The Rate of Cervical Length Shortening in the Management of Vasa Previa

Vasa previa in singleton pregnancies: diagnosis and clinical management based on an international expert consensus

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.

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.

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.

Perinatal Mortality Despite Prenatal Diagnosis of Vasa Previa: A Systematic Review

OBJECTIVE

To determine the causes and potential preventability of perinatal deaths in prenatally identified cases of vasa previa.

DATA SOURCES

Reports of prenatally identified cases of vasa previa published in the English language literature since 2000 were identified in Medline and ClinicalTrials.gov with the search terms "vasa previa," "abnormal cord insertion," "velamentous cord," "marginal cord," "bilobed placenta," and "succenturiate lobe."

METHODS OF STUDY SELECTION

All cases from the above search with an antenatally diagnosed vasa previa present at delivery in singleton or twin gestations with perinatal mortality information were included.

TABULATION, INTEGRATION, AND RESULTS

Cases meeting inclusion criteria were manually abstracted, and multiple antenatal, intrapartum, and outcome variables were recorded. Deaths and cases requiring neonatal transfusion were analyzed in relation to plurality, routine hospitalization, and cervical length monitoring. A total of 1,109 prenatally diagnosed cases (1,000 singletons, 109 twins) were identified with a perinatal mortality rate attributable to vasa previa of 1.1% (95% CI 0.6-1.9%). All perinatal deaths occurred with unscheduled deliveries. The perinatal mortality rate in twin pregnancies was markedly higher than that in singleton pregnancies (9.2% vs 0.2%, P <.001), accounting for 80% of overall mortality despite encompassing only 9.8% of births. Compared with individuals with singleton pregnancies, those with twin pregnancies are more likely to undergo unscheduled delivery (56.4% vs 35.1%, P =.01) despite delivering 2 weeks earlier (33.2 weeks vs 35.1 weeks, P =.006). An institutional policy of routine hospitalization is associated with a reduced need for neonatal transfusion (0.9% vs 6.0%, P <.001) and a reduction in the perinatal mortality rate in twin pregnancies (0% vs 25%, P =.002) but not in singleton pregnancies (0% vs 0.5%, P =.31).

CONCLUSION

Routine hospitalization and earlier delivery of twins may result in a reduction in the perinatal mortality rate. A smaller benefit from routine admission of individuals with singleton pregnancies cannot be excluded. There is currently insufficient evidence to recommend the routine use of cervical length measurements to guide clinical management.

Guideline No. 439: Diagnosis and Management of Vasa Previa

OBJECTIVE

To summarize the current evidence and to make recommendations for diagnosis and classification of vasa previa and for management of women with this diagnosis.

TARGET POPULATION

Pregnant women with vasa previa or low-lying fetal vessels.

OPTIONS

To manage vasa previa in hospital or at home, and to perform a cesarean delivery preterm or at term, or to allow a trial of labour when a diagnosis of vasa previa or low-lying fetal vessels is suspected or confirmed.

OUTCOMES

Prolonged hospitalization, preterm birth, rate of cesarean delivery, and neonatal morbidity and mortality.

BENEFITS, HARMS, AND COSTS

Women with vasa previa or low-lying fetal vessels are at an increased risk of maternal and fetal or postnatal adverse outcomes. These outcomes include a potentially incorrect diagnosis, need for hospitalization, unnecessary restriction of activities, an early delivery, and an unnecessary cesarean delivery. Optimization of diagnostic and management protocols can improve maternal and fetal or postnatal outcomes.

EVIDENCE

Medline, Pubmed, Embase, and the Cochrane Library were searched from inception to March 2022, using medical subject headings (MeSH) and keywords related to pregnancy, vasa previa, low-lying fetal vessels, antepartum hemorrhage, short cervix, preterm labour, and cesarean delivery. This document presents an abstraction of the evidence rather than a methodological review.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

Obstetric care providers, including obstetricians, family physicians, nurses, midwives, maternal-fetal medicine specialists, and radiologists.

TWEETABLE ABSTRACT

Unprotected fetal vessels in placental membranes and cord that are close to the cervix, including vasa previa, need careful characterization by sonographic examination and evidence-based management to reduce risks to the baby and the mother during pregnancy and delivery.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Directive clinique no 439: Diagnostic et prise en charge du vasa prævia

OBJECTIF

Résumer les données probantes actuelles et énoncer des recommandations pour le diagnostic et la classification du vasa prævia et pour la prise en charge des femmes ayant reçu ce diagnostic.

