Birth ball for pregnant women in labour research protocol: a multi-centre randomised controlled trial.

Background: Birth ball is one of the non-pharmacologic pain relief methods to help mothers cope with the labouring process. A randomised controlled trial (RCT) is conducted to evaluate the effectiveness, safety and harm of birth ball use by pregnant women in labour compared to treatment as usual group.

Methods: A prospective multi-centre randomised controlled trial (RCT) will be conducted in Obstetrics and Gynaecological units of five public hospitals in Hong Kong, China.