Is single umbilical artery an independent risk factor for perinatal mortality?

TRAP Sequence Clinical Case: Is a Single Umbilical Artery a Protective Ultrasound Marker for Fetal Heart Failure Development

Twin Reversed Arterial Perfusion (TRAP) sequence is a rare complication in monochorionic pregnancies, often leading to fetal heart failure (FHF) in the pump twin. We present a 17-year-old primigravida with a monochorionic monoamniotic twin pregnancy presented with an acardiac twin, single umbilical artery (SUA), and multicystic placenta appearance. Throughout the pregnancy, the pump twin exhibited normal growth without signs of FHF. The infant was delivered at 34 weeks via cesarean section, healthy and without cardiac anomalies. The nonexistence of an impacted intrauterine fetal development and FHF of the pump twin in our case may be explained by the presence of one umbilical artery, resulting in less blood flow to the parasitic twin, which can be accepted as a protective factor for the pump twin circulation. Our hypothesis-generating finding that SUA may play a protective role in the development of FHF in pump-twin is promising; however, it remains speculative, and further research is needed to confirm the protective role of SUA for pump-twin outcomes in TRAP pregnancies.

Single umbilical artery and associated birth defects in perinatal autopsies: prenatal diagnosis and management

BACKGROUND

The umbilical cord forms the connection between the fetus and the placenta at the feto-maternal interface and normally comprises two umbilical arteries and one umbilical vein. In some cases, only a single umbilical artery (SUA) is present. This study was conducted to evaluate associations between SUA and other congenital malformations discovered in perinatal autopsies and to ascertain the existence of preferential associations between SUA and certain anomalies.

METHODS

We evaluated records of all fetuses sent for autopsy to the Department of Pathology during the 10-year period from 2013 through 2022 (n = 1,277). The data were obtained from the hospital's pathology laboratory records. The congenital anomalies were grouped by organ or system for analysis and included cardiovascular, urinary tract, nervous system, gastrointestinal tract, musculoskeletal, and lung anomalies.

RESULTS

A SUA was present in 8.61% of the autopsies. The gestational age of the affected fetuses ranged between 13 to 40 weeks. An SUA presented as an isolated single anomaly in 44 cases (3.4%). Of the 110 SUA cases, 60% had other congenital anomalies. There was a significant association between birth defects and SUAs (p < .001). Strong associations between SUA and urinary tract, lung, and musculoskeletal anomalies were observed.

CONCLUSIONS

A SUA is usually seen in association with other congenital malformations rather than as an isolated defect. Therefore, examination for associated anomalies when an SUA is detected either antenatally or postnatally is imperative. The findings of this study should be helpful in counseling expectant mothers and their families in cases of SUA.

Clinically Relevant Prenatal Ultrasound Diagnosis of Umbilical Cord Pathology

Umbilical cord abnormalities are not rare, and are often associated with structural or chromosomal abnormalities, fetal intrauterine growth restriction, and poor pregnancy outcomes; the latter can be a result of prematurity, placentation deficiency or, implicitly, an increased index of cesarean delivery due to the presence of fetal distress, higher admission to neonatal intensive care, and increased prenatal mortality rates. Even if the incidence of velamentous insertion, vasa praevia and umbilical knots is low, these pathologies increase the fetal morbidity and mortality prenatally and intrapartum. There is a vast heterogeneity among societies’ guidelines regarding the umbilical cord examination. We consider the mandatory introduction of placental cord insertion examination in the first and second trimester to practice guidelines for fetal ultrasound scans. Moreover, during the mid-trimester scan, we recommend a transvaginal ultrasound and color Doppler assessment of the internal cervical os for low-lying placentas, marginal or velamentous cord insertion, and the evaluation of umbilical cord entanglement between the insertion sites whenever it is incidentally found. Based on the pathological description and the neonatal outcome reported for each entity, we conclude our descriptive review by establishing a new, clinically relevant classification of these umbilical cord anomalies.

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).

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.

10 cases of umbilical cord thrombosis in the third trimester

BACKGROUND

Thrombosis of umbilical vessels is a rare occurrence that is difficult to detect during routine antenatal examinations but can lead to poor perinatal outcomes.

OBJECTIVE

The aim of this study is to examine the association between meaningful clinical manifestations and features associated with thrombosis of umbilical vessels, and to evaluate optimal management options.

METHODS

A retrospective study of umbilical cord thrombi cases enrolled between 2015-2019 was carried out. Data were analyzed from the medical archives where the diagnosis of all cases was established by histopathology.

