Fertility in people with childhood-onset type 1 diabetes

Abstract

Aims/hypothesis To assess the number of live births in a population-based, retrospective cohort of women and men with childhood-onset type 1 diabetes, and matched controls. Methods The reproductive histories of people in a Finnish cohort of 2,307 women and 2,819 men with type 1 diabetes and two matched controls (for each case) were obtained from National Population Register data. All persons with diabetes were diagnosed with the disease in 1965-1979 at the age of 17 or under. A proportional hazards model was used to model the association between the rate of live births as a function of the age of an individual and the observed covariates (sex and age at onset of diabetes).Results Both women and men with diabetes had a smaller number of live births than the controls; the HR of having a first child for diabetic women compared with controls was 0.66 (95% CI 0.62, 0.71) and for men was 0.77 (95% CI 0.72, 0.83). In women, a birth cohort effect was detected; in more recent birth cohorts, the difference between diabetic women and controls as regards having children was significantly smaller than in earlier cohorts. Later age at onset of diabetes was associated with a higher rate of having a first child among men (p00.04) and having a second live birth among women (p00.002). Conclusions/interpretation Type 1 diabetes affects the number of live births in both women and men. The age at onset of diabetes is associated with the pattern of reproduction in both diabetic women and men.

Fertility is reduced in women and in men with type 1 diabetes: results from the Type 1 Diabetes Genetics Consortium (T1DGC)

“…Our results confirm those of previous German, Swedish and Finnish studies [1,3,7]. A German study in patients with type 1 diabetes (age of onset 23± 15 years) also described a reduced fertility rate in women (0.88) and an even lower rate in men (0.65), compared with a rate of 1.36 in the background female population.…”

“…In the Finnish study, in agreement with our findings, the reduction in fertility with type 1 diabetes was larger in women than in men. Furthermore, an influence of birth cohort on fertility was also found in the Finnish and Swedish studies, showing a 'normalisation trend' in later birth cohorts [1,3]. Indeed, the Swedish study concludes that it appears that normalisation in fertility has occurred among women with uncomplicated type 1 diabetes and an onset in the past 20 years [1].…”

“…More male than female patients were childless at the age of 41-45 years, but there was no available information about childlessness in the male background population [7]. Similarly, reduced fertility was observed in a population-based Swedish study that included women with childhood onset of type 1 diabetes [1] and in a recent Finnish study that included both women and men [3]. In the Finnish study, in agreement with our findings, the reduction in fertility with type 1 diabetes was larger in women than in men.…”

“…On the other hand, data about fertility in men with type 1 diabetes are scarce. One recent Finnish population-based study showed a reduced number of offspring both in women and in men with the disease [3].…”

Termination of pregnancy and sterilisation in women with childhood-onset type 1 diabetes

“…The indications for both procedures also differed between these groups of women. Previously [20], we reported that people with childhood-onset type 1 diabetes had fewer live-born children than people without diabetes. The unique and high-quality registry data available in Finland enable this type of study to be carried out.…”