Oxytocin Measures
Oxytocin Measures exists to promote the benefits of the licensed directions for intravenous administration of oxytocin.
Click on the link below
Watch the Midlands Midwifery Festival Video 2020
'Induction of Labour - Challenging Unlicensed Synthetic Oxytocin in Obstetrics'. We hope you enjoy our video. Take a moment to drop us a line if you have any questions. Correction to video previous role in B'ham
Why?
Because, in 2001 the Royal College of Obstetricians and Gynaecologists 'advised' in a new policy document for induction of labour, that synthetic oxytocin should be used according to more concentrated dilutions than are licensed, and that - at the same time - the rates of infusion can be increased skipping over several possible licensed steps at once.
We believe these sharp increases may diminish the normal pattern of release of natural oxytocin, so that the optimum rate of infusion to enhance or promote as natural a labour as possible, may be missed - unnecessarily.
We (Monica Tolofari and Linn Shepherd) who have, in the past, used synthetic oxytocin according to the licensed directions, achieving an extremely low postpartum haemorrhage rate, want to flag up the aforementioned change to practice as well as that the postpartum haemorrhage rate (35% instead of 3-5%) is off any previous scale.
Frequently asked questions
Take a look at our FAQ section where we’ve answered some of the most popular questions.
Blogs - Go to the Top menu for further blogs
Definitions of Oxytocin
When we began our research we had never considered the possibility of synthetic oxytocin in dry weight, but there it was in a medical dictionary online (since removed) stating that 1 mg = 500 International Units.
.
In Advances in Oxytocin Research (Pinkerton, 1965) obstetricians were calculating dosages on 1 mg = 450 International Units. (Berde noted.)
Prior to the synthesis of oxytocin (1953), when bovine oxytocin was in use, the weights and measures of medicines were in a different system of terminology, mentioned by Theobald et al (1948) in ‘The use of post-pituitary extract in physiological amounts in obstetrics’.
According to an entry in Wikipedia, this system was abolished in 1971 after a crossover period following decimalisation in 1965.
G W Theobald refused to use more than 5 mIU per minute on any of his patients. With this slow regime he successfully introduced induction of labour to prevent eclampsia with its inevitable losses, in all the women with raised blood pressure at home, who could be persuaded to become in-patients for diet, rest and blood pressure observations.
Theobald GW. Home on the second day: the Bradford experiment. British Medical Journal. December, 1959;2(5163):1364–1367
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1990899 (Full article)
CH Rodeck summarises the breadth and depth of Theobald’s thinking in Theobald’s obituary, having been one of Theobald’s students.
By the mid-1960s buccal oxytocin was being trialled. Chung (1966) followed the buccal oxytocin recommended dosage (illustrated) in his small trial report, as did other obstetricians with some severely adverse results (ruptured uteri), which prompted them to return to the very controllable dosage-per-minute synthetic oxytocin intravenous infusions.
Pre-synthesis, oxytocin’s use had been a voyage of carefully documented discovery (since 1927, Points from Letters, Archer, 1969) and likewise with early use of synthetic oxytocin by intravenous infusion, but due to failed inductions and the length of time (days) that it could take to induce a labour with<8mIU per minute during the pre-prostaglandins era, some obstetricians
experimented with off-licence regimes. Turnbull and Anderson, 1968, used a doubling regime -
After a similar experiment by Brindsen and Clark (1978) their note to the British Medical Journal of rising postpartum haemorrhage (PPH) rates prompted Mr I Z MacKenzie of Oxford to review past cases, noting that while PPH rates had risen, when the use of PGE2 had prompted labour without synthetic oxytocin, the PPH rate was lower. Oxford’s synthetic oxytocin infusion regime was not defined, so questions remain.
Beazley et al (1975) published Maintenance of Labour, finding 7 mIU per minute adequate. Steer et al (1975) found 8 mIU per minute maintained labour, the Abstract in Steer’s study commented that contractions were more robust when the membranes were left intact. (Prostaglandins were still being researched at this time and were not used in these two trials.)
Irregular presenting parts cushioned by the perfect circle of membranes for as long as possible may benefit the length and outcomes of labours.
In 2010, the World Health Organisation determined that the biological activity of 1 mg synthetic oxytocin = 600 International Units.
When rates and strengths of infused dilutions are always physiological, this protects the fetus from too much oxytocin, and maternal soft tissues from long term damage. Mylan, paragraph 4.8 Undesirable Effects
Now that we know the placenta produces oxytocin (Vrachnis et al, 2011), and that enhancement of contractions involves fetal tissues, we suggest that this knowledge should enter the thinking culture of labour wards.
Contined BLOG: PostPartum Haemorrhage and Synthetic oxytocin Dilutions in labour
How to administer the licensed ‘recommended dosage range’
via ‘variable speed motor-driven infusion pump’.
The reason for this study was a growing awareness of excessive rates of postpartum haemorrhage in association with unlicensed synthetic oxytocin