The polar bear reproduction process is complicated, involving
delayed implantation, meaning that the embryo takes four to eight months to implant.
As a result of this
delayed implantation, the female is technically pregnant for at least 6 months.
Delayed implantation is a special reproductive strategy of the giant panda (Zhang et al.
Penile prosthesis insertion in patients with refractory ischaemic priapism: early vs
delayed implantation. BJU Int 2014; 114: 576-81.
This is an example of
delayed implantation. That means the fertilized egg divided only a few times and then the growth is put on hold for quite some time.
Methods: The pregnant mice were ovariectomized on the evening on the third day of pregnancy with a single injection of medroxyprogesterone acetate to induce
delayed implantation (DI).
Female polar bears only release an egg after mating and they practise
delayed implantation, where the egg does not implant into the uterine wall until some months later.
(7) When considering the right timing for implants placement, there are two reasons in favor of the
delayed implantation. The first is in the fact that the successful osseointegration depends on osteoblasts capable for osteogenesis, and another reason is that the simultaneous implantation is proportionally more demanding and rarely meets prosthetic requirements.
The reproductive cycle of the river otter involves embryonic diapause or
delayed implantation of embryos (Renfree and Shaw, 2000; Melquist et al., 2003).
Bats have evolved various reproductive strategies such as delayed sperm maturation sperm storage delayed fertilization
delayed implantation and delayed development.
The gestation period for a panda ranges from 95 to 160 days and successfully predicting the due date is further complicated by a phenomenon known as
delayed implantation.