Preventing gestational diabetes with myo-inositol supplement

INTERVENTION: Randomisation will be done using an online system with a randomisation scheme based on permuted blocks of random block size (sizes 4, 6 and 8), stratified by participating site. No adaptive or minimisation strategies will be used in this trial. The treatment arm will receive myo‐inositol, and the control arm will receive a placebo. In both arms, the supplements are to be taken twice daily, from 12+0 to 15+6 weeks until delivery. After recruitment and randomisation, follow‐up visits will be at 20 weeks, 28 weeks, 34 weeks, and delivery, aligning with the routine antenatal appointments. CONDITION: Specialty: Reproductive health and childbirth, Primary sub‐specialty: Maternal/ Fetal medicine; UKCRC code/ Disease: Reproductive Health and Childbirth/ Other maternal disorders predominantly related to pregnancy, Metabolic and Endocrine/ Diabetes mellitus ; Pregnancy and Childbirth ; Diabetes mellitus arising in pregnancy PRIMARY OUTCOME: Process outcomes for the feasibility study:; 1. Proportion of screened women who are eligible; 2. Proportion of eligible women who are consented and randomised; 3. Attrition rates at 28 weeks of pregnancy, and up to delivery; 4. Adherence to treatment and to protocol; 5. Deviations from the study protocol; 6. Completeness of data collection; 7. Determination of level of support required for the trial conduct; Timepoint(s): End of the study SECONDARY OUTCOME: Acceptability of the study and intervention assessed through qualitative research interviews and questionnaires, aimed at the participants, those who refuse consent to the study, and healthcare professionals involved in the study. Women who decline trial participation are offered an optional short open‐ended questionnaire to capture any reasons. Interviews with participants will be carried out in a small proportion (approx. 10‐20 women), at around 20 weeks and 34 weeks of pregnancy. Interviews with 10‐15 healthcare professionals are carried out towards the end of the study. ; ; Preliminary estimates of the effect of the intervention: ; 1. Clinical outcomes for mother and baby are collected from their medical notes at delivery; 2. Laboratory outcomes of glucose metabolism tests, including an Oral Glucose Tolerance Test, are collected at the 28‐week visit; 3. Cost data including that of the intervention, lab tests, and clinic visits are assessed throughout the study; 4. QALYs are assessed through the EQ‐5D‐5L questionnaire administered at baseline and delivery INCLUSION CRITERIA: 1. Women with a singleton, viable pregnancy between 12+0 and 15+6 weeks gestation, based on ultrasound confirmation 2. Women with at least one of the following risk factors: family history of diabetes in any one of their first degree relatives, gestational diabetes in a previous pregnancy, obesity (BMI =30 Kg/m2), minority ethnic family origin with a high prevalence of diabetes (such as South Asian, Middle Eastern and Black Caribbean), polycystic ovary syndrome, or previous macrosomic baby (birth weight >4.5 kg)