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F Teasdale

Publications and source records attributed to F Teasdale.

30 records · Page 2Linked to original sources

Histomorphometry of the human placenta in pre-eclampsia associated with severe intrauterine growth retardation.

The morphological changes in the functional structure of the placenta in cases of pre-eclampsia associated with severe intrauterine growth retardation have been investigated with quantitative analyses. It has been demonstrated that in pregnancies complicated by severe pre-eclampsia, the placenta can suffer significant morphological alterations characterized by an abnormal maturation or arborization of the terminal villi. The findings of this study suggest that, among the pathogenic mechanisms responsible for the observed placental changes, uteroplacental ischaemia is probably a dominant factor, and that any ill effects on fetal growth and viability are very likely to be related not only to the inadequate maternal supply of oxygen and nutrients but also to placental ischaemic damage.

Adult↗

Intrauterine growth retardation: morphometry of the microvillous membrane of the human placenta.

The syncytiotrophoblast microvillous membrane of the human placenta has been investigated with quantitative analyses in cases of severe fetal growth retardation associated with a marked reduction in the surface area of exchange at the peripheral villous level. This study has shown that, in placentae of intrauterine growth-retarded infants of unknown origin, there were morphological changes in the microvillous membrane characterized by an increase in the microvillous surface density and surface enlargement factor, associated with a reduction of the intermicrovillous space. It is not possible to state whether these morphological changes represent a delayed maturation of the placental tissue, or compensatory mechanisms to improve the functional efficiency of the placenta. In pre-eclampsia, these placental changes were much less pronounced, possibly due to severe uteroplacental ischaemia in this complication of pregnancy. Despite these morphological changes, both groups of placentae showed significant reductions in absolute values for the microvillous and total trophoblastic surface areas, which can have major implications on the functional efficiency of the placenta.

Birth Weight↗

Histomorphometry of the placenta of the diabetic women: class A diabetes mellitus.

Different morphometric parameters have been applied to the study of the morphological differences between a group of normal placentae and a group of placentae collected from Class A diabetic women. It has shown that although fetal weights were significantly higher in the infants of the diabetic mothers, placental weights showed only a tendency to be heavier than the gestationally matched controls, though the difference was not statistically significant. However, the placentae of the Class A diabetic mothers were shown to differ from the control group by having significantly more parenchymal and villous tissues and a higher cellular content. There were also more surface areas of exchange between mother and fetus, in terms of peripheral and villous capillary surface areas and intervillous space volume. On a functional basis, these morphological changes suggest that, in diabetes mellitus Class A, the placenta can efficiently support the growth of a large fetus, and the perinatal associated with this condition is not likely to be related to decreased or insufficient function of the placenta.

Adult↗

Histomorphometry of the human placenta in Class B diabetes mellitus.

Different morphometric parameters have been applied to the study of the morphological differences between a group of normal placentae and a group of placentae collected from Class B diabetic mothers. The placentae of the diabetics were divided in two groups based on the growth characteristics and neonatal outcome of the infants at birth. It has been shown that the placentae of the appropriate for gestational age infants were morphologically very similar to the control group except for a well-developed villous vascularization. In contrast, the placentae of the large for gestational age infants were shown to differ from the controls by having heavier placentae due mainly to a significant accumulation of non-parenchyma and a moderate increase in parenchymal tissue. Consequently, although there was significantly more villous tissue in these placentae, the surface areas of exchange between mother and fetus in terms of capillary and villous surface areas were only moderately enlarged due to a relatively lower number of villi containing non-parenchymal tissue. However, on a functional basis, despite these morphological differences, the results of this study suggest that placental function is not adversely affected in Class B diabetics, and the perinatal morbidity associated with this condition is probably the result of metabolic abnormalities present in the mother and the fetus.

Adult↗

Idiopathic intrauterine growth retardation: histomorphometry of the human placenta.

