Endocrine Abstracts

Background: It is generally reported that female fertility is not affected by high-dose RAI treatment. AMH has been considered a reliable and accurate index of ovarian reserve. There are few data on AMH values in thyroid diseases. Recently, in DTC women who had undergone RAI ablation treatment, Acibucu et al. (2016) reported low AMH levels without significant impairment of fertility.

Aim: The aim of this single-center study was to evaluate AMH levels in association with the characteristics of spontaneous menstrual cycles and the levels of pituitary–gonadal hormones in our cohort of pre-menopausal women with a history of low-risk DTC.

Subjects: From a group of 68 women, 39 who were not on oral contraceptive therapy were enrolled. All hormone evaluations were performed on chemiluminescence assays. AMH, FSH, 17B-estradiol (E2) were assayed on day 2 and PRL and progesterone (P) levels on day 21–24 of the same menstrual cycle. Twenty-seven women (aged 40±6 years) were studied 7±4 years after primary DTC treatment, which included at least one RAI treatment (median activity 80 mCi). As a control group, 12 female DTC patients (aged 40±8 years) who had undergone only thyroidectomy were used.

Results: All women were free from DTC. Pregnancy (study group 62%; control group 50%) and abortion rates (17 and 33%) were similar. TSH and f-T4 were similar in both groups. Hyperprolactinemia was found only in one patient, while FSH >30 mU/l was found in 2 (1 study, 1 control). Regular (28±2 days) menses were reported in 33% of both groups. A high incidence of polymenorrhea was reported in the study group (33%), while a high incidence of oligomenorrhea was noted in the control group (50%). Ovulatory cycles (P>4 ng/ml) were noted in 72 and 60% of study and control women, respectively. AMH levels were found to be negatively correlated with age (P=0.002), but not with E2, FSH, TSH or f-T4 levels. AMH levels were 2.0±0.4 ng/ml and 2.3±1.5 ng/ml in the study and control groups, respectively.

Limitations: These data are preliminary, as data collection is still ongoing.

Conclusions: AMH should replace FSH in the evaluation of gonadal reserve in pre-menopausal DTC women. At present, age is the only predictor of AMH levels. About one out of two women with a history of DTC suffers from menstrual dysregulation, but infertility must be considered a low risk.