Abbreviations: ACOG: American College of Obstetricians and Gynecologists; AGREE II: Appraisal of Guidelines for Research and Evaluation II; CPG: clinical practice guideline or guidance; DCOI: declaration of conflict of interests; NICE: National Institute of Health and Care Excellence; NHLBI: National Institutes of Health, National Heart, Lung, and Blood Institute; PICO: patient population -intervention(s)-comparison(s)-outcome(s); and RCOG: Royal College of Obstetricians and Gynaecologists. *Comments specific to certain CPG(s) were indicated by parentheses.