dou•la
noun. Greek work meaning "A women who serves."
A doula is a trained labor assistant who provides emotional and physical support during childbirth, as well as information about pregnancy, childbirth, and parenting.
As defined by Doulas of North America (DONA)…

A Birth Doula:

• Recognizes birth as a key experience the mother will remember all her life
• Understands the physiology of birth and the emotional needs of a woman in labor
• Assists the woman in preparing for and carrying out her plans for birth
• Stays with the woman throughout the labor
• Provides emotional support, physical comfort measures and an objective viewpoint, as well as helping the woman get
  the information she needs to make informed decision
• Facilitates communication between the laboring woman, her partner and her clinical care providers
• Perceives her role as nurturing and protecting the woman's memory of the birth experience
• Allows the woman's partner to participate at his/her comfort level
~ DONA, 2009
  

Clinical studies have shown that using a birth doula improves outcomes of birth in the following ways:

• Reduced cesarean rate
• Shorter labors
• Reduced epidural use
• Reduced pitocin use
• Reduced use of analgesia
• Reduced use of forceps delivery
~ Mothering the Mother, Klaus, Kennell, and Klaus (1993)

According to a study about labor support at Brown University Medical School:

“Continuous caregiver support during childbirth has a number of benefits with minimal to no risks. It was less likely that women would need pain medications or have an operative vaginal delivery, a cesarean section, or a five-minute Apgar score of less than 7 when they had an experienced female care-giver…with them continuously during labor and delivery. Benefits were independent of whether the patient's husband or partner was also present.”
~ Julie Scott Taylor, M.D. Assistant Professor of Family Medicine Brown University Medical School

For more general information about doulas, please visit DONA.