European association of perinatal medicine (EAPM) position statement: Screening, diagnosis and management of congenital anomalies of the umbilical cord.

Congenital anomalies of the umbilical cord are associated with an increased risk of pregnancy and perinatal complications. Some anomalies of the cord have a higher prevalence than other fetal structural anomalies. The most common anomalies are the absence of an umbilical artery and velamentous insertion of the cord (with or without vasa previa). These anomalies, even when not associated with fetal structural defects, increase the risk of adverse perinatal outcome including, fetal growth restriction and stillbirth. In the absence of prenatal diagnosis, vasa previa is associated with the highest perinatal morbidity and mortality of all congenital anomalies of the umbilical cord. Most cases can be detected by ultrasound from the beginning of the second trimester and should be included in the routine mid-pregnancy ultrasound examination. Documentation should include cord insertion site, number of vessels in the cord, and if other pathologies have been detected. Pregnancies at increased risk of velamentous cord insertion should be screened for vasa previa using transvaginal ultrasound and colour Doppler imaging. If a velamentous cord insertion or isolated single umbilical artery is detected, individualised follow-up during pregnancy and tailored obstetric management are indicated.

Incorporation of vasa previa screening into a routine anomaly scan: A single center cohort study.

INTRODUCTION: Vasa previa (VP), defined as unprotected fetal vessels traversing the membranes over the cervix, is associated with a high perinatal mortality when undiagnosed prenatally. Conversely, prenatal diagnosis with ultrasound and cesarean delivery before the membranes rupture is associated with excellent outcomes. However, controversy exists regarding screening for VP. In the UK, routine screening for VP is not recommended. The objective of this study was to report the incidence of VP and our experience in the detection of VP with a universal screening protocol at the time of the second-trimester fetal anomaly scan with third-trimester confirmation in an unselected population of pregnancies. MATERIAL AND METHODS: We performed a single-center historical cohort study of all pregnant women who underwent routine second-trimester anomaly screening scans at West Middlesex University Hospital, London, UK, between 2012 and 2016. Over 5 years, every patient undergoing routine anomaly screening was evaluated for VP using a systematic protocol during their 20-week anomaly scan. Suspected cases of VP were rescanned in the third trimester by specialist sonographers with an interest in VP. The primary outcomes were the incidence and detection of VP. RESULTS: During the study period, 24 690 anatomy scans were performed. A total of 64 patients were identified as having potential VP at the second-trimester anomaly screening scan, of which 19 were confirmed by the specialist sonographer in the third trimester and at delivery. The screen positive rate was 0.26% (95% confidence interval [CI] 0.20%-0.32%). VP at birth was found in 19/24690 births (1:1299 [95% CI: 1:832-1:2030] births). Universal screening for VP using our protocol had a sensitivity of 100% and a specificity of 99.78% (95% CI: 99.72%-99.84%). The false-positive rate of the second-trimester screen was 0.18% (95% CI: 0.13-0.24). There were no false positives or false negatives at delivery. Of the 19 patients with confirmed VP, 17 had scheduled cesarean deliveries, and two required emergency deliveries due to antepartum hemorrhage. One baby died, giving a perinatal mortality of 5%. CONCLUSIONS: VP complicates approximately 1:1300 pregnancies. Routine screening for VP yielded a 100% detection rate. We suggest the inclusion of structured VP assessment in standard fetal anomaly screening programs.

Women- and clinician- important outcomes and priorities regarding vasa praevia: An international qualitative study to inform development of a core outcome set.

BACKGROUND: Many studies have reported interventions for women with vasa praevia to improve perinatal outcomes. However, which outcomes are important for women remains unclear. AIM: To explore what outcomes are important for women with lived experience of vasa praevia and why, in order to inform the development of a core outcome set for studies on vasa praevia. METHODS: An international qualitative study was conducted with women and clinicians. Semi-structured interviews were audio-recorded, transcribed, and analysed taking an inductive approach. FINDINGS: Eighteen women and six clinicians (four obstetricians, two midwives) from the United States, United Kingdom, Canada, and Australia were interviewed. Participants identified 47 patient-important outcomes and experience measures, which were grouped under five themes: baby's survival and health, mother's physical health, mother's mental and emotional health, quality of health care delivery, and resource use and cost. While survival of the baby without short- and long-term morbidity remained the main priority, other important considerations included the physical, mental, social and financial wellbeing of families, future access to antenatal screening and diagnosis, information on management options and consequences, continuity of care, clear and effective communication, peer support and the appreciation of individual variations to risk tolerance, values and resource availability. CONCLUSION: We have identified patient-important outcomes and experience measures that have been directly fed into the development of a core outcome set on vasa previa. Incorporating these considerations into both clinical practice and future research studies has the potential to improve outcomes and experiences for women with vasa praevia.

