Onset of the maternal-placental circulation was studied by Doppler ultrasonography in 65 pairs of agematched normal and abnormal pregnancies. In normal pregnancies intervillous blood flow increased with gestational age, being detected in 9 of 25 cases at 8 to 9 weeks but in 18 of 20 at 12 to 13 weeks (P ‫؍‬ 0.001). By contrast, in abnormal pregnancies flow was detected in nearly all cases (22 of 25) at 8 to 9 weeks (P < 0.001). In addition, regional differences were observed between the groups. Early flow was restricted to the peripheral regions of most normal placentas (P < 0.001), whereas in missed miscarriages it was most common in central regions or throughout the placenta (P < 0.05 and P < 0.001, respectively). Immunoreactivity for heat shock protein 70 and nitrotyrosine residues was greater in samples from peripheral than from central regions of normal placentas (P ‫؍‬ 0.028 and P ‫؍‬ 0.019, respectively), and from missed miscarriages compared to controls (P ‫؍‬ 0.005 and P ‫؍‬ 0.001, respectively). Our results indicate that oxidative damage to the trophoblast, induced by premature and widespread onset of the maternal placental circulation secondary to shallow trophoblast invasion, is a key factor in early pregnancy loss. High oxygen concentrations in the periphery of normal early placentas may similarly induce local regression of the villi, leading to formation of the chorion laeve. Placentation in the human is characterized by diffuse infiltration of the endometrium and the inner third of the myometrium by extravillous trophoblast cells.

No abstract

Ultrasound training in a rural setting supported remotely is feasible, efficient, and sustainable. It can help local healthcare workers to screen their prenatal populations for obstetric and neonatal risks, and therefore has the potential to improve outcomes at delivery and provide site-specific epidemiologic data that can be used to develop new healthcare provision strategies.

Objective To examine the relationship between ultrasound and histological features in the screening for molar changes in missed miscarriage. Methods

No abstract

Human chorionic gonadotropin (hCG), a heterodimeric glycoprotein hormone produced in abundance by placental syncytiotrophoblasts, is preferentially secreted into maternal circulation. Fetal circulation also contains low levels of hCG that are probably derived from fetal kidney, liver, anterior pituitary gland, etc. In addition, the fetus has access to hCG present in exocoelomic and amniotic fluids. hCG has been found in a number of fetal tissues known to stimulate fetal adrenal and testicular steroidogenesis and is also thought to play a role in growth and differentiation of fetal tissues. This led us to test the hypothesis that fetal nongonadal tissues, as in the adult, may also contain hCG/LH receptors. This hypothesis was tested by immunocytochemistry, Western blotting, in situ hybridization, and RT-PCR. The results demonstrate that kidney, liver, pancreas, lung, small and large intestines, and adrenals contained hCG/LH receptors. Although the role of fetal nongonadal hCG/LH receptors is not known, they may mediate the pleiotropic actions of hCG in the growing human fetus.

Our data show that a karyotype can be obtained from clean villous material collected at the time of surgical evacuation of miscarriage. Thus, it is not justified to subject women to transabdominal chorionic villus sampling to achieve a high karyotype success rate.

No abstract