Turner Syndrome Minipuberty Study

Rationale: Due to accelerated germ cell loss, infertility is a major problem in girls with Turner syndrome (TS). Therefore, cryopreservation of ovarian tissue or oocytes before exhaustion of the ovarian reserve may preserve fertility in patients with TS. However, in the majority of females with TS , the ovarian reserve is exhausted before the age of menarche. Early markers indicating and predicting the ovarian reserve are necessary. During mid-childhood the hypothalamic-pituitary-gonadal (HPG) axis is quiescent and gonadotropins are usually unmeasurable. Nonetheless, this axis is active during infancy. Therefore, gonadotropins are measurable with peak values at 3 months of age and with lower (but still measurable) values at 9 months of age, in a period called the minipuberty. The aim of this study is to find markers of ovarian capacity, during the minipuberty, in order to predict ovarian reserve in the future. Objective: The hormonal range of LH, FSH, AMH, inhibin B, testosterone and estradiol in girls with TS during the minipuberty and the relation of the hormone serum levels with the karyotype. Study design: A prospective, cohort study with a duration of 3 years. Study population: Girls with a pre- or perinatal diagnosis TS who are born in a medical centre in the Netherlands during the duration of the study Main study parameters/endpoints: Serum levels of FSH, LH, AMH, inhibin B, testosterone and estradiol at the age of 3 and 9 months.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The subjects will have twice an extra venapunction for collection of 3.5mL blood during their infancy, which is not stated in the guidelines for TS. There is very little risk for adverse events associated with this blood sample collection, however it is an extra procedure. The outcome parameters will not be helpful for individual study participants, however they are likely to help clinicians and researchers in understanding how the ovarian function operates develops in girls with TS. Furthermore, these markers could be used to estimate the ovarian reserve and the urgency of fertility preservation in young females with TS. This information could help clinicians, patients and their parents in decision making.