A method of enhancing in vitro development of a mammalian embryo is disclosed which comprises supplementing the culture medium with a prostaglandin, or a prostaglandin analog, in an amount effective to promote complete hatching of the embryo (i.e., freeing of the embryo from the zona pellucida). The quality of human blastocysts is enhanced in vitro by culturing with a prostacyclin agonist, Iloprost. The in vivo implantation potential and live birth potential of an in vitro fertilization embryo is thereby enhanced and establishment of a viable pregnancy is facilitated.