Impreovement in Endometrial Implantation of Humman Embryos with Assisted Hatching Using Micromanipulation in Intrauterine Embryo Transfer

Kim, Seok Hyun; Chae, Hee Dong; Kim, Kwang Rye; Lee, Jae Hoon; Ryu, Buom Yong; Oh, Sun Kyung; Suh, Chang Suk; Choi, Young Min; Kim, Jung Gu; Moon, Shin Yong; Lee, Jin Yong

Abstract

Although the fertilization rate exceeds to 80~90% with much progress in vitro fertilizaton and embyo transfer(IVF-ET) program, the prgnancy rate rmains at 20~30%, and the endometrial implantaion rate per embryo transferred at 10~15%. Recently, many attempts have been made to improve embrynic implantion after IVF-ET including serveral procedures of assisted hatching(AH) using micromanipulation, and pregnacies and births have been obtained after AH. This clinical study was performed to develop and estabilish AH as an effective procedure to improve embryonic implantioan in IVF-ET patients who had previous repeated failure of standard IVF-ET more than 2 times(Group R), were more than 37 years old(Group A), or had high basal serun FSH levels more than 15 mIU/ml(Group F). From January, 1995 to Februry, 1996, 132 cycles of AH using partial zona dissection(PZD) were performed in 104 infertile patients, and the outcomes of AH were analyzed according to pregnancy rate. The number of oocytes retrieved after controlled ovarian hyperstimulation(COH) was 9.9+/-7.1 in 71 cycles of 54 patients who had previous repeated failure more than two times(Group I: Group R,R+A,R+F, and R+A+F), 8.4+/-5.9 in 62 cycles of 46 patients whose age was more than 37 years old(Group II : Groups A, R+A, A+F, and R+A+F), and 8.7+/-6.5 in 49 cycles of 47 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 embroys transferred after AH was 4.7 +/-1.8 in Group I, 4.2 +/-1.9 in Group II, and 4.2+/-2.0 in Froup III. The mean cumulative embryo score(CES) was 56.8+/-30.0 in Group I, 52.6+/-30.6 in Group II, and 52.6+/-29.9 in Group III. There were no significant differences in the numbers of oocytes rerieved and embryos transferred, and CES among 3 groups. The overall clinical pregnancy rate was 14.4%(19/132) per cycle and 18.3%(19/104) per patient. THe clinical pregnancy rate per cycle and per patient was 12.7%(9/71) and 16.7%(9/54) in Group I, 4.8% (3/62) and 6.5%(3/46) in Group II, and 26.5%(13/49) and 27.7%(13/47) in Group III, and there was a significant difference between Group II and Group III. In conclusion, AH of human embryos using micromanipulation might be promising for IVF-ET patients, especially with the past history of repeated failure, old age, and high basal serum FSH level and AH will provide a range of novel techiques which may dramatically improve the implanatation and pregnancy rates in IVF-ET program and contribute much to effective management of infertile couples.