Blastocyst formation in in vitro fertilization versus intracytoplasmic sperm injection cycles: influence of the fertilization procedure.
OBJECTIVE
To compare the quality of early cleaving embryos and blastocysts obtained by IVF or intracytoplasmic sperm injection (ICSI).


METHODS
Retrospective study.


METHODS
Tertiary infertility center.


METHODS
Sibling oocytes of 104 patients in 104 IVF vs. ICSI cycles.


METHODS
Cumulus oocyte complexes (n = 1,358) were randomly subjected to ICSI or IVF.


METHODS
Embryo development and blastocyst formation rate. The blastocyst quality and cycle efficiency were also evaluated.


RESULTS
Early embryo cleavage was higher after ICSI (37.1%) compared to IVF (14.1%). The percentage of > or =4-cell embryos on day 2 and > or =8-cell embryos on day 3 was similar for both procedures. The overall blastocyst formation was not different between ICSI (50.2%) and IVF (54.8%), neither was the percentage of good-quality blastocysts (31.3% for ICSI and 36.0% for IVF). The total cycle efficiency (percentage of embryos transferred and frozen per two pronuclei [2PN]) was comparable for the two techniques (51.7% for ICSI and 57.4% for IVF).


CONCLUSIONS
No differences were found on sibling oocytes in the embryo development and blastocyst formation, irrespective of the fertilization procedure. Earlier suggestions that the ICSI technique may result in impaired blastocyst development were not confirmed in this study.
Van Landuyt
Lisbet
L
Center for Reproductive Medicine, University Hospital, Dutch-speaking Brussels Free University, Vrije Universiteit Brussel-VUB, Brussels, Belgium. lisbet.vanlanduyt@az.vub.ac.be
De Vos
Anick
A
Joris
Hubert
H
Verheyen
Greta
G
Devroey
Paul
P
Van Steirteghem
André
A
D000328:Adult; D001755:Blastocyst / Q000502:physiology*; D016001:Confidence Intervals; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods* / Q000706:statistics & numerical data; D018709:Statistics, Nonparametric