[Value of the morphological characteristics of polar body as a predictive factor of embryo development]

To determine the relation between polar body quality and perivitelline space with fertilization and segmentation rates and embryo quality.

Prospective and descriptive.

Sixty-one patients underwent the in vitro fertilization and embryo transfer program (IVF-ET). The intracytoplasmatic sperm-injection (ICSI) was applied for insemination. Controlled ovarian hyperstimulation was made with recombinant FSH. Oocytes were evaluated 4-6 hours after retrieval and polar body, perivitelline space, and pellucid zone were assessed too. Fertilization was evaluated 17 hours after ICSI, and segmentation rates were analyzed at 48 and 72 hours. The number of blastomeres and quality of each embryo was assessed prior transference. Statistical analysis was done with chi2 test.

We evaluated 883 oocytes, of which 43.8% had a normal polar body, 54.9% had a normal perivitelline space, and 69% a normal pellucid zone; 57% of retrieved oocytes with normal polar body developed an adequate fertilization rate, and oocytes with abnormal polar body had fertilization in less than 20%. Embryo cleavage was adequate in oocytes with normal polar body, in the abnormal oocytes was less than 20%, and 79% of the oocytes with fragmented polar body did not developed in embryo. There were not significant differences in fertilization rates and segmentation when compared with the pellucid zone and perivitelline space.

Oocyte quality has a great influence on fertilization and embryo development. One of the most important variables is the polar body quality, which correlates adequately with fertilization and embryo cleavage.