{
    "abstract": "To determine the effect of propranolol on myometrial contractions induced by low dose and high dose oxytocin.\nProspective ex\u00a0vivo laboratory study.\nMount Sinai Hospital, Toronto.\nFull-term parturients who underwent elective caesarean deliveries (CD).\nTwo models were developed in the organ bath chamber using myometrial samples obtained during CDs: (i) Labor induction-augmentation model with low-dose oxytocin consisting of 3 groups with the administration of propranolol before and during simulated labor, and a control group. (ii) Postpartum haemorrhage (PPH) model with high-dose oxytocin consisting of 4 groups with the administration of propranolol during and/or after augmented labor (desensitised with oxytocin), and a control group.\nMyometrial contractility was recorded using force transducers.\nIn the labor induction-augmentation model, propranolol pre-treatment produced a higher area under the curve (AUC) of myometrial contractility induced by low-dose oxytocin (relative percentage difference [diff]: 20.4%; 95% CI [1.4%, 43.2%], p\u2009=\u20090.035) compared to control; however, no difference was observed when propranolol was given after the initiation of labor. In the oxytocin-desensitised PPH model, the AUC of myometrial contractility induced by high-dose oxytocin was improved with propranolol pre-treatment (diff 25.4% [0.2%, 56.8%], p\u2009=\u20090.048), co-treatment (diff 26.7% [3.7%, 54.7%], p\u2009=\u20090.02), and both pre- and co-treatment (diff 28.4% [7.0%, 54.1%], p\u2009=\u20090.007) when compared to the control group.\nOur ex\u00a0vivo study suggests that propranolol can augment uterine activity by approximately 20%-25% when administered early during labor induction and augmentation. Clinical studies are warranted to determine the relevance of these findings in\u00a0vivo.\nClinicalTrials.gov Identifier: NCT03434444; https://clinicaltrials.gov/.",
    "authors": [
        {
            "affiliation": "Department of Anesthesia and Pain Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.\nDepartment of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.\nDepartment of Physiology, University of Toronto, Toronto, Ontario, Canada.\nLunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada.",
            "firstname": "Mrinalini",
            "initials": "M",
            "lastname": "Balki"
        },
        {
            "affiliation": "Department of Anesthesia and Pain Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "Lauren M",
            "initials": "LM",
            "lastname": "Miller"
        },
        {
            "affiliation": "Department of Anesthesia and Pain Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.",
            "firstname": "Jayalakshmi",
            "initials": "J",
            "lastname": "Caliaperumal"
        },
        {
            "affiliation": "Biostatistics Department, University Health Network, Toronto, Ontario, Canada.",
            "firstname": "Stella",
            "initials": "S",
            "lastname": "Wang"
        },
        {
            "affiliation": "Biostatistics Department, University Health Network, Toronto, Ontario, Canada.",
            "firstname": "Ella",
            "initials": "E",
            "lastname": "Huszti"
        },
        {
            "affiliation": "Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.\nLunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada.",
            "firstname": "John C",
            "initials": "JC",
            "lastname": "Kingdom"
        }
    ],
    "conclusions": null,
    "copyrights": "\u00a9 2025 The Author(s). BJOG: An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd.",
    "doi": "10.1111/1471-0528.18146",
    "journal": "BJOG : an international journal of obstetrics and gynaecology",
    "keywords": [
        "caesarean delivery",
        "labor augmentation",
        "labor induction",
        "myometrial contractility",
        "oxytocin",
        "primary postpartum haemorrhage",
        "propranolol"
    ],
    "methods": null,
    "publication_date": "2025-03-25",
    "pubmed_id": "40129234",
    "results": "In the labor induction-augmentation model, propranolol pre-treatment produced a higher area under the curve (AUC) of myometrial contractility induced by low-dose oxytocin (relative percentage difference [diff]: 20.4%; 95% CI [1.4%, 43.2%], p\u2009=\u20090.035) compared to control; however, no difference was observed when propranolol was given after the initiation of labor. In the oxytocin-desensitised PPH model, the AUC of myometrial contractility induced by high-dose oxytocin was improved with propranolol pre-treatment (diff 25.4% [0.2%, 56.8%], p\u2009=\u20090.048), co-treatment (diff 26.7% [3.7%, 54.7%], p\u2009=\u20090.02), and both pre- and co-treatment (diff 28.4% [7.0%, 54.1%], p\u2009=\u20090.007) when compared to the control group.",
    "title": "Propranolol and Oxytocin-Induced Contractility in Gravid Human Myometrium: An Ex\u00a0Vivo Laboratory Study.",
    "xml": "<Element 'PubmedArticle' at 0x788503464b30>"
}