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Obstetrics and Gynecology Sep 2023Vasa previa refers to unprotected fetal vessels running through the membranes over the cervix. Until recently, this condition was associated with an exceedingly high...
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.
Topics: Female; Pregnancy; Humans; Vasa Previa; Cesarean Section; Fertilization in Vitro; Fetus; Labor, Obstetric
PubMed: 37590981
DOI: 10.1097/AOG.0000000000005287 -
American Journal of Obstetrics and... Mar 2024There are limited data to guide the diagnosis and management of vasa previa. Currently, what is known is largely based on case reports or series and cohort studies.
BACKGROUND
There are limited data to guide the diagnosis and management of vasa previa. Currently, what is known is largely based on case reports or series and cohort studies.
OBJECTIVE
This study aimed to systematically collect and classify expert opinions and achieve consensus on the diagnosis and clinical management of vasa previa using focus group discussions and a Delphi technique.
STUDY DESIGN
A 4-round focus group discussion and a 3-round Delphi survey of an international panel of experts on vasa previa were conducted. Experts were selected on the basis of their publication record on vasa previa. First, we convened a focus group discussion panel of 20 experts and agreed on which issues were unresolved in the diagnosis and management of vasa previa. A 3-round anonymous electronic survey was then sent to the full expert panel. Survey questions were presented on the diagnosis and management of vasa previa, which the experts were asked to rate on a 5-point Likert scale (from "strongly disagree"=1 to "strongly agree"=5). Consensus was defined as a median score of 5. Following responses to each round, any statements that had median scores of ≤3 were deemed to have had no consensus and were excluded. Statements with a median score of 4 were revised and re-presented to the experts in the next round. Consensus and nonconsensus statements were then aggregated.
RESULTS
A total of 68 international experts were invited to participate in the study, of which 57 participated. Experts were from 13 countries on 5 continents and have contributed to >80% of published cohort studies on vasa previa, as well as national and international society guidelines. Completion rates were 84%, 93%, and 91% for the first, second, and third rounds, respectively, and 71% completed all 3 rounds. The panel reached a consensus on 26 statements regarding the diagnosis and key points of management of vasa previa, including the following: (1) although there is no agreement on the distance between the fetal vessels and the cervical internal os to define vasa previa, the definition should not be limited to a 2-cm distance; (2) all pregnancies should be screened for vasa previa with routine examination for placental cord insertion and a color Doppler sweep of the region over the cervix at the second-trimester anatomy scan; (3) when a low-lying placenta or placenta previa is found in the second trimester, a transvaginal ultrasound with Doppler should be performed at approximately 32 weeks to rule out vasa previa; (4) outpatient management of asymptomatic patients without risk factors for preterm birth is reasonable; (5) asymptomatic patients with vasa previa should be delivered by scheduled cesarean delivery between 35 and 37 weeks of gestation; and (6) there was no agreement on routine hospitalization, avoidance of intercourse, or use of 3-dimensional ultrasound for diagnosis of vasa previa.
CONCLUSION
Through focus group discussion and a Delphi process, an international expert panel reached consensus on the definition, screening, clinical management, and timing of delivery in vasa previa, which could inform the development of new clinical guidelines.
PubMed: 38494071
DOI: 10.1016/j.ajog.2024.03.013 -
Diagnostics (Basel, Switzerland) May 2024Vasa previa is a pregnancy complication that occurs when unprotected fetal blood vessels traverse the cervical os, placing the fetus at high risk of exsanguination and... (Review)
Review
Vasa previa is a pregnancy complication that occurs when unprotected fetal blood vessels traverse the cervical os, placing the fetus at high risk of exsanguination and fetal death. These fetal vessels may be compromised by fetal movement and compression, leading to poor oxygen distribution and asphyxiation. Diagnostic tools for vasa previa management and preterm labor (PTL) include transvaginal ultrasound, cervical length (CL) surveillance and use of fetal fibronectin (FFN) testing. These tools can prove to be quite useful as they allow for lead time in the prediction of PTL and spontaneous rupture of membranes which can result in devastating outcomes for pregnancies affected by vasa previa. We conducted a literature review on vasa previa management and the usefulness of FFN and CL surveillance in predicting PTL and found 36 related papers. Although there is limited research available to show the impact of FFN and CL surveillance in the management of vasa previa, there is sufficient evidence to support FFN and CL surveillance in predicting the onset of PTL, which can have devastating consequences for the pregnancies affected. It can be extrapolated that these tools, by helping to determine pregnancies at risk for PTL, could improve management and outcomes in patients with vasa previa. Future studies investigating the management of vasa previa with FFN and CL surveillance to reduce the burden of PTL and its associated comorbidities are warranted.
