The effect of pregnancy on subsequent relapse from Graves' disease after a successful course of antithyroid drug therapy.
OBJECTIVE
Pregnancy and the postpartum (PP) period are associated with profound changes of the immune system, which largely influence the clinical activity of autoimmune diseases. The aim of this study was to evaluate the effect of pregnancy and/or the PP period in driving a clinical relapse of hyperthyroidism in patients with Graves' disease (GD) who are in remission after antithyroid drug (ATD) treatment. Data were retrospectively collected from 150 female patients with GD, who were assigned to two groups according to the occurrence of a successful pregnancy after ATD withdrawal.


RESULTS
Relapsing Graves' hyperthyroidism was observed in 70 of 125 patients in group I (no pregnancy after ATD withdrawal) (56.0%) and 21 of 25 patients in group II (pregnancy after ATD withdrawal) (84.0%) (P < 0.05). Logistic regression analysis (dependent variable: relapse/nonrelapse; covariates: age, positive family history for autoimmune thyroid disease, duration of treatment with ATD, number pregnancies at diagnosis, number of pregnancies after ATD withdrawal) showed a significant effect only for the number of pregnancies after ATD withdrawal [4.257 (1.315-13.782)]. The effect was ascribed to the PP period rather than to pregnancy itself because in 20 of 21 patients of group II (95.2%), the relapse of Graves' hyperthyroidism occurred between 4 and 8 months after delivery.


CONCLUSIONS
The PP period is significantly associated with a relapse of hyperthyroidism in GD patients being in remission after ATD. We therefore recommend that patients with GD in remission after a course of ATD should have their thyroid function tested at 3 and 6 months after delivery.
Rotondi
Mario
M
Fondazione Salvatore Maugeri Istituto di Ricovero e Cura a Carattere Scientifico Chair of Endocrinology, University of Pavia, Via S. Maugeri 10, I-27100, Pavia, Italy.
Cappelli
Carlo
C
Pirali
Barbara
B
Pirola
Ilenia
I
Magri
Flavia
F
Fonte
Rodolfo
R
Castellano
Maurizio
M
Rosei
Enrico Agabiti
EA
Chiovato
Luca
L
D000328:Adult; D013956:Antithyroid Agents / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006111:Graves Disease / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D049590:Postpartum Period / Q000187:drug effects; D011247:Pregnancy / Q000502:physiology* / Q000706:statistics & numerical data; D011248:Pregnancy Complications / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology; D011379:Prognosis; D012008:Recurrence; D012074:Remission Induction; D012189:Retrospective Studies; D016896:Treatment Outcome
D013956:Antithyroid Agents