The occurrence of permanent thyroid failure in patients with subclinical postpartum thyroiditis.
OBJECTIVE
The long-term effect of the subclinical form of postpartum thyroid dysfunction (PPTD) has not been well established. This study was conducted to evaluate the outcome of permanent hypothyroidism in a large cohort of women with PPTD.


METHODS
Of 213 women with PPTD, 172 (81%) returned for follow-up. There were 27 (16%) with subclinical (group 1) and 145 (84%) with overt hypothyroidism (group 2). They were all treated with levothyroxine for 23 +/- 16 months and followed-up for thyroid function after thyroxine (T(4)) withdrawal.


RESULTS
In group 1, the time of occurrence of PPTD was longer, serum T(4) was higher and TSH was lower than in group 2. After T(4) withdrawal, 59 and 64% of patients became hypothyroid in groups 1 and 2 respectively; however, serum TSH was increased in group 2 as compared with group 1 (29.7 +/- 8.4 vs 16.4 +/- 15.4 mU/l, P < 0.002). The duration of euthyroidism, serum free T(4) and triiodothyronine indices and thyroperoxidase antibodies were not significantly different between the two groups.


CONCLUSIONS
It was concluded that a high percentage of patients with the subclinical form of PPTD proceed to permanent thyroid failure. The timely recognition of mild to severe cases of PPTD is important for the improvement of life for mothers and infants.
Azizi
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Endocrine Research Center, Shaheed Beheshti University of Medical Sciences, P O Box 19395-4763, Tehran, Islamic Republic of Iran. Azizi@erc.ac.ir
D000328:Adult; D001323:Autoantibodies / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D049590:Postpartum Period; D011446:Prospective Studies; D013967:Thyroiditis, Autoimmune / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use*; D014284:Triiodothyronine / Q000097:blood
D001323:Autoantibodies; C006606:anti-thyroglobulin; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine