Aj. Carrillo et al., OOLEMMA RUPTURE INSIDE THE INTRACYTOPLASMIC SPERM INJECTION NEEDLE SIGNIFICANTLY IMPROVES THE FERTILIZATION RATE AND REDUCES OOCYTE DAMAGE, Fertility and sterility, 70(4), 1998, pp. 676-679
Objective: To compare the effect on fertilization, oocyte damage, embr
yo freezing, and pregnancy rates of two different techniques for ruptu
ring the oolemma during intracytoplasmic sperm injection (ICSI). Desig
n: Retrospective study. Setting: Fertility Center, Alliant Health Syst
em Hospital. Patient(s): Seventy-nine consecutive IVF-ICSI cases. Inte
rvention(s): Patients in group I had ICSI performed by pushing the nee
dle into the oocyte until the oolemma was observed to break outside th
e needle. In group II the oolemma was aspirated into the needle until
it ruptured inside the needle. Main Outcome Measure(s): In group II IC
SI resulted in significantly higher fertilization and lower oocyte dam
age rates (66% and 13%) than in group I (39% and 29%). There were no s
tatistically significant differences in embryo cleavage rates or pregn
ancy rates per retrieval between the two groups. A greater number of c
ases had embryos cryopreserved in group II than in group I. Result(s):
Rupturing the oolemma by aspirating it into the ICSI needle (group II
) improved laboratory outcomes compared with the more traditional tech
nique of breaking this membrane by the stabbing action of the needle (
group I). This modification of the ICSI technique also increased the n
umber of patients with cryopreserved embryos and therefore could incre
ase the pregnancy rate per patient. Conclusion(s): The site and techni
que used to rupture the oolemma during ICSI has a significant effect o
n the fertilization and damage rates. (Fertil Steril(R) 1998;70:676-9.
(C) 1998 by American Society for Reproductive Medicine.).