Prenatal diagnosis and postnatal outcome of Type-III vasa previa: systematic review of literature.

OBJECTIVE: Type-III vasa previa (VP) is a rare form of VP, not necessarily associated with other placental or vascular anomalies, in which aberrant vessels run from the placenta to the amniotic membranes, near the internal cervical os, before returning to the placenta. Early diagnosis of Type-III VP is important but technically challenging. The objective of this study was to gather the current available evidence on the perinatal diagnosis and outcome of Type-III VP. METHODS: A systematic review of the literature on the perinatal diagnosis of atypical Type-III VP was carried out in PubMed, MEDLINE and EMBASE accordingto PRISMA guidelines from inception to March 2023. Data extraction and tabulation were performed by two operators and checked by a third senior author. The quality of the included studies was evaluated using the National Institutes of Health tool for the quality assessment of case-series studies. Our local ultrasound database was searched for previously unreported recent cases. Characteristics of prenatally and postnatally diagnosed Type-III VP, including clinical features and perinatal outcomes, were summarized using descriptive statistics. RESULTS: Eighteen cases of Type-III VP were included, of which 16 were diagnosed prenatally (14 cases were retrieved from 10 publications and two were unpublished cases from our center) and two were diagnosed postnatally (retrieved from two publications). All prenatal cases were diagnosed on transvaginal ultrasound at a mean gestational age of 29 weeks (median, 31 weeks; range, 19-38 weeks). Conception was achieved with in-vitro fertilization in 4/16 (25.0%) cases. There were no prenatal symptoms in 15/18 (83.3%) cases, while in two (11.1%) cases there was vaginal bleeding and in one (5.6%) preterm labor occurred. In 15/18 (83.3%) cases, at least one placental abnormality was observed, including low-lying insertion (9/17), succenturiate or accessory lobe (1/17), velamentous cord insertion (3/18) and marginal insertion (9/18). All prenatally diagnosed cases were liveborn and were delivered by Cesarean section before rupture of membranes at a median gestational age of 35 weeks (range, 32-38 weeks) without neonatal complications. Emergency Cesarean section was performed in 2/16 (12.5%) cases with a prenatal diagnosis and 1/2 (50.0%) cases with a postnatal diagnosis (P = 0.179). Among those with data available, an Apgar score of ≤ 7 was observed in the prenatally vs postnatally diagnosed group in 5/13 vs 1/1 cases, respectively, at the 1-min evaluation and 3/13 vs 1/1 cases, respectively, at the 5-min evaluation. CONCLUSIONS: The prenatal diagnosis of Type-III VP is challenging, with few cases reported in the literature; however, it is crucial for minimizing the risk of adverse outcome by enabling early-term elective Cesarean delivery prior to rupture of membranes. Given that clinical manifestations and risk factors are non-specific, and that Type-III VP cannot be excluded when there is a normal cord insertion or a singular placental mass, systematic screening by transvaginal ultrasound in the general pregnant population is recommended, particularly in those with a low-lying or morphologically abnormal placenta and those who conceived using assisted reproductive technology. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Incidence and causes of perinatal death in prenatally diagnosed vasa previa: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to estimate the perinatal mortality associated with prenatally diagnosed vasa previa and to determine what proportion of those perinatal deaths are directly attributable to vasa previa. DATA SOURCES: The following databases have been searched from January 1, 1987, to January 1, 2023: PubMed, Scopus, Web of Science, and Embase. STUDY ELIGIBILITY CRITERIA: Our study included all studies (cohort studies and case series or reports) that had patients in which a prenatal diagnosis of vasa previa was made. Case series or reports were excluded from the meta-analysis. All cases in which prenatal diagnosis was not made were excluded from the study. METHODS: The programming language software R (version 4.2.2) was used to conduct the meta-analysis. The data were logit transformed and pooled using the fixed effects model. The between-study heterogeneity was reported by I2. The publication bias was evaluated using a funnel plot and the Peters regression test. The Newcastle-Ottawa scale was used to assess the risk of bias. RESULTS: Overall, 113 studies with a cumulative sample size of 1297 pregnant individuals were included. This study included 25 cohort studies with 1167 pregnancies and 88 case series or reports with 130 pregnancies. Moreover, 13 perinatal deaths occurred among these pregnancies, consisting of 2 stillbirths and 11 neonatal deaths. Among the cohort studies, the overall perinatal mortality was 0.94% (95% confidence interval, 0.52-1.70; I2=0.0%). The pooled perinatal mortality attributed to vasa previa was 0.51% (95% confidence interval, 0.23-1.14; I2=0.0%). Stillbirth and neonatal death were reported in 0.20% (95% confidence interval, 0.05-0.80; I2=0.0%) and 0.77% (95% confidence interval, 0.40-1.48; I2=0.0%) of pregnancies, respectively. CONCLUSION: Perinatal death is uncommon after a prenatal diagnosis of vasa previa. Approximately half of the cases of perinatal mortality are not directly attributable to vasa previa. This information will help in guiding physicians in counseling and will provide reassurance to pregnant individuals with a prenatal diagnosis of vasa previa.

