Thyroid function analysis and treatment in 88 cases of pregnancy after 131I treatment of hyperthyroidism
10.3760/cma.j.cn321828-20230420-00108
- VernacularTitle:88例甲状腺功能亢进症 131I治疗后妊娠患者的甲状腺功能分析及治疗策略
- Author:
Zhisong TAO
1
;
Qi MU
;
Xuefeng FENG
Author Information
1. 南京大学医学院附属鼓楼医院核医学科，南京 210008
- Keywords:
Hyperthyroidism;
Radiotherapy;
Iodine radioisotopes;
Pregnancy;
Thyroid function tests
- From:
Chinese Journal of Nuclear Medicine and Molecular Imaging
2024;44(6):355-358
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the thyroid function status and levothyroxine ( L-T 4) replacement therapy strategy in pregnant women after 131I treatment of hyperthyroidism. Methods:From January 2005 to December 2019, 88 patients (age: (27.3±3.7) years) who received 131I treatment in Nanjing Drum Tower Hospital were retrospectively analyzed. They became pregnant at least half a year after 131I treatment with normal thyroid function and delivered successfully. Thyroid stimulating hormone (TSH), free triiodothyronine (FT 3) and free thyroxine (FT 4) were respectively detected at 1-3 months before pregnancy, 4-7, 8-12, 13-22, 23-28, ≥29 weeks of pregnancy, and 6 weeks, 3 months, 6 months of postpartum. According to the 2011 American Thyroid Association guidelines, L-T 4 replacement therapy was performed to maintain normal thyroid function. Repeated measures analysis of variance and the least significant difference t test were used to analyze data. Results:There were significant differences in TSH, FT 3, FT 4 and L-T 4 among different time periods before pregnancy, pregnancy and postpartum ( F values: 5.94, 3.32, 3.49, 9.63, all P<0.05). In order to maintain normal thyroid function in each period of pregnancy, the doses of L-T 4 replacement therapy were increased to (82.33±35.06) μg and (100.75±36.77) μg at 4-7, 8-12 weeks of pregnancy compared with the dose ((64.52±34.32) μg) before pregnancy ( t values: 7.33, 10.44, both P<0.001). The doses of L-T 4 were increased slowly after 13 weeks of pregnancy. In the third trimester (≥29 weeks), the dose was 76.69% higher than that before pregnancy. There were significant changes of TSH, FT 3 and FT 4 at 6 weeks of postpartum compared with those in the third trimester (TSH: (1.21±1.08) vs (2.99±1.42) mU/L, FT 3: (5.23±1.07) vs (3.90±0.55) pmol/L, FT 4: (21.29±4.96) vs (15.37±2.29) pmol/L, t values: -2.48, 6.05, 5.88, P values: 0.017, <0.001, <0.001). Compared with that in the third trimester, the dose of L-T 4 was decreased significantly at 6 weeks of postpartum ( t=-6.85, P<0.001), but doses of L-T 4 at 6 weeks, 3 months and 6 months of postpartum were still higher than that before pregnancy ( t values: 4.67-4.71, all P<0.001). Conclusions:TSH, FT 3 and FT 4 should be regularly monitored at 1-3 months before pregnancy, gestation period and 6 weeks of postpartum in pregnant women after 131I treatment of hyperthyroidism. The dose of L-T 4 should be adjust to the serum TSH level as soon as possible.
