Gestational diabetes (too much sugar in the blood in pregnancy) and pregnancy hypertensive disorders (high blood pressure that occurs in pregnancy, and which can lead to fits in the mother and death in the baby) cause significant maternal and neonatal mortality and morbidity in low and middle income countries and there is no systematic approach to prevention. The estimated global prevalence of gestational diabetes is 16%, with higher rates in in South Asia and Africa [1]. Gestational diabetes increases the incidence of the adverse outcomes of caesarean section, pregnancy induced hypertensive disease, excessive birthweight, birth injury, future obesity and future diabetes: untreated, it contributes to a cycle which promotes obesity and diabetes in future generations[2]. Pregnancy hypertensive disorders account for 17.3% of maternal deaths in low socio-economic countries, and are the second commonest cause of maternal death after haemorrhage[3]. In resource rich countries, testing for gestational diabetes is undertaken in women at high risk, together with treatment of those affected and regular self-monitoring of blood sugar levels. Such an approach is inappropriate in resource poor settings due to the high cost of testing and blood sugar monitoring, and the lack of availability of blood sugar monitoring kits. However, measurement of maternal body mass index (weight and height) cheaply and effectively identifies a high-risk group for both gestational diabetes and pregnancy hypertensive disorders. Additionally, one of the treatments (metformin) for gestational diabetes is relatively cheap, widely available, and safe, regardless of blood sugar levels [4-6]. Recent in vitro and clinical data suggest that metformin might reduce the incidence and severity of pregnancy hypertensive disorders [6-8]. We propose that metformin could be a pragmatic approach to preventing gestational diabetes and pregnancy hypertensive disorders in obese pregnant women in resource poor settings. This is a feasibility study of a clinical trial to determine whether metformin is effective in preventing gestational diabetes and pregnancy hypertensive disorders in women at high risk of both conditions. In this feasibility study, we will find out if it is possible for us to do a full trial, how big such a trial would be, and how expensive it would be. We will ask obese pregnant women in participating sites in Malawi and Zambia to take either metformin or matching placebo tablets. We will see how many women wish to participate, how many take the treatment, and what effect the treatment has. We will also be able to see how common gestational diabetes and pregnancy hypertensive disorders are in this population. Although this feasibility study is too small to answer the question "Is routine administration of metformin a pragmatic approach to preventing gestational diabetes and pregnancy hypertensive disorders in obese pregnant women in resource poor settings" it will facilitate a larger (and likely more expensive study) to be able to do so. Our group of clinicians, researchers and policy makers in Malawi, Zambia and the UK has the necessary expertise to carry out both the feasibility study and a further substantive study, and we are well placed to be able to translate the results of the research into clinical practice. References 1. International Diabetes Federation (IDF) IDF Diabetes Atlas, 7th Edition, 2015. 2. NICE, Diabetes in pregnancy. NICE guideline 2015. 3. Global Burden of Disease Maternal Mortality and Morbidity Collaborators, Lancet, 2016. 388: p. 1775-1812. 4. Balsells, M., et al., BMJ, 2015. 350: p. h102. 5. Chiswick, C., et al., Lancet Diabetes Endocrinol, 2015. 3: p. 778-86. 6. Syngelaki, A., et al., N Engl J Med, 2016. 374: p. 434-43. 7. Brownfoot, F.C., et al., Am J Obstet Gynecol, 2016. 214: p. 356 e1-356 e15. 8. Romero, R., et al., Am J Obstet Gynecol, 2017. 217: p. 282-302