Laser-assisted hatching of embryos is better than the chemical method for enhancing the pregnancy rate in women with advanced age

Objective: Assisted hatching may enhance embryo implantation. This study was conducted to examine the efficacy of the laser- and chemical-assisted hatching for promotion of implantation (IR), pregnancy (PR). and delivery rate (DR) in older women undergoing IVF cycles. Design: Prospective study. Setting: An IVF unit of a medical center. Patient(s): A total of 601 embryos from 141 women aged greater than or equal to38 years underwent controlled ovarian hyperstimulation (COH) and assisted hatching. Intervention(s): The study population was divided into two groups: group I had laser-assisted hatching (n = 85) and group 2 had chemical-assisted hatching (n = 56). Before the transfer, the day 3 embryos were hatched by using a 1.48-mum noncontact diode laser or acid Tyrode's solution. Main Outcome Measurement(s): The IR, PR, and DR between the groups were compared. Result(s): There were no statistical differences between groups in age, E-2 concentrations during hCG administration, gonadotrophin dosage, embryo grade, the numbers of oocytes retrieved, oocytes fertilized, and embryos transferred. Higher IR, PR, and DR were noted in the laser-assisted hatching group. The IR, PR. and DR were: group 1, 8.2%/31.8%/24.7% and group 2, 3.8%/16.1%/10.7%, respectively. Conclusion(s): Laser-assisted hatching of embryos is more effective than the chemical method in enhancing the IR and PR of women with advanced age. The laser system allows an easier, faster, and safer micromanipulation of the zona pellucida, which provided a better method in zona drilling. (C) 2002 by American Society for Reproductive Medicine.