MATERNAL RECOGNITION OF PREGNANCY AND EMBRYONIC LOSS

This review discusses the hypothesis that conceptuses, otherwise normal except lagging slightly in development, might fail to signal their presence in time to prevent regression of the corpus luteum. The principle signals for maternal recognition of pregnancy in sheep and cattle have been identified as proteins released by the trophectoderm for a limited period around the time of blastocyst elongation. They are known as oTP-1 and bTP-1, but more recently have been identified as functionally active interferons (IFN) in the IFN-αII subfamily. Because of its availability a somewhat related recombinant bovine IFN (rboIFN-αI1) has been tested for its effects on fertility in ewes. Preliminary experiments indicate that intramuscular injection of rboIFN-αI1 during the period of maternal recognition of pregnancy can improve pregnancy success. © 1990.