Cryopreservation of Ovarian Tissue for Pediatric Fertility

Abstract

Intensive treatments necessary to treat some childhood malignancies and other conditions, as well as certain anatomic variations, may lead to infertility in adulthood. Until recently, no fertility preservation options for prepubertal females were available. However, ovarian tissue cryopreservation has emerged as a safe and effective option for these children. In the next several years, it is likely that more pediatric patients, their families, and medical teams will pursue an ovarian cryopreservation protocol at their institutions. Patient selection, consenting, and laparoscopic oophorectomy can be done at many centers. Then, the ovarian tissue is initially processed and transported to a specialized center for processing for cryopreservation. The cryopreservation techniques are best performed at appropriately certified centers processing high volumes of reproductive cells/tissues with expert personnel and specialized equipment. This article aims to provide an overview for pediatric biobank professionals who may be called to participate in this or similar protocols.

Sohlh1 and Lhx8 are prominent biomarkers to estimate the primordial follicle pool in mice

“…The PFP is an essential subject in studies related to ovarian physiology and pathogenesis [4][5][6]. In clinical practice, the assessment of ovarian PFP in patients is mainly done indirectly by imaging and serology such as AMH, while there is no e cient method for the direct evaluation of ovarian tissue applied in clinical OTC, in vitro activation (IVA) and other ART [21][22][23]. Generally, the assessment of the exact number of PFP based on microscopic counting is considerably subjective, and the number of follicles reported by different teams varies dramatically [7], which makes it conceivably challenging to apply for rapid assessment in clinical applications and animal studies.…”

Scaling up Cryopreservation from Cell Suspensions to Tissues: Challenges and Successes

“…Most somatic mammalian cells can tolerate a relatively low cooling rate, down to 0.1-0.3°C/min, which is usually sufficient for dehydration to occur. T cells for example have shown similar optimal survival at rates of 1°C/min and as low as 0.1°C/min [41], and ovarian tissue samples are typically cooled at rates of 0.2-0.3°C/min [31, [61][62][63][64]. As can be seen in Table 1, most spheroid and organoid cryopreservation methods currently use passive coolers, where control of the cooling rate is limited and producing rates in the vicinity of/of approximately 1°C/min-moving to controlled rate freezers with lower and more precise rates would allow for more precise control over cell dehydration [15].…”

Resurrecting biodiversity: advanced assisted reproductive technologies and biobanking

“…Since the first mouse was born in 1996 following in vitro growth of primordial follicles ( Eppig & O’Brien 1996 ), there have been many published studies on this technique in a number of species including white-tailed deer ( Odocoileus virginianu ) ( Gastal et al 2018 ), domestic cat ( Felis catus ) ( Mouttham & Comizzoli 2016 ), collared peccary ( Pecari tajacu ) ( Lima et al 2019 ), yellow-toothed cavies ( Galea musteloides ) ( Praxedes et al 2017 ), brown trout ( Salmo trutta ) ( Lujić et al 2017 ), donkey ( Equus asinus ) ( Lopes et al 2018 ) and domestic cattle ( Figueiredo et al 1993 , 1994 a , b , Hulshof et al 1995 , Vasconcelos et al 2013 ). Following death, euthanasia or neutering, a portion of the ovary can be cryopreserved; the immature follicle-containing cortex is dissected and cut into small strips under sterile conditions before slow freezing ( Benesova & Trefil 2016 , Hinkle et al 2021 ). As the ovary contains many follicles, there is a potential to produce large numbers of oocytes from the tissue within a laboratory.…”