Good-quality blastocysts derived from vacuolized morulas show reduced viability

Late onset of vacuolization around compaction stage is a negative predictor of blastocyst formation and outcome.

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Volume 109, Issue 6, Pages 1025–1029


Richard B. Mayer, M.D., Omar Shebl, M.D., Peter Oppelt, M.D., Elisabeth Reiter, M.D., Reinhard Altmann, M.D., S. Enengl, M.D., Christina Allerstorfer, M.D., Thomas Ebner, Ph.D.



To study whether late spontaneous vacuolization on day 4 is an artefact or an alternate means of blastocele formation and to analyze its impact on pregnancy outcome and live birth.


Prospective observational study.


University teaching hospital.


A total of 424 patients who fulfilled inclusion criteria were subgrouped according to the spontaneous vacuolization on day 4: Group 1 had all morulas affected, group 2 showed no signs of vacuoles, and group 3 was mixed (some day 4 embryos had vacuoles and others did not).


Screening for the presence of vacuoles on day 4 and fresh single-blastocyst transfer.

Main Outcome Measure(s)

Morula and blastocyst scoring, utilization rate, pregnancy and live birth rates.


Patients of group 1 had a reduced blastocyst formation rate on day 5 (P<.01) and significantly fewer good-quality blastocysts for usage (P<.05). In addition, pregnancy (P<.001) and live birth (P<.01) rate were significantly worse in group 1 compared with groups 2 and 3.


Late onset of vacuolization around compaction stage is a negative predictor of blastocyst formation and outcome.

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Fertility and Sterility

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