Author/Country	Type of Study	Results
Untrained volunteer lay women as labor support persons
Sosa et al., 1980,[11] Guatemala	RCT; n = 40 Primagravidas at term	Support group had shorter labors,* less use of oxytocin,* fewer assisted and operative deliveries,* fewer depressed infants,* more time awake,† stroking,* talking with,‡ and smiling at‡ their infants
		No differences in use of analgesia or in amount of time spent in body-to-body contact, en face, looking at the baby, or nursing
Klaus et al., 1986,[12] Guatemala	RCT; n = 465Primigravidas at term	Support group had shorter labors,* less use of oxytocin,* fewer assisted,* and operative‡ deliveries, and fewer NICU admissions
		No differences in use of analgesia
Unfamiliar trained lay women (doulas) as labor support persons
Kennell et al., 1991,[4] USA	RCT; n = 616 Nulliparas at term 3 groups: support, no support, and observed only	Among women with SVDs, support and observed groups had less use of epidural analgesia*
		Among all participants: support group had shorter labors,† less use of oxytocin,* fewer assisted,* and operative‡ deliveries, fewer newborn sepsis evaluations,* and fewer NICU admissions‡; observed group had shorter labors,† less use of oxytocin,* fewer assisted* and operative‡ deliveries, fewer newborn sepsis evaluations,† and fewer NICU admissions†
Langer et al., 1998,[14] Mexico	RCT; n = 363 Nulliparas	Support group had shorter labors, higher rates of breastfeeding at 1 month and greater perceived control over delivery experience
		No differences in use of oxytocin or epidural analgesia, mode of delivery, or Apgar scores
Female relatives as labor support persons
Madi et al., 1999,[5] Botswana	RCT; n = 109 Primigravidas at term	Support group had less use of oxytocin† less use of analgesia,† fewer amniotomies to augment labor,† more vaginal deliveries,† fewer assisted and operative deliveries†

RCT = randomized controlled trial; n = number; SVD = spontaneous vaginal delivery; NICU = neonatal intensive care unit.
^*P < .001.
^†P </= .05.
^‡P </= .01.

Author/Country	Type of Study	Results
Gagnon et al., 1997,[15] Canada	RCT; n = 413 Nulliparas at term	Support group had less use of oxytocinNo differences in duration of labor, use of oxytocin or epidural analgesia, mode of delivery, perineal trauma, or NICU admissions
Hodnett et al., 2002,[16] USA/Canada	RCT; n = 6,915 Women with live singleton fetus or twins >/=34 weeks' gestation	Support group had less augmentation of labor* and less continuous EFM,† and supported women experienced greater control during childbirth†
		No differences in duration of labor, epidural use, mode of delivery, perineal trauma, postpartum complications and length of stay, neonatal outcomes, perceived control over delivery, or postpartum depression

RCT = randomized controlled trial; n = number; NICU = neonatal intensive care unit; EFM = electronic-fetal monitoring.
^*P </= .05.
^†P </= .01.

Author/Country	Type of Study	Results
Hodnett and Osborn, 1989,[17] Canada	RCT; n = 103 Women in last trimester whose husband or partner attended the birth	Support group had less use of analgesia,* anesthesia,* and stirrups,* had more intact perineums,* and had more use of oxytocin*
		No differences in rates of assisted or operative birth

Monitrice denotes a lay midwife or midwife-in-training acting solely as a birth attendant; RCT = randomized controlled trial; n = number.
*P < .001.