continued into the 1990s, the emphasis shifted to risk assessment in the first trimester, with the combination of maternal serum analytes and sonographic evaluation of the nuchal translucency.(1) Within the last decade, the introduction of non-invasive screening (NIPT/S) has shown great impact on the expansion and evolving practice of prenatal screening. Although in many places the standard for prenatal testing continues to include maternal serum analytes and sonographic evaluation, the role of each marker alone and in combination remains important. In the era of increasingly available screening tests, especially with NIPT/(NIPS), this article attempts to review the current role of ultrasound in prenatal care and elucidate the role of ultrasound markers in prenatal screening.

Prenatally diagnosed single umbilical artery: The role and relationship of additional risk factors in the fetus for congenital heart disease.

PURPOSE: Single umbilical artery (SUA) has been associated with an increased risk of congenital heart disease (CHD). Women carrying fetuses with an SUA are often referred for fetal echocardiography, but data to support the need for this testing remain controversial. METHODS: A retrospective review of the records for all women carrying fetuses with an SUA who had undergone fetal echocardiography between 2009 and 2012 at our center was performed. Data on the maternal and fetal risk factors for CHD were collected, and the fetuses were categorized into three groups: low risk (LR; an SUA with no additional risk factors for CHD), moderate risk (MR; an SUA with one additional risk factor for CHD), and high risk (HR; an SUA with two or more additional risk factors for CHD). RESULTS: In total, 101 such patients were identified: 69 LR, 26 MR, and 6 HR. No fetuses in the LR group, three in the MR group, and two in the HR group had CHD (p = 0.0005). CONCLUSIONS: An SUA in an LR fetus did not increase the risk of CHD in our cohort, whereas an SUA in the presence of additional risk factors was associated with significantly increased risk for CHD. Our results suggest that referral for a fetal echocardiogram is indicated for women carrying fetuses with an SUA when additional risk factors for CHD are present. In an LR fetus with an SUA, however, echocardiography may not provide additional benefit unless CHD is suggested on screening obstetric sonography.

Controversial ultrasound findings in mid trimester pregnancy. Evidence based approach.

Mid trimester fetal anatomy scan is a fundamental part of routine antenatal care. Some U/S soft markers or controversial U/S signs are seen during the scan and create some confusion regarding their relation to fetal chromosomal abnormalities. Example of these signs: echogenic focus in the heart, echogenic bowel, renal pyelectasis, ventriculomegaly, polydactely, club foot, choroid plexus cyst, single umbilical artery. We are presenting an evidence based approach from the literature for management of these controversial U/S signs.

Congenital Malformations Associated With a Single Umbilical Artery in Twin Pregnancies.

A single umbilical artery (SUA) was identified in 1.5% of twin pregnancies. The presence of a SUA in a twin pregnancy was associated with a 50% incidence of fetal anomalies, many of them complex and severe. The embryology and pathophysiological mechanisms associated with a SUA are reviewed. Aneuploidy is relatively common and should be considered, particularly in the presence of associated anomalies. Fetal growth restriction is frequent and preterm delivery is common.

Application of Umbilical Artery Classification in Complicated Monochorionic Twins.

UNLABELLED: We report our experience on the application of Gratacos' classification in a cohort of monochorionic pregnancies complicated by selective intra-uterine growth retardation based on the Doppler assessment of the umbilical artery. MATERIALS AND METHODS: A retrospective study was conducted on 52 cases of monochorionic twin pregnancies, in which one twin presented an abdominal circumference at or below the 10th percentile for gestational age. Cases were classified into three types according to the umbilical artery Doppler in the smaller twin. Subsequently, patients were divided into two groups: the selective IntraUterine Growth Retardation group and the Twin-to-Twin Transfusion Syndrome (TTTS) group. RESULTS: Of the total 52 cases, 37 were classified as Type I, 12 as Type II, and 3 as Type III cases. In the total group, progressive fetal deterioration of the smaller fetus requiring active management was observed in 66.7% of Type II and 11.1% of Type I cases (p < .001), and in no Type III case. Unexpected fetal death of the smaller twin was observed more frequently in Type III (two cases, 66.7%) than in Types I and II cases (5% and 33%, respectively). Among the 52 cases, TTTS with oligo-polyhydramnios sequence was diagnosed in 10 cases. The remaining 42 cases were therefore defined as selective intra-uterine growth retardation. In the selective IntraUterine Growth Retardation group, results were similar to those obtained for the whole population. CONCLUSIONS: Classification of complicated monochorionic twins based on the umbilical artery Doppler is particularly important for counseling, even when we include TTTS cases, and permits the prediction of clinical evolution and perinatal outcome.

Estimated fetal weight and birth weight associated with isolated single umbilical artery: the University of Utah experience.

OBJECTIVE: The objectives this study were to assess the role of third-trimester ultrasound in detection of fetal growth restriction associated with isolated single umbilical artery (SUA) and to correlate sonographic estimated fetal weight (EFW) with birth weight. METHODS: A retrospective cohort study was performed from 2000 to 2009 at a single academic center. In fetuses with isolated SUA, EFW at follow-up, birth weight, gestational age (GA) at birth, and pregnancy outcome were compared with expected values derived from a statewide database. Categorical variables were analyzed with Fisher exact test, and t tests were used to compare distributions of birth outcomes to expected outcomes. RESULTS: Two hundred twenty-five of 41,821 pregnancies had isolated SUA. One hundred ninety-one had available imaging and clinical data. Of 172 with third-trimester ultrasound, the mean EFW was 51st percentile; 4.7% were less than the 10th percentile for GA. Low birth weight (defined as <2500 g), preterm birth, and stillbirth were significantly more frequent in the cohort than in the state (17.3% vs 5.15%, 19.9% vs 8.0% and 3.5% vs 0.33%, respectively, P < 0.05). Mean birth weight in the cohort was significantly lower (2963 vs 3306 g, P < 0.001) than that in the state. Even in term births, the mean weight was significantly lower than that in the state (3169 vs 3379 g, P < 0.001). Cohort mean GA at birth was 38.1 versus 38.5 weeks in the state (P < 0.05). CONCLUSIONS: Follow-up growth scans, as performed in this retrospective cohort study, did not reliably predict birth weight. Birth weight was reduced in the cohort even in the subgroup delivered at term.

