In IVF, parthenogenesis refers to an unfertilized egg that begins dividing on its own without any genetic input from sperm. This spontaneous activation is uncommon but can happen after oocyte retrieval or micromanipulation procedures such as ICSI, since the physical or chemical stress of handling the oocyte can trigger calcium changes that mimic fertilization.
In these cases, the egg may undergo one or two abnormal divisions and form a few cells, but development soon stops because the embryo’s complete DNA isn’t present — only the egg’s DNA, with no paternal contribution. True parthenogenetic embryos generally do not form viable blastocysts, unless they are artificially activated with electrical or chemical stimuli in experimental research settings (not in the IVF lab). From Bos-Mikich et al. 2015.