Evidence of parthenogenetic origin of ovarian teratoma: case report

This case report represents one of the few documented cases of parthenote embryo retrieval from an IVF patient with a history of ovarian teratomas. A 29-year-old woman presented at our centre with a history of primary infertility for 6 years due to male factor. She had undergone left oophorectomy 4 years before due to an ovarian teratoma. An ultrasound scan performed during basal evaluation revealed two complex images in the right ovary suggesting teratomas, measuring 2.5 x 2.4 and 1.7 x 1.3 cm. A significant extent of sonographically normal ovarian parenchyma was present, and the patient underwent the long leuprolide acetate protocol of ovarian stimulation with recombinant FSH for an IVF-ICSI cycle. She had 13 metaphase II (MII), four metaphase I (MI), two germinal vesicle (GV) oocytes and one 4-cell embryo retrieved. Eight out of nine injected oocytes were fertilized normally while one was unfertilized. Embryo transfer was carried out 72 h after retrieval. The 4-cell (parthenote) embryo recovered at oocyte retrieval continued to cleave in culture, developing into a 7-cell embryo by the next day. The embryo was morphologically normal, presenting an evident nucleus in each blastomere. Fluorescent in situ hybridization (FISH) returned two signals for the X chromosome in each blastomere that was analysed. Of the eight normally fertilized embryos, three were transferred, resulting in a normal singleton pregnancy and the birth of a healthy baby.