Postnatal development of fetuses with a single umbilical artery: differences between malformed and non-malformed infants.

BACKGROUND: The presence of a single umbilical artery (SUA) is a fetal soft marker of congenital abnormalities. Among the most common related malformations, there are cardiological, nephrourological and digestive anomalies, most of which are considered to have a vascular etiology. There is an association between increased incidence of intrauterine growth retardation and adverse perinatal indicators, but whether this association is due to related anomalies or isolated SUA (iSUA) is controvisal. METHODS: We reviewed 96 cases of iSUA and non-isolated SUA (niSUA), diagnosed in a period of two years in a referral hospital for high-risk pregnancies. Data on prenatal explorations, including fetal ultrasonography and karyotyping, were obtained. niSUA was diagnosed when no malformations were found prenatally or in postnatal evaluation. RESULTS: Sixty-six newborns (68.8%) had no other anomalies and 30 (31.3%) presented with a variety of malformations including heart diseases, urophaties, digestive, nervous and musculoskeletal disorders, genetic abnormalities and complex malformations. Cardiological and nephrourological abnormalities were found to be the most frequent association with a SUA (both in 23.8% of malformed SUA newborns). Intrauterine growth restriction was not higher in iSUA newborns than in a normal population. Ultrasound allowed optimal prenatal diagnosis in most cases. CONCLUSIONS: The prognosis of the fetus with a SUA is determined by the presence of other malformations observed by an expert sonographer. If no other findings are made, only a routine physical examination should be performed in newborns, but no other complementary examinations are required.

Isolated single umbilical artery: evaluating the risk of adverse pregnancy outcome.

OBJECTIVE: To evaluate if isolated single umbilical artery (SUA) diagnosed on second-trimester ultrasound has an independent risk association with adverse pregnancy outcomes. STUDY DESIGN: We compared 136 singleton pregnancies with isolated SUA with 500 consecutive singleton pregnancies with a three-vessel cord (3 VC). Pregnancies complicated by chromosomal abnormalities and other congenital malformations were excluded. The rates of intrauterine growth restriction (IUGR) defined as birth weight less than the 3rd percentile, small for gestational age (SGA) fetuses, defined as a birth weight lower than the 10th percentile and the incidence of very preterm deliveries before 34 weeks of gestation were compared between the two groups. Multivariable logistic regression analysis was performed to evaluate the risk association between SUA and adverse pregnancy outcomes, while controlling for potential confounders. RESULTS: Fetuses with isolated SUA had significantly lower birth weight (2942.5 ± 783.7 vs. 3243.7 ± 585.6 g, p = 0.002), and were delivered at an earlier gestational age (38.7 ± 3.4 vs. 39.5 ± 2.2 weeks, p < 0.001), when compared to fetuses with a 3 VC. Fetuses with isolated SUA were at higher risk for IUGR (15.4% vs. 1.8%, p < 0.001), SGA (20.6% vs. 4.4%, p < 0.001) and very preterm delivery (6.6% vs. 1.4%, p = 0.002). Using a multiple logistic regression model, isolated SUA was shown to be an independent risk factor for IUGR (adjusted OR = 11.3, 95% CI 4.8-25.6; p < 0.001) and very preterm delivery (adjusted OR = 5.0, 95% CI 1.8-13.8; p = 0.002). CONCLUSIONS: The presence of isolated SUA is independently associated with an increased risk for IUGR, SGA and very preterm delivery.

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.

Should fetal growth be a matter of concern in isolated single umbilical artery?

OBJECTIVE: To examine birth weight in pregnancies with isolated single umbilical artery (ISUA). METHODS: Case control study with retrospective review of 131 singleton pregnancies with isolated single umbilical artery diagnosed before birth. Control group consisted of 730 singleton pregnancies recruited prospectively, that had histological confirmation of a 3 vessels cord. Pregnancies were classified as uncomplicated or high-risk according to the presence of diseases that increase the risk of placental insufficiency during pregnancy. Mean birth weight and frequency of low birth weight (< 2.500 g), very low birth weight (< 1.500 g) and fetal growth restriction below the 5th and 10th centiles were compared between groups. RESULTS: Mean birth weight difference between ISUA (n=131, 2840±701g) and control (n=730, 2.983 ± 671g) pregnancies was 143g (95% CI= 17-269; p=0.04) and birth weight below the 5thcentile was significantly more common in ISUA group [28/131 (21.4%) versus 99/730 (13.6%), p=0.02]. When only uncomplicated pregnancies were considered in both groups, no birth weight differences were observed. Amongst high-risk subgroups, birth weight below the 5th centile remained significantly more common in ISUA compared to control pregnancies [10/35 (28.6%) versus 53/377 (14.1%), p=0.04]. CONCLUSION: Isolated single umbilical artery does not increase the risk of fetal growth restriction in uncomplicated singleton pregnancies.