Velamentous cord insertion into the lower third of the uterus is associated with intrapartum fetal heart rate abnormalities

Prevalence, Risk Factors, and Perinatal Outcomes of Velamentous Umbilical Cord Insertion in Twin Pregnancies: A Single-Center Retrospective Study

BACKGROUND

The effect of velamentous cord insertion (VCI) on perinatal outcomes in twin pregnancies is unclear due to conflicting findings. This retrospective study aimed to examine VCI prevalence and related risk factors in twin pregnancies and its association with adverse perinatal outcomes.

METHODS

Women with twin pregnancies who delivered between January 2012 and December 2021 in a single tertiary hospital were included. The participants were divided into dichorionic (DC) and monochorionic diamniotic (MCDA) groups, and their maternal and fetal characteristics and VCI rates were compared. Logistic regression models were used to identify risk factors for VCI and VCI-related perinatal outcomes.

RESULTS

Among the 694 twin pregnancies included in this study, the VCI rate was significantly higher in MCDA than in DC twins. Body mass index and MCDA twins were significant risk factors for VCI, whereas assisted reproductive technology pregnancy was a significant protective factor against VCI. In DC twins, VCI did not affect perinatal outcomes. In MCDA twins, VCI was a significant risk factor for fetal growth restriction, twin-to-twin transfusion syndrome, and preterm birth at <36 weeks.

CONCLUSIONS

VCI was a prominent risk factor for adverse perinatal outcomes only in MCDA twins. Antenatal sonographic assessment of the umbilical cord insertion site would be beneficial.

Current practice of placental cord insertion documentation in Australia - A sonographer survey

Introduction

During pregnancy, the umbilical cord attaches to the placenta in a central, eccentric, marginal or velamentous location. Maternal and fetal complications are associated with marginal and velamentous cord insertions, the most clinically significant being perinatal mortality due to undiagnosed vasa praevia. Current literature describes a wide variation regarding regulation of placental cord insertion (PCI) documentation during antenatal ultrasound examinations. This prospective cross-sectional study aimed to assess the current practice of antenatal PCI documentation in Australia.

Methods

Members of the Australian Sonographer Accreditation Registry were invited to participate in an online survey which was distributed between February and March 2022.

Results

Four hundred ninety sonographers met the inclusion criteria for the study of which 330 (67.3%) have more than 10 years' experience as a sonographer and 375 (76.5%) are employed primarily in a public or private setting offering general ultrasound. Most respondents (89.6%) indicated documentation of the PCI site is departmental protocol at the second trimester anatomy scan (17-22 weeks gestation), but PCI documentation is protocol in less than 50% of other obstetric ultrasound examinations listed in the survey. The PCI site is included in the formal ultrasound report at a rate significantly less than inclusion in the departmental protocol and the sonographer's worksheet.

Conclusions

Considering the potential maternal and fetal complications associated with abnormal PCI and the ease at which the PCI site is identified in the first and second trimesters, we believe that standard inclusion of the PCI site in departmental protocol and in the formal ultrasound report from 11 weeks gestation, regardless of whether it is normal or abnormal, would prove invaluable.

Impact of velamentous cord insertion on perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

Velamentous cord insertion may be identified prenatally, but the clinical implications of this diagnosis remain controversial. This meta-analysis aimed to quantitatively summarize current data on the association of velamentous cord insertion and adverse perinatal outcomes.

DATA SOURCES

A systematic search was performed in MEDLINE, Scopus, and the Cochrane Library from inception until May 22, 2022 to identify eligible studies.

STUDY ELIGIBILITY CRITERIA

Observational studies including singleton pregnancies with velamentous cord insertion, either prenatally or postnatally identified, and comparing them with those with central/eccentric cord insertion were considered eligible.

METHODS

The quality of the studies was assessed with the Newcastle-Ottawa scale and the risk of bias with the Quality In Prognosis Studies (QUIPS) tool. The main outcome was small-for-gestational-age neonates. Heterogeneity of the studies was evaluated using a Q test and an I² index. Analyses were performed using a random-effects model, with outcome data reported as relative risk or mean difference with 95% confidence interval.

RESULTS

In total, 9 cohort and 2 case-control studies, of which 4 had prenatal and 7 had postnatal velamentous cord insertion diagnosis, were included. The overall prevalence of velamentous cord insertion was estimated to be 1.4% among singleton pregnancies. Compared with the central/eccentric cord insertion control group, pregnancies with velamentous cord insertion were at higher risk of several adverse perinatal outcomes, namely small-for-gestational-age neonates (relative risk, 1.93; 95% confidence interval, 1.54-2.41), preeclampsia (relative risk, 1.85; 95% confidence interval, 1.01-3.39), pregnancy-induced hypertension (relative risk, 1.58; 95% confidence interval, 1.46-1.70), stillbirth (relative risk, 4.12; 95% confidence interval, 1.92-8.87), placental abruption (relative risk, 2.94; 95% confidence interval, 1.72-5.03), preterm delivery (relative risk, 2.14; 95% confidence interval, 1.73-2.65), emergency cesarean delivery (relative risk, 2.03; 95% confidence interval, 1.22-3.38), 1-minute Apgar score <7 (relative risk, 1.53; 95% confidence interval, 1.14-2.05), 5-minute Apgar score <7 (relative risk, 1.97; 95% confidence interval, 1.43-2.71), and neonatal intensive care unit admission (relative risk, 1.63; 95% confidence interval, 1.32-2.02). In a subgroup analysis, prenatally diagnosed velamentous cord insertion was associated with small-for-gestational-age neonates (relative risk, 1.66; 95% confidence interval, 1.19-2.32), stillbirth (relative risk, 4.78; 95% confidence interval, 1.42-16.08), and preterm delivery (relative risk, 2.69; 95% confidence interval, 2.01-3.60). In a sensitivity analysis of studies excluding cases with vasa previa, velamentous cord insertion was associated with an increased risk of small-for-gestational-age neonates (relative risk, 2.69; 95% confidence interval, 1.73-4.17), pregnancy-induced hypertension (relative risk, 1.94; 95% confidence interval, 1.24-3.01), and stillbirth (relative risk, 9.42; 95% confidence interval, 3.19-27.76), but not preterm delivery (relative risk, 1.92; 95% confidence interval, 0.82-4.54).

