17 alpha-hydroxyprogesterone caproate to prevent prematurity in nulliparas with cervical length less than 30 mm

William A. Grobman, Elizabeth A. Thom, Catherine Y. Spong, Jay D. Iams, George R. Saade, Brian M. Mercer, Alan T.N. Tita, Dwight J. Rouse, Yoram Sorokin, Ronald J. Wapner, Kenneth J. Leveno, Sean Blackwell, M. Sean Esplin, Jorge E. Tolosa, John M. Thorp, Steve N. Caritis, J. Peter Van Dorsten