Postpartum thyroiditis: long-term follow-up.
OBJECTIVE
To determine the incidence of persistent hypothyroidism (PH) after a long follow-up in 45 patients with postpartum thyroiditis (PPT) from a nonselected population of 641 pregnant women (PPT incidence 7.8%) and the clinical and biochemical factors associated with PPT evolution.


METHODS
The 45 women who developed PPT were followed for 8.1 +/- 2.2 years after delivery.


METHODS
Age at delivery, family and personal history, smoking, newborn gender, breast-feeding, and PPT course were recorded. Thyrotropin (TSH) and free thyroxine (T(4)) concentrations and antithyroid antibodies were evaluated at each visit. PH was considered when it persisted one year after being diagnosed.


RESULTS
Fourteen of 45 patients with PPT developed PH with a probability of 56% after a PPT episode with hypothyroidism. None of the patients who developed hyperthyroidism alone during PPT evolved to PH. PH risk was higher if the newborn was a girl (relative risk [RR] 3.88) and increased for each additional TSH unit during PPT and for every additional year of the mother's age.


CONCLUSIONS
The probability of developing PH after a PPT with hypothyroidism episode is 56%. PPT screening in all women permits us to establish levothyroxine treatment, if necessary, before a new pregnancy.
Lucas
Anna
A
Department of Endocrinology and Nutrition, Hospital Universitari Germans Trias i Pujol, Badalona, Catalonia, Spain. alucas@ns.hugtip.scs.es
Pizarro
Eduarda
E
Granada
María Luisa
ML
Salinas
Isabel
I
Roca
Josep
J
Sanmartí
Anna
A
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007037:Hypothyroidism / Q000453:epidemiology; D015994:Incidence; D050032:Postpartum Thyroiditis / Q000453:epidemiology*; D013030:Spain / Q000453:epidemiology