Are recurrent pregnancies a risk in Type 1 diabetes?

Objective: To assess the significance of recurrent pregnancies for the progression of Type 1 diabetes as well as the glycemic level and the occurrence of pre-eclampsia in consecutive pregnancies of the same Type 1 diabetic women.

Methods: A retrospective population-based birth cohort from the years 1986-95, comprising data of all (n = 210) Type 1 diabetic mothers and their 296 births in a geographically defined catchment area. Of the 125 primiparous women, 46 had their first two pregnancies during the study period. The courses of their first and second pregnancies were compared to determine the level of glycemic control and the occurrence and recurrence of complications, such as pre-eclampsia and aggravated retinopathy. The characteristics of the 53 women who remained primiparous were evaluated.

Results: Retinopathy was aggravated more often during the first pregnancy (95% CI 0.1-1.0), but its incidence did not increase further by the beginning of the second pregnancy. Pre-eclampsia complicated 16.9% of all pregnancies: it was more common during the first than second pregnancy (95% CI 0.3-1.5) and its occurrence increased with the increasing severity of diabetes. Glycemic control was better in the second pregnancy, including both the periconceptional period (95% CI 0.7-2.8) and the later stages of pregnancy (95% CI 1.1-4.7). The women in the White classes F/R most often remained primiparous.

Conclusions: Retinopathy was aggravated most often during the first pregnancy, but its infrequent occurrence in the second pregnancy reflects the reversible nature of these changes. The significance of the past pregnancy experience contributed to the increased tendency for optimal glycemic control in the second pregnancy.