Endocrine Abstracts

The successful establishment of pregnancy is dependent on appropriate embryo development and uterine receptivity. The latter consists of secretory transformation of the glandular epithelial cells followed by decidualisation of the stromal compartment. This phase of the cycle is also characterised by extensive tissue remodelling in the superficial layer of the endometrium in preparation for the invasion and implantation of the proliferating trophoblast cells. Ovarian steroids a...

Many of the functions of ovarian steroids in regulating embryo-implantation occur through the actions of cytokines and growth factors on the uterus. One such cytokine, Leukaemia Inhibitory factor (LIF), is critical for implantation in a range of mammalian species. LIF is expressed transiently in the murine glandular uterine epithelium (GE) on day 1 and then day 4 of pregnancy (day of implantation) induced by estrogen. Female mice lacking a functional LIF gene cannot support em...

Recent advances in reproductive immunology have caused a fundamental shift in our appreciation of the nature of human pregnancy. For nearly 50 years, the subject has been dominated by Medawar's 'fetal allograft' hypothesis, in which an analogy is assumed between the fetus and a tissue transplant. In this framework, all maternal immune mechanisms are considered potentially harmful for the fetus and, therefore, must be overcome, bypassed or suppressed. Much progress has been mad...

In most species progesterone acts to inhibit cervical ripening and myometrial contractility throughout pregnancy and labour is heralded by prostaglandin stimulated withdrawal of progesterone. Human labour is associated with increased prostaglandin synthesis, via COX-2 but there is no clear systemic withdrawal of progesterone at the time of labour. There is upregulation of genes which are normally repressed by progesterone leading to the concept that human labour is associated ...