Plain English Summary
Background and study aims
Excessive bleeding after giving birth is a major complication of pregnancy globally. Bleeding after delivery is known as postpartum haemorrhage (PPH). PPH can result from a failure of the uterus (womb) to contract properly following birth. In the UK PPH occurs in 10% of births and additional treatments are needed to control the bleeding. This can include surgical removal of the womb, blood transfusion and prolonged hospital stay. Research has shown that women who experience PPH are less likely to want another child and 60% of those who have another pregnancy experience anxiety.
The current method of preventing PPH involves using a uterotonic drug to help the womb contract following delivery. The use of a uterotonic drug along with cutting of the umbilical cord and delivery of the placenta by controlled traction of the cord is known as Active Management of the Third Stage of Labour (AMTSL). AMTSL reduces the risk of PPH by 66%. Two thirds of pregnant women who experience PPH have no risk factors, so AMTSL is currently offered to all pregnant women. In the UK Syntometrine and Syntocinon are the two most commonly uterotonic drugs used in AMTSL. Both of these drugs mimic the natural hormone in the body that causes the uterus to contract. Syntometrine contains ergometrine which makes its affects last longer. However, this medication is associated with nausea, vomiting, and high blood pressure, and in some rare cases it has been linked to stroke which has been fatal. Syntometrine is known to be better at preventing moderate blood loss but not severe blood loss. Currently international guidelines recommend Syntocinon as the medicine of choice for AMTSL. At Southmead Hospital in Bristol a telephone survey of all consultant-lead maternity units in the UK was conducted to find out whether the guidelines for AMTSL were being followed. It was found that 71.4% of consultant-lead units still use Syntometrine as their first choice of uterotonic instead of Syntocinon as recommended. Many units reported that they had changed to Syntocinon following the publication of the guidelines but changed back to Syntometrine as they were concerned that their PPH rates had increased with Syntocinon. There is therefore a concern that women are being given a medicine (Syntometrine) that can cause potentially dangerous high blood pressure, and is contrary to national recommendations. A newer uterotonic called Carbetocin is offered for management of the third stage of labour after birth by caesarean section. This medication is not licenced for use in vaginal births. Studies have shown that Carbetocin is more effective at preventing bleeding following birth than Syntometrine. It also has fewer side effects than Syntometrine. Studies comparing Carbetocin and Syntocinon have shown that there is no significant difference in the risk of women bleeding heavily. Furthermore, Carbetocin reduces the need to have additional medication to aid the contraction of the womb. To date there have been no studies directly comparing Syntometrine, Syntocinon and Carbetocin for management of AMTSL in vaginal births. The aim of this study is to compare the effectiveness, side effects and cost of Syntocinon, Syntometrine and Carbetocin in AMTSL in vaginal births.
Who can participate?
Women aged 18 and over with a single pregnancy who are planning to have a vaginal birth
What does the study involve?
Participants are randomly allocated to receive a single dose of either Syntocinon, Syntometrine or Carbetocin, given as an injection into the leg muscle after the vaginal birth of their baby and after the cord has been clamped. All participants are followed up until day 14 after giving birth. The proportion of women requiring additional uterotonic drugs to treat or prevent PPH is measured, along with incidence of PPH, blood transfusion, side effects, health-related quality of life, and cost.
What are the possible benefits and risks of participating?
Carbetocin may cause less nausea, vomiting and high blood pressure than Syntometrine, and Syntocinon causes less of these side effects than Syntometrine. Women who are allocated to either Carbetocin or Syntocinon may have a better overall birth experience because having fewer side effects may allow them to bond with their baby during the first few hours after birth. Not all participants will benefit from taking part in the study but their participation might be helpful to the NHS and to women giving birth in the future. All three drugs are currently used in routine care therefore no serious side effects are expected.
Where is the study run from?
1. Southmead Hospital, North Bristol NHS Trust (UK)
2. St Michael's Hospital, University Hospitals NHS Foundation Trust (UK)
3. Royal United Hospital Bath NHS Trust (UK)
4. Gloucestershire Hospitals NHS Foundation Trust (UK)
5. Nottingham University Hospitals NHS Trust of City Hospital (UK)
6. The Great Western Hospital NHS Foundation Trust (UK)
When is the study starting and how long is it expected to run for?
February 2014 to August 2019
Who is funding the study?
