Maternal Serum Iron Research Articles

Zinc, copper, and iron metabolism during porcine fetal development.

Zinc, copper, and iron levels in maternal and fetal pig tissues and fluids were measured starting on d 30 of gestation and continuing to term (d 114) at 10-d intervals. Fetal hematocrit increased from a low of 19% on d 30 to 32% by d 50, after which it remained above 30% to term. Amniotic fluid zinc, copper, and iron all reached maximal levels by d 60 of gestation. Maternal serum zinc levels fluctuated little during gestation, but fetal serum zinc concentration was significantly elevated above maternal levels during the second trimester. Fetal serum copper levels were significantly lower than maternal values throughout gestation and this was also the case for ceruloplasmin oxidase activity. Maternal serum iron reached its lowest level by d 80 of gestation when rate of transfer of iron to the developing fetuses was high. Fetal serum iron declined throughout gestation, reaching its lowest level on d 100. In general, fetal liver concentrations of zinc, copper, and iron were higher than the corresponding maternal values throughout gestation. Distinct increases were noted for fetal hepatic zinc and copper concentrations during the second trimester of pregnancy and these were accompanied by increases in cytosolic and metallothionein-bound zinc and copper levels. Maternal hepatic iron declined during the second trimester, reaching its lowest point on d 80, indicative of the shunting of maternal iron reserves to fetal tissues. Fetal kidney metal levels did not demonstrate any distinctive developmental patterns with respect to zinc, copper, or iron concentrations, but a general accumulation of each metal was observed as gestation progressed. The results of this study highlight some of the distinct changes occurring in the metabolism of zinc, copper, and iron in both maternal and fetal tissues and fluids during gestation in the pig.

Distribution of iron and iron-binding proteins in first trimester human pregnancies

To investigate the iron distribution between the maternal and embryonic compartments in the first trimester of pregnancy.Coelomic and amniotic fluids (AF) and maternal serum were collected from 36 apparently normal pregnancies at 7-13 weeks of gestation. Iron, transferrin, ferritin, and lactoferrin were measured in all samples. Iron concentrations were also measured in placental villi, liver, gut, and brain samples collected from two embryos.Significantly (median value) lower iron and transferrin levels and higher levels of ferritin were found in the coelomic fluid (iron 4.8 mumol/L; transferrin 0.22 g/L) than in maternal serum (iron 21 mumol/L; transferrin 2.5 g/L). The AF contained significantly lower levels of iron and ferritin (iron less than 1.8 mumol/L; ferritin 2.0 micrograms/L) than both coelomic fluid (iron 4.8 mumol/L; ferritin 287 micrograms/L) and maternal serum (iron 21 mumol/L; ferritin 49 micrograms/L). Transferrin was undetectable (less than 0.08 g/L) in AF samples, and lactoferrin was undetectable (less than 2 micrograms/mL) in both embryonic fluids. The iron concentration in the coelomic fluid increased significantly (P < .001) with advancing gestation (iron at 7-9 weeks 3.8 mumol/L; 9.1-11 weeks 5.9 mumol/L). There was a nonsignificant correlation between coelomic fluid and maternal serum iron and iron-binding protein levels. The highest iron levels were found in the liver (52 mmol/kg dry weight) and brain (49 mmol/kg dry weight) tissues.The distribution of iron and iron-binding proteins between the maternal and embryo-placental compartments in the first trimester is comparable to that found later in gestation, suggesting that placental iron transfer may occur as early as tertiary villi are formed. The exocoelomic fluid is probably the main iron reservoir in early pregnancy, and the secondary yolk sac is probably the principal route of entry of iron to the embryo.

Metoclopramide for breast milk production

The efficacy of a dopamine antagonist-metoclopramide to recommend for healthy mothers with lactational insufficiency was evaluated in healthy mothers with lactational insufficiency. Thirty-two mothers with babies 10 days to 120 days of age who had inadequate lactation confirmed by failure to gain weight of their babies and two consecutive measurements of breast milk by pump that proved to be less than the daily requirements of the baby. The drug was started to the mothers with lactational insufficiency only after a brief educational period to make sure the proper technique for breast feeding being used and a second measurement one week later that was still less than the requirements of the baby. Mothers were given 300–500μgr/kg of metoclopramide (10 mg×3) in 3 divided doses orally. A control group of 32 mothers with adequate lactation was also included in the study. A ‘true control group’ of women with lactational failure that placebo should be given was not approved by the ethical committee. The therapy group and control group were comparable in parity, socioeconomic status, age of the mothers and the age of the babies. About half of the babies were premature in each group. The amount, (twice in the initial measurement) and the osmolality of breast milk, the blood pressure, prolactin and aldosterone levels of the mothers, and maternal blood counts, ferritin and serum iron and iron binding capacity were determined. The laboratory analyses were repeated after 15 days both in the drug therapy and control groups. Daily milk production increased by 28.5%. (from 378±28(SD) ml to 690±37ml) which was statistically significant (P<0.001). An increase of 34% in prolactin levels were also recorded from 69.5SI(2293μIU/ml) to 93.3 SI (3079μIU/ml) which was also significant (P<0.05). Aldosterone levels were also increased in the therapy group but did not exceed the mean levels of the control group. Blood pressure levels of the mothers and the osmolality of breast milk did not differ significantly after the drug. However in mothers of term babies an increase in the osmolality of breast milk was noted. This effect was not recorded in the mothers of premature infants. The elevation of the osmolaiity of milk was most evident in subjects who had higher blood pressures initially. Initial prolactin levels were inversely correlated with initial diastolic pressures. The increase of daily milk production significantly and inversely correlated with the age of the mothers (P<0.01, r=−47). No. significant side effects were recorded in the mothers of babies. 25 of 32 (78%) mothers had a sufficient response (meeting the daily calorie and liquid requirements of the infant) to metoclopramide. In seven treated mothers daily milk production was still below the infants' daily requirements. These mothers were relatively older in age, no other factors were associated with failure of response to metoclopramide. Metoclopramide seems to be a safe and effective drug for the treatment of lactational failure especially in young mothers and is worth a trial before recommending formula feeding even in mothers of premature babies.

