Recovery of Oxytocin Responsiveness in Pregnant Human Myometrial Explants After Oxytocin-Induced Desensitization
Status:
Completed
Trial end date:
2014-06-01
Target enrollment:
Participant gender:
Summary
Postpartum hemorrhage (PPH) is a leading cause of maternal morbidity and mortality worldwide
and is caused most commonly by poor uterine muscle tone after delivery. The first line agent
used in the prevention and treatment of PPH is oxytocin, which acts by binding with oxytocin
receptors (OTR) found on myometrial cells to cause uterine contraction.
Women who require augmentation of labour with oxytocin because of inadequate labour
progression are at increased risk of PPH because they have received intravenous oxytocin
which exposes the uterus (and OTR) to doses greater than would normally be found without
medical intervention. This exposure results in OTR desensitization and decreased uterine
sensitivity to oxytocin which may lead to the use of much higher doses of oxytocin (up to 9x)
or other agents for preventing and treating PPH with the potential for causing serious
drug-related morbidity or fatality to the mother.
Currently, in women who have failed labour augmentation and need to have a Cesarean delivery,
it is not known if it would be beneficial to wait a certain period of time after
discontinuing intravenous oxytocin before proceeding with the operation. The goal of the
waiting time would be to allow the OTRs to recover and resensitize the uterus to the effects
of oxytocin to avoid the need for high doses or additional uterus-contracting agents.
Our hypothesis is that there will be a positive correlation between the magnitude of recovery
of the myometrium's response to oxytocin and the time elapsed from the desensitizing oxytocin
pretreatment (simulated labour augmentation).
Phase:
N/A
Details
Lead Sponsor:
Samuel Lunenfeld Research Institute, Mount Sinai Hospital