POPULATION CIBLE

Femmes enceintes présentant un vasa prævia ou des vaisseaux ombilicaux péricervicaux.

OPTIONS

En cas de diagnostic soupçonné ou confirmé de vasa prævia ou de vaisseaux ombilicaux péricervicaux, prendre en charge la patiente à l'hôpital ou à domicile, puis pratiquer une césarienne avant terme ou à terme ou entreprendre une épreuve de travail. RéSULTATS: Hospitalisation prolongée, accouchement prématuré, césarienne et morbidité et mortalité néonatales. BéNéFICES, RISQUES ET COûTS: Les femmes ayant un vasa prævia ou des vaisseaux ombilicaux péricervicaux présentent un risque accru d'issues défavorables maternelles, fœtales ou postnatales, à savoir un diagnostic potentiellement erroné, un besoin d'hospitalisation, une restriction inutile des activités, un accouchement précoce et une césarienne inutile. L'optimisation des protocoles de diagnostic et de prise en charge peut améliorer les issues maternelles, fœtales et postnatales. DONNéES PROBANTES: Des recherches ont été effectuées dans les bases de données Medline, PubMed, Embase et Cochrane Library, de leur création jusqu'à mars 2022, à partir de termes MeSH et de mots clés liés à la grossesse, au vasa prævia, aux vaisseaux prævia, à l'hémorragie ante partum, au col court, au travail prématuré et à la césarienne. Le présent document est un résumé des données probantes et non pas une revue méthodologique. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Fournisseurs de soins obstétricaux, y compris obstétriciens, médecins de famille, infirmières, sages-femmes, spécialistes en médecine fœto-maternelle et radiologistes. RéSUMé POUR TWITTER: En cas de cordon et de vaisseaux ombilicaux non protégés dans les membranes près du col (vasa prævia y compris), une caractérisation échographique et une prise en charge avisée s'imposent pour réduire les risques pour le bébé et la mère pendant la grossesse et l'accouchement.

Vasa previa: A rare obstetric complication-A case series and a literature review

Vasa previa is a rare condition. However, since the increase in assisted reproductive technologies (ARTs), clinicians are more frequently confronted with this complication. In this study, we present five cases of vasa previa prenatally diagnosed from a tertiary referral hospital with approximately 2000 births yearly.

Placental Types and Effective Perinatal Management of Vasa Previa: Lessons from 55 Cases in a Single Institution

BACKGROUND

We aimed to identify clinical characteristics and outcomes for each placental type of vasa previa (VP).

METHODS

Placental types of vasa previa were defined as follows: Type 1, vasa previa with velamentous cord insertion and non-type 1, vasa previa with a multilobed or succenturiate placenta and vasa previa with vessels branching out from the placental surface and returning to the placental cotyledons.

RESULTS

A total of 55 cases of vasa previa were included in this study, with 35 cases of type 1 and 20 cases of non-type 1. Vasa previa with type 1 showed a significantly higher association with assisted reproductive technology, compared with non-type 1 (p = 0.024, 60.0% and 25.0%, respectively). The diagnosis was significantly earlier in the type 1 group than in the non-Type 1 group (p = 0.027, 21.4 weeks and 28.6 weeks, respectively). Moreover, the Ward technique for anterior placentation to avoid injury of the placenta and/or fetal vessels was more frequently required in non-type 1 cases (p < 0.001, 60.0%, compared with 14.3% for type 1).

CONCLUSION

The concept of defining placental types of vasa previa will provide useful information for the screening of this serious complication, improve its clinical management and operative strategy, and achieve more preferable perinatal outcomes.

Variations in reported outcomes in studies on vasa previa: a systematic review

OBJECTIVE

To evaluate reported outcomes of published studies on the diagnosis and management of vasa previa in pregnancy.

MATERIALS AND METHODS

Databases such as MEDLINE, Embase, Cochrane, PubMed, and ClinicalTrials.gov were searched up to March 2018 for all published studies on vasa previa using combinations of the following medical subject headings and key words: vasa previa, placenta previa, low-lying placenta, succenturiate lobe or placenta, bilobed or bilobate placenta, and velamentous insertion. All original human research that described maternal, obstetric, placental, fetal or neonatal outcomes relating to pregnancies with vasa previa were included for analysis. Title and abstract screening and data extraction was conducted independently and in duplicate by 2 reviewers for all studies until total agreement for eligibility was achieved. Data extraction was also conducted in duplicate in approximately 50% of studies reviewed.