An ovine model of maternal iron poisoning in pregnancy

An ovine model of maternal iron poisoning in pregnancy was used to examine the placental transport of deferoxamine and ferrioxamine and to follow maternal and fetal serum iron concentrations when maternal serum iron levels exceeded total iron-binding capacity. Ewes in the third stage of gestation underwent hysterotomy and delivery of the fetal head through an abdominal incision while under ketamine and halothane anesthesia. The fetal external jugular vein was catheterized for sampling of venous blood while the fetus remained in utero. Administration of deferoxamine mesylate or ferrioxamine mesylate IV to ewes was not accompanied by measurable deferoxamine or ferrioxamine in fetal blood. In a final experiment, four gravid ewes in a control group received 2 mg/kg maternal body wt iron IV over 60 minutes. An experimental group comprising another four ewes received similar doses of iron but then received 50 mg/kg deferoxamine mesylate IV over 15 minutes. Control and deferoxamine ewes reached similar peak maternal serum iron concentrations (2,479 +/- 266 and 2,121 +/- 343 micrograms/dL, respectively). The markedly elevated maternal serum iron concentrations were not accompanied by meaningful elevations in fetal serum iron levels over baseline values. Maternal deferoxamine infusion resulted in a more rapid fall in maternal serum iron concentrations but had no effect on fetal serum iron levels. The ovine fetus appears to be protected from elevated maternal serum iron concentrations in the last trimester of pregnancy. It could not be demonstrated that meaningful quantities of deferoxamine or ferrioxamine cross the placenta in the last trimester.(ABSTRACT TRUNCATED AT 250 WORDS)

Trace metals in postdate pregnancy.

Maternal and cord serum calcium, copper, iron and zinc concentrations were analyzed in 20 women with a postdate pregnancy. The control group consisted of 20 parturients with delivery at term and their newborns. Serum free estriol (E3) was also determined. Maternal serum copper, zinc and E3 were statistically significantly lower, while cord serum copper and fetomaternal ratio of zinc were significantly higher in the study group than in the control group. Further, a positive correlation between E3 and maternal serum copper level (r = 0.63) was found.

Effect of Total Dose Infusion of Iron Dextran on the Storage Iron Content of the Human Placenta