RESULTS

Gross examination reported additional cord abnormalities (7/10), including the irregular length of the umbilical cord, narrowed cord with hyper-coiling, swollen cord with deficiency of Wharton's jelly, placenta velamentous and umbilical infarction. Pathological examination accounted for 10 cases of umbilical cord thrombosis including umbilical artery embolism (3/10), umbilical vein thrombi (5/10) and funisitis (2/10). Clinical findings depicted that the chief complaint was decreased fetal movement companied by nonreactive NST tests (5/10). With the exception of two stillbirths, the remaining pregnancies (8/10) were terminated by cesarean section. All neonates are alive, including one VLBW and three LBW cases.

CONCLUSION

We have observed that umbilical structural dysplasia, maternal coagulation disorder, vascular endothelial injury and elevated blood glucose may lead to the formation of thrombosis. Focus on specific signs during a prenatal ultrasound, EFM monitoring and counting fetal movements can help in early identification of umbilical cord thrombi. Our results support the more effective approach of emergency cesarean section during the third trimester.

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.

Intrauterine Transfusion Complicated by Umbilical Artery Thrombosis

Background

Fetal anemia results from several conditions; however intrauterine transfusion (IUT) remains the treatment for severe cases. The complications of this procedure are rare and yet can result in preterm delivery or fetal death.

Case

31 y/o G3P2002 with Rh alloimmunization underwent IUT from 19 to 35 weeks. Umbilical artery thrombosis was noted after her 5^th IUT. Further transfusions were performed without any complications and she delivered a full term male infant with APGARS of 8 and 9 at 1 and 5 minutes, respectively.

Conclusion

The complication of umbilical artery thrombosis is unusual and the optimal management is unclear. We report such a case and propose that the presence of Hyrtl's anastomosis near the placental cord insertion may explain the reassuring fetal status throughout the pregnancy.

Perinatal Outcomes of Small for Gestational Age Neonates Born With an Isolated Single Umbilical Artery

Objective: To investigate pregnancy outcomes of small for gestational age (SGA) neonates born with isolated single umbilical artery (iSUA) compared to SGA neonates without iSUA. Study Design: This was a population-based retrospective cohort analysis. The study group was defined as a singleton SGA neonate born with iSUA, while an SGA neonate without iSUA comprised the comparison group. We evaluated adverse perinatal outcomes in all SGA neonates born at the Soroka University Medical Center between the years 1998-2013. Multiple gestations, fetuses with known congenital malformations or chromosomal abnormalities and patients with lack of prenatal care were excluded from the study. Multivariate logistic regression models were constructed to identify independent factors associated with adverse perinatal outcomes. Results: Of 12,915 SGA deliveries, 1.2% (162) were complicated with iSUA. Women in the study group were older with a significantly lower gestational age at delivery compared with the comparison group. Rates of women who conceived after infertility treatments were higher in the study group. Additionally, patients in the study group had significantly higher rates of preterm deliveries, placental abruption, cord prolapse, non-reassuring fetal heart rates and cesarean delivery were noted in the study group. These neonates had a significantly lower birth weight (1988.0 ± 697 vs. 2388.3 ± 481 p < 0.001) and higher rates of low APGAR scores at the first and fifth minutes after birth compared with controls. Perinatal mortality was also found to be significantly higher among SGA neonates complicated with iSUA. Preterm delivery as well as perinatal mortality were found independently associated with iSUA among SGA neonates (aOR 4.01, 95% CI 2.88-5.59, aOR 2.24, 95% CI 1.25-4.01, respectively). Conclusion: SGA pregnancies complicated with iSUA are at higher risk for adverse pregnancy and perinatal outcomes as compared to SGA pregnancies without iSUA.

An epigenetic association of malformations, adverse reproductive outcomes, and fetal origins hypothesis related effects

VACTERL, the prototype for associated congenital anomalies, also has connections with functional issues such as pregnancy losses, prematurity, growth delays, perinatal difficulties, and parental subfertility. This segues into a broader association with similar connections even in the absence of malformations. DNA methylation disturbances in the ovum are a likely cause, with epigenetic links to individual components and to folate effects before conception, explaining diverse fetal and placental findings and providing a link to fetal origin hypothesis-related effects. The association encompasses the following: (1) Pre- and periconceptual effects, with frequent fertility issues and occasional imprinting disorders. (2) Early malformations. (3) Adverse pregnancy outcomes (APOs), as above. (4) Developmental destabilization that resolves soon after birth. This potentiates other causes of association findings, introducing multiple confounders. (5) Long-term fetal origins hypothesis-related risks. The other findings are exceptional when the same malformations have Mendelian origins, supporting a distinct pathogenesis. Expressions are facilitated by one-carbon metabolic issues, maternal and fetal stress, and decreased embryo size. This may be one of the commonest causes of adverse reproductive outcomes, but multifactorial findings, variable onsets and phenotypes, and interactions with multiple confounders make recognition difficult. This association supports VACTERL as a continuum that includes isolated malformations, extends the fetal origins hypothesis, explains adverse effects linked to maternal obesity, and suggests possible interventions.

