Rapid Estimation of Plasma Fibrinogen Concentration and Its Use as a Guide to Therapy of Intravascular Defibrination**The author is indebted to Drs. William C. Moloney and Charles L. Sullivan of St. Elizabeth’s Hospital, Brighton, Mass.; to Drs. Harold N. Gordon and George H. Agnew of Florence Crittenton Hospital, to Drs. Palmer E. Sutton and William Η. Koehler of Woman’s Hospital, and especially to Dr. Robert G. Braden, of Herman Kiefer Hospital, Detroit, for availability and timely notification of cases of abruptio placentae.††This investigation was supported in part by a grant from the Medical Research Development Board, Office of the Surgeon General, Department of the Army. The opinions or assertions contained herein are the private ones of the author and are not to be construed as official or reflecting the view of the Department of the Army.