Context: Autoimmune Addison's disease (AAD) tends to affect young and middle-aged women. It is not known whether the existence of undiagnosed or diagnosed AAD influences the outcome of pregnancy.
Objective: The aim of the study was to compare the number of children and pregnancy outcomes in individuals with AAD and controls.
Design and setting: We conducted a population-based historical cohort study in Sweden.
Patients: Through the Swedish National Patient Register and the Total Population Register, we identified 1,188 women with AAD and 11,879 age-matched controls who delivered infants between 1973 and 2006.
Main outcome measures: We measured parity and pregnancy outcome.
Results: Adjusted odds ratios (ORs) for infants born to mothers with deliveries 3 yr or less before the diagnosis of AAD were 2.40 [95% confidence interval (CI), 1.27-4.53] for preterm birth (≤37 wk), 3.50 (95% CI, 1.83-6.67) for low birth weight (<2500 g), and 1.74 (95% CI, 1.02-2.96) for cesarean section. Compared to controls, women who gave birth after their AAD diagnosis were at increased risk of both cesarean delivery (adjusted OR, 2.35; 95% CI, 1.68-3.27) and preterm delivery (adjusted OR, 2.61; 95% CI, 1.69-4.05). Stratifying by isolated AAD and concomitant type 1 diabetes and/or autoimmune thyroid disease in the mother did not essentially influence these risks. There were no differences in risks of congenital malformations or infant death. Women with AAD had a reduced overall parity compared to controls (P<0.001).
Conclusion: Clinically undiagnosed and diagnosed AAD both entail increased risks of unfavorable pregnancy outcomes. AAD also influences the number of childbirths.