A two–centre Randomised Double Blind Controlled Trial comparing Intramuscular Diamorphine and Intramuscular Pethidine for labour analgesia – the IDvIP study


To evaluate maternal and neo-natal efficacy and safety of intramuscular diamorphine 7.5mg versus intramuscular pethidine 150mg for labour pain.



Primary maternal outcome measures are pain intensity using visual analogue scores (VAS) over a period of three hours after administration of the trial drug and average pain intensity over that period.

Primary neonatal outcome measures are the need for neonatal resuscitation and Apgar scores of <7 at 1 minute.


Secondary outcome measures include the following:-

a) Pain intensity on VAS on each measurement occasion;

b) Average verbal pain intensity over first 3 hours;

c) Verbal pain intensity on each measurement occasion;

d) Average pain relief score over the first 3 hours;

e) Pain relief score on each measurement occasion;

f) Average maternal sedation and nausea score over first 3 hours;

g) Neonatal meconium staining, CTG trace, umbilical artery and venous pH, oxygen saturation over first 2 hours, time from delivery to first breath, Apgar scores, use of naloxone and admission to NICU;

h) Neonatal breast feeding behaviour during the first 2 hours of delivery and time of delivery to first feed.


To ascertain women’s overall views on whether they would use the same analgesia again

To ascertain health professional’s, particularly midwives’ views on the efficacy of the trial drug and its side effects in terms of maternal sedation, nausea and vomiting.



Research for Patient Benefit grant and Western Comprehensive Local Research Network support costs over 3 years.


BU researchers

Michael Wee (Chief investigator) – Poole Hospital NHS Foundation Trust

Jenny Tuckey (Principal investigator) – Royal United Hospital, Bath



Peter Thomas, Professor of Health Care Statistics and Epidemiology (Bournemouth University), Dorset Research and Development Support Unit

Debra Bick, Professor of Evidence Based Midwifery Practice, Kings College, London.

Elizabeth Davey, Senior Lecturer in Midwifery, Bournemouth University.

Robert Sawdy, Consultant Obstetrician, Poole Maternity Unit