The morphological changes in the functional structure of the placenta in cases of idiopathic intrauterine growth retardation (IUGR) have been investigated with quantitative analyses. It has shown that the placentae of the small-for-gestational-age (SGA) infants were 45 per cent smaller than the controls, due to an almost equal reduction in parenchymal (48 per cent) and non-parenchymal (42 per cent) tissues. Consequently, in relative values the placentae of the SGA infants were shown to be otherwise very similar to the controls. In contrast, in absolute values, the placentae of the growth-retarded infants were shown to differ from the controls by having significantly less surface area of exchange between mother and fetus, mainly in terms of peripheral capillary (3.85 vs 7.21 m2; P less than 0.02) and villous (4.31 vs 8.74 m2; P less than 0.005) surface areas, and intervillous space volume (53.71 vs 103.26 cm3; P less than 0.001). The total number of cells (53 418 x 10(6) vs 104 820 x 10(6); P less than 0.005) was also shown to be markedly decreased in the placentae of the SGA infants, compared with the controls, and the placental membrane showed a 51 per cent decrease in trophoblast mass or cellular content. On a functional basis, these findings suggest that, in these cases of idiopathic IUGR, the placental morphological changes are bound to produce placental insufficiency and fetal growth retardation.

Capillaries↗

Morphometric evaluation of the microvillous surface enlargement factor in the human placenta from mid-gestation to term.

The factor by which the villous surface area is enlarged owing to the presence of microvilli has been evaluated with quantitative analyses in human placental tissues from mid-gestation to term. It has shown that, between 25 and 36 weeks of gestation, the peripheral villous surface area is enlarged by a constant factor of approximately 9.47 +/- 0.28 (mean +/- s.d.). Then, from 36 weeks to term, it has shown a significant decrease in the microvillous surface enlargement factor (9.44 to 7.67; P less than 0.01). Consequently, the actual surface area of exchange between mother and fetus was shown to be significantly decreased during that same period (93.91 to 67.02 m2; P less than 0.01). On a functional basis, these findings support the theory that, during that last four weeks of pregnancy, the increasing physiological needs of the fetus are probably met by profound functional changes in the permeability and transfer functions of the cells that constitute the placental barrier.

Female↗

Histomorphometry of the human placenta in Class C diabetes mellitus.

Placentae from Class C diabetic mothers were compared by histomorphometric analyses with a group of normal placentae. The placentae of the diabetics were divided in two groups based on the growth characteristics and neonatal outcome of the infants at birth. This study has demonstrated that the placentae of both groups were somewhat heavier than the controls due to a parallel increase in parenchymal and non-parenchymal tissues. The placentae were also shown to be characterized by a relative increase in the surface areas of exchange between mother and fetus, in terms of peripheral villous and capillary surface areas and intervillous space volume. Consequently, the results of this study suggest that, in Class C diabetics, placental morphology and placental function are probably not more adversely affected than in other less severe forms of the disease during pregnancy. Furthermore, the findings in this investigation support the hypothesis that the placental changes, and the perinatal morbidity associated with this condition, are probably the results of hormonal and metabolic abnormalities present in the mother and the fetus.

Adult↗

Morphometry of the microvillous membrane of the human placenta in maternal diabetes mellitus.

The syncytiotrophoblast microvillous membrane of the human placenta has been investigated with quantitative analyses in a group of placentae from diabetic mothers, these placentae being compared to a group of normal placentae. This study has shown that, in the placentae of the diabetic mothers, there was a significant increase in the surface density of the microvilli and in the microvillous surface enlargement factor as compared to those of the controls. Consequently, it has demonstrated that the already large villous surface area found in the placentae of diabetic mothers can be enlarged very significantly by the microvilli, in terms of the total trophoblastic surface area which is in contact with the maternal blood. On a functional basis, these findings support the theory that placental function is probably not adversely affected in these placentae, and that these placentae can efficiently support the growth of large fetuses.

Female↗

[Is extracorporeal membrane oxygenation necessary?].

In order to evaluate our hospital center needs for extracorporeal membrane oxygenation (ECMO), a retrospective study was carried out over a two-year-period to determine the mortality rates of infants < or = 35 weeks of gestation and > or = 2000 grams with severe respiratory failure. The data was obtained from a perinatal center that serves a population that has 50,000 newborn deliveries per year. During the period of the study there were 75 infants meeting the above criteria admitted to the NICU with severe respiratory failure (defined as need for mechanical ventilation and 100% O2). Forty-four patients were excluded because of improvement of their respiratory status on conventional therapy, and 16 were ineligible for ECMO because of their primary diagnosis. Of the 15 infants considered ECMO candidates, there were 2 deaths as a result of streptococcal beta hemolytic septicemia. The result of this study showed that few infants in the population served by this perinatal center would have benefited from ECMO.

Carbon Dioxide↗