Background: For patients with differentiated thyroid carcinoma (DTC), the effect of radioactive iodine (RAI) therapy on gona-dal and reproductive function is an important consideration. Objective and methods 127 children were operated on thyroid in case of DTC during 1975-2015. 87 pts were treated by RAI (1-13 times). Average age is 15 years (4-18). Histological types of DTC were papillary (69%), follicular (27%), other (4%). Average follow up period is 3 year (2-40). We analyzed effect of therapeutic RAI on sex steroid level; on ovarian function, menses, ovulation in women; sperm in men; future fertility; pregnancy outcomes. Result(s): Early side effects (during 1stweek after RAI) included-nausea and vomiting(29%), sialoadenitis (22%), temporal bone marrow dysfunction (6%). Late side effects included permanent salivary glands' dysfunction (2%), permanent bone marrow dysfunction (4%), lung fibrosis (5%), second tumors - leucosis, breast cancer (4%), fertility disorder (7%). Fertility was analyzed in 78 pts. Sterility (2%), amenorrhea (4%), changes in menstrual period (5%), miscarriage (4%). Conclusion(s): RAI should be prescribed only for indications. Sexual cell should be cryopreserve before RAI.
