Official Title: “Thyroid Hormone Dose Adjustments During Pregnancy in Women With Primary Hypothyroidism.”

Our aim is to compare the safety and efficacy of 2 different empiric levothyroxine dose adjustment recommendations to be made at the first confirmation of pregnancy in women with a history of hypothyroidism. Subjects will be women with a prior diagnosis of hypothyroidism who are taking thyroid hormone replacement and who are less than 8 weeks pregnant. Upon confirmation of pregnancy, subjects will be randomized to increase their weekly thyroid hormone dose by either 2 or 3 tablets (28 or 42%). Thyroid function will be evaluated every two weeks in the first 20 weeks and then again at week 30 and post-partum. Primary endpoints will be the proportion of women in each group who remain euthyroid throughout the first trimester and throughout pregnancy.

Study Type: Interventional

Study Design: Treatment, Randomized, Open Label, Historical Control, Parallel Assignment, Safety/Efficacy Study

Study Primary Completion Date: July 2009

Our aim is to compare the safety and efficacy of 2 different empiric levothyroxine dose adjustment recommendations to be made at the first confirmation of pregnancy in women with a history of hypothyroidism. Subjects will be women with a prior diagnosis of hypothyroidism who are taking thyroid hormone replacement and who are less than 8 weeks pregnant. Upon confirmation of pregnancy, subjects will be randomized to increase their weekly thyroid hormone dose by either 2 or 3 tablets (28 or 42%). Thyroid function will be evaluated every two weeks in the first 20 weeks and then again at week 30 and post-partum. Primary endpoints will be the proportion of women in each group who remain euthyroid throughout the first trimester and throughout pregnancy

Intervention(s) in this Clinical Trial

• Drug: Anticipatory dose increase of levothyroxine
  • as it is know that levothyroxine requirement increases in pregnancy, both study arms will increase levothyroxine dose, though by different amounts.
• Drug: levothyroxine
  • patients will increase levothyroxine dosage by 2 extra tablets of their current dose per week
• Drug: levothyroxine
  • patients will increase levothyroxine by 3 extra tablets of their current dose per week.

Arms, Groups and Cohorts in this Clinical Trial

• Active Comparator: 2 tablet increase
  • Patients will increase their current levothyroxine dose by 2 extra tablets per week (~29% increase)
• Active Comparator: 3 tablet increase
  • Patients will increase their levothyroxine dosage by 3 extra tablets per week (~43%).

Primary Measures

• proportion of patients in each treatment arm euthyroid through gestation
  • Time Frame: 9 months
    Safety Issue?: Yes

Secondary Measures

• the proportion of patients in each arm who required, and the gestation week at which, levothyroxine dose adjustments (either increased or decreased) occurred to maintain a euthyroid state
  • Time Frame: 9 months
    Safety Issue?: Yes
• Determination of the necessary frequency of serum evaluation of TSH during the first half of gestation.
  • Time Frame: 9 months
    Safety Issue?: Yes

Inclusion Criteria:

• women with a prior diagnosis of hypothyroidism, currently receiving levothyroxine therapy
• less than 8 weeks pregnant

Exclusion Criteria:

• cardiac disease, renal failure
• not euthyroid biochemically within 6 months pre-pregnancy

Gender Eligibility for this Clinical Trial: Female

Minimum Age for this Clinical Trial: N/A

Maximum Age for this Clinical Trial: N/A

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: Brigham and Women's Hospital

Overall Clinical Trial Officials and Contacts

Erik Alexander, MD Principal Investigator Brigham and Women's Hospital  

Overall Contact: Rachael Fawcett, MD 617-732-5208 rfawcett@partners.org

Information obtained from ClinicalTrials.gov on August 29, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00230802

Study ID Number: DK44128

ClinicalTrials.gov Identifier: NCT00230802

Health Authority: United States: Institutional Review Board