Group C was added after the trial, when it became clear that the presence of a silent observer improved outcomes, possibly by influencing staff behavior or by ensuring that the women were not alone. Independent doulas are employed directly by the parents. They usually have telephone contact and at least one prenatal meeting with their clients to establish a relationship. When labor begins, the doula arrives and stays with the woman until after the birth. A postpartum meeting to process the birth is usually included in the doula's service.
Most doulas charge a flat fee for their services, and many base their fees on a sliding scale.
Some doula programs are associated with or administered by a hospital or community service agency. The doulas may be volunteers or paid employees of the hospital or agency. These programs vary widely in their design. In some, the hospital or agency contracts with an independent community-based doula group to provide the doulas. Others train and employ their own staff of doulas.