Expert consensus sheds light on diagnosis and management of vasa previa

Expert consensus sheds light on diagnosis and management of vasa previa | Image Credit: © MQ-Illustrations - © MQ-Illustrations - stock.adobe.com.

An expert consensus has been reached about statements relating to the diagnosis and management of vasa previa to provide support for health care providers and patients, according to a recent review published in the American Journal of Obstetrics & Gynecology.¹

Undiagnosed vasa previa during the prenatal period has been linked to an increased risk of perinatal death. Approximately 1 in 1200 pregnancies are impacted by the condition, with 3 different types identified.

Type 1 vasa previa is characterized by a velamentous cord insertion, type 2 by unprotected fetal vessels over the cervix between the main placenta and an accessory placental lobe, and type 3 by unprotected fetal vessels running from the placental edge through fetal membranes. Fetal membrane rupture late in pregnancy has been linked to a 56% perinatal mortality rate.²

While ultrasound allows for prenatal diagnosis of vasa previa, data about diagnosis and management remains limited.¹ Therefore, investigators conducted a comprehensive literature review to reach expert consensus on clinical issues in the diagnosis and management of vasa previa.

The review included articles published in the PubMed database, identified using key words “Vasa Previa” and “Vasa Praevia.” The publication records of experts were evaluated to determine which would fit within the review. Experts were defined as individuals with more than 2 publications as the first or senior author.

The focus group discussion (FGD) prioritized the creation of a list of statements for the first round of a Delphi process. The core group included experts with the greatest number of publications. There were 4 total online group discussions to account for differences in time zones and improve the efficacy of discussions.

Discussions were led by 2 moderators who provided open questions about the diagnosis and management of vasa previa. The transcripts of these discussions were reviewed using thematic analysis to identify the main areas of discussion.

The Delphi method was used to address questions unanswered by existing literature. After multiple iterative rounds with adaptations made based on feedback from the previous round, the expert panel reached a consensus.

There were 3 distinct rounds in the Delphi study. During the first round, experts rated each statement on a 5-point Likert scale, with a higher score indicating agreement. Statements with a median score of at least 4 received additional refinement during the second round. Finally, experts either agreed or disagreed with the revised statements in the third round.

Eighteen experts participated in the FGD and 57 in the first round of the Delphi survey. The Delphi survey respondents had a median 20 years of experience managing vasa previa and a median of 10 patients with the condition per year.

Four categories of vasa previa requiring attention were identified in the FGDs, including vasa previa definition, screening and diagnosis, management, and timing of delivery in asymptomatic patients. Screening and diagnosis subcategories included universal vs targeted screening, imaging modalities and screening techniques, and timing of screening.

Management included characteristics of monitoring and ultrasound frequency, hospitalization, and miscellaneous factors such as sexual intercourse and physical activity.

There were 44 statements in the first Delphi round, with a consensus reached on 12, nonconsensus on 14, and a median score of 4 on 18. Twenty-four statements were included in the second Delphi round, with a consensus reached on 11, nonconsensus on 5, and a median score of 4 on 8.

The final Delphi round had 3 statements, all of which reached agreement levels over 75%. Overall consensus was reported for 26 statements.

This process allowed for expert consensus opinions to be reached toward the diagnosis and clinical management of vasa previa. Investigators concluded this consensus will be helpful for the development of new clinical guidelines.

References

1. Oyelese Y, Javinani A, Gudanowski B, et al. Vasa previa in singleton pregnancies: diagnosis and clinical management based on an international expert consensus. Am J Obstet Gynecol. 2024;231:638.e1-24. doi:10.1016/j.ajog.2024.03.013
2. Zhang W, Geris S, Al-Emara N, Ramadan G, Sotiriadis A, Akolekar R. Perinatal outcome of pregnancies with prenatal diagnosis of vasa previa: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2021;57(5):710-719. doi:10.1002/uog.22166