Endocrine

, Volume 44, Issue 3, pp 710–715

The pattern of thyroid function of subclinical hypothyroid women with levothyroxine treatment during pregnancy

  • Xiaohui Yu
  • Yanyan Chen
  • Zhongyan Shan
  • Weiping Teng
  • Chenyang Li
  • Weiwei Zhou
  • Bo Gao
  • Tao Shang
  • Jiaren Zhou
  • Bin Ding
  • Ying Ma
  • Ying Wu
  • Qun Liu
  • Hui Xu
  • Wei Liu
  • Jia Li
  • Weiwei Wang
  • Yuanbin Li
  • Chenling Fan
  • Hong Wang
  • Hongmei Zhang
  • Rui Guo
Original Article

DOI: 10.1007/s12020-013-9913-2

Cite this article as:
Yu, X., Chen, Y., Shan, Z. et al. Endocrine (2013) 44: 710. doi:10.1007/s12020-013-9913-2

Abstract

In this study, we researched the pattern of thyroid function of subclinical hypothyroid (SCH) women with levothyroxine (LT4) throughout pregnancy and determined the optimal dosages of LT4 for such women. 56 SCH pregnant women were followed regularly prospectively. They were divided into three groups: group A (n = 29. Baseline TSH between 2.5 and 5.0 mIU/L) received 50 μg/day of LT4; group B (n = 17. Baseline TSH between 5.0 and 8.0 mIU/L) received 75 μg/day of L-T4; group C (n = 10. Baseline TSH >8.0 mIU/L) received 100 μg/day of LT4. All the patients started LT4 therapy around the 8th gestational week. Serum TSH, free T4, and free T3 were measured at 4-week intervals throughout pregnancy. Among the thyroid function indexes, serum TSH changed quickly and decreased significantly 4 weeks after LT4 therapy. The change of serum FT4 responded drastically at the 12th gestational week. We also found that serum FT3 did not change much after LT4 therapy. 50, 75, and 100 μg/day can maintain serum TSH level of 79.3, 82.4, and 90.0 % of SCH women in definitive therapeutic goal in group A, B, and C, respectively. The LT4 dose need to be adjusted one or more times in 20.7, 17.6, and 10.0 % of the SCH women in group A, B, and C, respectively. The different LT4 dose can be chosen according to the baseline TSH levels of SCH women. The constant LT4 dose can maintain serum TSH levels of 79.3–90 % patients in the ideal range. A small part of patients require adjust therapy also during the second and third trimester. Therefore, careful follow-up of SCH pregnant women should be taken, and thyroid function should be tested every month until the end of pregnancy.

Keywords

Subclinical hypothyroidismLevothyroxine treatmentPregnancyThyroid function

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Xiaohui Yu
    • 1
  • Yanyan Chen
    • 1
  • Zhongyan Shan
    • 1
  • Weiping Teng
    • 1
  • Chenyang Li
    • 2
  • Weiwei Zhou
    • 3
  • Bo Gao
    • 4
  • Tao Shang
    • 5
  • Jiaren Zhou
    • 5
  • Bin Ding
    • 2
  • Ying Ma
    • 6
  • Ying Wu
    • 7
  • Qun Liu
    • 8
  • Hui Xu
    • 8
  • Wei Liu
    • 9
  • Jia Li
    • 10
  • Weiwei Wang
    • 1
  • Yuanbin Li
    • 1
  • Chenling Fan
    • 1
  • Hong Wang
    • 1
  • Hongmei Zhang
    • 1
  • Rui Guo
    • 1
  1. 1.Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine DiseasesThe First Affiliated Hospital of China Medical UniversityShenyangChina
  2. 2.Department of Gynaecology and ObstetricsShenyang No. 5 People’s HospitalShenyangChina
  3. 3.Department of Gynaecology and ObstetricsWomen and Infants Hospital of ShenyangShenyangChina
  4. 4.Department of Gynaecology and ObstetricsShenyang No. 4 People’s HospitalShenyangChina
  5. 5.Department of Gynaecology and ObstetricsSecond Affiliated Hospital, China Medical UniversityShenyangChina
  6. 6.Department of Gynaecology and ObstetricsShenzhou Hospital of ShenyangShenyangChina
  7. 7.Department of Gynaecology and ObstetricsShenyang No. 9 People’s HospitalShenyangChina
  8. 8.Department of Gynaecology and ObstetricsWomen and Infants Hospital of Heping District of ShenyangShenyangChina
  9. 9.Department of Gynaecology and ObstetricsShenyang No. 8 People’s HospitalShenyangChina
  10. 10.Department of Endocrinology and MetabolismThe Fourth Hospital of China Medical UniversityShenyangChina