Who is the main contact?
Intramuscular oxytocics: a multi-centre randomised comparison study of intramuscular carbetocin, syntocinon and syntometrine for the third stage of labour following vaginal birth
A quarter of all global pregnancy-related deaths occur due to excessive bleeding after childbirth, or “post partum haemorrhage” (PPH). Active Management of the Third Stage of Labour (AMTSL) after vaginal birth, which includes use of a preventative uterotonic drug, reduces the risk of PPH by 66%.
Syntometrine is most commonly used for this purpose in the UK. Syntocinon is the drug which national guidelines recommend first-line. This is because Syntocinon is less likely to cause nausea , vomiting and transient high blood pressure, and is just as effective as Syntometrine at preventing PPH >1000ml. However, Syntometrine is more effective at preventing PPH of 500-1000ml. This is why maternity units still choose to use it, despite the nausea and vomiting experienced by ~25% of patients.
Carbetocin, a newer uterotonic drug already used during caesarean section, is more expensive but potentially more effective. Previous studies suggest that patients receiving Carbetocin may need fewer additional drugs to treat and prevent PPH than those receiving Syntocinon. Compared with Syntometrine, patients receiving Carbetocin lose less blood and experience fewer side effects. No studies have directly compared these three drugs.
The aim of the study is to compare carbetocin, syntometrine and syntocinon when administered intramuscularly after vaginal birth to prevent primary postpartum haemorrhage, in order to directly compare the:
1. Clinical effectiveness of each drug
2. Maternal side effects experienced with the use of each drug
3. Overall cost of each intervention
NRES Committee South Central - Oxford B, 28/10/2014, ref: 14/SC/1312
Randomised; Interventional; Design type: Treatment, Drug
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
See additional files
Specialty: Reproductive health and childbirth, Primary sub-specialty: Reproductive and Sexual Medicine; UKCRC code/ Disease: Reproductive Health and Childbirth/ Complications of labour and delivery
Patients are randomised to receive Carbetocin, Syntometrine or Syntocinon during the third stage of labour. The intervention is a single dose of intramuscular injection of the randomly allocated study drug (10iU Syntocinon, 500μg/5iU Syntometrine or 100μg Carbetocin) given after vaginal birth of the baby, once the cord has been clamped. Study participants are followed up until day 14 postnatal. Standard intrapartum care will be adopted leading up to, and after, this single-dosed intervention. The primary outcome measure will be the proportion of women requiring additional uterotonic drugs to treat or prevent PPH. Secondary outcomes will include incidence of PPH, blood transfusion, maternal side effects, health-related quality of life, and cost.
Carbetocin, Syntometrine, Syntocinon
Primary outcome measures
Requirement for additional uterotonic drugs. This is defined as the administration, following the administration of Imox IMP and prior to discharge from Delivery Suite (and not more than 24 hours after delivery), of any of the following: Syntocinon (IM/IV), Syntometrine (IM), Carboprost (IM), Carbetocin (IM/IV), Misoprostol (PO/PV/PR). This information is taken from the participant’s medical notes or the maternal database where the information is recorded routinely.
