| While the thyrotoxicosis of PPT always resolves, several longterm studies of the hypothyroid phase have documented persistence of hypothyroidism in 20-30% of cases(24). The immunological associations of this are discussed below but a recently completed long term followup assessment of anti-TPO positive women (at 16 weeks gestation) 9 years later showed that the rate of development of hypothyroidism was significantly greater (48% vs 8%) in those who had had PPT compared to those who were euthyroid(25). Recurrence of transient PPT has been observed by several workers in small numbers of patients(26) while a recurrence rate of 30- 40% was noted in larger series(27). In fiftyfour subjects, extensively studied in two pregnancies, there was a 70% chance of developing recurrent PPT after a first attack and a 25% risk even if the woman was only anti-TPO positive without thyroid dysfunction during the first postpartum period(28). |
