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.

Perinatal outcome of pregnancies with prenatal diagnosis of vasa previa: systematic review and meta-analysis.

OBJECTIVES: To derive accurate estimates of perinatal survival in pregnancies with and without a prenatal diagnosis of vasa previa based on a systematic review of the literature and meta-analysis. METHODS: A search of MEDLINE, EMBASE and The Cochrane Library was performed to review relevant citations reporting on the perinatal outcomes of pregnancies with vasa previa. We included prospective and retrospective cohort and population studies that provided data on pregnancies with a prenatal diagnosis of vasa previa or cases diagnosed at birth or following postnatal placental examination. Meta-analysis using a random-effects model was performed to derive weighted pooled estimates of perinatal survival (excluding stillbirths and neonatal deaths) and intact perinatal survival (additionally excluding hypoxic morbidity). Incidence rate difference (IRD) meta-analysis was used to estimate the significance of differences in pooled proportions between cases of vasa previa with and those without a prenatal diagnosis. Heterogeneity between studies was estimated using Cochran's Q and the I2 statistic. RESULTS: We included 21 studies reporting on the perinatal outcomes of 683 pregnancies with a prenatal diagnosis of vasa previa. There were three stillbirths (1.01% (95% CI, 0.40-1.87%)), five neonatal deaths (1.19% (95% CI, 0.52-2.12%)) and 675 surviving neonates, resulting in a pooled estimate for perinatal survival of 98.6% (95% CI, 97.6-99.3%). Based on seven studies that included cases of vasa previa with and without a prenatal diagnosis, the pooled perinatal survival in pregnancies without a prenatal diagnosis (61/118) was 72.1% (95% CI, 50.6-89.4%) vs 98.6% (95% CI, 96.7-99.7%) in cases with a prenatal diagnosis (224/226). Therefore, the risk of perinatal death was 25-fold higher when a diagnosis of vasa previa was not made antenatally, compared with when it was (odds ratio (OR), 25.39 (95% CI, 7.93-81.31); P < 0.0001). Similarly, the risk of hypoxic morbidity was increased 50-fold in cases with vasa previa without a prenatal diagnosis compared with those with a prenatal diagnosis (36/61 vs 5/224; OR, 50.09 (95% CI, 17.33-144.79)). The intact perinatal survival rate in cases of vasa previa without a prenatal diagnosis was significantly lower than in those with a prenatal diagnosis (28.1% (95% CI, 14.1-44.7%) vs 96.7% (95% CI, 93.6-98.8%)) (IRD, 73.4% (95% CI, 53.9-92.7%); Z = -7.4066, P < 0.001). CONCLUSIONS: Prenatal diagnosis of vasa previa is associated with a high rate of perinatal survival, whereas lack of an antenatal diagnosis significantly increases the risk of perinatal death and hypoxic morbidity. Further research should be undertaken to investigate strategies for incorporating prenatal screening for vasa previa into routine clinical practice. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Vasa previa: when antenatal diagnosis can change fetal prognosis.

OBJECTIVES: Evaluate ultrasound diagnostic accuracy, maternal-fetal characteristics and outcomes in case of vasa previa diagnosed antenatally, postnatally or with spontaneous resolution before delivery. METHODS: Monocentric retrospective study enrolling women with antenatal or postnatal diagnosis of vasa previa at Sant'Anna Hospital in Turin from 2007 to 2018. Vasa previa were defined as fetal vessels that lay 2 cm within the uterine internal os using 2D and Color Doppler transvaginal ultrasound. Diagnosis was confirmed at delivery and on histopathological exam. Vasa previa with spontaneous resolutions were defined as fetal vessels that migrate >2 cm from uterine internal os during scheduled ultrasound follow-ups in pregnancy. RESULTS: We enrolled 29 patients (incidence of 0.03%). Ultrasound antenatally diagnosed 25 vasa previa (five had a spontaneous resolution) while four were diagnosed postnatally, with an overall sensitivity of 96.2%, specificity of 100%, positive predictive value of 96.2%, and negative predictive value of 100%. Early gestational age at diagnosis is significally associate with spontaneously resolution (p 0.023; aOR 1.63; 95% IC 1.18-2.89). Nearly 93% of our patient had a risk factor for vasa previa: placenta previa at second trimester or low-lying placenta, bilobated placenta, succenturiate cotyledon, velametous cord insertion or assisted reproduction technologies. CONCLUSIONS: Maternal and fetal outcomes in case of vasa previa antenatally diagnosed are significally improved. Our data support the evaluation of umbilical cord insertion during routine second trimester ultrasound and a targeted screening for vasa previa in women with risk factor: it allows identification of fetus at high risk, reducing fetal mortality in otherwise healthy newborns.

