Interventions for preventing and treating hyperthyroidism in pregnancy

  • Review
  • Intervention

Authors

  • Rachel Earl,

    Corresponding author
    1. The University of Adelaide, Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, Adelaide, Australia
    • Rachel Earl, Discipline of Obstetrics and Gynaecology, School of Paediatrics and Reproductive Health, The University of Adelaide, Medical School North Building, Frome Road, Adelaide, 5005, Australia. rachel.earl@adelaide.edu.au.

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  • Caroline A Crowther,

    1. The University of Adelaide, ARCH: Australian Research Centre for Health of Women and Babies, Discipline of Obstetrics and Gynaecology, Adelaide, South Australia, Australia
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  • Philippa Middleton

    1. The University of Adelaide, ARCH: Australian Research Centre for Health of Women and Babies, Discipline of Obstetrics and Gynaecology, Adelaide, South Australia, Australia
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Abstract

Background

Women with hyperthyroidism in pregnancy have increased risks of miscarriage, stillbirth, preterm birth, and intrauterine growth restriction; and they can develop severe pre-eclampsia or placental abruption.

Objectives

To assess the effects of interventions for preventing or treating hyperthyroidism in pregnant women.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (28 July 2010).

Selection criteria

We intended to include randomised controlled trials comparing antithyroid treatments in pregnant women with hyperthyroidism.

Data collection and analysis

Two review authors would have assessed trial eligibility and risk of bias, and extracted data.

Main results

No trials were located.

Authors' conclusions

As we did not identify any eligible trials, we are unable to comment on implications for practice, although early identification of hyperthyroidism before pregnancy may allow a woman to choose radioactive iodine therapy or surgery before planning to have a child. Designing and conducting a trial of antithyroid drugs for pregnant women with hyperthyroidism presents formidable challenges. Not only is hyperthyroidism a relatively rare condition, both of the two main drugs used have potential for harm, one for the mother and the other for the child. More observational research is required about the potential harms of methimazole in early pregnancy and about the potential liver damage from propylthiouracil.

摘要

背景

預防及治療懷孕期間甲狀腺機能亢進的介入措施

患有甲狀腺機能亢進的女性在懷孕期間有較高的風險發生流產、死產、早產和子宮內胎兒生長遲滯,而且可能發展成嚴重的子癇前症或胎盤早剝。

目標

評估對孕婦預防或治療甲狀腺機能亢進的介入措施的效果。

搜尋策略

我們搜尋了Cochrane Pregnancy and Childbirth Group's Trials Register (2010年7月28日) 。

選擇標準

我們計畫納入針對患有甲狀腺機能亢進的孕婦,比較抗甲狀腺治療的臨床對照試驗。

資料收集與分析

原本將會由兩位作者評估試驗的合適性和偏誤風險並且擷取資料。

主要結論

沒有發現任何試驗。

作者結論

我們沒有發現任何符合標準的試驗,也無法對治療結果做出評論,不過懷孕前早期發現甲狀腺機能亢進,能使女性在計畫生育前選擇進行放射性碘療法或手術。對患有甲狀腺機能亢進的孕婦設計並進行抗甲狀腺藥物的試驗要面對許多難以克服的挑戰。不僅僅是因為甲狀腺機能亢進是一個相對罕見的狀況,兩種主要藥物更各別對母親和小孩可能造成傷害。對methimazole在懷孕初期的潛在傷害和propylthiouracil對肝臟可能造成的損傷都還需要更多觀察性研究。

翻譯人

本摘要由劉家毓翻譯。

此翻譯計畫由臺灣國家衛生研究院 (National Health Research Institutes, Taiwan) 統籌。

總結

針對患有甲狀腺機能亢進孕婦的治療藥物沒有發現任何臨床對照試驗證據:在懷孕期間患有甲狀腺機能亢進是十分罕見而嚴重的狀況,它可能增加流產、死產、早產和子宮內胎兒生長遲滯的危險性。甲狀腺機能亢進孕婦也可能罹患嚴重的子癇前症或胎盤早剝。這些女性大多患有格雷夫斯病,一種通常發生於20至40歲女性的自體免疫疾病。大部分有甲狀腺機能亢進的女性在受孕前已被診斷出甲狀腺疾病且接受了治療。通常對有甲狀腺機能亢進的孕婦只會考慮使用藥物治療。放射性碘治療不在懷孕期間使用,因為它會破壞胎兒的甲狀腺,使其一出生就罹患永久性甲狀腺機能低下。主要的抗甲狀腺藥物有thionamides、propylthiouracil (PTU) 、methimazole和carbimazole。PTU是目前在懷孕期間比較受到青睞的藥物,因為它比methimazole更不容易造成畸形 (頭皮損傷) 。然而,已有報告指出PTU會對肝臟造成傷害,對在第一孕程的甲狀腺機能亢進女性以PTU來治療 (避免methimazole導致畸形) ,之後再換成methimazole應該是合理的。我們找不到任何臨床試驗來幫助女性及醫師了解哪一種抗甲狀腺藥物是最有效且潛在傷害最低的。

Plain language summary

No evidence located from randomised trials for drugs to treat pregnant women with hyperthyroidism

Hyperthyroidism in pregnancy is a rare, serious condition which can increase the risks of miscarriage, stillbirth, preterm birth, and intrauterine growth restriction. Pregnant women who are hyperthyroid may also develop severe pre-eclampsia or placental abruption. Most of these women have Graves' disease, an autoimmune disease most common in women aged 20 to 40 years. Most pregnant women with hyperthyroidism are diagnosed with thyroid disease prior to conception and will have previously received treatment for the condition. Generally only drug therapy is considered for treating pregnant women with hyperthyroidism. Radioiodine treatment is not used in pregnancy because it destroys the fetal thyroid gland, resulting in permanent hypothyroidism in the newborn.

The main antithyroid drugs used are the thionamides, propylthiouracil (PTU), methimazole and carbimazole. PTU is currently the favoured drug for use in pregnancy, as it is associated with fewer teratogenic effects (scalp lesions) than methimazole. However, since there have been reports of liver damage in people taking PTU, it may be reasonable for pregnant hyperthyroid women to be treated with PTU in the first trimester (to reduce any teratogenic effects of methimazole) and then to change to methimazole.

We could not identify any randomised trials to help inform women and their doctors about which antithyroid drugs are most effective, with the lowest potential for harm.