Blood pressure levels but not hypertensive complications have increased in Type1 diabetes pregnancies during 1989-2010

Aims The pre-pregnancy BMI and the third trimester HbA(1c) levels increased in Finnish parturients with Type1 diabetes during 1989-2008. The aim of the present study was to investigate whether these trends have been accompanied by increases in blood pressure or hypertensive complications. Hypertension trends were analysed using the definitions of hypertension of both the American College of Obstetricians and Gynecologists and the American Diabetes Association. The associations of hypertension, as defined by the latter criteria, with perinatal complications were also studied. Methods The records of a cohort of 1007 consecutive patients with Type1 diabetes with a singleton live childbirth during 1989-2010 at the Helsinki University Central Hospital were studied. Results The frequencies of hypertensive pregnancy complications did not change, but the mean diastolic blood pressure increased in normotensive parturients in all trimesters. The proportion of patients with systolic blood pressure >130mmHg or diastolic blood pressure >80mmHg in the first, second and third trimesters of pregnancy increased from 25 to 33%, from 26 to 35% and from 57 to 71%, respectively. Systolic blood pressure of 131-139mmHg or diastolic blood pressure of 81-89mmHg in the third trimester was associated with umbilical artery pH <7.15. Conclusions Blood pressure of patients with Type1 diabetes during pregnancy is increasing. A growing proportion of women with Type1 diabetes exceed the American Diabetes Association's definition of hypertension during pregnancy.