[Velamentous cord insertion associated with vasa praevia]. / Le cas clinique du mois. Insertion vélamenteuse du cordon ombilical associée à un vasa praevia.

Velamentous cord insertion is a rare placental abnormality, that may be associated with vasa praevia, i.e. the presence of an umbilical vessel near the internal cervical orifice. In case of spontaneous rupture of the membranes, there is a major risk of fetal haemorrhage, which is often lethal for the unborn baby. The challenge of care is based on the prenatal diagnosis during the 2nd trimester ultrasound. In case a vasa praevia is confirmed during the 3rd trimester, elective caesarean section should be carried out prior to the onset of labour, between 34 and 36 weeks of pregnancy. Corticosteroid treatment for fetal lung maturation is recommended at 32 weeks of gestation because of the increased risk of preterm delivery. Velamentous cord insertion may be associated with other adverse pregnancy outcomes such as intrauterine growth restriction, death in utero, placental abnormalities.

L'insertion vélamenteuse du cordon ombilical est une anomalie placentaire rare, pouvant être associée à un vasa praevia, c'est-à-dire la présence d'un vaisseau ombilical en regard de l'orifice interne du col utérin. En cas de rupture spontanée des membranes, le risque d'hémorragie fœtale est majeur et, le plus souvent, létal pour l'enfant à naître. Le défi de la prise en charge est le diagnostic anténatal à l'échographie du 2ème trimestre. En cas de vasa praevia confirmé lors du 3ème trimestre, une césarienne doit être programmée avant la mise en travail spontanée, aux alentours de 34-36 semaines d'aménorrhée. Une cure de maturation pulmonaire par corticostéroïdes est recommandée à 32 semaines d'aménorrhée en raison du risque accru de prématurité. L'insertion vélamenteuse du cordon peut être associée à d'autres complications périnatales telles qu'un retard de croissance intra-utérin, une mort fœtale in utero, des anomalies placentaires.

Society for Maternal-Fetal Medicine (SMFM) Consult Series #44: Management of bleeding in the late preterm period.

Third-trimester bleeding is a common complication arising from a variety of etiologies, some of which may initially present in the late preterm period. Previous management recommendations have not been specific to this gestational age window, which carries a potentially lower threshold for delivery. The purpose of this document is to provide guidance on management of late preterm (34 0/7-36 6/7 weeks of gestation) vaginal bleeding. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend delivery at 36-37 6/7 weeks of gestation for stable women with placenta previa without bleeding or other obstetric complications (GRADE 1B); (2) we do not recommend routine cervical length screening for women with placenta previa in the late preterm period due to a lack of data on an appropriate management strategy (GRADE 2C); (3) we recommend delivery between 34 and 37 weeks of gestation for stable women with placenta accreta (GRADE 1B); (4) we recommend delivery between 34 and 37 weeks of gestation for stable women with vasa previa (GRADE 1B); (5) we recommend that in women with active hemorrhage in the late preterm period, delivery should not be delayed for the purpose of administering antenatal corticosteroids (GRADE 1B); (6) we recommend that fetal lung maturity testing should not be used to guide management in the late preterm period when an indication for delivery is present (GRADE 1B); and (7) we recommend that antenatal corticosteroids should be administered to women who are eligible and are managed expectantly if delivery is likely within 7 days, the gestational age is between 34 0/7 and 36 6/7 weeks of gestation, and antenatal corticosteroids have not previously been administered (GRADE 1A).

Vasa previa: prenatal diagnosis and management.

