Day 3 embryo shape as a morphologic selection parameter in in vitro fertilization.
OBJECTIVE
To investigate whether embryo shape is a useful morphologic predictor of developmental competence in IVF cycles.


METHODS
Two hundred eighteen day 3 single embryo transfer (SET) cycles and 225 day 3 double embryo transfer (DET) cycles in which only 8-cell non-fragmented embryos with symmetric blastomeres were transferred and in which the developmental fate of each embryo was known were analyzed for IVF outcomes with respect to embryo shape. Embryo shape was quantitatively calculated after digitizing embryo images using MATLAB, where a score of 1.0 represented a perfectly circular embryo.


RESULTS
The SET data did not reveal a significant impact of embryo shape on embryo developmental fate. The DET data revealed a trend toward the best outcomes in cycles where both embryos exhibited "roundness" scores in the highest tertiles (T3) for embryo shape. However only one subgroup (T2/T1-one embryo in the middle shape tertile (T2) and one in the lowest shape tertile (T1)) was associated with significantly lower odds of live-birth as compared to the referent group (T3/T3). When SET and DET data were combined, embryo shape was not found to be a predictor of IVF outcome.


CONCLUSIONS
Based on this retrospective analysis, the weak association of day 3 embryo shape with implantation potential suggests that this morphological characteristic is unlikely to be a useful additional marker for embryo selection after cell number, fragmentation, and blastomere symmetry. Further studies are planned to assess applicability of these conclusions to embryos of varying stages and grades.
Harvard Medical School, Boston, MA, USA.
Sophia C
SC
Kamran
David E
DE
Reichman
Stacey A
SA
Missmer
Katharine F
KF
Correia
Nilay
N
Karaca
Aasia
A
Romano
Catherine
C
Racowsky
D000328:Adult; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011247:Pregnancy; D018873:Pregnancy Rate; D019836:Preimplantation Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D056826:Single Embryo Transfer; D013997:Time Factors; D016896:Treatment Outcome