Secondary outcome measures
1. Blood transfusion requirement is measured as the need to have a blood transfusion (including number of units given) following delivery (within 24 hours), at day 1 postnatal and at any point from day 1 to day 14 postnatal
2. Volume of own blood returned to participant (if Cell Salvage used) (ml). Method is this a yes or no documented in the notes. If yes, volume returned within 24 hours of birth
3. Requirement for any other blood products including fresh frozen plasma, cryoprecipitate, Factor VII (number of units of each given) Method is this a yes or no documented in the notes. If yes, number of units within 24 hours of birth
4. Estimated blood loss at delivery (including estimated total blood loss (ml or L) until transfer from Delivery Suite i.e. if there is excessively heavy lochia within 24 hours of birth (ml)
5. Use of prophylactic Syntocinon infusion to reduce the risk of hemorrhage before a diagnosis of PPH; was prophylactic Syntocinon infusion given immediately after birth, yes or no
6. Whether or not a Syntocinon infusion was used to either augment or induce labour. Was Syntocinon infusion given during labour? Yes or no
7. Whether terbutaline 0.25mg was given subcutaneously to reduce uterine hypercontractility during the 2nd stage of labour. Yes or no
8. Duration of third stage of labour (mins)
9. Need for manual removal of placenta in theatre – yes or no, within 24 hours following birth
10. Need for examination under anaesthetic in theatre - yes or no, within 24 hours following birth
11. Use of interuterine balloon tamponade/uterine compression sutures/hysterectomy to control PPH, yes or no, within 24 hours following birth
12. Maternal hypertension in first two postnatal hours, following administration of study drug. Blood pressure readings taken at 1 hour and 2 hours following drug administration
13. Postpartum systolic BP >140mmHg on any occasion in first two postnatal hours (and maximum systolic BP in first two postnatal hours). Blood pressure readings taken at 1 hour and 2 hours following drug administration
14. Postpartum diastolic BP >90mmHg on any occasion in first two postnatal hours (and maximum diastolic BP in first two postnatal hours). Blood pressure readings taken at 1 hour and 2 hours following drug administration
15. Maternal hypotension (BP <90/60) in first two postnatal hours. Blood pressure readings taken at 1 hour and 2 hours following drug administration
16. Intrapartum vomiting – yes or no for vomiting during labour
17. Post-partum vomiting in first two postnatal hours - yes or no for vomiting during two hours postnatal
18. Need for antiemetics in first two postnatal hours - yes or no for for antimetics given during two hours postnatal
19. Time from delivery to discharge from Delivery Suite (either to postnatal ward or home) (mins)
20. Time spent in recovery (mins)
21. Maternal side effects including hypertension, nausea and vomiting, headache, abdominal pain and dizziness will be captured using a maternal questionnaire at 2 hours postnatal. Participants are asked to score their experiences as either none, mild, moderate, severe or severe
22. Health-related quality of life, measured using EQ5D- 5L questionnaire antenatally from 20 weeks gestation, at 1 day postnatal, and day 14 postnatal
23. Cost per patient – length of hospital stay following birth and cost of additional uterotonics
Overall trial start date
Overall trial end date
Participant inclusion criteria
Women must be:
1. ≥18 years of age at time of baby’s birth
2. Must be planning to have a vaginal birth (spontaneous and instrumental)
3. Must have a singleton pregnancy
4. Can be any gestational age
Target number of participants
Planned Sample Size: 6285; UK Sample Size: 6285
Participant exclusion criteria
1. Significant antepartum haemorrhage (>50ml) or suspected or proven placenta abruption
2. Maternal coagulation disorder
3. Multiple pregnancy (twins or higher order)
4. Intrauterine fetal death
5. Patients who would decline blood products if required (i.e., Jehovah's Witnesses - clinicians may have a lower threshold for administering additional prophylactic uterotonic drugs to these patients)
6. Known or suspected hypertensive disorders, including pre-eclampsia,
pregnancy induced hypertension, essential hypertension (even if blood pressure well controlled), and patients with hypertension in labour
7. Patients with peripheral, hepatic or cardiac disease
8. Patients with an allergy or hypersensitivity to any of the active ingredients in Carbetocin, Syntometrine or Syntocinon
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Southmead Hospital (lead site)
Southmead Road Westbury-on-Trym
Trial participating centre
Royal United Hospital Bath NHS Trust
Obstetric/Anaesthetic Research Office 1st Floor PAW Zone D (by D10) RUH Combe Park
Trial participating centre
Gloucestershire Hospitals NHS Foundation Trust
Trust HQ 1 College Lawn
Trial participating centre
Nottingham University Hospitals NHS Trust
City Hospital Hucknall Road
Trial participating centre
University Hospitals Bristol NHS Foundation Trust
Trust Headquarters Marlborough Street
Trial participating centre
The Great Western Hospital NHS Foundation Trust
Funding Body Type
private sector organisation
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The protocol will be published in an open-access peer-reviewed journal. Planned publication of the results in a high-impact peer reviewed journal within 1 year of the last patient last visit.
IPD sharing statement
Anonymised participant-level data will be publicly available for free access within the University of Bristol Research Data Management Depository (https://data.bris.ac.uk/data/group/health-sciences ) for 5 years after the end of the study. The specific DOI will be made available in the publication of results.
Intention to publish date
Participant level data
Stored in repository
Results - basic reporting
- ISRCTN10232550_PIS_V5_05Mar18.pdf Uploaded 06/03/2018