title: The effect of pregnancy on subsequent relapse from Graves' disease after a successful course of antithyroid drug therapy.
abstract: 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.
authors.affiliation: 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.
authors.forename: Mario
authors.initials: M
authors.lastname: Rotondi
authors.forename: Carlo
authors.initials: C
authors.lastname: Cappelli
authors.forename: Barbara
authors.initials: B
authors.lastname: Pirali
authors.forename: Ilenia
authors.initials: I
authors.lastname: Pirola
authors.forename: Flavia
authors.initials: F
authors.lastname: Magri
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Fonte
authors.forename: Maurizio
authors.initials: M
authors.lastname: Castellano
authors.forename: Enrico Agabiti
authors.initials: EA
authors.lastname: Rosei
authors.forename: Luca
authors.initials: L
authors.lastname: Chiovato
mesh_terms: 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
chemical_list: D013956:Antithyroid Agents