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 of isolated single umbilical artery with perinatal outcomes: Systemic review and meta-analysis

Objective

The aim of this study was to evaluate the association between prenatally diagnosed isolated single umbilical artery (iSUA) and perinatal outcomes.

Methods

We searched Medline, Embase, the Cochrane Library, and KoreaMed from inception to January 2016, with no language or regional restrictions, for cohort and case-control studies reporting on the relationship of iSUA and perinatal outcomes. We assessed the odds ratios (ORs) and 95% confidence intervals (CIs) for the occurrence of small for gestational age, preterm birth, pregnancy-induced hypertension, neonatal intensive care unit admission, and perinatal mortality in fetuses with iSUA compared with those in fetuses with three vessel cord.

Results

Eleven articles totaling 1,731 pregnancies with iSUA met the selection criteria. Studies varied in design, quality, outcome definition, and results. Meta-analysis carried out within predefined groups showed that the presence of an iSUA was associated with small for gestational age (OR, 2.75; 95% CI, 1.97 to 3.83; P<0.00001), preterm birth (OR, 2.10; 95% CI, 1.72 to 2.57; P<0.00001), pregnancy-induced hypertension (OR, 1.62; 95% CI, 1.00 to 2.63; P=0.05), neonatal intensive care unit admission (OR, 2.06; 95% CI, 1.33 to 3.19; P=0.001), and perinatal mortality (OR, 2.29; 95% CI, 1.32 to 3.98; P=0.003).

Conclusion

Pregnancies complicated by iSUA are at increased risk for small for gestational age, preterm birth, pregnancy-induced hypertension, neonatal intensive care unit admission and perinatal mortality. Further, large prospective cohort studies are required to improve the quality of prenatal counseling and the neonatal care for pregnancies with iSUA.

Embryonic hypocellularity, blastogenetic malformations, and fetal growth restriction

An association between congenital malformations and fetal growth restriction (FGR) can be largely explained by a relationship with early embryonic hypocellularity. The malformations include the VACTERL association, which is exceptional as a Mendelian syndrome, but is commonly associated with monozygotic twinning, maternal diabetes, and some forms of aneuploidy, all characterized by a small embryo early in development. Parsimony suggests that these different links to VACTERL are related to the hypocellularity as a single common factor, rather than as an expression of three independent pathogenetic processes. A distinct non-genetic pathogenesis is further supported by increased frequencies in the same conditions of a single umbilical artery (SUA), which is also unusual in Mendelian disorders. SUA often involves the atrophy of one artery, which may be facilitated by altered hemodynamics in a smaller embryo, providing a direct link to hypocellularity. Hypocellularity may also explain a possible connection between VACTERL and certain mitochondrial disorders, where reduced energy might slow early cell division and growth, reducing the size of the embryo. © 2016 Wiley Periodicals, Inc.

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.

Isolated single umbilical artery is an independent risk factor for perinatal mortality and adverse outcomes in term neonates

OBJECTIVE

To determine whether an isolated single umbilical artery (iSUA) is an independent risk factor for perinatal mortality in term neonates with normal estimated fetal weight (EFW) prior to delivery.

METHOD

A population-based study was conducted, including all deliveries occurring between 1993 and 2013, in a tertiary medical center. Pregnancies with and without iSUA were compared. Multiple gestations, chromosomal, and structural abnormalities were excluded from the cohort. Only pregnancies delivered at term with normal EFW evaluated prior to delivery were included. Stratified analysis was performed using multiple logistic regression models to evaluate the risk of adverse outcomes and perinatal mortality for iSUA fetuses.

RESULTS

During the study period, 233,123 deliveries occurred at "Soroka" University Medical Center, out of which 786 (0.3 %) were diagnosed with iSUA. Different pregnancy complications were more common with iSUA fetuses including: placental abruption (OR = 3.4), true knot of cord (OR = 3.5) and cord prolapse (OR = 2.8). Induction of labor and cesarean delivery were also more common in these pregnancies (OR = 1.5 and OR = 1.9, respectively). iSUA neonates had lower Apgar scores at 1 and 5 min (OR = 1.8, OR = 1.9, respectively) compared to the control group and perinatal mortality rates were higher both antenatally (IUFD, OR = 8.1) and postnatally (PPD, OR = 6.1).

