MBM Trial Information
Stillbirth directly affects over 2,700 families in Australia and New Zealand (ANZ) each year and is associated with devastating and long-lasting psychosocial impact. Stillbirth rates have shown little improvement for over two decades. Maternal reporting of decreased fetal movements (DFM), the most frequent cause for unscheduled antenatal visits, is strongly associated with an increased risk of stillbirths. Maternal perception of DFM has been proposed as a simple, inexpensive screening tool for stillbirth. However women’s awareness of the importance of DFM and/or delay in seeking health care is suboptimal. The Lancet’s Stillbirth Series included DFM in the top 10 research priorities for stillbirth prevention, and preliminary data suggests that interventions to increase maternal awareness of DFM, including the option of counting fetal movements, reduces delays in women reporting to health care facilities and stillbirth rates. Robust evidence is needed to assess the benefits and potential harms, including unnecessary intervention and negative psychosocial impact.
The objective of the MBM trial is evaluate the effectiveness of the MBM package of interventions on stillbirth at 28 weeks or more, across maternity facilities in Australia and New Zealand.
A stepped wedge cluster randomised controlled trial.
Women with a singleton pregnancy attending for antenatal care; and midwives and doctors providing maternity care at the participating hospitals.
Maternity hospitals rather than individual patients will be randomised in a stepped design to sequentially introduce the intervention. The intervention includes the MBM package of interventions consisting of (1) a mobile phone software program designed to increase maternal awareness of fetal movements and reduce delay in reporting of DFM, and (2) an education program for clinicians around the use of MBM and best-practice management of women reporting DFM.
Primary outcome: Stillbirth at 28 weeks or more gestation.
Secondary outcomes: a) composite measure of adverse neonatal outcomes; b) health service utilisation measures; and c) woman’s psychosocial outcomes and health seeking behaviour and acceptability.
The study will include 27 hospitals in ANZ with an average of 3,170 singleton births per year (range: 1400, 7000) giving 256,700 total births over 3 years. The current stillbirth rate >28weeks is 3 per 1000. We therefore would expect (without the MBM package to raise maternal awareness and early reporting of DFM) 770 stillbirths (>28weeks), with 10% due to major congenital abnormalities where the intervention is unlikely to have an effect, leaving 693 stillbirths. MBM is hypothesised to reduce the rate to 2 per 1000.
Statistical power assumptions: significance level of 5%; analysis by generalised linear mixed model; births equally distributed across hospital groupings; baseline stillbirth rate 0.3%; intervention stillbirth rate: 0.2%; intra-class correlation (ICC)=0.005.
We propose sequential introduction of the intervention into 8 groups of 3-4 hospitals at four month intervals; over a total of three years. This will give 89% power to detect a 30% relative risk reduction in stillbirth rates (from 3/1000 to 2/1000), 85% power to detect a 25% reduction, and 80% power to for a 15% reduction. The trial methods have been harmonised with that of a trial in Scotland (led by Jane Norman) (330,000 births over 3 years). Combining data from the two trials (786,700 births), would give 89% power to detect a 10% decrease in stillbirth rates.
8 August 2016