Whether for the prepubertal or pubertal child, the goal of fertility preservation is to obtain cells or tissues to be used to produce future children. For the prepubertal child, preservation efforts involve germ cells, earlier forms of sperm, and immature follicles, rather than mature spermatozoa or follicles. Options for prepubertal children include for boys freezing testicular tissue and extracting testicular sperm or for girls obtaining ovarian cortical or follicular tissue for storage. These procedures involve extraction and storage of immature gametes for subsequent in vitro maturation, although attempts for sperm currently involve only animal studies. For adolescent subjects who have sufficient gonadal development and reserve, sperm, oocytes, and ovarian cortex can be retrieved as among adults.
Modern medicine now offers hope for many patients who would have been infertile in the past. Fertility preservation and assisted reproduction in adults has received considerable attention. In women, discussion of fertility preservation typically arises in patients with malignancies or nononcologic conditions that either require treatment with gonadotoxic drugs, ovariectomy, or pelvic radiation. Among adult men, fertility preservation should be considered whenever testicular damage may result from medical/surgical therapy or from trauma. Fertility preservation is a consideration that should be discussed in those undergoing treatment for malignancy as well as those with genetic or other congenital conditions.
The dramatic success noted in the treatment for childhood cancers has resulted in a marked increase in survival rates creating many long-term cancer survivors with unique medical challenges. Preservation of fertility is one such challenge that has mandated the need to assess future reproduction among these individuals. Topics related to fertility preservation in pediatric and adolescent patients being treated for cancers, including ethical considerations, have recently been summarized. Given the recent improvements in fertility preservation, this issue must now become part of an overall care plan for such children and adolescents.
Awareness of current and developing techniques is appropriate for the pediatric endocrinologist because of the improved potential for fertility in children with malignancy who have undergone chemotherapy or radiation therapy as well as children and adolescents with other diagnoses, including endocrinopathy, who have long been considered to be infertile.
Efforts to address fertility preservation should be considered as soon as the risk is realized. This applies to those with gonadal failure previously considered to be incompatible with biologic parenthood such as Turner or Klinefelter syndromes. Parenthood may also be possible, albeit at considerable expense, for patients with hypogonadotropic hypogonadism, polycystic ovarian disease, or other ovulatory dysfunction. The potential for such therapies should be assessed at an early age.
Attainment of fertility potential in the human
Although fertility potential is not normally attained until early or midpuberty, a low level of gonadal activity is present during childhood with limited follicular development and early stages of spermatogenesis. Even though mature sperm are not present until a mean age of 14 years, meiosis results in development of spermatids in the prepubertal testis. Semen cryopreservation has been reported to be feasible in roughly two-thirds of boys aged 13.7 to 18.9 years. Although sperm counts cannot accurately be predicted by hormone measurements, it is likely that an adequate sample for preservation could be obtained around midpuberty in those without chronic debilitating illness. Similar findings have also been noted in 14- to 17-year-old boys with malignancies. Among females, there is no conclusive evidence of further oocyte production after birth and meiosis occurs during follicular maturation. There is potential for in vitro maturation of primordial oocytes into oogonia. Before ovarian failure, all females will produce mature follicles in response to gonadotropin stimulation. In fact most females are capable of ovulation by midpuberty.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
