Pregnancy characteristics as risk factors for future maternal diabetes and other diseases

In Sweden approximately 2-3% of all preganncies are affected by Gestational Diabetes (GDM). Hyperglycemia during pregnancy is a riskfactor for adverse pregnancy outcome. GDM causes an increased risk for Caesarean section, large for gestational age infants (LGA) and preeclampsia. In addition, women with previous GDM have a high risk of developing type 2 diabetes (T2D) and also an increased risk of cardiovascular disease later in life. Aims I. investigate if women diagnosed with diabetes later in life had hyperglycemia related complications of previous pregnancies. II. analyse the impact of BMI and gestational weight gain on the risk of developing T2D and other metabolic disesaes later in life. III. analyse the pregnancy outcome in relation to a predisposition for diabetes (defined as onset of T2D later in life), with or without elevated BMI during pregnancy. IV. analyse glucose control and pregnancy outcome in GDM pregnancies in regard to treatment modality in two different time periods. Methods: We used the populationbased MISS-cohort (Melanoma in Southern Sweden). It was established in 1990, with o follow up in 2000 and consists of almost 30000 women in the ages 25-65 years. Self-reported data regarding social status, medication, previous illnesses etc. is included in the data base. Data regarding current medication is retrieved from the Swedish Prescribed Drug Register. From the Swedish Medical Birth Register (SMBR) we collected data from 1973-2005 regarding pregnancy outcome. A novel database from the Specialized Maternity Care Unit in Lund included women with GDM pregnancies 2012-2013 and 2016-2017 was used. Additional data regarding the pregnancy was retrieved from Obstetrix and data regarding the woman ́s glucose values was retrieved from Diasend. Results: Women who later in life developed T2D had hyperglycemia-related adverese outcomes during previous pregnancies. They had higher BMI, a lower Gestational Weight Gain (GWG), higher frequency of macrosomia and caesarean section compared to women without diabetes later in life. Women with over weight during pregnancy had more than six fold increase in the risk of developing diabetes and more than two-fold risk of developing cardiovascular disease 10-17 years after pregnancy. Being overweight during pregnancy and having a predispostion for diabetes was equal riskfactors for macrosomia. If the women had both riskfactors there was an almost eight times higher frequency of LGA. The mean glucose values have improved among women with GDM 2016-2017 compared to 2012-2013,with less frequenct use of insulin and more use of metformin. There is more heredity for diabetes and non-Scandinavian origin among the women with GDM. Conclusion: Having a predisposition for diabetes impacts the pregnancy outcome and increases the risk of hyperglycemia related adverse events during pregnancy and delivery. Having a high BMI at the beginning of pregnancy increases the risk of future T2D and cardiovascular disease. Having a predisposition for T2D and being overweight synergistically increases the risk of macrosomia. Despite changing demographics, improved metabolic control can be achieved and favorable pregnancy outcome maintained, while using more metformin and less insulin.