CONCLUSION

Velamentous cord insertion is associated with several adverse perinatal outcomes, including stillbirth, and these associations persist when only prenatally diagnosed cases are considered and when vasa previa cases are excluded. According to these findings, the exact pathophysiology should be further investigated and an effective prenatal monitoring plan should be developed.

Impact of marginal cord insertion on perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

Despite its high prevalence and the possible link with perinatal complications, marginal cord insertion is surrounded by considerable controversy regarding management. This meta-analysis aimed to study its association with several perinatal outcomes in a manner that provides trustworthy and exact effect measures, enabling us eventually to evaluate its overall risk for pregnancy.

DATA SOURCES

A systematic search was performed in Medline, Scopus, and the Cochrane Library on July 30, 2022, to identify eligible studies.

STUDY ELIGIBILITY CRITERIA

Observational studies, including singleton pregnancies and comparing MCI with central cord insertion or eccentric cord insertion, either prenatally or postnatally identified, were considered eligible.

METHODS

The Newcastle-Ottawa Scale was used to assess study quality, and the Quality in Prognosis Studies tool was used to assess bias risk. The main outcome was small-for-gestational-age neonates. A Q test and an I² score were used to assess study heterogeneity. The analyses were performed using a random-effects model, and the results were expressed as relative risk or mean difference with a 95% confidence interval.

RESULTS

Overall, 15 studies (13 cohort studies and 2 case-control studies) contributed data to the analysis. There was a prenatal diagnosis in 7 studies and a postnatal diagnosis in 8 studies. The overall prevalence of marginal cord insertion was 6.15% (range, 1.13%-11.3%). Pregnancies with marginal cord insertion compared with pregnancies with central cord insertion were found to be at higher risk of small-for-gestational-age neonates (relative risk, 1.25; 95% confidence interval, 1.21-1.29), preeclampsia (relative risk, 1.61; 95% confidence interval, 1.54-1.67), placental abruption (relative risk, 1.53; 95% confidence interval, 1.34-1.75), stillbirth (relative risk, 1.97; 95% confidence interval, 1.02-3.78), preterm delivery (relative risk, 1.47; 95% confidence interval, 1.24-1.75), lower mean gestational age at birth (mean difference, -0.20; 95% confidence interval, -0.38 to -0.01), emergency cesarean delivery (relative risk, 1.39; 95% confidence interval, 1.35-1.44), lower mean birthweight (mean difference, -139.19; 95% confidence interval, -185.78 to -92.61), 5-minute Apgar score of <7 (relative risk, 1.48; 95% confidence interval, 1.00-2.19), and neonatal intensive care unit admission (relative risk, 1.57; 95% confidence interval, 1.20-2.06). When only pregnancies with prenatally diagnosed MCI were considered, the risk remained high regarding small for gestational age (relative risk, 1.34; 95% confidence interval, 1.21-1.48), preeclampsia (relative risk, 1.42; 95% confidence interval, 1.01-1.99), stillbirth (relative risk, 2.99; 95% confidence interval, 1.03-8.70), preterm delivery (relative risk, 1.41; 95% confidence interval, 1.19-1.68), lower mean gestational age at birth (mean difference, -0.22; 95% confidence interval, -0.33 to -0.11), and lower mean birthweight (mean difference, -122.41; 95% confidence interval, -166.10 to -78.73).

CONCLUSION

Here, the higher risk that marginal cord insertion poses for pregnancy, regarding several adverse outcomes, became evident. Many of these associations persisted among the prenatally diagnosed pregnancies. The underlining pathophysiology should be investigated, and further research is needed on the effect of increased surveillance in improving perinatal outcomes.

Obstetric Outcomes in Singleton Pregnancies with Abnormal Placental Cord Insertions

OBJECTIVE

There is wide variation in the management of pregnancies complicated by abnormal placental cord insertion (PCI), which includes velamentous cord insertion (VCI) and marginal cord insertion (MCI). We tested the hypothesis that abnormal PCI is associated with small for gestational age (SGA) infants.

STUDY DESIGN

This is a retrospective cohort study of all pregnant patients undergoing anatomic ultrasound at a single institution from 2010 to 2017. Patients with abnormal PCI were matched in a 1:2 ratio by race, parity, gestational age at the time of ultrasound, and obesity to patients with normal PCIs. The primary outcome was SGA at delivery. Secondary outcomes were cesarean delivery, preterm delivery, cesarean delivery for nonreassuring fetal status, 5-minute Apgar score < 7, umbilical artery pH < 7.1, and neonatal intensive care unit admission. These outcomes were compared using univariate and bivariate analyses.