PubMed: 38786314
DOI: 10.3390/diagnostics14101016 -
Acta Obstetricia Et Gynecologica... Nov 2023Vasa previa, a condition where unprotected fetal blood vessels lie in proximity to the internal cervical opening, is a potentially lethal obstetric complication. The...
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.
Topics: Female; Humans; Infant, Newborn; Pregnancy; Adrenal Cortex Hormones; Cohort Studies; Inpatients; Labor, Obstetric; Obstetric Labor Complications; Outpatients; Premature Birth; Ultrasonography, Prenatal; Vasa Previa
PubMed: 37537788
DOI: 10.1111/aogs.14595 -
BMJ Open Sep 2023To derive accurate estimates of the incidence of vasa praevia (VP) in a routine population of unselected pregnancies. (Meta-Analysis)
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.
Topics: Infant, Newborn; Female; Pregnancy; Humans; Incidence; Prospective Studies; Retrospective Studies; Vasa Previa; Databases, Factual
PubMed: 37730391
DOI: 10.1136/bmjopen-2023-075245 -
Women and Birth : Journal of the... Apr 2024Many studies have reported interventions for women with vasa praevia to improve perinatal outcomes. However, which outcomes are important for women remains unclear.
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.
PubMed: 38669723
DOI: 10.1016/j.wombi.2024.101614 -
Case Reports in Women's Health Dec 2023Type 3 vasa previa is a new concept. Herein, a case is reported of a 35-year-old woman, pregnant following in vitro fertilization, in whom vasa previa was detected on...
Type 3 vasa previa with no low-lying placenta, with central umbilical cord insertion at the upper uterine segment, and with aberrant vessels on the broad membrane: A case report.
Type 3 vasa previa is a new concept. Herein, a case is reported of a 35-year-old woman, pregnant following in vitro fertilization, in whom vasa previa was detected on color Doppler ultrasound at 26 weeks, with no finding of a low-lying placenta. A cesarean section was performed at 34 weeks and 3 days. Gross examination of the placenta showed Type 3 vasa previa with findings somewhat different from previous reports: two aberrant fetal vessels with branching on the broad membrane, and central cord insertion which was farther from the longitudinal center of the placenta than were the running vessels on the membrane. Vasa previa cannot be excluded due to normal cord insertion at the upper uterine segment, absence of placenta previa, or a low-lying placenta in the second trimester. Careful ultrasound screening can promote neonatal survival in patients with Type 3 vasa previa.
PubMed: 37946796
DOI: 10.1016/j.crwh.2023.e00558 -
AJP Reports Apr 2024Vasa previa occurs when fetal vessels lie above the cervical os. A novel type of vasa previa, known as type III, is characterized by an abnormal branching of fetal...
Vasa previa occurs when fetal vessels lie above the cervical os. A novel type of vasa previa, known as type III, is characterized by an abnormal branching of fetal vessels from the placenta in the absence of velamentous cord insertion (as seen in type I) or multilobed placenta (as seen in type II). Here, we present a case of a type III vasa previa after a resolution of a low-lying placenta. The presence of any known risk factors of vasa previa, including low-lying placenta, should prompt screening for vasa previa in the third trimester. Accurate and timely diagnosis of vasa previa will confer significant survival benefit for the neonate.
PubMed: 38736707
DOI: 10.1055/a-2315-7550 -
SAGE Open Medical Case Reports 2024Vasa previa is a critical obstetric condition marked by unprotected fetal vessels near the cervical os, traditionally divided into Types 1 and 2, based on its...
Vasa previa is a critical obstetric condition marked by unprotected fetal vessels near the cervical os, traditionally divided into Types 1 and 2, based on its association with velamentous cord insertion and accessory placental lobes, respectively. The recent introduction of Type 3 vasa previa addresses atypical cases. We report a unique intrapartum diagnosis of Type 3 vasa previa in a 39-year-old at 38 weeks of gestation, identified during labor induction without prior risk indicators. Despite lacking traditional risk factors, advanced imaging and clinical vigilance led to a primary cesarean delivery, confirming the diagnosis through intraoperative findings of three aberrant vessels with marginal cord insertion. This case emphasizes the critical importance of considering vasa previa in prenatal and intrapartum care to prevent adverse outcomes, advocating for universal screening practices to identify this rare but significant condition.
PubMed: 38764916
DOI: 10.1177/2050313X241253747 -
BMC Pregnancy and Childbirth Oct 2023Antepartum 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...
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.
Topics: Pregnancy; Female; Humans; Vasa Previa; Fetal Death; Umbilical Cord; Stillbirth; Ultrasonography, Prenatal; Hemorrhage
PubMed: 37789298
DOI: 10.1186/s12884-023-06019-0