The follow-up and evaluation of thyroid function, pregnancy in women of childbearing age (78 cases) and male (5 cases) after Iodine 131 treatments for hyperthyroidism and their offsprings

Objectives: To investigate the follow-up and evaluation of thyroid function, birth, growth and development of children of childbearing-age women and men in hyperthyroidism after 131 iodine treatments.

Methods: From 2003 to 2017, more than 13000 patients of hyperthyroidism after 131 iodine treatments in the two departments of nuclear medicine were retrospectively analyzed. In which, 78 cases of pregnancy, childbirth and fertility of female and 5 cases of male, and also their children were followed up and evaluated. 78 cases of women in the reproductive period (24~40 years) had 101 times of iodine treatment (62 patients of a single treatment, 2 times for 12 patients, 3 times for 1 patient, 4 times for 3 patients), and the treatment dose was 246.9 ± 102.7MBq (55.5~740.0 MBq). In 78 pregnant women, 55 cases (70%) taken euthyrox (50 ± 25μg/d) for subclinical hypothyroidism, 10 cases (12%) of subclinical hyperthyroidism taken Propylthiouracil (25 ± 12.5 mg/d), and 13 cases (16%) were in normal FT3, FT4 and TSH (< 2.5). The interval period of iodine administration and conception of 78 cases were 23±12 months, 2 cases were 2.5 months, 2 cases were 4.5 months, the rest 74 cases were over six-months, the longest interval was more than 75-months.Results and Discussion: 78 cases of women had 85 fetuses, including 71 singletons, 4 twins, 2 children of 2 cases, 1 cases with monozygotic twins. There were 44 boys and 41 girls, and 74 cases (95%) were full-term birth, and 71 cases (91%) had normal fetal weights (2.5 to 4kg).After iodine treatment, 4 of 5 cases taken euthyrox. After 11 to 78 months periods, 1 boy and 4 girls were born (both full-term birth and in normal weight).Up to December 2017, 90 children (from 2 months to 9.5 years old, 4.9±2.1 years) were followed-up, and there were no obvious abnormalities in their height, weight and intelligent developments. And 1 cases of interval of 4.5 months, the two twins children now are 7 years old, and they are in good health.Conclusion: It is safe for 131 iodine treatment for hyperthyroidism, while the iodine administration and conception interval should be more than 6 months for pregnant.In pregnant women, sub-hyperthyroidism or sub-hypothyroidism can be controlled by different drugs ( euthyrox or PTU ) to ensure that FT3 and FT4 in the normal range and TSH (<2.5). For male patients with hyperthyroidism, thyroid function after 131 iodine treatment control can also be maintained in the normal range. 131 iodine treatments for hyperthyroidism do not affect fertility, and do not cause genetic damage. It is particularly necessary to point out that in our study, in 4 cases of the less than 6-months’ period, their 5 children are in good health.