RESULTS

Abnormal PCI was associated with an increased risk of SGA (relative risk [RR]: 2.43; 95% confidence interval [CI]: 1.26-4.69), increased risk of preterm delivery <37 weeks (RR: 3.60; 95% CI: 1.74-7.46), and <34 weeks (RR: 3.50; 95% CI: 1.05-11.63) compared with patients with normal PCI. There was no difference in rates of cesarean delivery, Apgar score of <7 at 5 minutes, acidemia, or neonatal intensive care unit admission between normal and abnormal PCI groups. In a stratified analysis, the association between abnormal PCI and SGA did not differ by the type of abnormal PCI (p for interaction = 0.46).

CONCLUSION

Abnormal PCI is associated with an increased risk of SGA and preterm delivery. These results suggest that serial fetal growth assessments in this population may be warranted.

KEY POINTS

· Abnormal PCI is associated with SGA infants and preterm birth.. · If an abnormal PCI is identified, the provider should consider serial growth ultrasounds.. · There is no difference in obstetric outcomes between VCI and MCI..

Assisted Reproductive Technique and Abnormal Cord Insertion: A Systematic Review and Meta-Analysis

Abnormal cord insertion (ACI) is associated with adverse obstetric outcomes; however, the relationship between ACI and assisted reproductive technology (ART) has not been examined in a meta-analysis. This study examines the association between ACI and ART, and delivery outcomes of women with ACI. A systematic review was conducted, and 16 studies (1990–2021) met the inclusion criteria. In the unadjusted pooled analysis (n = 10), ART was correlated with a higher rate of velamentous cord insertion (VCI) (odds ratio (OR) 2.14, 95% confidence interval (CI) 1.64–2.79), marginal cord insertion (n = 6; OR 1.58, 95%CI 1.26–1.99), and vasa previa (n = 1; OR 10.96, 95%CI 2.94–40.89). Nevertheless, the VCI rate was similar among the different ART types (blastocyst versus cleavage-stage transfer and frozen versus fresh embryo transfer). Regarding the cesarean delivery (CD) rate, women with VCI were more likely to have elective (n = 3; OR 1.13, 95%CI 1.04–1.22) and emergent CD (n = 5; OR 1.93, 95%CI 1.82–2.03). In conclusion, ART may be correlated with an increased prevalence of ACI. However, most studies could not exclude confounding factors; thus, further studies are warranted to characterize ART as a risk factor for ACI. In women with ACI, elective and emergent CD rates are high.

Fetal heart rate evolution patterns in cerebral palsy associated with umbilical cord complications: a nationwide study

Background

The aim of the present study was to clarify fetal heart rate (FHR) evolution patterns in infants with cerebral palsy (CP) according to different types of umbilical cord complications.

Methods

This case–control study included children born: with a birth weight   ≥2000 g, at gestational age   ≥33 weeks, with disability due to CP, and between 2009 and 2014. Obstetric characteristics and FHR patterns were compared among patients with CP associated with (126 cases) and without (594 controls) umbilical cord complications.

Results

There were 32 umbilical cord prolapse cases and 94 cases with coexistent antenatal umbilical cord complications. Compared with the control group, the persistent non-reassuring pattern was more frequent in cases with coexistent antenatal umbilical cord complications (p = 0.012). A reassuring FHR pattern was observed on admission, but resulted in prolonged deceleration, especially during the first stage of labor, and was significantly identified in 69% of cases with umbilical cord prolapse and 35% of cases with antenatal cord complications, compared to 17% of control cases (p < 0.001).

Conclusion

Hypercoiled cord and abnormal placental umbilical cord insertion, may be associated with CP due to acute hypoxic-ischemic injury as well as sub-acute or chronic adverse events during pregnancy, while umbilical cord prolapse may be characterized by acute hypoxic-ischemic injury during delivery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04508-2.

Clinical features of velamentous umbilical cord insertion and vasa previa: A retrospective analysis based on 501 cases

To identify the risk factors associated with velamentous cord insertion (VCI) and investigate the association between adverse pregnancy outcomes and VCI in singleton pregnancies and those with vasa previa.A total of 59,976 single cases admitted from Qinhuangdao Maternal and Child Health Hospital and Qinhuangdao Beidaihe Hospital from January 2004 to January 2014 were included in this study. We retrospectively analyzed the perinatal complications, neonatal complications, and the clinical features, as well as the Color Doppler ultrasonography findings of the velamentous placenta and placenta previa.We reviewed the clinical data of 59,976 women with singleton pregnancies delivered in Qinhuangdao Maternal and Child Health Hospital and Qinhuangdao Beidaihe Hospital from January 2004 to January 2014. Risk factors and the risks of adverse pregnancy outcomes including admission to a neonatal unit, fetal death, preterm delivery, low birth weight of <2500 g, the infant being small for its gestation age, low Apgar scores (<7) at 1 and 5 minute were evaluated separately among women with and without VCI by means of logistic regression analyses.The prevalence of velamentous umbilical cord insertion was 0.84%, and the prevalence of vasa previa was 0.0017%. The independent risk factors for VCI were nulliparity, obesity, fertility problems, placenta previa, and maternal smoking. VCI was associated with a 1.83-, 2.58-, 3.62-, and 1.41-fold increase in the risk of retention in the neonatal unit, preterm delivery (<37 gestation weeks), low birth weight, and small-for-gestational age, compared to pregnancies involving normal cord insertion. Of the women with VCI, 16.1% underwent emergency cesarean section compared to 8.9% (P < .001) of women without VCI.The prevalence of VCI was 0.84% in singletons. The results suggest that VCI is a moderate risk condition resulted in increased risks of prematurity and impairment of fetal growth.