Inpatient versus outpatient management of prenatally diagnosed vasa praevia: A systematic review and meta-analysis.

OBJECTIVE: Vasa praevia is a serious pregnancy complication that is potentially life-threatening for the fetus. The possible benefits of prophylactic hospital admission of asymptomatic women diagnosed with vasa praevia antenatally remain unclear. This study aims to compare the pregnancy outcomes of inpatient versus outpatient management in women with a prenatal diagnosis of vasa praevia. METHODS: A systematic search of four electronic databases was conducted and two reviewers independently screened studies for eligibility. The inclusion criteria incorporated studies with prenatally diagnosed vasa praevia, a distinction on whether women were managed as inpatients and/or outpatients and where perinatal mortality was recorded as an outcome. The primary outcome of the study was perinatal mortality with additional outcomes of perinatal morbidity, need for emergency caesarean and antenatal steroid administration. Reporting of the results followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. RESULTS: The search produced 2,300 studies with ten of these studies included in the qualitative synthesis and four included in the quantitative analysis. There was no significant difference in perinatal mortality (OR 1.12, 95 % CI 0.10-12.07, p = 0.93, I2 = 0 %) or morbidity between women managed as inpatients or outpatients. The prophylactic inpatient group had higher rates of earlier gestational delivery and antenatal corticosteroid administration (OR 10.78, 95 % CI 1.07-108.74, p = 0.04, I2 = 82 %), but lower rates of emergency caesareans (OR 0.35, 95 % CI 0.17-0.72, p = 0.004, I2 = 0 %). CONCLUSION: There were no significant differences in perinatal mortality or morbidity rates observed between inpatient and outpatient management of asymptomatic women with antenatally diagnosed vasa praevia. However, outpatient management is associated with prolonged gestation, a decrease in antenatal corticosteroid administration, and higher odds of emergency caesarean. Outpatient management of prenatally diagnosed vasa praevia seems appropriate for carefully selected asymptomatic women.

Third-trimester fetoscopic ablation therapy for types II and III vasa previa.

