Human oocyte and ovarian tissue vitrification in fertility preservation for women: an audit and prospective study

Date
2022-04
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH SUMMARY: Introduction: Female fertility preservation [FP] is of interest, due to the advancement in cancer therapy and the resultant increased survival rate. Methods of FP include embryo vitrification, oocyte vitrification [OV] and ovarian tissue cryopreservation [OTC]. Research on FP techniques, their success rates and new developments are encouraged. Relevant information is important for accurate patient counselling on indications for FP. This study investigated two of the FP methods: ovarian tissue vitrification [OTV] and OV. Aims & Objectives: Two separate studies were performed: Study A (prospective) and Study B (retrospective audit). Study A investigated OTV, and aimed to observe the survival rates of vitrified-thawed ovarian tissue using a commercial vitrification kit [Kitazato], to determine the effectiveness of the method, as an option for FP. Study B was an audit of OV programmes at Drs Aevitas Fertility Clinic (and a participating clinic) that was done to determine the success of this treatment as a form of FP. Materials & Methods: Study population A: consenting, oophorectomy surgery patients, from whom an ovary/ovaries were removed, prepared, vitrified, thawed, and tested for survival using a H&E histological evaluation and a Ki-67 proliferation test. The sample size was N = 2 patients [from ethical approval (8th October 2018) to November 202]. Fifty follicles from each group (fresh ovarian tissue [FOT] and vitrified-thawed ovarian tissue [VTOT]) were evaluated. Study population B: consenting patients with vitrified-thawed oocyte treatment (own and donor oocytes)] at Drs Aevitas Fertility Clinic and a participating clinic. The sample size for study B was N = 196 patients (January 2015-December 2019) and used medical records only. Results: Study A - the overall percentage of H&E morphologically normal follicles were not significantly different between the 2 sample groups [FOT (36.0%) vs. VTOT (22.0%)]. Most follicles showed detachment of the oocyte from the granulosa cell layer. The Ki-67 proliferation index was 68.0% for both groups. Study B - the overall oocyte survival rate [SR] was 76.63%, fertilization rate [FR] 77.54%, and the blastulation rate [BR] 43.45%. The CPR and LBR outcomes were 37.68% and 28.26%, respectively. Sub-analysis results showed that Group A (own vitrified-thawed oocytes), had significantly poorer outcomes compared to Group B (donor vitrified-thawed oocytes at Drs Aevitas Fertility Clinic) and Group C (vitrified oocytes thawed at a participating clinic) respectively - SR: 65.25%, 76.62% and 83.52%, FR: 69.91%, 76.81% and 83.4%. BR: 16.27%, 49.49% and 37.53%, CPR: 15.00%, 37.78% and 53.57%, LBR: 15.00%, 33.33% and 30.0% [p<0.05]. The only confounding factor that had a significant effect was the recipient age – older patients had a significantly higher CPR [p<0.05]. Conclusion: Study A – Based on results of histological evaluations and immunochemistry staining, ovarian tissue survival was achieved after vitrification and thawing of the ovarian tissue. Study B - The clinical outcomes observed (SR, FR, BR, CPR and LBR) in patients making use of OV programmes at Drs Aevitas Fertility Clinic and a participating clinic, were comparable to the results found in the literature and can be considered an effective treatment option for FP in female patients.