Velamentous cord insertion: results from a rapid review of incidence, risk factors, adverse outcomes and screening

BACKGROUND

Velamentous cord insertion (VCI) is an umbilical cord attachment to the membranes surrounding the placenta instead of the central mass. VCI is strongly associated with vasa praevia (VP), where umbilical vessels lie in close proximity to the internal cervical os. VP leaves the vessels vulnerable to rupture, which can lead to fatal fetal exsanguination. Screening for VP using second-trimester transabdominal sonography (TAS) to detect VCI has been proposed. We conducted a rapid review investigating the quality, quantity and direction of evidence available on the epidemiology, screening test accuracy and post-screening management pathways for VCI.

METHODS

MEDLINE, Embase and the Cochrane Library were searched on 5 July 2016 and again on 11 October 2019, using general search terms for VP and VCI. Only peer-reviewed articles reporting on the epidemiology of VCI, the accuracy of the screening test and/or downstream management pathways for VCI pregnancies were included. Quality and risk of bias of each included study were assessed using pre-specified tools.

RESULTS

Forty-one relevant publications were identified; all but one were based on non-UK pregnancy cohorts, and most included relatively few VCI cases. The estimated incidence of VCI was 0.4-11% in singleton pregnancies, with higher incidence in twin pregnancies (1.6-40%). VCI incidence was also increased among pregnancies with one or more other risk factors, including in vitro fertilisation pregnancies or nulliparity. VCI incidence among women without any known risk factors was unclear. VCI was associated with adverse perinatal outcomes, most notably pre-term birth and emergency caesarean section in singleton pregnancies, and perinatal mortality in twins; however, associations varied across studies and the increased risk was typically low or moderate compared with pregnancies without VCI. In studies on limited numbers of cases, screening for VCI using TAS had good overall accuracy, driven by high specificity. No studies on post-screening management of VCI were identified.

CONCLUSIONS

Literature on VCI epidemiology and outcomes is limited and low-quality. The accuracy of second-trimester TAS and the benefits and harms of screening cannot be determined without prospective studies in large cohorts. Modelling studies may indicate the feasibility and value of studying the epidemiology of VCI and the potential impact of detecting VCI as part of a population screening programme for VP.

Clinical characteristics and perinatal outcomes of eight cases of umbilical cord vascular rupture

Objectives

To analyze the clinical characteristics and perinatal outcomes of umbilical cord vascular rupture, and to investigate the diagnosis and treatment strategies for reducing adverse perinatal outcomes.

Methods

Clinical data of patients with a singleton pregnancy with umbilical cord rupture who were admitted to Fujian Maternity and Child Health Hospital were collected. The incidence, related factors, clinical features and perinatal outcomes of umbilical cord rupture were retrospectively analyzed.

Results

There were eight cases of umbilical cord rupture (incidence rate: 1/8370). Among them, seven were secondary to umbilical cord insertion abnormality, and one may have been related to a relatively short umbilical cord and umbilical cord traction. There were eight cases of abnormal fetal heart rate, two of vaginal bleeding, five of bloody amniotic fluid, five of premature rupture of the membranes, and two of placental abruption. With regard to outcomes, 50% of patients had cesarean section, 12.5% had forceps delivery, and 50% had perinatal mortality.

Conclusions

Vaginal bleeding, amniotic fluid, fetal heart rate, and umbilical cord insertion should be closely monitored in pregnancy. When abnormal conditions occur, obstetricians should be aware of rupture of the umbilical vessels and terminate pregnancy as soon as possible, which could improve perinatal outcomes.

Early detection of velamentous cord insertion at the eighth week of gestation

Velamentous cord insertion can be diagnosed at 8 weeks of gestation, earlier than previously reported. Fetal surveillance may be informed and prognosis may be impacted by early diagnosis once viability is reached.

Diagnosis and Management of Vasa Previa: A Comparison of 4 National Guidelines

Importance

Vasa previa represents an uncommon and life-threatening condition for the fetus. The prenatal identification of the condition may improve the outcome.

Objective

The aim of this study was to synthesize and compare published evidence of 4 national guidelines on diagnosis and management of vasa previa.

Evidence Acquisition

A descriptive review of 4 recently published national guidelines on vasa previa was conducted: Royal College of Obstetricians and Gynaecologists on "Vasa Praevia: Diagnosis and Management," Society for Maternal-Fetal Medicine on "Diagnosis and Management of Vasa Previa," Society of Obstetricians and Gynaecologists of Canada on "Guidelines for the Management of Vasa Previa," and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists on "Vasa Praevia." These guidelines were compared regarding recommendations on diagnosis and management, while the quality of evidence was also reviewed based on each method of reporting.

Results

There were many similar recommendations in the compared guidelines regarding the diagnosis and management of vasa previa. Early prenatal diagnosis using ultrasound and color Doppler imaging, hospitalization or management as outpatients, and cesarean delivery in a tertiary center with experienced clinicians are the main recommendations.

