Embryo biopsy and development: the known and the unknown.

Preimplantation genetic diagnosis (PGD) has been introduced in clinical practice as a tool for selecting 'healthy' embryos before their transfer in utero. PGD protocols include biopsy of cleaving embryos (blastomere biopsy (BB)) or blastocysts (trophectoderm biopsy (TB)), followed by genetic analysis to select 'healthy' embryos for transfer in utero. Currently, TB is replacing the use of BB in the clinical practice. However, based on the European Society of Human Reproduction and Embryology Preimplantation Genetic Diagnosis Consortium reports, BB has been used in >87% of PGD cycles for more than 10 years. An exhaustive evaluation of embryo biopsy (both BB and TB) risks and safety is still missing. The few epidemiological studies available are quite controversial and/or are limited to normalcy at birth or early childhood. On the other hand, studies on animals have shown that BB can be a risk factor for impaired development, during both pre- and postnatal life, while little is known on TB. Thus, there is an urgent need of focused researches on BB, as it has contributed to give birth to children for more than 10 years, and on TB, as its application is significantly growing in clinical practice. In this context, the aim of this review is to provide a complete overview of the current knowledge on the short-, medium- and long-term effects of embryo biopsy in the mouse model.

Successful autotransplantation of cryopreserved ovarian tissue with recovery of the ovarian function.

OBJECTIVES: The aim of the study was autotransplantation of cryopreserved ovarian tissue to a patient suffering from premature ovarian failure caused by aggressive oncological therapy. MATERIAL AND METHODS: A 28-year-old woman, GII PI, was diagnosed with invasive adenocarcinoma of the cervix at 18 weeks of gestation. At 31 weeks of gestation, a cesarean section was performed, resulting in the delivery of a healthy male newborn, followed by simultaneous, radical hysterectomy with bilateral salpingo-oophorectomy and lymphadenectomy. Half of each ovary was cryopreserved. The patient was scheduled for radiochemotherapy, supplemented with brachytherapy. After the intervention, the patient experienced menopausal symptoms. The basal hormonal levels were: estradiol - 2 pg/ml, FSH - 96.52 IU/ml, LH - 37.55 IU/ml, AMH - 0.03 ng/ml. Thirteen months after surgery, the peritoneal pocket was formed on the anterior abdominal wall during laparoscopy and heterotrophic autotransplantation of the frozen-thawed ovarian tissue was performed, replacing 59% of the tissue. RESULTS: Nine weeks after transplantation, symptom resolution, an increase in estradiol (53 pg/ml), and a decrease in FSH (64.89 IU/ml) and LH (33.39 IU/ml) levels were noted. Twenty-four weeks after transplantation, high estradiol levels (269 pg/ml), normal level of FSH (5.92 IU/ml) and LH (4.09 IU/ml), and an increase in AMH (0.37 ng/ml) were observed. Follicular development in the transplanted ovarian tissue was confirmed. CONCLUSIONS: Cryopreservation and transplantation of ovarian tissue allowed to restore the ovarian function. It could offer an alternative physiological solution to treating premature ovarian failure caused by oncological therapy.