- One study was retrieved that met inclusion criteria. This study was a recent systematic review examining the benefits and risks of vertical compared to lateral positions during second stage labour. It included an assessment of the use of birth stools compared to the supine position.
- The systematic review reported an increase in second degree perineal tears (OR=3.18 95% CI 1.68 to 6.06) in women using birth/squatting stools compared to women in the supine position. There was no statistical difference (OR=1.54, 95% CI 0.26 to 9.00) in the incidence of third and forth degree tears in women using the birth/squatting stool compared to those using the supine position.
- The methodology of the review met the validity criteria and therefore the potential for bias is minimal.