['The purpose of this study was to compare the accuracy of first-trimester pelvic sonography done by physicians after a 2-week emergency ultrasound elective to similarly numbered examinations done by physicians longitudinally over several years of residency training.', 'We conducted a secondary analysis of a previously reported prospective study of pelvic sonography for symptomatic first-trimester pregnancy. The 21st through 40th examinations were compared between those who completed an emergency ultrasound elective and those who did not. The reference standard was pelvic sonography done by the department of radiology.', 'Eighty-six examinations (34%) were done by 12 operators who did not participate in an emergency ultrasound elective, and 171 examinations (67%) were done by 13 operators who completed an emergency ultrasound elective. There was no statistical difference between the groups with regard to identifying an intrauterine pregnancy, molar pregnancy, ectopic pregnancy, or adnexal mass.'] Does a 2-week elective experience provide comparable training as longitudinal exposure during residency for pelvic sonography?