<qa>  What is the random permuted block method of randomization used?Patients will be assigned to one of two treatment groups with a randomization sequence prepared and maintained centrally by the database. The random permuted block method of randomization will be used because it guarantees that at no time during randomization will the imbalance be large and at certain points the number of patients in each group will be equal. Because the study is unblinded, random block sizes will be used. Randomization will be stratified by clinical center, parity, and age to assure balance between the two treatment groups with respect to anticipated differences in the patient population and possible differences in patient management. 