The reference was made by the UK High Court following an appeal by International Stem Cell Corporation to the UK IPO's rejection of two patent applications concerning methods of producing pluripotent human embryonic stem cells from parthenogenetically-activated oocytes. The Court of Justice has left it to the UK High Court to determine whether or not, in the light of knowledge "which is sufficiently tried and tested by international medical science", the organisms which are the subject of ISC's patent applications have the inherent capacity of developing into a human being.
This is a sensible carve-out from the Court of Justice to the broad definition given by the Court previously in the Brüstle decision to the term 'human embryo'. An unfertilised human ovum whose cell division is stimulated by parthenogenesis and which cannot develop into a viable human being cannot by any stretch of the imagination be considered to be a human embryo. Whether the use of such ova and their progeny might be objectionable on societal and ethical grounds is an entirely separate question to whether such cells constitute a human embryo.
For further details and commentary, see the authors' previous article following Advocate General Cruz Villalón's opinion of July 2014, which the Court of Justice has followed.