CONCLUSION

iSUA appears to be an independent predictor of adverse perinatal outcomes in term neonates.

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.

Maternal Floor Infarction/Massive Perivillous Fibrin Deposition Associated with Hypercoiling of a Single-Artery Umbilical Cord: A Case Report

Maternal floor infarction is a rare and idiopathic placental disorder associated with adverse obstetric outcomes and a high rate of recurrence in subsequent pregnancies. The pathogenesis of maternal floor infarction is unclear but has been linked to diverse underlying maternal conditions, including gestational hypertension/preeclampsia, immune-mediated diseases, and thrombophilia. Few reports link maternal floor infarction to fetoplacental conditions. We report a 34-week, macerated, growth-restricted male fetus for which the placenta showed maternal floor infarction. The umbilical cord showed excessive coiling and a single umbilical artery. These cord changes are postulated to have resulted in increased placental villous resistance and decreased fetal blood flow, creating a hydrostatic pressure gradient between the villous stroma and the intervillous space. The pressure changes could then lead to trophoblast damage and fibrinoid deposition, contributing to the maternal floor infarction in this case.

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.

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.

Umbilical artery blood flows among pregnancies with single umbilical artery: a prospective case-control study

OBJECTIVES

To evaluate peak systolic velocity (PSV) in the umbilical artery (UA) among patients with single umbilical artery (SUA) as compared with patients with three vessel cords.

METHODS

A prospective case-control study was performed. UA blood flow velocimetry was obtained from fetuses with SUA and from a control group with three vessel cord. PSV and pulsatility index (PI) were measured. Patients' characteristics were compared for statistical differences and a linear regression model was constructed for the different groups.

RESULTS

UA Doppler velocimetry measurements were obtained from 29 patients with SUA and from 29 controls matched for gestational age. The differences between UA PI with and without SUA were significant (F = 3.471; p = 0.0379) showing a lower PI in the SUA group. However, no significant statistical difference was found in PSV between these two groups (F = 0.149; p = 0.86).

CONCLUSIONS

While the impedance in the UA of patients with a SUA was lower compared with patients with a normal umbilical cord, the PSV did not differ.

Pregnancy prognosis associated with an isolated single umbilical artery in twin pregnancy

To determine the prognosis of an isolated single umbilical artery (SUA) in a twin pregnancy, we selected twin pregnancies with a second trimester ultrasound diagnosing a SUA in at least one fetus at our tertiary hospital. This was confirmed by placental histopathology or by expert review of ultrasound images. Cases were identified by searching the hospital ultrasound database over a period of 7.5 years. Higher order multiples or coexistent aneuploidy or major anomalies were excluded. Each case of an isolated SUA was assigned three consecutive twin pregnancy controls paired for chorionicity and maternal age. Primary outcomes were preterm birth <34 weeks, small for gestational age (SGA) or perinatal death. Other outcomes included antenatal growth restriction, mode of delivery, and admission to neonatal intensive care or special care nursery. Nine pregnancies (18 fetuses) were identified for analysis as cases. Isolated SUA was associated with preterm birth <34 weeks (odds ratio = 12.2; 95% CI = 2.0-75.2; p = .005) but not for SGA. There was also no difference in SGA between the affected twin and its normal co-twin. Perinatal death was increased but after controlling for gestational age and clustering this finding was no longer significant. We conclude that isolated SUA in twins adds a degree of risk to an already high-risk pregnancy but does not increase the need for surveillance for growth restriction.

Congenital heart disease and adverse perinatal outcome in fetuses with confirmed isolated single functioning umbilical artery

To examine the association between isolated single umbilical artery (SUA) and congenital heart disease/adverse perinatal outcome in an Australian tertiary centre. The study population was comprised of fetuses diagnosed with SUA at the mid-trimester scan between May 2003 and March 2009 during detailed ultrasound examination at The Royal Women's Hospital Melbourne, Australia. Colour Doppler was used to visualise the umbilical arteries adjacent to the fetal bladder and in a section of a free loop of cord. The diagnosis of SUA was confirmed on histopathology examination of the placenta and umbilical cord. Monochorionic twins, fetuses with chromosomal abnormalities or concurrent extracardiac anomalies were excluded from the study. A total of 261 fetuses with SUA were identified in the study period and 146 (59%) cases were isolated; no chromosomal or extracardiac abnormalities were present. Complete data were available in 104/146 pregnancies (71.2%). The mean gestational age at diagnosis was 21 weeks. A cardiac anomaly was detected in 19 of these fetuses (13.0%): six hypoplastic left heart syndromes; three coarctations of the aorta; two tetralogies of Fallot; two hypoplastic right heart syndromes; two pulmonary atresia/stenosis; one absent ductus venosus with cardiomegaly; one left isomerism; one right isomerism and one transposition of the great arteries. Fetal growth restriction was present in 9.8% (10) and preterm delivery before 34 weeks occurred in nine cases (8.7%). Our study has shown that isolated SUA is associated with cardiac anomalies, but is not associated with increased frequency of FGR and preterm delivery before 34 weeks.

