2024-09-08-世界卫生组织-Report_on_the_third_meeting_of_the_WHO_Technical_Advisory_Group_on_Gestational_Weight_Gain_TAG-GWG_53页_1mb

WHO Technical Advisory Group on Gestational Weight Gain (TAG-GWG) Third Meeting Summary

The Third Meeting of the WHO TAG-GWG, held from 12-14 March 2024, focused on advancing the development of global gestational weight gain (GWG) standards. The meeting aimed to review progress on study eligibility criteria, data harmonization and acquisition, and statistical methods for constructing GWG standards. Key points from the report are summarized below.

Key Objectives and Outcomes

1. Project Rationale and Methodology:

   • The WHO is developing global GWG standards to address inconsistencies in current guidelines (e.g., based on Institute of Medicine [IOM] guidelines from high-income countries). The project aims to create standards that are globally relevant and applicable across all body mass index (BMI) categories and geographic locations.
   • The standards will incorporate data from retrospective cohort studies and address potential confounders like pre-existing comorbidities and socioeconomic factors.

2. Literature Review on GWG and Outcomes:

   • The systematic review highlighted the risks of both insufficient and excessive GWG, including preterm birth, low birth weight, macrosomia, and postpartum weight retention. Studies were limited by language, data availability, and methodological inconsistencies.

3. Working Group Progress:

   • Working Group 1:
     • Identified determinants and outcomes for eligibility criteria, such as maternal age, singleton pregnancy, pre-pregnancy BMI, and outcomes like gestational diabetes and pre-eclampsia.
     • Debated the need for subgroup-specific charts (e.g., by race/ethnicity) and settled on focusing on clinically meaningful outcomes rather than distribution shifts alone.
   • Working Group 2:
     • Proposed methodologies for harmonizing variables like self-reported weight and gestational age, including using Bland & Altman plots for agreement analysis.
     • Addressed data gaps from low-and-middle-income countries but emphasized clinical relevance over statistical uniformity.
   • Working Group 3:
     • Defined outlier detection strategies, heterogeneity assessment methods using standardized site differences (SSD), and techniques for modeling GWG trajectories with fractional polynomials.
     • Stressing caution regarding heterogeneity in outcomes, noting geographic and subpopulation differences.

4. Data Acquisition:

   • As of late 2024, 40 eligible studies were identified from 31 countries, representing 15.7% of WHO regions. Data sharing agreements were signed for several studies, with ongoing efforts to address eligibility criteria and incorporate more inclusive contexts.

5. Terminology and Product Labels:

   • While the project outputs are not fully prescriptive, they aim to balance global applicability with regional flexibility. The chosen terminology emphasized "referenced" or "chart" instead of strictly "standard" to avoid stigma and align with clinical utility.

Next Steps

• TAG-GWG Phase 1 Deliverables: Completion of individual-level eligibility criteria by April 2025.
• Statistical Methodology: Finalization of outlier detection and heterogeneity assessment protocols.
• Data Harmonization: Data acquisition will conclude in September 2024, with harmonization planned for spring 2025.
• GWG Standards Construction: Scheduled for January-June 2025.
• IPD Meta-Analysis: Planned methodology adaptations to account for heterogeneity, including multilevel modeling and country-specific analysis.

Significance and Recommendations

The meeting underscored the need for robust statistical methods, dynamic implementation frameworks, and careful terminology to minimize stigma while maximizing clinical utility. WHO is moving towards a standardized but flexible approach, with a focus on implementation strategies for diverse contexts. Future priority areas include user testing and developing context-specific thresholds for guidelines.