Fertility preservation: a case report of a newborn following 13 years of oocyte cryopreservation

OBJECTIVE: Oocyte cryopreservation enables the storage of genetic material, especially in situations where the ovarian function is compromised, also for women desiring to postpone maternity. Before 2012, oocyte cryopreservation was still experimental, and the success of the procedure was uncertain; however, it was the only possibility that women had for fertility preservation. Thus, we aim to report a case of a birth after 13 years of elective oocyte cryopreservation. CASE DESCRIPTION: At 49 years of age, the patient returned to our reproductive center with the desire to get pregnant, using oocytes that had been frozen for 13 years. The endometrium was prepared, and the oocytes were thawed using the slow procedure method. Four of the six oocytes thawed survived (66%) and were inseminated; three fertilized and started their development. The transfer of two embryos on the third day of development was performed. Clinical pregnancy was confirmed via ultrasound and came to term with the birth of a healthy boy. DISCUSSION: Although the vitrification procedure has shown to be a better cryopreservation technique when compared to slow freezing, the latter represented an important role when patients wanted to cryopreserve oocytes in the early 2000s. Even many years later, this technique reveals its efficacy, preserving the viability and quality of oocytes stored in nitrogen tanks. After a literature review, this case seems to be the largest interval between oocyte cryopreservation and its use, with achieved pregnancy, in Brazil.