This study was undertaken to determine whether applying modern formulas for mean sac diameter and crown-rump length to data from the recently published US mifepristone-misoprostol abortion trial would result in differences in assigned gestational ages and a higher rate of complete abortion.
Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Magee-Womens Hospital, Pennsylvania 15213-3180, USA.