BMC Pregnancy and Childbirth 2011, 11:22 doi:10.1186/1471-2393-11-22
http://www.biomedcentral.com/1471-2393/11/22

In a randomized controlled trial in Sweden, Li Thies-Lagergren et al compared birth on a birth seat with birth in any other position. The researchers chose the BirthRite Birthing Seat for use in the trial.

The researchers found that women giving birth on the birth seat had a shorter duration of labour. While the birth seat did not reduce the number of instrumental vaginal births, giving birth on a birth seat had no adverse consequences for perineal outcomes (ie, perineal lacerations, tearing or perineal edema), and it was considered that it may even be protective against episiotomies.

The study showed increased blood loss for the birth seat group, but only in the 500–1000 mL range which other studies cited by the researchers have suggested is physiological in a healthy population. There was no significant difference in blood loss over 1000 mL between the experimental and control groups. The researchers noted that blood loss was increased regardless of birth position if women had been exposed to synthetic oxytocin augmentation during the first stage of labour.

Who decides the position for birth? A follow-up study of a randomized controlled trial. [Submitted]. 2013
http://publications.ki.se/xmlui/handle/10616/41433

“Despite randomisation, women who gave birth on the birth seat reported to a higher degree that they themselves had made the decision about birth position and felt that they had been given the opportunity to take their preferred position. Women who gave birth on the birth seat reported more often that they felt powerful, protected and self-confident.”

See also research citations from the teaching film, The BirthRite Experience