Impact of assisted hatching on the outcome of intracytoplasmic sperm injection: a prospective, randomized clinical trial and pregnancy follow-up.
OBJECTIVE
To evaluate the overall effect of assisted hatching (AH) on the implantation, pregnancy, and live birth rates in women undergoing intracytoplasmic sperm injection (ICSI) cycles; and to determine the effect of AH on the cytogenetic outcome (chromosomal constitution) of pregnancy.


METHODS
Prospective, randomized study.


METHODS
Academic research environment.


METHODS
A total of 172 couples were enrolled in the study.


METHODS
Assisted hatching was carried out on day-3 ICSI embryos.


METHODS
Implantation, clinical pregnancy, and live birth rates; cytogenetic analysis of abortuses and umbilical cord blood samples from newborns.


RESULTS
Biochemical, clinical, and ongoing pregnancy rates were not significantly different between the AH and control groups. The implantation rate was higher in the AH group than in the control group (16% vs. 8%), especially in women aged > or =35 years. Postnatal umbilical cord blood samples were collected and cytogenetically analyzed from 39 live births (20 from the AH group, 19 from the control group). Two abnormal karyotypes were found (one AH, one control). There were seven spontaneous losses during the study interval. Six of the abortuses underwent cytogenetic study (five AH, one control), and four were found to have an abnormal karyotype (three AH, one control).


CONCLUSIONS
We found that AH improves implantation rates of ICSI cycles and seems to be most effective in women aged > or =35 years. A larger sample size is needed to determine whether AH improves the take-home-baby rate. Assisted hatching did not affect the rate of chromosomal abnormalities in live births in this study.
Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, British Columbia, Canada. sai@interchange.ubc.ca
Sai
S
Ma
Timothy
T
Rowe
Basil Ho
BH
Yuen
D000328:Adult; D010064:Embryo Implantation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007247:Infertility, Female / Q000453:epidemiology / Q000628:therapy; D050498:Live Birth / Q000453:epidemiology*; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D027724:Reproductive Techniques, Assisted / Q000639:trends; D020554:Sperm Injections, Intracytoplasmic