The histochemical examination of a placenta obtained from a stillbirth, which occurred 3 days after the mother had received a total-dose infusion of iron dextran (at 32 weeks of gestation), revealed large amounts of hemosiderin in the trophoblast. This is in contrast to a study of iron-deficient patients, treated with total-dose infusion of iron dextran, which shows no resulting increase of stainable iron in the placenta. Further studies were made to assess in more detail the effect on placental iron of infusions of iron dextran given at different stages of pregnancy. In addition to histochemical examination of the placenta, the two forms of storage iron, hemosiderin and ferritin, were estimated respectively as the water-insoluble and water-soluble fractions of the non-heme iron. The results of these studies are given in the present report. Observations were made on placentas obtained in an uncontrolled manner at various intervals after total-dose infusion and after varying doses of iron dextran. The latter was infused over 6 hours in either 5 per cent dextrose or in normal saline. Control placentas were obtained from women delivered at full term who had not been anemic during pregnancy and had not received parenteral iron. The interval between the infusion and the onset of delivery varied greatly. One patient was delivered the same day, and several others went into labor within 10 days; but in most cases, the infusion was given more than 3 weeks before delivery. The most striking changes were in the placenta associated with the stillbirth, in which almost every villus contained large amounts of Prussian blue-positive material in the trophoblast or immediately beneath it (Fig. 1). No other placenta showed so much iron, but in those obtained at 4 days and at 6 days, there was still a large amount of similarly distributed Prussian blue material in the villi. In placentas obtained at 8 days or longer after the infusion, the findings were the same as in the controls, namely, occasional specks of Prussian blue-positive material found mainly in the stroma of the villi. There was virtually none in the trophoblast itself. In the study of water-insoluble non-heme iron (hemosiderin), a total of 35 duplicate analyses of homogenates were made, with a range of values from 6 to 108 mg of iron per 100 g dry weight (0.108 to 2.94 mmol). The largest difference between duplicates was 12 per cent, but in 30 cases the difference was less than 6 per cent. The mean of the duplicates was therefore taken. In 11 controls, the placental hemosiderin iron ranged from 4.2 to 12 mg per 100 g dry weight (0.076 to 0.216 mmol). In 26 specimens obtained after iron dextran infusion, the placental hemosiderin ranged from control levels up to 128 mg (2.30 mmol) per 100 g dry weight. The highest values were found in placentas obtained within 2 weeks of the infusion. Much lower concentrations occurred in placentas collected between 3 and 20 weeks after the infusion. The high concentrations found within 2 weeks of infusion were, however, quite variable. Two placentas were obtained 4 days after infusion, two at 6 days, and two at 12 days. There were large deficiencies in hemosiderin within each of these pairs. In two of the pairs, the differences could be related to differences in the dose of iron dextran, but the remaining pair came from a twin pregnancy and were therefore exposed to the same maternal blood level. All but two of the highest hemosiderin concentrations were associated with the largest doses of iron dextran, but they were also cases in which the placentas were obtained within 14 days of infusion. In cases with longer intervals between infusion and delivery (the majority), the placental iron concentrations did not vary with the dose of iron dextran. The water-soluble non-heme iron was determined in 17 treated cases. No estimation was made in any of the controls, but the results after treatment fell into two groups. In three of six cases with increased concentrations of hemosiderin iron, the ferratin iron was higher than in the remaining 14 cases. In most of the latter, the concentrations of hemosiderin iron were within the control range. In some patients, the maternal serum iron was measured at the time of delivery. The concentrations were high in most of these, due to the presence of circulating irondextran.

Cord serum and placental tissue iron status in maternal hypoferremia

Studies on 85 mothers with term infants and 32 mothers with preterm infants revealed that the cord scrum and placental tissue iron levels were significantly reduced (P < 0.001) in the mothers with hypoferremia (serum iron ≤ 50 µg/100 ml). These levels were found to have linear correlations with the maternal serum iron levels, suggesting that the fetus and the placenta extracted iron in amounts proportional to the levels available in the mother. The high serum iron values in cord blood compared to the maternal blood even in the mothers with hypoferremia suggested that the process of active transfer of iron from mother to the fetus was maintained in maternal iron deficiency.

Maternal serum metabolites during prolonged starvation in pregnant pigs

Pregnancies in pigs were sustained during periods of prolonged starvation in spite of maternal body weight losses exceeding 40 kg. Maternal stores of protein were made available for feto-placental development during starvation of the dam. Concentrations of maternal serum proteins, urea nitrogen, electrolytes, and iron were determined in sequential blood samples of healthy Yorkshire pigs during a prolonged period of 40 days inanition (water only) in either the middle third (days 30–70) or last third (days 70–110). Serum protein levels remained similar to full-diet controls throughout these two periods, whereas serum concentrations of albumin and urea N increased primarily during the last third of gestation in starved dams. Serum Na + levels declined during prolonged inanition while Ca 2+ increased and K + remained unchanged. It was only near term that Fe 2+ levels decreased in those dams starved during a period of 40 days in the last third of pregnancy. These results indicated that maternal serum components were sustained at adequate levels to maintain normal development of conceptuses during prolonged starvation in either the middle third or last third of pregnancy in the pig.

Neonatal and maternal serum iron levels at birth.

SummaryThe serum iron levels in mothers and their newborn full‐term infants at the time of birth has been measured. There is no correlation between the maternal and neonatal levels, and the high cord blood serum levels bear no relation to sex or birthweight.

Placental Transfer of a High Molecular Ferric Carbohydrate

IN 1953, I suggested1 that the placental transfer of iron in the rat is brought about by the placental structures building up a fairly high concentration of some hydrolysable iron compound or compounds, partly or wholly ferritin, the source of which was supposed to be the maternal serum iron. The fœtal needs for the metal were taken to determine the rate at which these intermediate placental iron compounds were mobilized. The iron transfer from the maternal to the fœtal organism thus seemed to be regulated in a manner not very different from that suggested by Granick2 for the gastro-intestinal absorption of iron. Since Nissim3 first introduced saccharated colloidal iron for parenteral use, several papers on this subject have appeared. Considering the possibility of an untoward effect upon the fœtus brought about by the colloidal iron preparation, it seemed important to investigate this therapeutic agent, particularly as to permeability of the placenta to it, before recommending its use in the anaemias of pregnancy. In doing so, I have used the material and techniques described in my earlier communication1, in which measured values in normal untreated pregnancy were given; these values have been used as controls in the present investigation.