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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Receptor-mediated endocytosis is generally assumed to be the process by which the haemochorial placenta takes up iron from transferrin. The involvement of an additional nonendocytic process cannot, however, be excluded. It appears from a study of iron transport mechanisms and of the maturation of the transfer process that placental ferritin is involved in the transfer of iron from mother to fetus. The metabolic relationship between the ferritin pool and the placental transfer pool remains to be elucidated. There is no evidence for short-term regulation of placental transfer capacity in response to changes in the maternal iron supply or to changes in the trophoblastic iron content. This cannot yet be said of fetal feedback control of placental iron uptake because the experiments performed so far do not permit conclusions on this point. The capacity for iron uptake and transfer seems to increase in accordance with the ontogenetically determined placental growth pattern. This does not exclude long-range adaptive modifications of the transfer capacity in response to early maternal or fetal disturbances. The results obtained from studying placental maturation suggest that a possible long-term regulatory interaction between growing placenta and fetus may occur. Clinical evidence so far is inconclusive. The relatively moderate reductions in the fetal iron stores which are generally associated with severe iron-deficient pregnancies might be seen as an argument in favour of long-term placental control. The marked impact of pregnancy on maternal iron metabolism in rodents, as compared to other mammals, is possibly met by means of direct placental control of mucosal iron uptake. In primates, mucosal iron uptake during pregnancy seems to be governed by factors related to systemic iron deficiency only.
Placenta
PMID:Regulatory aspects of placental iron transfer--a comparative study. 304 6

To determine whether placental ratio is influenced by maternal anaemia, a retrospective observational study was performed in a regional tertiary hospital in Hong Kong. The gestational age, birthweight, placental weight, and placental ratio were studied in 152 mothers with anaemia due to thalassaemia trait, 232 mothers with anaemia due to iron deficiency, and 279 non-anaemic mothers as controls. All had singleton pregnancies. Compared to the control group, the iron deficiency group had higher placental weight (P = 0.001) and placental ratio (P < 0.001) while the thalassaemia trait group had higher placental ratio (P = 0.011) and, after including gestational age as covariate for analysis, higher placental weight (P = 0.019) as well. There was, however, no difference in the placental weight or ratio between the two anaemia groups. The placental ratio was not correlated to the haemoglobin levels at booking, third trimester, or the lowest one, in any group, but it was correlated with these three haemoglobin levels with the three groups combined. Placental ratio was also correlated to gestational age in all groups. The results confirm the observation that the placental ratio is increased in anaemic pregnancies, and indicate that anaemia, rather than underlying iron deficiency, is the cause for an increased placental ratio.
Placenta 1997 Sep
PMID:Placental ratio--its relationship with mild maternal anaemia. 929 Jan 56

To investigate the effects of maternal iron deficiency and anaemia on the placenta the composition and vascularization of the placental labyrinth was investigated in iron-restricted rats. Rats in the experimental groups were placed on iron-restricted diets either 1 or 2 weeks before mating and continued on these diets throughout gestation. Placentae were studied at day 21 of gestation. Tissue sections were stained with lectin to allow identification of fetal capillaries and analyzed using stereological techniques. Capillary surface area density and total capillary surface area were decreased in both iron-restricted groups compared with the control group. Capillary length density was decreased in both iron-restricted groups compared with the control group. Total capillary length was significantly reduced in the 1-week, but not in the 2-week, iron-restricted group compared with the control group. Endothelial cell volume was increased in both iron-restricted groups compared to the controls. There were no significant differences in the volume of fetal capillaries, the volume of the maternal blood spaces or the surface area of the maternal-fetal interface between the control and iron-restricted groups. Labyrinthine volume, labyrinthine tissue volume and the surface area of the maternal fetal interface were increased in the 2-week group when compared with the 1-week group. These changes in placental vascularization may contribute to the fetal growth retardation observed in iron-restricted litters.
Placenta 2001 Jul
PMID:Effects of maternal iron restriction on placental vascularization in the rat. 1144 May 41

Iron deficiency relatively often observed in pregnant women is assumed to be enhanced by cigarette smoking. The present studies are designed to determine the effect of maternal cigarette smoking during pregnancy on iron status of newborns. The levels of ferritin, as well as other iron-markers were determined in placenta tissue and in serum of umbilical cord blood. Placenta tissues and umbilical cord blood from healthy women (n = 30) were divided into smoking and non-smoking groups according to mothers plasma and urine cotinine levels. It is shown that total iron concentration in serum of umbilical cord was similar in both studied groups. In smoking group it was accompanied by higher total iron binding capacity which indicated that functional iron deficiency is possible. Iron storage ferritin in umbilical cord blood was 94 ng/ml and 163 ng/ml in smoking and non-smoking respectively. In placenta tissue mean level of ferritin was 252 micrograms/g in the smoking women whereas in the group of tobacco abstinent it was 320 micrograms/g. Low concentration of ferritin both in placenta and umbilical cord blood indicated that smoking during pregnancy could lead to subclinical iron deficiency in matched maternal-cord pairs.
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PMID:Effect of maternal smoking on some markers of iron status in umbilical cord blood. 1253 65