Occurrence and developmental consequences of vacuoles throughout preimplantation development.
OBJECTIVE
Since little is known about the actual incidence and fate of vacuoles at different stages of development this preliminary study was set up to accurately measure vacuoles and track them to day 5.


METHODS
Prospective study.


METHODS
Women's General Hospital in Austria.


METHODS
A total of 223 consecutive IVF and intracytoplasmic sperm injection (ICSI) cycles (206 patients).


METHODS
Accurate measurement of vacuoles. Affected gametes and embryos were cultured individually and tracked until day 5.


METHODS
Size and number of vacuoles, fertilization rate, blastocyst formation rate, blastocyst quality.


RESULTS
There was a significant relationship between size of the vacuole (cut-off value 14 microm) and fertilization (P<.05). At zygote stage the incidence of vacuoles was higher (P<.01) in ICSI (11.6%) than in IVF (5.3%). Only 32.2% of affected ICSI-embryos reached blastocyst stage on day 5 compared with 53.0% of the normal ones (P<.001). In terms of blastocyst formation vacuolization on day 4 (P<.001) turned out to be the most severe one. At blastocyst stage inner cell mass was affected less frequently than the trophectoderm (P<.05).


CONCLUSIONS
Three types of vacuoles could be identified: (1) those already present at oocyte collection, which develop during maturation (day 0); (2) those artificially created by ICSI (day 1); and (3) those accompanied with developmental arrest (day 4). The later that vacuoles arose, the more detrimental their effect on blastocyst formation.
Ebner
Thomas
T
IVF Unit, Women's General Hospital, Linz, Austria. thomas.ebner@gespag.at
Moser
Marianne
M
Sommergruber
Michael
M
Gaiswinkler
Ute
U
Shebl
Omar
O
Jesacher
Klaus
K
Tews
Gernot
G
D001755:Blastocyst / Q000473:pathology / Q000502:physiology; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects; D006801:Humans; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects; D014617:Vacuoles / Q000473:pathology / Q000502:physiology*