International Expert Consensus on the Diagnosis and Clinical Management of Primary Fetal Pleural Effusion

Fetal pleural effusion is a rare condition that may significantly impact fetal and neonatal outcomes. Currently, no universal standardized approach exists for diagnosing and managing primary fetal pleural effusions. This study aimed to develop structured, expert-based clinical guidelines for the diagnosis, monitoring, management, and follow-up care of primary fetal pleural effusion.

A Delphi method was employed to achieve consensus among an international panel of experts in fetal medicine. Experts were selected based on their clinical expertise, affiliations, and relevant publications. A three-round anonymous electronic survey was sent to the full panel. In the initial two rounds, participants rated each statement on a Likert scale (1-5) and provided suggestions for modifications. Statements with a median score of five and no suggested changes were accepted as consensus. Statements with a median score below four were rejected. Statements scoring a median of four were revised according to suggestions and reconsidered in the subsequent round. In the final round, participants indicated their agreement or disagreement with the remaining statements. Consensus was defined as agreement from more than 70% of participants with no suggestions for further changes.

A total of 101 expert clinicians accepted the invitation and completed the first round with 73 (72%) completing all three rounds. Consensus statements were achieved on aspects of diagnosis, monitoring, intervention, post-intervention management, and delivery. Key recommendations concerning the diagnosis of primary fetal pleural effusion include the use of ultrasound as the primary modality for identifying fetal pleural effusion and excluding secondary causes through detailed genetic, infectious, and metabolic evaluations. Management strategies emphasized thoracoamniotic shunting as the preferred intervention in hydropic fetuses with primary pleural effusion. Experts reached consensus that shunt placement could be offered as early as 16 weeks. No consensus was reached for isolated effusion without hydrops, as management was considered case-dependent. The importance of ultrasonographic monitoring of fetal status at least weekly post-intervention was strongly endorsed.

The Delphi method facilitated the development of a consensus-based protocol for diagnosing and managing primary fetal pleural effusion. These standardized guidelines are intended to enhance clinical practice across various settings, improve perinatal outcomes, and serve as a foundation for future research for this high-risk fetal condition.