A protocol for developing a core outcome set for ectopic pregnancy oleh Krystle Y. Chong, Sarah Solangon, James Kemper, Kurt Barnhart, Pamela Causa Andrieu, Perrine Capmas, Carolina Chacon, George Condous, Liesl de Waard, James M. N. Duffy, Andrew Horne, Maria Memtsa, Femke Mol, Munira Oza, Annika Strandell, Madelon van Wely, Janneke van’t Hooft, Lan N. Vuong, Jian Zhang, Davor Jurkovic, Ben W. Mol, International Collaboration on Core Outcomes in Ectopic Pregnancy