Prevalence and characteristics of postpartum thyroid dysfunction in São Paulo, Brazil

Abstract

We conclude that the prevalence of postpartum thyroid dysfunction in our geographical area ranges from 6.7% to 13.3%, considering, respectively, all pregnant women that were examined (n = 754) or only the number of puerperal women actually followed-up (n = 368). A transient form of thyroid autoimmune reaction characterized by elevated serum levels of anti-TPO that progressively declined or disappeared was observed in 29 puerperal women. Sonographic structural and echogenicity changes in the thyroid gland and borderline positive anti-TPO levels (between 60 and 100 U/ml) during pregnancy were considered to be of predictive value for development of postpartum thyroid dysfunction.

Value of Combined Clinical Information and Thyroid Peroxidase Antibodies in Pregnancy for the Prediction of Postpartum Thyroid Dysfunction

“…Thyroid peroxidase antibodies are considered markers for the development of PPTD when measured in early pregnancy 4–7,12 . When TPOAb is positive, there is always lymphocytic infiltration into the thyroid, and therefore there is ‘subclinical autoimmune thyroiditis’, 13 which may be exacerbated after delivery.…”

“…Postpartum thyroid dysfunction is a known complication of the postpartum period, characterized by transitory hyperthyroidism and more frequently hypothyroidism (or both), and by the presence of TPOAb 4,5,12,16 . Its prevalence is around 8%, varying from 1.1% to 16.7%.…”

“…Postpartum thyroid dysfunction (PPTD) is caused by an autoimmune destructive process of the thyroid. It is characterized by the development of transient hyperthyroidism, hypothyroidism, or both, during the first 6 months of the postpartum period 4,5 . It occurs in 5–9% of women during the first postpartum year and hypothyroidism becomes permanent in up to 25–30% of them 5 …”

Estudo longitudinal do eixo hipófise-tireóide durante a gravidez

“…Além dos riscos já citados para o feto, a hipofunção tireoidiana pode levar a complicações maternas, como gestose hipertensiva, pré-eclâmpsia, eclâmpsia, descolamento prematuro de placenta, anemia e hemorragia pós-parto (17). Acrescente-se o risco aumentado de desenvolvimento de tireoidite pósparto nas gestantes com títulos elevados de anticorpos, com maior probabilidade ulterior de hipotireoidismo definitivo (18). Por isso, recomenda-se o estudo da glândula pelo menos até 18 meses após a gestação (19).…”

“…Em nosso estudo, a prevalência de pacientes com anti-TPO positivo no decorrer da gestação foi de 13,9%. Um grupo brasileiro observou que pacientes anti-TPO positivo que evoluíam com hipotireoidismo durante a gravidez mantinham a disfunção no pós-parto, a despeito dos anticorpos declinarem ou até negativarem (18).…”