The effect of oil and water-soluble contrast medium in hysterosalpingography on thyroid function

Hysterosalpingography (HSG) using iodinated contrast medium is X-ray diagnostic test that examines the inside of the uterus and fallopian tubes in infertile women. In this study, we compared thyroid function (thyroid stimulating hormone: TSH and free-T4: FT4 levels) after HSG with an oil-soluble contrast medium (OSCM) and a water-soluble contrast medium (WSCM). One hundred and sixty-four and 94 patients with normal thyroid function received HSG with OSCM and WSCM, respectively. Approximately 25% of the women in the OSCM group developed subclinical hypothyroidism (SCH), whereas only less than 10% of the patients in the WSCM group developed SCH. Our data clearly indicate that WSCM is safe for thyroid function in women who plan to get pregnant.