PURPOSE OF REVIEW: Vasa previa is a rare disorder of placentation associated with a high rate of perinatal morbidity and mortality when undetected before delivery. We have evaluated the recent evidence for prenatal diagnosis and management of vasa previa. RECENT FINDINGS: Around 85% of cases of vasa previa have one or more identifiable risk factors including in-vitro fertilization, multiple gestations, bilobed, succenturiate or low-lying placentas, and velamentous cord insertion. The development of standardized prenatal targeted scanning protocols may improve perinatal outcomes. There is no clear consensus on the optimal surveillance strategy including the need for hospitalization, timing of corticosteroids administration and the value of transvaginal cervical length measurements. Outpatient management is possible if there is no evidence of cervical shortening on ultrasound and there are no symptoms of bleeding or uterine contractions. Recent national guidelines and expert reviews have recommended scheduled cesarean section of all asymptomatic women presenting with vasa previa between 34 and 36 weeks' gestation. SUMMARY: Prenatal diagnosis of vasa previa is pivotal to prevent intrapartum fetal death. Although there is insufficient evidence to support the universal mid-gestation ultrasound screening for vasa previa, recent evidence indicates the need for standardized prenatal targeted screening protocols of pregnancies at high-risk of vasa previa.

Prenatal diagnosis and management of vasa previa in twin pregnancies: a case series and systematic review.

BACKGROUND: Twin pregnancies are at higher risks of velamentous cord insertion and vasa previa. In vitro fertilization is an additional risk factor of abnormal cord insertion and thus the incidence of vasa previa is likely to increase over the next decades. OBJECTIVE: We sought to evaluate the role of ultrasound imaging in optimizing the management of twins diagnosed with vasa previa antenatally. STUDY DESIGN: We searched our database for twin pregnancies diagnosed with vasa previa and managed antenatally using measurements of cervical length and performed a systematic review of articles that correlated prenatal diagnosis of vasa previa in twins and pregnancy outcome. PubMed and MEDLINE were searched for studies published from 1987 through October 20, 2016, using specific medical subject heading terms, key words, and their combination. The primary eligibility criteria were articles that correlated prenatal ultrasound imaging of vasa previa and pregnancy outcome in twins. The secondary eligibility criteria was the use of cervical length in the management of twin pregnancies diagnosed antenatally with vasa previa. Two authors independently assessed inclusion criteria, data extraction, and analysis. The final selection included 3 case report series, 9 retrospective cohort studies, and 1 retrospective case-control study of vasa previa diagnosed prenatally and confirmed at birth in twin pregnancies. RESULTS: The search of our databases identified 6 cases of dichorionic-diamniotic twins and 1 case of monochorionic-diamniotic twins diagnosed prenatally with vasa previa between 22-29 weeks and managed using cervical length. Two cases were delivered by emergency because of rapid changes in cervical length in one and bleeding on placenta previa in the other at 33 and 30 weeks, respectively. The systematic review identified data on 56 cases. The incidence of twin pregnancies diagnosed antenatally with vasa previa in the cohort and case-control studies was 11.0%. Data on chorionicity were available in only 34 cases and cervical length measurements were used by only the authors of 2 case reports and 4 cohort studies. Velamentous cord insertion was the most common additional ultrasound findings in twins presenting with vasa previa in both our series and the systematic review. CONCLUSION: Vasa previa is associated with specific prenatal and obstetric complications with different outcomes in singletons compared to twins. Data on the diagnosis and management of vasa previa in twin pregnancies are limited but there is enough evidence to warrant guidelines for targeted screening. To enable the development of efficient management protocols tailored to the need of individual cases, future studies of the screening, diagnosis, and management of vasa previa should be prospective and multicentric with detailed data on twins including chorionicity and use of cervical length.

No. 231-Guidelines for the Management of Vasa Previa.

OBJECTIVES: To describe the etiology of vasa previa and the risk factors and associated condition, to identify the various clinical presentations of vasa previa, to describe the ultrasound tools used in its diagnosis, and to describe the management of vasa previa. OUTCOMES: Reduction of perinatal mortality, short-term neonatal morbidity, long-term infant morbidity, and short-term and long-term maternal morbidity and mortality. EVIDENCE: Published literature on randomized trials, prospective cohort studies, and selected retrospective cohort studies was retrieved through searches of PubMed or Medline, CINAHL, and the Cochrane Library, using appropriate controlled vocabulary (e.g., selected epidemiological studies comparing delivery by Caesarean section with vaginal delivery; studies comparing outcomes when vasa previa is diagnosed antenatally vs. intrapartum) and key words (e.g., vasa previa). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated into the guideline to October 1, 2008. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and from national and international medical specialty societies. VALUES: The evidence collected was reviewed by the Diagnostic Imaging Committee and the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS: The benefit expected from this guideline is facilitation of optimal and uniform care for pregnancies complicated by vasa previa. SPONSORS: The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENT: A comparison of women who were diagnosed antenatally and those who were not shows respective neonatal survival rates of 97% and 44%, and neonatal blood transfusion rates of 3.4% and 58.5%, respectively. Vasa previa can be diagnosed antenatally, using combined abdominal and transvaginal ultrasound and colour flow mapping; however, many cases are not diagnosed, and not making such a diagnosis is still acceptable. Even under the best circumstances the false positive rate is extremely low. (II-2) RECOMMENDATIONS.

