Postpartum thyroiditis is defined as a syndrome of transient orpermanent thyroid dysfunction occurring in the first year after deliveryand based on an autoimmune inflammation of the thyroid gland.Classically, it is in the form of a thyrotoxic phase is followed by ahypothyroid phase. During pregnancy, an enhanced state of autoimmunetolerance ensues, leading to an amelioration of existing thyroidautoimmunity. A rebound reaction to this pregnancy-associated immunesuppression. After delivery explains the aggravation of autoimmunesyndromes in the puerperal period e.g. the occurrence of clinically overtPPT. On the other hand,