| Abstract
| - Mechanical partial zonal dissection (PZD) is one of the micro-insemination techniques developed to improve the chances of fertilization by in-vitro insemination in subfertile males. We developed a new and safe laser method (erbium laser ablation) for PZD, with the aim of producing a precise opening as well as ablation of some layers of the zona pellucida. From February 1992 to March 1993, 104 couples suffering from male factor infertility were treated in our centre. All patients were affected by severe oligoasthenozoospermia and had previously undergone one failed in-vitro fertilization attempt each. Photoablation of the zona pellucida was induced in 512 oocytes by exposure to an erbium-yytrium aluminium garnet (Yag) laser. The openings obtained were ∼ 14μm in diameter. Of the laser-treated oocytes, 158 (30%) fertilized and 139 (88%) cleaved. Nineteen (18.3%) clinical pregnancies resulted and produced 17 newborns, all in good health. In our series there were four miscarriages, 23 damaged oocytes (4.4%) and 13 with three or more pronuclei (2.5%). Considering that the incidence of damaged oocytes and polyspermy is low, it seems that in some cases of male factor infertility erbium—Yag laser photoablation of the oocyte zona pellucida can be considered a procedure which is effective in enhancing fertilization and which is safe, allowing normal embryo development.
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