作者单位:University of Utah, Department of Obstetrics and Gynecology, 30 North 1900 East, Salt Lake City, UT[1]Planned Parenthood of Orange and San Bernardino Counties, Orange, CA, United States[2]University of Michigan, Department of Obstetrics and Gynecology, Ann Arbor, MI, United States[3]University of Utah School of Medicine, Salt Lake City, UT, United States[4]