BACKGROUND: Vasa previa is an obstetrical condition in which fetal vessels located near the cervix traverse the fetal membranes unprotected by underlying placenta. Type I vasa previa arises directly from a velamentous cord root, whereas types II and III arise from an accessory lobe or a distal lobe of the same placenta, respectively. Fetoscopic laser ablation for types II and III vasa previa is a novel therapeutic option with benefits that include surgical resolution of the vasa previa, avoidance of prolonged hospitalization, and opportunity for a term vaginal delivery. The potential risks of fetoscopy can be mitigated by delaying laser surgery until a gestational age of 31 to 33 weeks, immediately before anticipated hospitalized surveillance. OBJECTIVE: This study aimed to assess feasibility and outcomes of types II and III vasa previa patients treated via fetoscopic laser ablation in the third trimester. STUDY DESIGN: This is a retrospective study of singleton pregnancies with types II and III vasa previa treated with fetoscopic laser ablation at a gestational age ≥31 weeks at a single center between 2006 and 2022. Pregnancy and newborn outcomes were assessed. Continuous variables are expressed as mean±standard deviation. RESULTS: Of 84 patients referred for vasa previa, 57 did not undergo laser ablation: 19 either had no or resolved vasa previa, 25 had type I vasa previa (laser-contraindicated), and 13 had type II or III vasa previa but declined laser treatment. Of the remaining 27 patients who underwent laser ablation, 7 were excluded (laser performed at <31 weeks and/or twins), leaving 20 study patients. The mean gestational age at fetoscopic laser ablation was 32.0±0.6 weeks, and total operative time was 62.1±19.6 minutes. There were no perioperative complications. All patients had successful occlusion of the vasa previa vessels (1 required a second procedure). All patients were subsequently managed as outpatients. The mean gestational age at delivery was 37.2±1.8 weeks, the mean birthweight was 2795±465 g, and 70% delivered vaginally. Neonatal intensive care unit admission occurred in 3 cases: 1 for respiratory distress syndrome and 2 for hyperbilirubinemia requiring phototherapy. There were no cases of neonatal transfusion, intraventricular hemorrhage, sepsis, patent ductus arteriosus, or death. CONCLUSION: Laser ablation for types II and III vasa previa at 31 to 33 gestational weeks was technically achievable and resulted in favorable outcomes.

Impact of Universal Vasa Previa Screening With Color Doppler During the OB Ultrasound Anatomy Scan.

OBJECTIVES: Our institution introduced universal vasa previa (VP) screening utilizing transabdominal ultrasound with color Doppler for all pregnancies at the second trimester anatomy scan. Our study sought to describe the clinical impact of this intervention. METHODS: Radiology records from the 12 months pre- and post-intervention were queried for "vasa previa." Records included for analysis were those with a first-time diagnosis or discussion of VP at the anatomy scan. Cases were categorized by outcome: (Group 1) True VP, with subgroups A, unresolved by time of delivery and B, resolved by delivery; (Group 2) False positives; (Group 3) Possible VP without definitive diagnosis; and (Group 4) VP ruled out, for example, "no features of VP." Group size was expressed as a percentage of total anatomy scans during pre- or post-intervention periods respectively. Absolute and relative percent change were calculated for each group. RESULTS: In the pre-intervention period, 1 case (0.36% of total scans) was categorized in Group 1A, 1 case (0.36%) in Group 3, and 7 cases (2.53%) in Group 4. In the post-intervention period, 2 cases (0.30%) were in Group 1A, 4 cases (0.61%) in Group 1B, 2 cases (0.30%) in Group 2, 1 case (0.15%) in Group 3, and 7 cases (1.06%) in Group 4. There was a +153% relative change in true positives, from 0.36 to 0.91%. CONCLUSIONS: Universal color Doppler screening may have increased detection (sensitivity) while simultaneously increasing false positives (decreased specificity). While decreasing sensitivity is not ideal, this is acceptable given the potential catastrophic outcome of a missed VP.

Intrauterine death in vasa previa without hemorrhage: case reports.

Antepartum and intrapartum hemorrhage from vasa previa (VP) is one of the main causes of intrauterine fetal death (IUFD). Here, we present two cases with type I VP in which velamentous cord insertion below the fetal head and overlying the cervix were reported by prenatal ultrasound scanning, and IUFD occoured after 35 weeks with no signs of prenatal bleeding but with engaged fetal head at presentation. We hypothesized that the IUFD may attributed to the compression of the unprotected umbilical vessels by the engaged fetal head. Thus we suggest that VP with a velamentous cord insertion should be considered for earlier termination of the pregnancy to avoid the risk of non-hemorrhagic adverse fetal outcomes.

The Impact of Assisted Reproductive Technology on Umbilical Cord Insertion: Increased Risk of Velamentous Cord Insertion in Singleton Pregnancies Conceived through ICSI.

