Pathways to pregnancy and parturition online dating
Studies of implantation particularly in sheep have contributed immensely towards understanding the molecular mechanisms underlying implantation generally in mammalian species (Lee and Demayo, 2004 and Spencer et al., 2004) because of a number of reasons peculiar to pregnancy in this species.Firstly, the protracted peri-implantation period in sheep of about 15 days () unlike 4 days in mouse that has made it suitable to understand the mechanism of event during early gestation.Secondly the superficial mode of implantation in this species that also enables better elucidation of the mechanism involved, since the micro-architectural transformations undergone by the endometrial luminal epithelia (LE) and trophoblast during the implantation process are retained and can be studied in detail unlike in mouse where this is erased due to haemochorial placentation ().
Pregnancy loss especially at the early state of gestation is a major cause of infertility in both human and animal species.
This has been attributed to the impaired interaction between the maternal endometrium and the developing embryo and/or inadequate hormonal support for the pregnancy continuation.
Progesterone is the hormone of pregnancy and is essential for establishment and sustainance of pregnancy in most mammals.
It is principally produced by the corpus luteum which undergoes regression mostly due to luteolytic action of prostaglandins F at certain period of the oestrous cycle.
Maternal recognition of pregnancy (MRP) is the phenomenon through which luteolysis of corpus luteum is abrogated for continuous production of progesterone in a conceptive cycle and is achieved by different agents in different mammalian species.