Vasa previa rupture in velamentous insertion of the umbilical cord: an analysis and report of a case.

Ruptured vasa previa in tenn pregnancy is rare but usually catastrophic if emergency delivery is not achieved. The authors present a case of ruptured vasa previa in velamentous cord insertion placenta. The fetus survived after intensive treatment immediately after delivery by cesarean section, but, unfortunately, died after the family gave him up. Defects in the vessel wall architecture were'visualized and confirmed 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.

#37: Diagnosis and management of vasa previa.

Vasa previa occurs when fetal blood vessels that are unprotected by the umbilical cord or placenta run through the amniotic membranes and traverse the cervix. If membranes rupture, these vessels may rupture, with resultant fetal hemorrhage, exsanguination, or even death. Prenatal diagnosis of vasa previa by ultrasound scans is approximately 98%. Approximately 28% of prenatally diagnosed cases result in emergent preterm delivery. Management of prenatally diagnosed vasa previa includes antenatal corticosteroids between 28-32 weeks of gestation, considerations for preterm hospitalization at 30-34 weeks of gestation, and scheduled delivery at 34-37 weeks of gestation.

Systematic review of accuracy of ultrasound in the diagnosis of vasa previa.

OBJECTIVE: Vasa previa is an obstetric complication in which the fetal blood vessels lie outside the chorionic plate in close proximity to the internal cervical os. In women with vasa previa, the risk of rupture of these vessels is increased, thus potentially causing fetal death or serious morbidity. Our objective was to assess the accuracy of ultrasound in the prenatal diagnosis of vasa previa. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library and PubMed for studies on vasa previa. Two reviewers independently selected studies on the accuracy of ultrasound in the diagnosis of vasa previa. The studies were scored on methodological quality using the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2). Data on sensitivity and specificity were subsequently extracted. RESULTS: The literature search revealed 583 articles, of which two prospective and six retrospective cohort studies were eligible for inclusion in the qualitative analysis. All studies documented methods suitable for the prenatal diagnosis of vasa previa. Four out of the eight studies used transvaginal ultrasound (TVS) for primary evaluation, while the remaining four studies used transabdominal ultrasound and performed a subsequent TVS when vasa previa was suspected. The QUADAS-2 tool reflected poor methodology in six of the eight included studies, and prenatal detection rates varied from 53% (10/19) to 100% (total of 442,633 patients, including 138 cases of vasa previa). In the two prospective studies (n = 33,795, including 11 cases of vasa previa), transvaginal color Doppler performed during the second trimester detected all cases of vasa previa (sensitivity, 100%) with a specificity of 99.0-99.8%. CONCLUSION: The accuracy of ultrasound in the diagnosis of vasa previa is high when performed transvaginally in combination with color Doppler.

Management of vasa previa during pregnancy.

In order to prevent fetal mortality due to vasa previa, it is necessary to obtain an antenatal diagnosis and perform elective cesarean section prior to membrane rupture. Under present circumstances, management strategies for vasa previa depend on each institutional policy. In our institution, patients are not routinely admitted, although precise outpatient management, including confirming the presence of uterine contractions and monitoring the cervical length, fetal growth and fetal heart rate, is provided for pregnant females with vasa previa. In the present report, we reviewed 21 cases of vasa previa managed at our hospital. Some 71% (15/21) of them were required inpatient management due to its complications, resulting in emergency delivery in about half of them. Therefore, our results suggest that only carefully selected asymptomatic patients may be successfully managed as outpatients.

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.

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.