Baylor College of Medicine, Houston, Texas*; and Institute of Hematology and Blood Transfusion, Prague, Czech Republic †
Correspondence: Raymond H. Kaufman, MD, Departments of Obstetrics and Gynecology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030.
* Supported by contract #200-92-0537 Centers for Disease Control and Prevention, Atlanta, GA.
† Supported by the Internal Grant Agency of The Ministry of Health, Czech Republic No.: IGA - MZ 4069-3 and by the Granting Agency of Czech Republic No.: 312/99/0542.