Outcomes of preimplantation genetic diagnosis using either zona drilling with acidified Tyrode's solution or partial zona dissection / 대한생식의학회지

OBJECTIVE: To review the outcomes of preimplantation genetic diagnosis (PGD) using zona drilling with acid Tyrode's solution (chemical zona pellucida drilling, chemical ZD) and those of partial zona dissection (PZD). METHODS: Clinical outcomes of seventy-one couples undergoing 85 PGD cycles from January 2005 to December 2010 were included. Blastocyst formation and the hatching rate, clinical pregnancy rate, ongoing pregnancy rate, implantation rate, and fetal gender ratio of the PZD and chemical ZD groups were compared. RESULTS: Application of PZD resulted in a significantly higher rate of clinical pregnancy (40.7% vs. 15.4%, p=0.022), ongoing pregnancy (35.6% vs. 11.5%, p=0.023), and implantation (18.1% vs. 5.7%, p=0.007) compared with chemical ZD. Among non-transferred embryos, the rate of blastocyst formation on day 5 (49.1% vs. 39.5%, p=0.016) and hatching on day 6 (47.2% vs. 26.5%, p<0.001) were also significantly higher in the PZD group. CONCLUSION: The mechanical zona dissection method showed better outcomes than chemical ZD in terms of the blastocyst development and pregnancy rate. In this study, the fact that chemical ZD was conducted in different period from mechanical method should be considered in interpreting the result.

Clinical Efficacy of Assisted Hatching with Partial Zona Dissection in Intrauterine Embryo Transfer / 대한산부인과학회잡지

OBJECTIVE: To investigate the clinical efficacy of assisted hatching (AH) with partial zona dissection (PZD) in intrauterine embryo transfer in the patients who failed more than 2 times with standard IVF-ET protocol (Group R), were more than 37 years old (Group A), or had high basal serum FSH levels more than 15 mIU/ml (Group F). METHODS: From January, 1998 to June, 2002, 156 cycles of AH with partial zona dissection were performed in 117 infertile patients in Department of Obstetrics and Gynecology, Seoul National University Hospital. The outcomes of AH were analyzed according to pregnancy rate. RESULTS: The number of oocytes retrieved after controlled ovarian hyperstimulation (COH) was 8.3 +/- 5.2 in 104 cycles of 75 patients who failed more than 2 times with standard IVF-ET protocol (Group I: Groups R, R+A, R+F, and R+A+F), 7.7 +/- 5.0 in 82 cycles of 67 patients who were more than 37 years old (Group II: Groups A, R+A, A+F, and R+A+F), and 7.2 +/- 4.9 in 38 cycles of 30 patients who had high basal serum FSH levels more than 15 mIU/ml (Group III: Groups F, R+F, A+F, and R+A+F). The number of embryos transferred after AH was 4.1 +/- 1.5 in Group I, 3.7 +/- 1.3 in Group II, and 4.0 +/- 1.7 in Group III. The mean cumulative embryo score (CES) was 81.9 +/- 46.5 in Group I, 75.9 +/- 43.0 in Group II, and 75.7 +/- 40.2 in Group III. There were no significant differences in the numbers of oocytes retrieved, embryos transferred and CES among 3 groups. The overall clinical pregnancy rate was 22.4% (35/156) per cycle and 29.9% (35/117) per patient. The clinical pregnancy rate per cycle and per patient was 18.3% (19/104) and 25.3% (19/75) in Group I, 15.9% (13/82) and 19.4% (13/67) in Group II, and 31.6% (12/38) and 40.0% (12/30) in Group III, and there was a significant difference between Group II and Group III. CONCLUSION: AH of human embryos with PZD might be promising for the improvement of pregnancy rates, especially in the patients with the past history of repeated failure, old age, or high basal serum FSH level.