Successful embryo implantation requires the synchronization of embryo development and uterine preparation. The embryo must have developed to the blastocyst stage and the endometrium must be in a receptive phase. Wilcox et al1 have estimated that 65% of conceptions end in unrecognized losses....

The hypothalamic neuropeptide corticotropin-releasing hormone (CRH), as well as its receptors, have been identified in several reproductive organs, including the endometrial glands, the decidualized endometrial stroma and the placental trophoblast, synctiotrophoblast and decidua.1-9...

The unusual tolerance against fetal antigens is still one of the greatest miracles of pregnancy. Dealing with reproductive immunology, the question arises as to how the maternal immune system handles the foreign fetal antigens leading to that tolerance. Focussing on the various subsets of...

The mechanisms of acceptance of the fetus by the maternal immune system are mediated in part by immunomodulatory proteins expressed by placental cells. The recent discovery of novel members of the B7 family of immunomodulators has prompted much excitement among the scientific community because...

Infertility and pregnancy wastage affect one of every nine couples in Western Europe and in the United States. The molecular events of embryonic attachment to the endometrial epithelium and subsequent invasion and nidation into the stroma have long been of interest, scientifically to...

Phylogenetic analysis suggests that the internalization of reproduction and the develop ment of hemochorial placentation have been accompanied by conservation of primitive genitourinary genes. The products include the renin-angiotensin system and the innate immune system. This explains what...

During pregnancy some cells traffic between the fetus and mother and recent studies indicate low levels persist in the respective hosts decades later. Microchimerism (Mc) refers to a small population of cells or DNA harbored by one individual that derive from a genetically distinct individual....

Prematurity as a result of preterm birth is the major cause of perinatal mortality and morbidity in the developed world (Fig. 1). The world-wide prevalence of preterm birth (PTB) is 13 million births per year, though the incidence ranges from 5.8% in Oceania to 12% in North America. The incidence...

Since it has been reported that in humans 90% of embryos are aneuploid as a result of malsegregation mechanisms in maternal meiosis I,1 the detection of abnormal oocytes in IVF treatments has become of considerable importance. Taking into account the results obtained from the study of...

Cases of recurrent abortions, preeclampsia or babies born with hemolytic diseases of the new born, still puzzle us with the question “Why did your mother reject you?” Although, after looking at the complexity of the maternal-fetal immune interaction and the cases of successful pregnancies,...