Metformin Impact Maternal and Infant Cardiometabolic Health: MIMICH

  • Research type

    Research Study

  • Full title

    Metformin Impact Maternal and Infant Cardiometabolic Health: MIMICH

  • IRAS ID

    288949

  • Contact name

    Jenny Myers

  • Contact email

    jenny.myers@manchester.ac.uk

  • Sponsor organisation

    University of Manchester

  • ISRCTN Number

    ISRCTN13866189

  • Duration of Study in the UK

    4 years, 11 months, 31 days

  • Research summary


    The prevalence of diabetes in pregnancy is increasing rapidly. Women with a combination of diabetes and vascular disease are six times more likely to develop fetal growth restriction. This means that whilst fetal overgrowth remains a common problem in women with hyperglycaemia, a very important minority of women (~3%) will develop placental disease leading to a small for gestational age infant.
    Metformin is known to reduce fetal growth in pregnancies complicated by diabetes.
    Current practice is to offer metformin to all women with diabetes (type 2 and gestational) irrespective of potential risk factors for placental disease. The effect of metformin on placental function and fetal growth is poorly understood. Given the uncertainty regarding the potential benefits, but possible negative effects on placental function and fetal growth highlighted by recent research, a trial of metformin in women hyperglycaemia and risk factors for placental disease is urgently needed.

    Design: Open label RCT comparing fetal growth trajectory and placental function in women treated with or without metformin

    Trial Participants: Women with type 2 diabetes and GDM, who have concomitant risk factors for the development of placental disease, for whom metformin would be routinely recommended

    Planned Sample Size: A target sample size of 225 women will be recruited from antenatal clinics within Manchester Foundation Trust.

    Intervention: Participants will be allocated 1:1 to the intervention (diet & lifestyle ± insulin) or standard care (diet & lifestyle, metformin ± insulin). Both groups will be offered insulin if fasting hyperglycaemia (≥5.3mmol/L) and/or postprandial hyperglycaemia (≥7.8mmol/L) persists. All other aspects of antenatal and delivery care will follow usual clinical care pathways underpinned by NICE 2015 guidelines for diabetes in pregnancy.

    Duration: From randomisation (6-30 weeks) until the end of the pregnancy.

    Follow up duration: Outcome data will be collected during the antenatal period and birth up to primary hospital discharge or 28 days post-birth, whichever occurs sooner

  • REC name

    London - Chelsea Research Ethics Committee

  • REC reference

    21/LO/0462

  • Date of REC Opinion

    8 Jul 2021

  • REC opinion

    Further Information Favourable Opinion