RESULTS

A total of 160 published studies (1004 pregnancies) were included. There was a wide range of reported outcomes, many of which were sparingly reported. The most commonly reported maternal outcomes included mode of delivery, presence of antepartum hemorrhage, time of diagnosis, and rupture of membranes. The presence of known risk factors for vasa previa such as a low-lying placenta, succenturiate or bilobed placenta, and (velamentous) cord insertion was incorrectly reported as "outcomes" in many studies. The most commonly reported fetal/neonatal outcomes included fetal heart rate, gestational age at delivery, birthweight, Apgar score, presence of neonatal anemia, cord blood gas measurements, need for blood transfusion, and death. Of note, only 3 studies reported outcomes related to life impact, maternal social and emotional functioning, perceived delivery of care, or resource utilization.

CONCLUSION

Despite the profound effect the diagnosis of vasa previa has on pregnant women, families, and healthcare systems, studies on vasa previa seldom report outcomes related to life impact and resource utilization. There is a need for the development of a core outcome set-a minimum standard set of outcomes deemed important by pregnant women and other stakeholders involved in their care-to standardize outcome reporting in future studies on vasa previa.

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.

Atypical Vasa Previa in a Velamentous Cord Insertion Identified During Sonographic Examination

Vasa previa is a life-threatening complication of a velamentous cord insertion. Understanding variations of this condition is vital to ensuring optimal patient outcomes. The case presented is of a 27-year-old primigravida woman whose condition was diagnosed during her second-trimester obstetric sonographic examination. The case demonstrated an unusual variation of vasa previa, in which a single fetal vessel separated from the membranous insertion located near the fundal placenta and traversed posteriorly through the chorionic membrane to within 0.83 cm of the internal os. The case was followed with the most up-to-date standards recommended by the American Institute of Ultrasound in Medicine.

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.

Impact of targeted scanning protocols on perinatal outcomes in pregnancies at risk of placenta accreta spectrum or vasa previa

BACKGROUND

Placenta accreta spectrum and vasa previa (VP) are congenital disorders of placentation associated with high morbidity and mortality for both mothers and newborns when undiagnosed before delivery. Prenatal diagnosis of these conditions is essential to allow multidisciplinary management and thus improve perinatal outcomes.

OBJECTIVE

The objective of the study was to compare perinatal outcome in women with placenta accreta spectrum or vasa previa before and after implementation of targeted scanning protocols.

STUDY DESIGN

This retrospective study included 2 nonconcurrent cohorts for each condition before and after implementation of the corresponding protocols (2004-1012 vs 2013-2016 for placenta accreta spectrum and 1988-2007 vs 2008-2016 for vasa previa). Clinical reports of women diagnosed with placenta accreta spectrum and vasa previa during the study periods were reviewed and outcomes were compared.

RESULTS

In total, there were 97 cases of placenta accreta spectrum and 51 cases with vasa previa, all confirmed at delivery. In both cohorts, the prenatal detection rate increased after implementation of the scanning protocols (28 of 65 cases [43.1%] vs 31 of 32 cases [96.9%], P < .001, for placenta accreta spectrum and 9 of 18 cases [50%] vs 29 of 33 cases [87.9%], 87.9%, P < .01 for vasa previa). The perinatal outcome improved also significantly in both cohorts after implementation of the protocols. In the placenta accreta spectrum cohort, the estimated blood loss and the postoperative hospitalization stay decreased between periods (1520 ± 845 vs 1168 ± 707 mL, P < .01, and 10.9 ± 14.1 vs 5.7 ± 2.2 days, P < .05, respectively). In the vasa previa cohort, the number of 5 minute Apgar score ≤5 and umbilical cord pH <7 decreased between periods (5 of 18 cases [27.8%] vs 1 of 33 cases [3%]; P < .05, and 4 of 18 cases [22.2%] vs 1 of 33 cases [3%], P < .05, respectively).

CONCLUSION

The implementation of standardized prenatal targeted scanning protocols for pregnant women with risk factors for placenta accreta spectrum and vasa previa was associated with improved maternal and neonatal outcomes. The continuous increases in the rates of caesarean deliveries and use of assisted reproductive technology highlights the need to develop training programs and introduce targeted scanning protocols at the national and international levels.