Pregnancy recognition and abnormal offspring syndrome in cattle.

Development of the post-hatching conceptus in ruminants involves a period of morphological expansion that is driven by complex interactions between the conceptus and its intrauterine environment. As a result of these interactions, endometrial physiology is altered, leading to establishment of the pregnancy and continued development of the placenta. Disruption of normal fetal and placental development can occur when embryos are exposed to manipulations in vitro or when inappropriate endocrine sequencing occurs in vivo during the pre- and peri-implantation periods. The present review addresses the development of the post-hatching bovine conceptus, its interactions with the maternal system and changes in development that can occur as a result of in vivo and in vitro manipulations of the bovine embryo.