Background and Objectives: Vasa previa (VP) is a significant perinatal complication that can have serious consequences for the fetus/neonate. Velamentous cord insertion (VCI) is a crucial finding in prenatal placental morphology surveillance as it is indicative of comorbid VP. Assisted reproductive technology (ART) has been identified as a risk factor for VCI, so identifying risk factors for VCI in ART could improve VP recognition. This study aims to evaluate the displacement of umbilical cord insertion (CI) from the placental center and to examine the relationship between the modes of conception. Materials and Methods: We conducted a retrospective study at the Obstetrics Department of Osaka Metropolitan University Hospital in Japan between May 2020 and June 2022. The study included a total of 1102 patients who delivered after 22 weeks of gestation. They were divided into three groups: spontaneous pregnancy, conventional in vitro fertilization (cIVF), and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). We recorded patient background information, perinatal complications, perinatal outcomes, and a numerical "displacement score", indicating the degree of separation between umbilical CI and the placental center. Results: The displacement score was significantly higher in the cIVF and IVF/ICSI groups compared with the spontaneous conception group. Additionally, the IVF/ICSI group showed a significantly higher displacement score than the cIVF group. Conclusions: Our study provides the first evidence that the methods of ART can affect the location of umbilical CI on the placental surface. Furthermore, we found that IVF/ICSI may contribute to greater displacement of CI from the placental center.

Incidence of vasa praevia: a systematic review and meta-analysis.

OBJECTIVES: To derive accurate estimates of the incidence of vasa praevia (VP) in a routine population of unselected pregnancies. DESIGN: Systematic review and meta-analysis. DATA SOURCES: A search of MEDLINE, EMBASE, CINAHL and the Cochrane database was performed to review relevant citations reporting outcomes in pregnancies with VP from January 2000 until 5 April 2023. ELIGIBILITY CRITERIA FOR SELECTION OF STUDIES: Prospective or retrospective cohort or population studies that provided data regarding VP cases in routine unselected pregnancies during the study period. We included studies published in the English language after the year 2000 to reflect contemporary obstetric and neonatal practice. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently screened the retrieved citations and extracted data. The methodological quality of studies was assessed using the Newcastle-Ottawa Scale, and Preferred Reporting Items for Systematic reviews and Meta-Analyses was used to ensure standardised reporting of studies. RESULTS: A total of 3847 citations were screened and 82 full-text manuscripts were retrieved for analysis. There were 24 studies that met the inclusion criteria, of which 12 studies reported prenatal diagnosis with a systematic protocol of screening. There were 1320 pregnancies with VP in a total population of 2 278 561 pregnancies; the weighted pooled incidence of VP was 0.79 (95% CI: 0.59 to 1.01) per 1000 pregnancies, corresponding to 1 case of VP per 1271 (95% CI: 990 to 1692) pregnancies. Nested subanalysis of studies reporting screening for VP based on a specific protocol identified 395 pregnancies with VP in a population of 732 654 pregnancies with weighted pooled incidence of 0.82 (95% CI: 0.53 to 1.18) per 1000 pregnancies (1 case of VP per 1218 (95% CI: 847 to 1901) pregnancies). CONCLUSION: The incidence of VP in unselected pregnancies is 1 in 1218 pregnancies. This is higher than is previously reported and can be used as a basis to assess whether screening for this condition should be part of routine clinical practice. Incorporation of strategies to screen for VP in routine clinical practice is likely to prevent 5% of stillbirths. PROSPERO REGISTRATION NUMBER: CRD42020125495.

Individualized management of vasa previa and neonatal outcomes.