The impact of isolated single umbilical artery on labor and delivery outcome

OBJECTIVE

Data regarding the association between isolated single umbilical artery (SUA) and pregnancy outcome are inconsistent and mainly address the risk of pregnancy complications. Thus, we aimed to focus on the association between isolated SUA, and labor and delivery.

METHODS

We conducted a case-control study of all singleton pregnancies diagnosed with isolated SUA (no known chromosomal/structural anomalies/fetal growth restriction) attempting vaginal delivery. Obstetric and neonatal outcome was compared with that of a control group of pregnancies with a three-vessel cord in a 1:2 ratio matched by parity. Composite adverse outcome included the following: Cesarean section (CS) and/or operative delivery due to non-reassuring fetal heart rate (NRFHR), prolonged neonatal admission, low Apgar score and umbilical artery pH < 7.2.

RESULTS

Out of 34 196 deliveries, 162 (0.5%) were diagnosed with SUA, and 91 (0.27%) were diagnosed with isolated SUA. Isolated SUA was associated with a higher rate of CS due to NRFHR (5.5% vs 1%, p = 0.02), small for gestational age (SGA) (14.3% vs 4.9%, p = 0.009), lower birth weight, and a higher rate of composite adverse outcome (20.9% vs 8.8%, p = 0.005). On multivariable analysis, isolated SUA was independently associated with an increased risk for composite adverse outcome (OR 2.34, 95% CI 1.05-5.21).

CONCLUSION

Isolated SUA is associated with increased risk for CS due to NRFHR and increased rate of SGA.

MANAGEMENT OF REDUCED FETAL MOVEMENTS

Reduced fetal movement (RFM) is commonly defined as any reduction in maternal perception of fetal activity. Perceived fetal activity may be movement of limbs, trunk or head movement, but excludes fetal hiccoughs (as this is involuntary movement). The perception of fetal movement by an expectant mother is the first, and ongoing, non-sonographic indicator of fetal viability. The “normal” pattern of fetal movements varies from pregnancy to pregnancy, and often does not become established until 28 weeks’ gestation. Many babies have particularly active periods of the day, usually corresponding to periods of maternal rest and inactivity (which may in itself reflect increased maternal awareness of fetal movement). A variable percentage of sonographically observed fetal movements are perceived by prospective mothers (commonly 30–40%, although some studies report rates as high as 80%).

The incidence of isolated single umbilical artery in twins and adverse pregnancy outcomes

OBJECTIVES

The aim of this study was to estimate the incidence of single umbilical artery (SUA) in twin pregnancies and to investigate whether SUA in twin gestations is associated with adverse obstetric outcomes.

METHODS

We performed a retrospective cohort study of consecutive twin pregnancies over 17 years at a tertiary care hospital. Primary exposure was SUA in one or both twins documented at routine second trimester anatomic survey. Adverse obstetric outcomes included small for gestational age (SGA), placental abruption, and preterm birth, evaluated in univariable and multivariable analyses. Analysis was performed both at the pregnancy level and at the fetal level using paired analyses to account for the non-independence of twin pairs.

RESULTS

Of the 2378 twin pregnancies without major anatomic abnormalities, 1.7% (n = 40) had SUA. Only one pregnancy (one monochorionic twin pair) was complicated by both twins having SUA. Twin fetuses with SUA are at increased risk for SGA (aOR = 2.1 (1.2-4.1), p = 0.03) after adjusting for pertinent confounding factors, similar to the findings of previous studies in singleton pregnancies. In addition, twins with SUA may be at increased risk for preterm delivery before 28 weeks compared with twin pregnancies with normal three-vessel umbilical cords (adjusted odds ratio (aOR) 3.2 (1.3-7.89.4), p = 0.01).

CONCLUSIONS

The incidence of SUA in twin gestations in this cohort is significantly less than the recently published data. Similar to reports in singleton gestations, SUA appears to be associated with an increased risk for SGA in twins.