Evaluation of the Quality of Evidence Supporting Obstetrical Recommendations in ACOG Practice Bulletins and RCOG Green Top Guidelines [ID 1034]

INTRODUCTION: Practice Bulletins (PBs) by the American College of Obstetricians and Gynecologists (ACOG) and Green-top Guidelines (GTGs) by the Royal College of Obstetrics and Gynaecology (RCOG) guide clinical practices. Previous analyses reveal that most recommendations lack Grade A evidence, and are not based on randomized clinical trials (RCTs). This descriptive study evaluates the quality of evidence supporting ACOG and RCOG obstetrical recommendations. METHODS: We reviewed obstetrical RCOG GTGs available as of September 2024, checking each citation in PubMed for RCT status. Quality assessments were not made independently. The senior author verified a random 10% of data (B.J.F.H.). We used an established ACOG obstetrical PB database previously reviewed by our group using the same methodology. Data were recorded and summarized in Excel. RESULTS: The American College of Obstetricians and Gynecologists lists 48 obstetrical PBs with 507 recommendations linked to 800 references. The Royal College of Obstetrics and Gynaecology has 37 obstetrical GTGs with 1,858 recommendations supported by 3,674 references. When omitting recommendations based on expert opinion, 137/317 (43%) of ACOG and 98/560 (18%) of RCOG recommendations are Grade A (based on high-quality evidence). Thirty-seven percent of PBs and 43% of GTGs rely on consensus and expert opinion. Of the cited references, 13% for PBs and 10% for GTGs are Evidence Level 1 (highest quality), with 7% being RCTs for both. CONCLUSIONS/IMPLICATIONS: Among the recommendations, 71% of PBs and 69% of GTGs have identifiable references. However, 37% of PB and 43% of GTG references are nonanalytical studies or expert opinions. Our findings highlight the need for more high-quality evidence in guidelines and suggest further research in evidence-based obstetrical care.