Aims/hypothesis: The aim of this study was to explore the association between type 1 diabetes and reproductive health indicators in women, focusing on termination of pregnancy and sterilisation.

Methods: We conducted a registry-based cohort study involving 2281 women with childhood-onset type 1 diabetes, matched for age and birthplace with women without diabetes: two control participants for each woman with diabetes. We compared the frequencies of termination of pregnancy and sterilisation over a 25 year period between women with type 1 diabetes and women without, and estimated standardised incidence ratios (SIRs). Smoothed age and period effects in the incidence of termination of pregnancy or sterilisation were tested statistically.

Results: There were more terminations of pregnancy (SIR 1.67; 95% CI 1.51, 1.86) and sterilisations (SIR 1.69; 95% CI 1.56, 1.83) in women with diabetes than in control women. During recent years, sterilisations in women with diabetes have decreased and the difference compared with control women has vanished. The indications for both procedures showed a statistically highly significant difference: maternal medical indications were almost absent (< 1%) in procedures among control women, but comprised 23.6% of terminations of pregnancy and 22.9% of sterilisations in women with diabetes.

Conclusions/interpretation: The indications for termination of pregnancy and sterilisation are different in women with diabetes compared with other women. Pregnancies in women with type 1 diabetes are still terminated more often than in women without diabetes, but the difference in sterilisation rates has disappeared during recent years.