Reproductive aspects
Social freezing to postpone child bearing has also become a topic of interest. So far, it is limited to cryopreservation of oocytes. Although social freezing is already widely offered and carried out, it is still controversial (von Wolff et al., 2015). For example, social freezing may not solve social problems but only postpone them. Pregnant women are potentially becoming older, leading to higher obstetrical risks. Social freezing usually requires IVF. In mice and humans, IVF has been found to increase risk of malformations and functional disorders, such as an increased carotis–intima–media thickness, leading to an increased pulmonary blood pressure (von Wolff et al., 2015). The increased risk of malformation may be attributed to a general predisposition owing to the infertility itself; however, functional disorders, which are probably caused by epigenetic modifications, cannot. Therefore, social freezing using ovarian tissue followed by IVF is possibly associated with an increased health risk for the offspring.
Pregnancies may also be achieved after transplantation of ovarian tissue without IVF. Tissue transplanted into the remaining ovary and even into a peritoneal pocket can lead to spontaneous pregnancies (Liebenthron et al., 2015). Therefore, cryopreservation of ovarian tissue might also be an interesting alternative to social freezing. Data on the technique's efficacy and on children's outcome after having used this technique are still limited; therefore, cryopreservation of ovarian tissue to postpone child bearing cannot yet be generally recommended.
Discussion