Conclusions

Evidence-based guidelines may increase the awareness of the diagnosis and management of vasa previa among health care professionals and lead to more favorable perinatal outcomes.

Umbilical cord length affects the efficacy of amnioinfusion for repetitive variable deceleration during labor

Objectives: Although amnioinfusion (AI) for repetitive variable deceleration has been reported to reduce the frequency of variable deceleration and cesarean section (CS) rate, CS is sometimes unavoidable even after therapeutic AI. The purpose of this study was to investigate prenatal factors related to the efficacy of therapeutic AI during labor.Methods: This retrospective study investigated 80 singleton pregnancies that underwent transcervical therapeutic AI for repetitive variable deceleration during labor. AI was performed with 500 mL of warmed saline through an intrauterine pressure catheter by gravity infusion. Prenatal factors related to emergency CS for fetal distress even after therapeutic AI were investigated.Results: Emergency CS was performed for 12 of the 80 cases due to fetal distress. Z-score for umbilical cord length was significantly smaller in the CS group (-0.68 SD) than in the vaginal delivery group (0.15 SD, p < .001). No CSs were performed in cases with Z-score for umbilical cord length >-0.05 SD. No significant differences between CS and vaginal delivery groups were seen in gestational age at delivery, cervical dilatation at AI, birth weight, Z-score of birth weight, incidence of the nuchal cord or incidence of abnormal umbilical cord insertion.Conclusions: Therapeutic AI for repetitive variable deceleration was considered useful, in many cases avoiding emergency CS. Short umbilical cord length (lower Z-score) was related to emergency CS after therapeutic AI for repetitive variable deceleration. Umbilical cord length may offer an important factor for assessing the risk of fetal distress that is difficult to avoid, if methods to accurately determine umbilical cord length can be developed.

First trimester ultrasound prediction of velamentous cord insertions: a prospective study

INTRODUCTION

The marginal and velamentous cord insertions complicate around 8% of pregnancies and are at higher risk of adverse perinatal outcomes. Their visualisation seems to decrease with advancing gestational age. Our aim was to analyse whether an umbilical cord insertion in the lower third of the uterus during the first trimester could predict abnormal cord insertions later in pregnancy.

METHODS

This was a prospective multicentre study in two hospitals. During the first trimester, the cord insertions were inspected as well as their location (lower third of the uterus or not). Finally, all cord insertions were described at delivery.

RESULTS

During the study period the cord insertion was described in 1620 patients of which 87.7% had a normal cord insertion, 11.9% (n = 192) a low cord insertion, and in 3.8% the insertion could not be situated. We find that 4.7% of those who have a low-lying cord insertion versus 0.7% in the normal cord insertion group during the first trimester will have a velamentous cord insertion subsequently (OR = 6.67; 95% CI = 2.67-16.63).

CONCLUSION

The detection of a low lying umbilical cord insertion during the first-trimester ultrasound can help to predict an abnormal cord insertion at delivery particularly a velamentous cord insertion.

Accuracy of fetal anatomy survey in the diagnosis of velamentous cord insertion: a case-control study

Objective

Our objective was to determine the accuracy of ultrasound at the time of the fetal anatomy survey in the diagnosis of velamentous cord insertion (VCI).

Study design

This retrospective case–control study identified placentas with VCI (cases) and randomly selected placentas with normal placental cord insertion (PCI) (controls) as documented by placental pathology for mothers delivered from 2002 through 2015. Archived ultrasound images for PCI at the time of the fetal anatomy survey were reviewed. Data analysis was by calculation of sensitivity, specificity, and accuracy and their 95% CI for the ultrasound diagnosis of VCI.

Results

The prevalence of VCI was 1.6% of placentas submitted for pathologic examination. There were 122 cases of VCI and 347 controls with normal PCI. The performance criteria calculated for the diagnosis of VCI at the time of fetal anatomy survey were as follows: sensitivity 33.6%; 95% CI: 25.3, 42.7; specificity 99.7%; 95% CI: 98.4, 99.9 and accuracy 82.5; 95% CI: 80.5, 82.9.

Conclusion

The identification of a VCI at the time of fetal anatomy survey is highly specific for the presence of a VCI as documented by placental pathology. The sensitivity in this study was less than expected. Sensitivity could be improved by reducing the number of nonvisualized PCIs, creating an awareness of risk factors for VCI, and obtaining more detailed images in the case of an apparent marginal PCI.

A poor long-term neurological prognosis is associated with abnormal cord insertion in severe growth-restricted fetuses

OBJECTIVE

To clarify and compare if the neurological outcomes of fetal growth restriction (FGR) cases with abnormal cord insertion (CI) are associated with a higher risk of a poor neurological outcome in subjects aged 3 years or less versus those with normal CI.

METHODS

A multicenter retrospective cohort study was conducted among patients with a birth weight lower than the 3rd percentile, based on the standard reference values for Japanese subjects after 22 weeks' gestation, who were treated at a consortium of nine perinatal centers in Japan between June 2005 and March 2011. Patients whose birth weights were less than the 3rd percentile and whose neurological outcomes from birth to 3 years of age could be checked from their medical records were analyzed. The relationship between abnormal CI and neurological outcomes was analyzed. Univariate and multivariate models of multivariate logistic regression were employed to estimate the raw and odds ratio (OR) with 95% confidence intervals comparing marginal (MCI) and velamentous cord insertion (VCI) to normal CI.

