The pre-pregnancy BMI and the third trimester HbA1c levels increased in Finnish parturients with Type 1 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 Type 1 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 > 130 mmHg or diastolic blood pressure > 80 mmHg 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 131–139 mmHg or diastolic blood pressure of 81–89 mmHg in the third trimester was associated with umbilical artery pH < 7.15.Conclusions
Blood pressure of patients with Type 1 diabetes during pregnancy is increasing. A growing proportion of women with Type 1 diabetes exceed the American Diabetes Association's definition of hypertension during pregnancy.