Metformin in the prevention of type 2 diabetes after gestational diabetes in postnatal women (OMAhA): a UK multicentre randomised, placebo-controlled, double-blind feasibility trial with nested qualitative study

• Published in: BMJ open 2023-11, Vol.13 (11), p.e073813-e073813
• Main Authors: Bolou, Angeliki, Drymoussi, Zoe, Lanz, Doris, Amaefule, Chiamaka Esther, Gonzalez Carreras, Francisco Jose, Pardo Llorente, Maria del Carmen, Dodds, Julie, Pizzo, Elena, Thomas, Amy, Heighway, James, Harden, Angela, Sanghi, Anita, Hitman, Graham, Zamora, Javier, Pérez, Teresa, Huda, Mohammed S B, Thangaratinam, Shakila
• Format: Article
• Language: English
• Subjects: Antidiabetics; diabetes & endocrinology; Diabetes and Endocrinology; diabetes in pregnancy; Diabetes Mellitus, Type 2 - drug therapy; Diabetes Mellitus, Type 2 - prevention & control; Diabetes, Gestational - drug therapy; Diabetes, Gestational - prevention & control; Double-Blind Method; Feasibility; Feasibility Studies; Female; Gestational diabetes; Glucose; Health services; Humans; Informed consent; Inner city; Insulin resistance; Intervention; Medical personnel; Metformin - therapeutic use; Midwifery; Ovaries; Polycystic ovary syndrome; postpartum women; Pregnancy; Prevention; preventive medicine; public health; Qualitative research; Schedules; State Medicine; United Kingdom; Womens health
• ISSN: 2044-6055; 2044-6055
• DOI: 10.1136/bmjopen-2023-073813

ObjectiveTo determine the feasibility of a definitive trial of metformin to prevent type 2 diabetes in the postnatal period in women with gestational diabetes.DesignA multicentre, placebo-controlled, double-blind randomised feasibility trial with qualitative evaluation.SettingThree inner-city UK National Health Service hospitals in London.ParticipantsPregnant women with gestational diabetes treated with medication.Interventions2 g of metformin (intervention) or placebo (control) from delivery until 1 year postnatally.Primary outcome measuresRates of recruitment, randomisation, follow-up, attrition and adherence to the intervention.Secondary outcome measuresPreliminary estimates of glycaemic effects, qualitative exploration, acceptability of the intervention and costs.ResultsOut of 302 eligible women, 57.9% (175/302) were recruited. We randomised 82.3% (144/175) of those recruited, with 71 women in the metformin group and 73 women in the placebo group. Of the participants remaining in the study and providing any adherence information, 54.1% (59/109) took at least 75% of the target intervention dose; the overall mean adherence was 64% (SD 33.6). Study procedures were found to be acceptable to women and healthcare professionals. An increased perceived risk of developing type 2 diabetes, or a positive experience of taking metformin during pregnancy, encouraged participation and adherence to the intervention. Barriers to adherence included disruption to the medication schedule caused by the washout periods ahead of each study visit or having insufficient daily reminders.ConclusionsIt is feasible to run a full-scale definitive trial on the effectiveness of metformin to prevent type 2 diabetes in women with gestational diabetes, during the early postnatal period. Adherence and engagement with the study could be improved with more regular reminders and potentially the addition of ongoing educational or peer support to reinforce messages around type 2 diabetes prevention.Trial registration numberISRCTN20930880.