Preconception management of thyroid dysfunction

Abstract

Uncorrected thyroid dysfunction in pregnancy has well-recognized deleterious effects on foetal and maternal health. The early gestation period is one of the critical foetal vulnerability during which maternal thyroid dysfunction may have lasting repercussions. Accordingly, a pragmatic preconception strategy is key for ensuring optimal thyroid disease outcomes in pregnancy. Preconception planning in women with hypothyroidism should pre-empt and mirror the adaptive changes in the thyroid gland by careful levothyroxine dose adjustments to ensure adequate foetal thyroid hormone delivery in pregnancy. In hyperthyroidism, the goal of preconception therapy is to control hyperthyroidism while curtailing the unwanted side effects of foetal and maternal exposure to antithyroid drugs. Thus, pregnancy should be deferred until a stable euthyroid state is achieved, and definitive therapy with radioiodine or surgery should be considered in women with Graves' disease planning future pregnancy. Women with active disease who are imminently trying to conceive should be switched to propylthiouracil either preconception or at conception in order to minimize the risk of birth defects from carbimazole or methimazole exposure. Optimal strategies for women with borderline states of thyroid dysfunction namely subclinical hypothyroidism, isolated hypothyroxinaemia and thyroid autoimmunity remain uncertain due to the dearth of controlled interventional trials. Future trial designs should aspire to recruit and initiate therapy before conception or as early as possible in pregnancy.

Should radioiodine now be first line treatment for Graves’ disease?

“…Thionamides are increasingly used as first line therapy for Graves' disease globally, even in the United States where radioiodine has traditionally been preferred [4]. The extent to which this will change in the UK with the advent of NICE is uncertain since radioiodine would remain unsuitable for a sizable proportion of the Graves' disease population including patients with orbitopathy, pregnant women, individuals intending pregnancy [28], or patients with young children. Some patients may prefer thionamides due to concerns with permanent hypothyroidism, weight gain, or reduced quality of life on levothyroxine.…”

Schilddrüse: Fertilität, Schwangerschaft und Laktation

“…Bei bestehendem Schwangerschaftswunsch wird bei ansonsten gesunden Frauen, welche eine natürliche Konzeption anstreben, aufgrund unzureichender Evidenzlage von diversen Fachgesellschaften keine generelle Empfehlung für oder gegen ein Screening auf Schilddrüsenfunktionsstörungen abgegeben, wobei jedoch in der gängigen Praxis häufig eine Schilddrüsenhormonbestimmung durchgeführt wird [8,11]. Wir, als Autoren dieses aktuellen Artikels, präferieren trotz der diesbezüglich noch offenen Diskussion im Hinblick auf die Detektion von möglichen bisher unerkannten manifesten Schilddrüsenfunktionsstörungen, die zu ca.…”

“…Schilddrüsenhormone haben diverse Funktionen bei Schwangerschaft, Fertilität und Laktation, weswegen auch praktische Anfragen bzgl. Diagnostik und Therapie von Schilddrüsenerkrankungen in diesem Kontext sehr häufig gestellt werden [1][2][3][4][5][6][7][8][9][10][11][12]. In diesem kurzen Übersichtsartikel möchten wir auf praxisrelevante Themen und rezente Erkenntnisse in diesem Zusammenhang eingehen, wobei wir eine Untergliederung in die Bereiche Fertilität/ präkonzeptionelle Phase, Schwangerschaft und postpartale Zeit/Laktation vornehmen.…”

Hypothyroidism in Pregnancy

“…Approximately 1% of pregnant women are established on levothyroxine prior to pregnancy. In women established on levothyroxine prior to pregnancy, initial control in pregnancy is often sub-optimal 39 and may be associated with increased odds of foetal loss 39 , and optimization should ideally occur prior to conception 40 . Women of child-bearing age on levothyroxine should be reminded to increase their pre-conception dose of levothyroxine by 30-50% as soon as pregnancy is confirmed.…”