RESULTS

Among 365 neonates, 63 cases of MCI and 14 cases of VCI were observed. After excluding 24 cases with neonatal or infant death from the total FGR population, the assessment of the outcomes of the infants aged 3 years or younger showed the following rates of neurological complications: 7.3% (n=25) for cerebral palsy, 8.8% (n=30) for developmental disorders, 16.7% (n=57) for small-for-gestational-age short stature (SGA), 0.6% (n=2) for impaired hearing, 0.9% (n=3) for epilepsy, 1.2% (n=4). The ORs (95% confidence intervals) based on multivariate analysis were as follows: cerebral palsy=10.1 (2.4-41.5) in the VCI group and 4.3 (1.6-11.9) in the MCI group, developmental disorders=6.7 (1.7-26) in the VCI group and 3.9 (1.1-14.2) in the single umbilical artery (SUA) group, 5.1 (1.4-18.7) for birth weight <1000 g and 2.8 (1.2-6.7) for placental weight <200 g.

CONCLUSIONS

The present results indicate that growth-restricted fetuses diagnosed with a birth weight below the 3rd percentile exhibiting abnormal umbilical CI are at a high risk for poor neurological outcomes, including cerebral palsy and/or developmental disorders.

Second trimester marginal cord insertion is associated with adverse perinatal outcomes

Objectives: To determine the feasibility in visualizing placental cord insertion (PCI) during second-trimester fetal anatomical survey and the association between marginal cord insertion (MCI) and preterm delivery (PTD) and low birth weight (LBW). Our secondary objectives were to evaluate the association of MCI with adverse composite obstetrical and neonatal outcomes. Methods: A prospective cohort study was performed over a 28-month period. Women with singleton pregnancies presenting for routine anatomical survey between 18 and 22 weeks' gestation were included. PCI site was visualized on 2D grayscale and color Doppler and the shortest distance from the sagittal and transverse planes to the placental edge were recorded. MCI was diagnosed when any of measured distances was ≤2 cm. Correlations were assessed via bivariate chi-squared, independent t-test analyses and Fisher's exact tests. Regression models evaluated associations between MCI and adverse composite outcomes. Results: Three hundred one women were included and PCI was feasible in all cases. The incidence of MCI was 11.3% (n = 34). Baseline characteristics between those with and without MCI were similar, except for story of prior PTD, which was greater among those with MCI (17.65 versus 7.17%, p = .04). MCI was associated with increased likelihood of LBW (RR four; 95%CI, 1.46-10.99) and PTD (RR 3.2; 95%CI, 1.53-6.68); in multivariate analysis, we found associations between MCI and composite adverse obstetrical (RR 2.33; 95%CI, 1.30-4.19) and neonatal (RR 2.46; 95%CI, 1.26-4.81) outcomes. Conclusions: Evaluation of PCI is feasible in all cases. Second-trimester MCI is associated with increased likelihood for LBW, PTD, and composite adverse obstetrical and neonatal outcomes.

Perinatal Outcomes Associated With Isolated Velamentous Cord Insertion in Singleton and Twin Pregnancies

OBJECTIVES

To evaluate perinatal outcomes in singleton and twin pregnancies with pathologically confirmed velamentous cord insertion without vasa previa.

METHODS

This retrospective case-control study included all nonanomalous singleton and twin pregnancies with pathologically confirmed velamentous cord insertion delivered in a single institution between January 1, 2005, and July 1, 2015, and having an ultrasound examination by maternal-fetal medicine. For each case, the next 2 consecutive deliveries matched for gestational age at delivery ± 1 week and, in twins, amnionicity and chorionicity served as controls. Primary outcomes included surgical delivery for a nonreassuring intrapartum fetal heart rate tracing, umbilical arterial cord pH of less than 7.2, 5-minute Apgar score of less than 7, birth weight below the 10th percentile, neonatal intensive care unit admission, fetal or neonatal death, and cord avulsion necessitating manual placental extraction.

RESULTS

Outcomes were available for 53 singletons with 103 matched controls and 33 twin pregnancies with 65 matched controls. In singletons, velamentous cord insertion was associated with cord pH of less than 7.2 (odds ratio [OR] 3.5; 95% confidence interval [CI], 1.1-11.2; P = .039), 5-minute Apgar score of less than 7 (OR, 5.3; 95% CI, 0.99-28.1; P = .045), and cord avulsion requiring manual placental extraction (7.5% versus 0%; P = .012). Associations were suggested with increased surgical delivery for a nonreassuring intrapartum fetal heart rate tracing (OR, 2.4; 95% CI, 0.9-6.9; P = .14), birth weight below the 10th percentile (OR, 2.1; 95% CI, 0.8-5.9; P = .21), and fetal or neonatal death (3.8% versus 0%; P = .11). Velamentous cord insertions were also associated with placental abruption in singletons (7.5% versus 0%; P = .013). Among twins, velamentous cord insertion was associated with fetal or neonatal death (9.1% versus 0%; P = .036).

CONCLUSIONS

Isolated confirmed velamentous cord insertion is associated with adverse perinatal outcomes in singleton and twin gestations.

