Are zona pellucida laser drilling and polar body biopsy safe for in vitro matured oocytes?

Introduction: Preconception diagnosis requires first polar body biopsy. When the hole in the zona pellucida is made with a laser beam, heat propagation could, like the biopsy itself, be deleterious. Our aim was to evaluate the effect of this technique on human in vitro matured oocyte and embryo development.

Methods: One hunded fifty five retrieved immature oocytes from 75 women, matured in vitro, were distributed in 3 groups: 50 oocytes in a control group, without laser drilling and first polar body biopsy, 52 oocytes in a group with only laser drilling, and 53 oocytes in a group with both laser drilling and first polar body biopsy. Safety was evaluated using four criteria: [1] oocyte lysis rate, [2] oocyte activation rate, [3] oocyte development after calcium ionophore treatment, [4] and embryo chromosome breakage incidence after Tarkowski preparation.

Results: No difference in the four criteria was observed between the 3 oocyte groups.

Conclusions: We did not find evidence of deleterious effect of laser drilling and first polar body biopsy on in vitro matured oocytes, according to our criteria.