Study of the impact of insulin pump therapy, augmented with continuous glucose monitoring, on outcomes for mother and baby, in pregnant women with Type 1 diabetes when compared to conventional treatment with insulin pump therapy alone or multiple daily insulin injections.

Participants with type 1 diabetes and plans for pregnancy or currently pregnant (first trimester) will be recruited from preconception clinics, diabetes clinics and diabetes in pregnancy clinics. Women will be offered involvement in the intervention arm if they unable to achieve a target HbA1c of 6.5% or less on current therapy, or are acheiving HbA1c target but with significant hypoglycaemia. They must be willing to undertake education involved for adequate CSII and CGMS use. The primary intervention involves the use of a sensor augmented Minimed 640G insulin pump with predictive suspend before low/SmartGuard feature. Components of this intervention include: 1. The Minimed 640G insulin pump will be offered on loan to women either preconception or early pregnancy (before 12 weeks gestation) if they meet inclusion criteria. Pump therapy will continue for the duration of pregnancy to 4 weeks post partum, at which point they will be supported to transition back to multiple daily injections. Women will receive information and support about how to access their own pump during pregnancy in case they wish to pursue this as ongoing therapy after returning the loan pump. 2. CGMS that involves the subcutaneous insertion of an Enlite sensor that continuously communicates interstitial glucose readings to the Minimed 604G pump. Women will be able to see their blood sugars 'real time'. Women will be required to calibrate their CGMS by taking 3-4 fingerprick blood glucose levels per day. Women in the intervention arm will be offered sensors for continuous use with their pumps in the first and third trimester, peri/post partum and also if they are admitted with a diagnosis of preeclampsia. They will return to conventional monitoring with 4-6 daily fingerprick blood glucose measurements in the second trimester. 3. Use of the SmartGuard feature of the Minimed 640G insulin pump. This feature uses an algorithm to predict hypoglycaemia within the next 30 minutes and suspends insulin delivery to prevent reaching the low threshold. This feature will be set up for use with the sensor at each of the above time points aiming to potentiate tighter glycaemic control with fewer hypoglycaemic episodes. Women in the intervention arm will be offered extra individual, face to face appointments prior to and soon after starting the SAP therapy. These include: 1. Up to 3 additional dietician appointments (for up to 1 hour each) for education about carbohydrate counting (by dietician with over 10 years experience). Women will be given summary hand outs and recommendations about reference guides (mobile phone applications and books) that may be helpful for further information. 2. Up to 4 additional appointments (up to 1 hour each) with a credentialed diabetes educator (with over 10 years experience) to learn use of the Minimed 640G insulin pump and CGMS use and to set up the SmartGuard feature. Women will be given summary hand outs and instruction manuals that may be helpful to troubleshoot any issues with the pump and/or CGMS if required. Phone support will also be offered if needed. The Minimed 640G pump will be downloaded: 1. By the CDE at each appointment review (endocrinologist/CDE/Dietician). 2. By the participant from their home computer between appointments and reviewed by the treating study team. At each download, the patient will receive suggestions about changes to insulin pump settings to optimise glycaemia (either face to face or via phone and/or email). All women will receive routine care in pregnancy to optimise their diabetes and reduce risk of potential pregnancy adverse outcomes, including regular review for titration of their insulin pump settings. They will be offered usual antenatal care including routine scans (nuchal translucency, morphology and regular growth and well being scans in the third trimester). They will be requested to undertake a Diabetes Quality of Life Questionnaire prior to starting insulin pump therapy and repeat it at the end of the first trimester.