Pregnant Women with Type 1 Diabetes or Family History

This research study is called 'PRenatal and Obstetric Maternal Exposures and ISlet Autoantibodies in Early Life: The PROMISE Study'. The purpose of this study is to find out more about how exposures during pregnancy, such as having an infection, diet and growth may impact later risk of type 1 diabetes (TID) and islet autoimmunity in the child. We are also interested in finding out more about why having a father or sibling with T1D increases risk of autoimmunity in the child more than having a mother with T1D. We are enrolling women who are pregnant and either have T1D or another first degree relative (father or full sibling) of the baby has T1D. The biological father is also invited to enroll in study, as it is important to understand how the father's health and genetics may contribute to the child's risk of developing T1D. The study procedures for the mother, father and baby are explained below. Mother: Pregnant women will be asked to complete a visit once per trimester (3 visits) during pregnancy and one visit up to 12 weeks after delivery. At each visit, mothers will consent to a blood draw, collection of biological samples and the completion of questionnaires. . Mothers who have T1D will also be asked to download any diabetes device data they have, such as continuous glucose monitor or insulin pump data. Father: The (biological) father will be invited to enroll in a single visit. He will consent to a blood draw and completion of questionnaires. Fathers with T1D will also be asked to download any diabetes device data they have, such as continuous glucose monitor or insulin pump data. Baby: The baby will have blood collected at birth to determine the genetic risk for T1D. Families will consent to the completion of questionnaires about growth, health and diet at 6, 12, 18 and 24 months of age and between 5-7 years of age, and to complete blood testing for islet autoantibodies at 24 months and between 5-7 years of age. For those children with a high genetic risk score, we will also collect blood for autoantibody testing at 6, 12, and 18 months of age.