in mammals, a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months.

usually, the fertilized egg implants in the wall of the female's uterus shortly after mating and fertilization. However, in delayed implantation, the fertilized egg does not implant in the female's uterus until much later, thus implantation is delayed. Once implantation occurs the fertilized egg quickly becomes a developing embryo. This process is found in family Mustelidae (weasel family) and family Ursidae (bear family).

a condition found in some mammals where a fertilized egg will develop to the blastula stage, then lie dormant, perhaps for months, before implantation and further development