Historical trends in the timing of informed consent for research into intrapartum complications.

Obtaining informed consent for clinical trials involving the management of intrapartum complications is complex. This article describes the strategies used to obtain consent over the last 60 years using data from the Cochrane Library. Of 138 intrapartum randomised studies, 37% had no record of the consent procedures. Of the remainder, 74% sought consent only when the complication developed, 11% sought consent from all women in early labour, and 13% gave all women antenatal information and then sought written consent when the complication arose. Despite the existence of ethics guidelines for intrapartum consent, many studies fail to follow their advice.