Association of coexisting morphological umbilical cord abnormality and clinical cord compromise with hypoxic and thrombotic placental histology

To assess the usefulness and limitations of placental histology when morphological umbilical cord (UC) abnormality coexists with clinical UC compromise, 5634 consecutive placentas were divided into four groups and statistically compared: group 1-182 placentas from pregnancies with clinical features of UC compromise (variable decelerations, UC entanglement, prolapse, or true knot at delivery); group 2-1355 placentas with abnormal UC morphology or insertion; group 3-152 placentas with at least one phenotype from group 1 and one from group 2; group 4-3945 placentas with no clinical or morphological UC-related phenotypes (control group).Differences were analyzed by ANOVA or χ (2). Of 68 phenotypes studied, 13 clinical and 18 placental phenotypes were statistically significant. In group 1, 2 phenotypes were most common (oligohydramnios and abnormal fetal heart rate tracing). In group 2, 6 phenotypes were most common, including 4 clinical (abnormal umbilical artery Dopplers, nonmacerated stillbirth, multiple pregnancy, and fetal growth restriction) and 2 placental. In group 3, 23 phenotypes were most common, including 7 clinical (gestational hypertension, polyhydramnios, induction of labor, cesarean section, macerated stillbirth, congenital malformations, and abnormal 3rd stage of labor) and 16 placental. The existence of clinical signs of UC compromise alone was associated with the absence of pathomorphological placental abnormalities. However, the coexistence of clinical and abnormal morphological UC phenotypes was statistically significantly associated with placental histological signs of decreased fetal blood flow, hypoxia (acute and chronic post uterine), shallow placental implantation, and/or amnion nodosum. Thus, confirmation of clinical UC compromise should not be expected on placental examination if no morphological UC abnormality or abnormal UC insertion has been found.

Comprehensive imaging review of abnormalities of the umbilical cord

A complete fetal ultrasonographic (US) study includes assessment of the umbilical cord for possible abnormalities. Knowledge of the normal appearance of the umbilical cord is necessary for the radiologist to correctly diagnose pathologic conditions. Umbilical cord abnormalities can be related to cord coiling, length, and thickness; the placental insertion site; in utero distortion; vascular abnormalities; and primary tumors or masses. These conditions may be associated with other fetal anomalies and aneuploidies, and their discovery should prompt a thorough fetal US examination. Further workup and planning for a safe fetal delivery may include fetal echocardiography and karyotype analysis. Doppler US is a critical tool for assessment and diagnosis of vascular cord abnormalities. US also can be used for follow-up serial imaging evaluation of conditions that could result in fetal demise. Recent studies suggest that three- or four-dimensional Doppler US of the fetal umbilical cord and abdominal vasculature allows more accurate diagnosis of vascular abnormalities. Doppler US also is invaluable in assessment of fetal growth restriction since hemodynamic changes in the placenta or fetus would appear as a spectral pattern of increased resistance to forward flow in the fetal umbilical artery. Early detection of umbilical cord abnormalities and close follow-up can reduce the risk of morbidity and mortality and assist in decision making.

[Vasa praevia rupture in velamentous insertion of the umbilical cord: the importance of prenatal diagnosis]

Vasa praevia is a rare condition in which the foetal blood vessels cross the foetal membranes of the lower segment of the uterus below the presenting part. It has a high foetal mortality due to foetal exsanguination resulting from foetal vessels tearing when the membranes rupture. Prenatal diagnosis can reduce or even prevent foetal mortality, but it requires a high level of suspicion. For this reason, pregnant women with risk factors of vasa praevia should be examined using transvaginal ultrasound in combination with colour Doppler, and if the diagnosis is made, elective delivery by caesarean and aggressive resuscitation of the new born is indicated.

Velamentous cord insertion in a singleton pregnancy: an obscure cause of emergency cesarean-a case report

Approximately 2% of low-risk pregnant women still require an emergency Cesarean section after the onset of labor. Because it is likely that half of these cases are associated with placental and umbilical cord abnormalities, it is thought that prenatal detection of such abnormalities would reduce the number of emergency cesarean sections in low-risk women. Velamentous cord insertion is an abnormal cord insertion in which the umbilical vessels diverge as they traverse between the amnion and chorion before reaching the placenta. With a reported incidence of 1% in singleton pregnancies, it has been associated with several obstetric complications. This condition has been diagnosed by ultrasonography with a sensitivity of 67% and specificity of 100% in the second trimester. The present case highlights the importance of the systematic assessment of the placental cord insertion site at routine obstetric ultrasound and the potential of identifying pregnancies with velamentous insertion and, therefore, those at risk for obstetric complications.

Can ultrasonography of the placenta previa predict antenatal bleeding?

PURPOSE

To evaluate the abnormal sonographic (US) findings in patients with placenta previa and bleeding.

METHODS

A total of 182 cases of singleton pregnancies with placenta previa were reviewed. The US findings including the type of placenta previa, placental location, presence of placenta lacunae, lack of clear zone, sinus venosus at the margin of the placenta, velamentous cord insertion, sponge-like echo in the cervix and cervical length were evaluated in relation to episodes of bleeding that required in-patient treatment during pregnancy and/or emergency cesarean section.

RESULTS

Episodes of antenatal bleeding occurred in 102/182 (56%) patients with placenta previa. An emergency cesarean section was performed in 66 (64.7%) of these 102 patients. In the 80 patients without episodes of antenatal bleeding, an emergency cesarean section was performed in only 1 (1.3%). Detection of US findings just prior to cesarean section was not associated with the need for emergency cesarean section due to uncontrollable bleeding from the placenta previa. Frequencies of each US finding at 20 weeks of gestation were not different between the patients who underwent emergency cesarean sections and the others. Frequency of marginal sinus was slightly higher in cases with bleeding episode (16% versus 0%, p < 0.05), but the other US findings were not associated with the occurrence of bleeding episodes during pregnancy.

