Rescue intracytoplasmic sperm injection: a prospective randomized study.
OBJECTIVE
To determine the optimum rescue time by comparison of results of rescue intracytoplasmic sperm injection (ICSI).


METHODS
A total of 112 couples of total fertilization failure, who had retrieved at least four mature oocytes, were prospectively randomized into two groups: the earlier rescue group, rescue ICSI performed between 4 and 6 hours after insemination, and the control group, rescue ICSI performed between 6 and 8 hours after insemination.


RESULTS
There were no statistically significant differences in woman's age, duration of infertility, number of oocytes retrieved every cycle, and number of embryos transferred every cycle between the two groups. The normal fertilization rate of the earlier rescue group was increased compared with that of control group (63.1% vs. 55.7%, p < 0.05), whereas the abnormal fertilization rate in the earlier rescue group was decreased compared with control group (3.5% vs. 6.2%, p < 0.05). There was a trend suggesting an increase in the clinical pregnancy rate and implantation rate in the earlier rescue group compared with control group, though this failed to be significantly different.


CONCLUSIONS
Rescue ICSI is an effective method of eliminating totalfertilization failure. Rescue ICSI performed earlier could result in a better pregnancy rate in this select group of patients.
Reproductive Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No.1095 Jiefang Road, Wuhan 430030, People's Republic of China.
Lixia
L
Zhu
Qingsong
Q
Xi
Rui
R
Nie
Wen
W
Chen
Hanwang
H
Zhang
Yufeng
Y
Li
D000022:Abortion, Spontaneous; D000328:Adult; D010064:Embryo Implantation; D005260:Female; D006801:Humans; D007246:Infertility / Q000628:therapy*; D007315:Insemination, Artificial; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*; D013997:Time Factors; D017211:Treatment Failure