Fertility preservation in Turner syndrome: Karyotype does not predict ovarian response to stimulation.

Objective: Turner syndrome (TS) is responsible for gonadal dysgenesis with high risk of premature ovarian insufficiency. Little is known about fertility preservation (FP) strategies is this population.
Design: Data from women with TS consulting with a fertility specialist in our FP centre from 2014 to 2018 were retrospectively collected.
Measurement: Total number of mature oocytes cryopreserved using vitrification.
Patients: Nine women with TS were referred. Three women with different karyotypes underwent controlled ovarian stimulation (COS) for oocyte vitrification. Mean age at TS diagnosis was 13.7 years [9-20]. Mean referral delay between TS diagnosis and fertility consultation was 9.7 years [7-14]. First counselling for FP was provided at 23.7 years [18-28]. Mean AMH serum level prior to COS was 53.8 pmol/L [3.6-95].
Results: All three women succeeded in obtaining cryopreserved oocytes with a mean number of 15.3 per woman [9-20] and 9.2 per COS cycle [2-20]. Ovarian response to COS was unexpectedly remarkable for the woman with a complete 45,X monosomy. Procedure was well tolerated for all women. None of them have used oocytes for in vitro fertilization yet.
Conclusions: Independently of karyotype, antral follicular count, AMH and FSH levels seemed to be reliable predictive markers of oocyte cryopreservation success. In a monosomic TS woman, cryptic ovarian mosaicism could explain a successful ovarian response to stimulation with a high number of retrieved oocytes. In case of spontaneous menarche, TS adolescents should be referred during transition to adulthood for FP counselling to avoid referral delay and limit time-related diminished ovarian reserve.
(© 2019 John Wiley & Sons Ltd.)