Impact of the presence of one or more multinucleated blastomeres on the developmental potential of the embryo to the blastocyst stage.

A retrospective study of 5,982 embryos in 619 blastocyst-stage embryo transfer cycles revealed that detection of multinucleated blastomeres either on day 2 or 3 signifies a poor prognosis for blastocyst formation and that no good-quality blastocyst can be expected from an embryo with more than one multinucleated blastomere. Patients should be counseled regarding a poor prognosis when multiple embryos with multinucleated blastomeres are present.