OBJECTIVE: To describe our individualized management protocol for women with an antenatal diagnosis of vasa previa (VP) and to report maternal and neonatal outcomes in patients managed according to our protocol. METHODS: A retrospective study of prospectively collected data of antenatally diagnosed VP managed at our hospital between 2014 and 2021. Obstetric and neonatal outcomes were reviewed and analyzed. RESULTS: Fourteen cases of antenatally diagnosed VP in 5150 total deliveries were analyzed (0.3%) Five cases (36%) of VP were diagnosed during the routine fetal morphological ultrasound screening, and nine cases (64%) were referred to our hospital due to perinatal complications. There were nine cases that required hospitalization (due to fetal growth restriction [FGR] [1], preterm labor [3], patients' request [5]). The other five were asymptomatic. Eight patients were delivered by scheduled cesarean section at around 36 weeks and only three neonates were admitted to NICU with transient tachypnea of newborn. However, six patients required CS before the scheduled dates because of other complications (preterm labor [3], abnormal cardiotocogram patterns [1], FGR [1] and twin pregnancy [1]). Four neonates born by CS before their scheduled dates were admitted to NICU. No cases required prolonged hospitalization and there were no serious neonatal complications. CONCLUSION: Individualized management may lead to favorable outcomes with VP. Outpatient management may be considered in patients without risk factors. However, maternal hospitalization and earlier scheduled CS should be considered in symptomatic patients or those at risk for preterm delivery.

Inpatient vs outpatient management of pregnancies with vasa previa: A historical cohort study.

INTRODUCTION: Vasa previa, a condition where unprotected fetal blood vessels lie in proximity to the internal cervical opening, is a potentially lethal obstetric complication. The precarious situation of these vessels increases the risk of fetal hemorrhage with spontaneous or artificial rupture of membranes, frequently causing fetal/neonatal demise or severe morbidity. As a result, in many centers, inpatient management forms the mainstay when vasa previa is diagnosed antenatally. This study aimed to determine whether a subpopulation of pregnancies diagnosed antenatally with vasa previa could be safely managed as outpatients. MATERIAL AND METHODS: We reviewed all cases of vasa previa in singleton pregnancies, with no fetal anomalies, diagnosed at Mount Sinai Hospital, Toronto, from January 2008 to December 2017. Cases were categorized into three arms for analysis: outpatients (OP), asymptomatic hospitalized (ASH) and symptomatic hospitalized (SH). The SH arm included patients admitted with any antepartum bleeding or suspicious fetal non-stress test. Those that presented with symptomatic uterine activity/threatened preterm labor and delivered within 7 days of diagnosis were excluded from the study. Records were analyzed for details on hospitalization, antenatal corticosteroid administration, cervical length measurements, and fetal/neonatal mortality and morbidity. RESULTS: Of the 84 antenatally-diagnosed cases of vasa previa, 47 fulfilled eligibility criteria. A total of 15 cases were managed as OP, 22 as ASH and 10 as SH. Unplanned cesareans were highest in the SH arm (40% vs. 0% ASH vs. 13.3% OP). Those in the SH arm delivered earliest (median 33.8 weeks, interquartile range (IQR) 33.2-34.3 weeks). Of the asymptomatic patients, those in the ASH arm delivered earlier than those in the OP arm (35.3 [34.6-36.2] weeks vs. 36.7 [35.6-37.2] weeks, p = 0.037). There were no cases of fetal/neonatal death, anemia or severe neonatal morbidity and no significant differences between groups based on cervical length or antenatal corticosteroid administration. CONCLUSIONS: Our study suggests that asymptomatic women with an antenatal diagnosis of vasa previa, singleton pregnancies, and at low risk for preterm birth may safely managed as outpatients, as long as they are able to access hospital promptly in the event of antepartum bleeding or early labor.

Vasa Previa.

Vasa previa refers to unprotected fetal vessels running through the membranes over the cervix. Until recently, this condition was associated with an exceedingly high perinatal mortality rate attributable to fetal exsanguination when the membranes ruptured. However, ultrasonography has made it possible to diagnose the condition prenatally, allowing cesarean delivery before labor or rupture of the membranes. Several recent studies have indicated excellent outcomes with prenatally diagnosed vasa previa. However, outcomes continue to be dismal when vasa previa is undiagnosed before labor. Risk factors for vasa previa include second-trimester placenta previa and low-lying placentas, velamentous cord insertion, placentas with accessory lobes, in vitro fertilization, and multifetal gestations. Recognition of individuals who are at risk and screening them will greatly decrease the mortality rate from this condition. Because of the relative rarity of vasa previa, there are no randomized controlled trials to guide management. Therefore, recommendations on the diagnosis and management of vasa previa are based largely on cohort studies and expert opinion. This Clinical Expert Series review addresses the epidemiology, pathophysiology, natural history, diagnosis and management of vasa previa, as well as innovative treatments for the condition.