BACKGROUND The paca is a South American rodent with potential as a commercial food animal. We examined paca placenta as part of a wider effort to understand the reproductive biology of this species. METHODS Thirteen specimens between midgestation and term of pregnancy were studied by light and transmission electron microscopy. RESULTS The placenta is divided into several lobes separated by ...

Preeclampsia, particularly the severe cases that occur early in pregnancy, is associated with defects in the (placental) cytotrophoblast differentiation pathway that leads to uterine invasion. At a morphologic level, interstitial invasion often is shallow. Perhaps more significantly, endovascular invasion, particularly the arterial component, is rudimentary. The latter defect is thought to lead...

The mammalian placenta exhibits striking interspecific morphological variation, yet the implications of such diversity for reproductive strategies and fetal development remain obscure. More invasive hemochorial placentas, in which fetal tissues directly contact the maternal blood supply, are believed to facilitate nutrient transfer, resulting in higher fetal growth rates, and to be a state of r...

Successful implantation of embryo and placentation depend on proper trophoblast proliferation and differentiated into specialized invasive trophoblast. However, little is known about the regulatory factors and mechanisms in trophoblast proliferation and differentiation. Osteopontin (OPN) is a member of the small integrin-binding ligand N-linked glycoprotein family and participates in cell adhes...

OBJECTIVE To summarize the efficacy of postabortion uterine artery embolization in cases of refractory hemorrhage. METHODS Forty-two women were identified who had postabortion uterine artery embolization at San Francisco General Hospital between January 2000 and August 2007. Seven underwent embolization for hemorrhage caused by abnormal placentation. RESULTS Embolization was successful in 9...

Doppler interrogation of the uterine arteries provides information on the physiologic transformation of the spiral arteries during pregnancy. Lack or suboptimal conversion of such arteries by the late second or third trimester of pregnancy is a strong indicator of increased risk for adverse pregnancy outcome, in particular, iatrogenic prematurity due to severe fetal growth restriction or preecl...

Placenta percreta is an obstetric condition in which the placenta invades through the myometrium. This is the most severe form of placenta accreta and may result in spontaneous uterine rupture, a rare complication that threatens the life of both mother and fetus. In this case report, we describe a 32-year-old woman in her fourth pregnancy, diagnosed with repeated placenta accreta, which was eve...

We review recent advances in our understanding of placental evolution with particular focus on the interhaemal barrier. It seems likely that the non-invasive, epitheliochorial placentation of living eutherians is a derived state. However, there is disagreement on whether the last common ancestor of eutherian mammals had an endotheliochorial placenta or a haemochorial one. Research has been stim...

Placentation arose in mammalian evolution some 150-200 M years ago and integrates a rather ingenious manner large number of previously evolved multicellular regulatory pathways which include: angiogenesis, inflammatory cytokines interleukins, HLA expression, immune peptides, receptors (for NK decidual cells, T B including Tregs, macrophages, antigen-presenting cells ), endothelial fibroblasts, ...