P–462 First live birth after fertility preservation using vitrified oocytes in a woman with mosaic Turner syndrome
Authors: Strypstein L , Va. Moer E , Nekkebroeck J , Segers I , Tournaye H , Verpoest W , Vos M D 
Published: August 2021

Abstract

Study question
Is oocyte vitrification an option for preserving the fertility of women diagnosed with Turner syndrome (TS)?

Summary answer
We report the first live birth achieved using cryopreserved oocytes in a woman diagnosed with mosaic Turner syndrome.

What is known already
Women with TS are at extremely high risk for premature ovarian insufficiency (POI) and infertility. Although the desire of becoming parents may be fulfilled through egg donation or adoption, fertility preservation using ovarian tissue cryopreservation or oocyte vitrification has been offered to adolescents with TS before complete exhaustion of their follicular stockpile. However, women with TS exhibit higher rates of pregnancy loss and obstetric complications, and the feasibility of fertility preservation in TS is hampered by the reduced follicular pool and by concerns about the X chromosomal content of oocytes and follicular cells.

Study design, size, duration
Case report in a university hospital.

Participants/materials, setting, methods
A 25-year-old woman with Turner syndrome mosaicism (45,X0[14]/46,XX[86]) was referred for fertility preservation (FP) counseling. Serum antimüllerian hormone (AMH) level was normal (6.4 µg/L). In view of parenthood postponement and because of the unpredictable rate of follicle loss, the woman underwent two cycles of ovarian stimulation using recombinant follicle stimulating hormone (rFSH), 200–250 IU/day for 8 resp. 12 days, in a GnRH antagonist protocol.

Main results and the role of chance
In total, 29 metaphase II oocytes (MII) were vitrified. Five years later, the patient returned to the clinic with a desire for pregnancy. Because of evidence of considerable AMH decline (–56% in an interval of four years), the patient was advised to utilize her cryopreserved oocytes for in-vitro fertilization with preimplantation genetic testing for aneuploidy screening (PGT-A). All 29 MII oocytes were thawed; 26 oocytes survived (89.7%) and were inseminated using intracytoplasmic sperm injection (ICSI). Thirteen oocytes were fertilized normally. Three good quality blastocysts ensued and were vitrified after trophectoderm biopsy for PGT-A using array-CGH. Two blastocysts were found euploid. One was thawed and transferred into the uterus using a HRT priming protocol. An uneventful pregnancy occurred. The patient delivered a healthy baby girl weighing 3490 g at 40 weeks of gestation.

Limitations, reasons for caution
Cryopreservation of oocytes and/or ovarian tissue in selected postmenarchal girls or young women with Turner syndrome is an investigational FP approach that may result in genetic parenthood. The feasibility of FP in TS individuals is limited to those with evidence of ovarian function, before POI occurs.
Wider implications of the findings: Cryopreservation of mature oocytes after ovarian stimulation is a realistic option for FP in selected postmenarchal individuals with mosaic TS. Whether PGT-A may reduce the risk of pregnancy loss in TS has to be confirmed by further studies.

Trial registration number
Not applicable