AFRIKAANS OPSOMMING: Introduksie: Fertiliteitsbewaring [FB] vir vroue ontlok belangstelling wat kan toegeskryf word aan die vooruitgang in kankerterapie, wat verhoogde kankeroorlewingskoerse tot gevolg gehad het. Die FB metodes wat tans gebruik word, is embriovitrifikasie [EV], oösietvitrifikasie [OV] en ovariale-weefsel kryopreservering [OWK]. Voortgesette navorsing van FB tegnieke, suksessyfers en nuwe ontwikkelings, word aangemoedig. Die beskikbaarheid van relevante inligting is belangrik vir akkurate berading van pasiënte wat FB behandeling, vir beide onkologiese en nie-onkologiese redes, verlang. Hierdie studie het twee van die FB metodes ondersoek: ovariele-weefsel vitrifikasie [OWV] en OV. Doelwit & Doele: Twee studies is onderneem: Studie A (vooruitskouend), Studie B (retrospektiewe oudit). Studie A het OWV behels, met die doel om die oorlewingssyfer van vitrifiseerd/ontdooide ovariale weefsel vas te stel deur ‗n kommersiele vitrifikasie ―kit‖ [Kitazato] te gebruik.en te bepaal of hierdie metode ‗n effektiewe behandelingsopsie vir FB is. Studie B ( retrospektiewe) is ‗n oudit van OV programme by Drs Aevitas Fertiliteits Kliniek (en ‗n deelnemende kliniek) om die sukses van hierdie behandeling, as ‗n vorm van FB te bepaal.. Metodes & Materiaal: Studiepopulasie A: Instemmende, oophorektomie chirurgie pasiënte van wie ‗n ovarium/ovaria verwyder ,voorberei, vitrifiseerd, en ontleed is vir oorlewing met ‗n H&E morfologiese and Ki-67 proliferasie toets. Die steekproefgrootte was N=2 pasiënte [vanaf etiese goedkeuring (8 Oktober 2018) tot November 2021]. Vyftig follikels van elke groep (vars ovariale-weefsel [VOW] en vitrifiseerd/ontdooide ovariale weefsel [VOOW]) is ontleed. Studiepopulasie B: Instemmende, vitrifiseerd/ontdooide [VO] ova behandeling (eie en donor ova) pasiënte by Drs Aevitas Fertilieits Kliniek (en ‗n deelnemende kliniek). Die steekproefgrootte van studie B was N=196 (Januarie 2015 – Desember 2019) slegs mediese rekords is gebruik. Resultate: Studie A – die algehele persentasie H&E morfologies-normale follikels het nie betekenisvol verskil tussen die twee groepe nie [VOW (36.00%) vs VOOW (22.00%)]. Die meerderheid follikels het gewysdat oösiete losgetrek het van die granulosa-sellaag, veral die gevitrifiseerde groep. Die Ki-67 proliferasie-indeks was 68.0% in VOW en VOOW. Studie B – die algehele oösiet-oorlewingskoers [OK] was 76.63%, bevrugtingskoers [BK] 77.54% en blastulasiekoers [BLK] 43.45%. Die kliniese swangerskap [KSK] lewende geboorte [LGK] koers was 38.0% en 28.0% onderskeidelik. Sub-analiese resultate het gewys dat Groep A [eie vitrifiseerd/ontdooide ova ] betekenisvol swakker uitkomste gehad het vergelykende die van Groep B [donor vitrifiseerd/ontdooide ova - Aevitas Kliniek] en C [donor vitrifiseerd/ontdooide ova - ontdooi by deelnemende kliniek], onderskeidelik - OK: 65.25%, 76.62% en 83.52%, BK: 69.91%, 76.81% en 83.4%. BLK: 16.27%, 49.49% en 37.53%, KSK: 15.00%, 37.78% en 53.57%, LGK: 15.00%, 33.33% en 30.0% [p<0.05]. De enigste ―confounding‖ faktor wat ‗n betekenisvolle effek gehad het was die ouderdom van die ontvanger pasiënt. Ouer ontvanger pasiënte het ‗n betekenisvol beter KSK getoon. Gevolgtrekking: Studie A – Gebasseer op die resultate van die histologise en immunochemiese evaluasies kan afgelei word dat VOOW monsters wel die vitrifikasie proses oorleef. Studie B: Die kliniese uitkomste (OK, BK, BlK, KSK en LGK) waargeneem vir pasiënte wat van die OV-program by Drs Aevitas Fertilitets Kliniek
Description
Thesis (MSc)--Stellenbosch University, 2022.
Keywords
Ovum -- Cryopreservation, Ovarian tissue -- Cryopreservation, Fertility preservation, Vitrification cryopreservation, UCTD
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