The role of infection in miscarriage.
Bottom Line: It is also associated with significant health care costs.Q fever, adeno-associated virus, Bocavirus, Hepatitis C and Mycoplasma genitalium infections do not appear to affect pregnancy outcome.The latest data on rubella and syphilis indicate increased antenatal screening worldwide and a decrease in the frequency of their reported associations with pregnancy failure.
Affiliation: Centre for Reproductive Health, University of Edinburgh, Edinburgh EH16 4TJ, UK.Show MeSH
Related in: MedlinePlus
Mentions: The human endometrium is composed of several different cell types, including luminal and glandular epithelial cells, stroma with stromal fibroblastic cells, immune cells and blood vessels. During every menstrual cycle, in response to ovarian estrogen and progesterone via a process called ‘decidualisation’, the endometrial stromal compartment undergoes morphological and structural transformation to become receptive to implantation. Prior to implantation, the trophoblast differentiates into the growing blastocyst as it travels from the Fallopian tube to the uterus. The ‘implantation window’, during which the uterus is receptive to the embryo, is usually between 6 and 12 days after ovulation (Rashid et al., 2011). The blastocyst attaches to the receptive endometrium utilizing adhesion proteins, called integrins, during the implantation window (Fig. 2A, Merviel et al., 2001). Placenta formation begins as the trophoblast comes into contact with the epithelium and differentiates further into syncytiotrophoblast that invades the epithelial layer. Various other molecules, both from the maternal and fetal side, are involved in this process (reviewed in Dimitriadis et al., 2005; Tranguch et al., 2005; Achache and Revel, 2006; Chen et al., 2009). Syncytiotrophoblasts, supported by the decidualised stroma (Godbole et al., 2011), penetrate the endometrium and surround the embryo, whilst it embeds itself in the decidual stroma. A second trophoblast layer, the cytotrophoblast, is an inner layer without contact with the maternal cells. During the trophoblast invasion, cavities called lacunae develop, which, as they get filled with maternal blood, bring the maternal circulation into contact with the placental villi, thus marking the onset of placental circulation that includes exchange of nutrients and waste between the embryo and mother. At days 10–12 of gestation, the embryo is completely embedded in the endometrium, the epithelium has grown over it and the implantation process is complete (Fig. 2B). The three placental zones are now distinguishable: the early chorionic plate near the embryo, the intervillous space with the villous trees and the primitive basal plate in contact with the maternal endometrium (Pijnenborg et al., 1980, 1981). Simultaneously, endovascular trophoblast cells stemming from the basal plate invade the walls of the spiral arteries, replacing the maternal muscular and endothelial cells with trophoblast cells, transforming the arteries into large diameter and low resistance blood vessels (Lyall, 2005).Figure 2
Affiliation: Centre for Reproductive Health, University of Edinburgh, Edinburgh EH16 4TJ, UK.