Cervical Pessary versus Expectant Management for the Prevention of Delivery Prior to 36 Weeks in Women with Placenta Previa: A Randomized Controlled Trial oleh Irene A. Stafford, Thomas J. Garite, Kimberly Maurel, C. Andrew Combs, Kent Heyborne, Richard Porreco, Michael Nageotte, Susan Baker, Sameer Gopalani, Chi Dola, Helen How, Anita F. Das