PubMed · 4046888
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M I Evans. 1985. Chorionic villus sampling detects more than 100 fetal abnormalities.. https://pubmed.ncbi.nlm.nih.gov/4046888/
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OBJECTIVE: To test the hypothesis that the characteristics of umbilical artery Doppler flow velocity waveforms in growth-restricted fetuses indicate angiogenesis within placental stem and gas-exchanging villi. METHODS: We examined 18 placentas from singleton fetuses that were normal structurally and chromosomally but were growth-restricted, preterm, and complicated by preeclampsia. Ten cases with positive end-diastolic flow and eight with absent or reverse end-diastolic flow were compared with six gestational age-matched controls. Sections of villous placenta were examined to determine structural composition (percentage of fibrinoid, intervillous space, and villous tissue), relative proportion of villous types (stem, immature intermediate, and gas-exchanging villi), and the frequency distribution of stem arterial vessel calibers and their branching pattern. RESULTS: Placentas with positive end-diastolic flow had a significantly (P < .05) higher percentage of gas-exchanging villi (median 69.6%, range 62.5-80.8%) than those with absent or reverse end-diastolic flow (58.3%, 29.9-71.9%) or controls (60.8%, 43.1-65.6%). The gas-exchanging villi from placentas with absent or reverse end-diastolic flow were slender, elongated, poorly branched, and poorly capillarized. There was a progressive trend toward reduced branching of the stem arteries from the controls (median 22%, range 2-38%), through the positive end-diastolic group (17%, 11-20%), to the absent or reverse end-diastolic group (13%, 4-23%). CONCLUSION: Compared with absent or reverse end-diastolic flow, the placentas from growth-restricted fetuses with positive end-diastolic flow showed a normal pattern of stem artery development, accompanied by increased capillary angiogenesis and terminal villous development. These features suggest an adaptive pathway for the placenta in the face of uteroplacental ischemia.
In order to fulfill its many functions as the selective interface between maternal and fetal circulations it is imperative that the human placenta remains intact and in good operational order. That damage of some sort occurs during its short but extremely active life seems inevitable given the dynamic environment in which the placenta exists, and evidence has accumulated that disruption is indeed a regular event. The implications of such damage, one could speculate, may impact on functions such as transport and hormone secretion as well as mutual protection against attack by maternal and fetal immune systems. Consequently, it would seem a theoretical necessity for discontinuities in the placenta surface to be repaired as soon as possible. We have used a combination of ex vivo observation, in vitro modelling, immunohistochemistry and correlative microscopy to provide evidence for a wound response in the placenta and to begin dissecting the detail of how this may operate. Evidence for small lesions caused by fusion and subsequent tearing of the syncytiotrophoblast in vivo, as well as plugging of such wounds by underlying cells is shown. We also identify a putative role for migratory cytotrophoblasts in the healing of larger scale injuries and demonstrate that certain molecules, common to wound repair in other tissues, appear to be involved in placenta repair also. Taken together these results clearly show that the human placenta is capable of a degree of self-maintenance by activating what appears to be an endogenous wound healing mechanism.
Pyruvate carboxylase (PC) deficiency is a rare metabolic disorder in infants and children, most frequently with fatal outcome. Its prenatal diagnosis by radiometric assay in cultured amniocytes has previously been reported. We present and discuss the prenatal diagnosis of PC deficiency by direct measurement of PC activity in chorionic villi, in two subsequent pregnancies in a family who previously lost a child affected by PC deficiency. In the next pregnancy PC was unmeasurably low in chorionic villi whereas in control samples its activity was between 0.8 and 3.3 nmol min-1 mg protein-1. Following elective termination of the pregnancy PC was shown to be totally inactive in post-mortem fetal liver. In the most recent pregnancy of the proband's mother PC was normally active in the chorionic villi. The product of this pregnancy was a normal boy.