CONCLUSIONS

No US finding could predict bleeding episodes and the eventual need for an emergency cesarean section. The obstetrician should be aware that sudden bleeding during pregnancy may occur in patients with placenta previa, even in the absence of any other US findings.

Velamentous cord insertion caused by oblique implantation after in vitro fertilization and embryo transfer

We present a case of a 36-year-old pregnant female after intracytoplasmic sperm injection. Ultrasonographic examination at 8 weeks' gestation revealed umbilical cord insertion with a viable fetus located on the septum membrane of dichorionic twin pregnancy near the anterior wall, while the other fetus was observed to have vanished. Next, this umbilical cord was seen to connect to the anterior wall and the placenta developed on the posterior wall later in the pregnancy. As a result, velamentous cord insertion with long membranous umbilical vessels developed at the time of delivery. The present case indicates that the assessment of the cord insertion site during the early gestation period is very important to predict any abnormality of the cord insertion site at the time of delivery. Furthermore, this case is valuable to understand the pathophysiological development of the placenta and velamentous cord insertion.

Umbilical cord insertion site in early gestation and development of placenta

AIM

To study the relation of umbilical cord insertion (CI) site in early gestation and placental development from the chorion villosum.

METHODS

We ultrasonically measured the distance between the internal cervical Os and the CI site (CID), the distance between the internal cervical Os and lower placenta edge (PLD), and placental thickness at early (10-12 weeks) and mid-gestation (18-20 weeks).

RESULTS

CID in early gestation (CID-Early) correlated with CID in mid-gestation (r(2)=0.171; P<0.01). CID-Early correlated with PLD in mid-gestation (r(2)=0.093; P<0.01). Thickness of chorion villosum or placenta in early gestation did not correlate with that at mid-gestation. Increasing thickness of placenta was significantly higher in long CID-Early (> or =20 mm) cases than short cases (<20 mm) (P<0.05).

CONCLUSIONS

The process of placental development and the placental location are affected by CI location at early gestation, and suggests that this process might be affected by poor blood supply from the low uterine segment when CI site is close to the internal cervical Os.

FETAL BRADYCARDIA. A PRACTICAL APPROACH

Fetal bradycardia may herald fetal demise. This article highlights arrhythmic fetal bradycardia rather than bradycardia caused by perinatal distress. We briefly examine the embryonic conduction system's development and physiology and we review the classification, aetiology, evaluation, and approach to fetal bradycardia. Our aim is to provide the clinician with practical information about fetal bradycardia that enlightens causative conditions and aids management.

Ruptured vasa previa in velamentous cord insertion placenta

Ruptured vasa previa is rare but usually catastrophic if delivery is not imminent. We present a case of ruptured vasa previa in velamentous cord insertion placenta. The fetus survived despite 6 h of a venous rupture because of the tamponade effect from fetal head engagement. Defects in the vessel wall architecture were revealed by histopathologic examination and might be responsible for the vessel rupture. Prenatal sonographic identification of cord insertion site into the placenta is encouraged as standard of practice to prevent this accident.

Cord insertion into the lower third of the uterus in the first trimester is associated with placental and umbilical cord abnormalities

OBJECTIVES

To assess the feasibility of detecting the cord insertion site during the late first trimester, and to investigate the possible association between perinatal complications and a cord insertion in the lower third of the uterus in the first trimester.

METHODS

This was a prospective cohort study in which the positional relationship between the uterus and the cord insertion site was examined using gray-scale transvaginal sonography at 9-11 weeks of gestation. The distance between the internal os and the fundus was divided equally into three parts. Cord insertions located in the upper or middle thirds were defined as normal (controls), and those located in the lower third were defined as cases, regardless of their relationship to the chorion villosum. Third-trimester sonography and pathological examination of the placenta and cord at delivery were performed to check for placental/cord abnormalities. The univariate association between the location of the cord insertion in the first trimester and placental and umbilical cord abnormalities and perinatal complications was assessed.

RESULTS

The cord insertion site was identified in 318/340 (93.5%) cases at 9-11 weeks of gestation and it was in the lower third of the uterus in 35 (11.0%) cases. Of these 35, the cord insertion was found at delivery to be low in nine cases (26%) and the placenta was low-lying at delivery in eight (23%). None of the 283 cases with a normal cord insertion in the first trimester was found to have a low-lying placenta at delivery (P < 0.0001). Ten (29%) of the cases with a low cord insertion and four (1.4%) with a normal cord insertion in the first trimester had a velamentous or marginal cord insertion at delivery (P < 0.0001). At delivery, five (14%) of the low cord insertion cases and four (1.4%) of the normal cord insertion cases (P < 0.0001) had some form of placental malformation, including accessory placenta and infarction of the placenta. An emergency Cesarean section was performed in four (11%) and six (2.1%) of the low and normal cord insertion cases, respectively (P = 0.003).

CONCLUSION

Developmental abnormalities of the placenta and umbilical cord occur frequently in cases in which the cord insertion is in the lower third of the uterus in the first trimester. We suggest that screening for the cord insertion site at 9-11 weeks of gestation may have clinical significance for predicting abnormalities of the cord and the placenta at delivery.