A Pilot RCT on the Management of Term Prelabour Rupture of Membranes

Overview

This is a pilot study that will eventually result in a main randomised controlled trial that will look at what management is associated with a higher rate of normal birth and a lower rate of chorioamnionitis (maternal infection) when women break their waters but labour does not start. Spontaneous rupture of the membranes (when the waters break) at term (37-42 weeks gestation) is a physiological event that happens during labour. However, according to Gunn et al. (1970) in 8-10 % of the cases the membranes rupture before labour starts. The time between the rupture and the onset of labour is called latent phase and time wise is variable. Studies have showed no statistically significant differences in terms of neonatal infection or chorioamnionitis when the investigators induce labour with prostaglandins compared to when labour starts spontaneously (Hannah et al 1996). Seaward et al. (1997) noted a number of confounding factors that might relate to the incidence of chorioamnionitis (maternal infection), the strongest predictor was having more than 8 vaginal examinations since the rupture of membranes and before delivery which was a stronger predictor than the duration of the latent phase. It is thought that by reducing the number of internal examinations, chorioamnionitis may be reduced, and hence neonatal infection may also be reduced. The main RCT will compare clinical outcomes and maternal satisfaction when women consent to be randomized to four groups: (1) Active management and routine internal examinations during labour, (2) Active management and reduced internal examinations, (3) Expectant management and routine internal examinations, (4) Expectant management and reduced internal examinations. This application seeks ethics approval for the pilot phase to ensure that a definitive study can be undertaken appropriately. It is important to test that all the components work well individually and as a whole, to estimate sample size and ultimately to test the integrity of the research protocol before embarking on the main trial.