Thyroid Hormone Dose Adjustment in Pregnancy

Condition(s) targeted: Pregnancy; Hypothyroidism

Intervention: Anticipatory dose increase of levothyroxine (Drug); levothyroxine (Drug); levothyroxine (Drug)

Phase: N/A

Status: Recruiting

Sponsored by: Brigham and Women's Hospital

Official(s) and/or principal investigator(s):
Erik Alexander, MD, Principal Investigator, Affiliation: Brigham and Women's Hospital

Overall contact:
Rachael Fawcett, MD, Phone: 617-732-5208, Email: rfawcett@partners.org

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.

Official title: Thyroid Hormone Dose Adjustments During Pregnancy in Women With Primary Hypothyroidism.

Study design: Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Primary outcome: proportion of patients in each treatment arm euthyroid through gestation

Secondary outcome:

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

Determination of the necessary frequency of serum evaluation of TSH during the first half of gestation.

Detailed description: 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

Minimum age: N/A. Maximum age: N/A. Gender(s): Female.

Criteria:

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

Rachael Fawcett, MD, Phone: 617-732-5208, Email: rfawcett@partners.org

Brigham and Women's Hospital, Boston, Massachusetts 02115, United States; Recruiting
Erik Alexander, MD, Phone: 617-732-4148

Starting date: July 2005
Last updated: February 9, 2011