- 50% reduction in the cesarean rate
- 25% shorter labor
- 60% reduction in epidural requests
- 40% reduction in oxytocin use
- 30% reduction in analgesia use
- 40% reduction in forceps delivery 
 Mothering the Mother: How a Doula Can Help You Have a Shorter Easier and Healthier Birth, Klaus, Kennell, and Klaus (1993).
Women who received continuous labour support were more likely to give birth ‘spontaneously’, i.e. give birth with neither caesarean nor vacuum nor forceps. In addition, women were less likely to use pain medications, were more likely to be satisfied, and had slightly shorter labours. Their babies were less likely to have low five-minute Apgar scores. No adverse effects were identified. We conclude that all women should have continuous support during labour. Continuous support from a person who is present solely to provide support, is not a member of the woman’s social network, is experienced in providing labour support, and has at least a modest amount of training, appears to be most beneficial.
 Continuous support for women during childbirth. Hodnett ED, Gates S, Hofmeyr G, Sakala C Published Online: 15 July 2013 http://summaries.cochrane.org/CD003766/PREG_continuous-support-for-women-during-childbirth
American Journal of Public Health:
[W]omen supported by doulas were more racially/ethnically diverse, were slightly older (27 vs 25 years), and had lower reported rates of gestational hypertension (3.8% vs 7.8%). Medicaid-funded births to women with doula support had a cesarean rate of 22.3% (95% CI = 19.8, 24.8), significantly lower than the cesarean rate in the general Medicaid population of 31.5% (95% CI = 31.3, 31.6). The average preterm birth rate was lower for women who received doula support than for Medicaid beneficiaries generally (6.1% vs 7.3%), but this difference was not statistically significant in uncontrolled comparisons.
 Doula Care, Birth Outcomes, and Costs Among Medicaid Beneficiaries. Am J Public Health. Katy Backes Kozhimannil, PhD, MPA, Rachel R. Hardeman, MPH, Laura B. Attanasio, BA, Cori Blauer-Peterson, MPH, and Michelle O’Brien, MD, MPH Published online 2013 April. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3617571/