TABLET

• Research type

  Research Study

• Full title

  A Randomised Controlled Trial of the Efficacy and Mechanism of Levothyroxine Treatment on Pregnancy and Neonatal Outcomes in Women with Thyroid Antibodies. (TABLET: Thyroid AntiBodies and LEvoThyroxine Study)

• IRAS ID

  61927

• Contact name

  Aravinthan Coomarasamy

• Sponsor organisation

  University of Birmingham

• Eudract number

  2011-000719-19

• ISRCTN Number

  tbc

• Research summary

  Approximately 11 - 19% of women of child-bearing age have thyroid antibodies. In such women, the risks of miscarriage and preterm birth are more than doubled compared with those who do not have thyroid antibodies. Miscarriage is the commonest complication of pregnancy, affecting 1 in 5 women. There is evidence from two small studies that giving thyroxine tablets to women with thyroid antibodies may halve the risk of miscarriages and preterm births. However, the evidence is not strong enough for recommending thyroxine treatment. The TABLET Trial is large, high quality randomised controlled trial which will run in around 20 early pregnancy assessment units throughout the UK. Women who have had a recent miscarriage will be screened to determine if they have thyroid antibodies ?? about 20% will do. Those that do, but have otherwise normal thyroid function, and agree to participate will be randomly allocated to receive levothyroxine or a dummy drug. Neither the doctors nor the woman will know which group they are in. Participants will take a daily oral tablet for up to a year whilst trying to get pregnant and throughout the pregnancy if they do, we need to screen about 4500 women to recruit about 900 to the randomised trial over 18 months. We will follow-up all pregnancies to compare the number of live births beyond 34 weeks?? of gestation between the thyroxine and dummy drug groups. We will also study why women with thyroid antibodies are more likely to have miscarriages and preterm delivery, and how thyroxine may be helpful. We think that women with thyroid antibodies fail to alter their immune response appropriately during pregnancy and that the relatively low thyroid hormone levels affect the development of the placenta.

• REC name

  South West - Central Bristol Research Ethics Committee

• REC reference

  11/SW/0036

• Date of REC Opinion

  5 Apr 2011

• REC opinion

  Favourable Opinion