Abstract
Seventy-two Graves' disease patients with normal thyroid function or latent hyperthyroidism on the basis of antithyroid drug (ATD) use in the first trimester of pregnancy were adopted as subjects in this study. The subjects were divided into either a ATD-continuity group of patients who took at least one tablet a day at the time of delivery (n=32), or a ATD-discontinuity group (n=40) . We attempted to predict discontinuation of oral therapy at the time of delivery on the basis of the TRAb titer and ATD dose alone but it was impossible. Though we also performed a bivariate analysis using TSH receptor antibody (TRAb) titer and ATD dose, clear discrimination was also impossible. We therefore performed a nominal logistic analysis using two factors : y = 3.507-0.080 × TRAb-0.329 × ATD dose The value of y was used in the prediction formula below, and the higher value was adopted as the prediction result. Probability (ATD discontinuity) =1/ {1 + Exp (y) } Probability (ATD continuity) = Exp (y) × 1 / {1 + Exp (y) } Calculation of the correct diagnosis rate for the outcome of 50 new pregnancy and delivery patients using this formula yielded 90%. This formula made possible prediction of the subjects condition at the time of delivery making this formula very useful in clinical practice.
