Study of maternal influences on fetal iron status at term using cord blood transferrin receptors

AIMS: To determine effects of maternal iron depletion and smoking on iron status of term babies using serum transferrin receptors (STfR) and their ratio to ferritin (TfR-F index) in cord blood. METHODS: Iron, ferritin, STfR, and haemoglobin (Hb) concentration were measured and TfR-F index calculated in 67 cord /maternal blood pairs. Twenty six mothers were iron depleted (ferritin <10 microg/l) and 28 were smokers. RESULTS: Maternal iron depletion was associated with decreased cord ferritin (113 v 171 microg/l) and Hb (156 v 168 g/l) but no change in STfR or TfR-F index. Smoking was associated with increased cord Hb (168 v 157 g/l) and TfR-F index (4.1 v 3.4), and decreased ferritin (123 v 190 microg/l). Cord TfR-F index and Hb were positively correlated (r = 0.48). CONCLUSIONS: Maternal iron depletion is associated with reduced fetal iron stores but no change in free iron availability. Smoking is associated with increased fetal iron requirements for erythropoiesis.     

Iron studies in infants born to an iron overloaded mother with beta-thalassemia major: possible effects of maternal desferrioxamine therapy

A 30-year-old woman with transfusion-dependent, homozygous beta-thalassemia major and transfusional hemosiderosis had 2 successful pregnancies after ovulation induction and in vitro fertilization. Treatment with subcutaneous desferrioxamine (DF) was discontinued before the conception but restarted at 6 months of gestation. Elective cesarean section was performed at 35 weeks of pregnancy because of partial placenta previa. The infant was clinically normal. At the time of delivery, the maternal serum ferritin was 2000 ng/mL, serum iron/iron binding capacity (SI/TIBC) were 274/380 microg/dL, and % saturation 72%. Serum ferritin level in the infant was 42 ng/mL, SI/TIBC were 53/222 microg/dL, and % saturation 23%. During a twin pregnancy 2 years later, DF therapy was totally withheld. Elective cesarian section was performed at 36 weeks of gestation. Both twins were clinically normal. At delivery, the maternal serum ferritin was 1700 ng/mL, SI/TIBC 447/450 microg/dL, and % saturation 99%. Serum ferritins of the twins were 227 and 203 ng/mL, SI/TIBC were 30/182 and 27/203 microg/dL, and % saturations 16% and 13%. Despite elevated iron studies in the mother during both pregnancies, the SI/TIBC of the infants were quite low. In the first pregnancy in which DF was administered in last months of gestation, a low level of serum ferritin was present in the newborn that was even lower at 3 months of age. In the second pregnancy, high normal, levels of ferritin were present in both twin newborns. Despite comparable gestational ages, hemoglobin levels were lower in the first pregnancy than the second. These studies indicate that very high maternal levels of SI/TIBS and serum ferritin were not associated with increased fetal SI/TIBC, which were, in fact, quite low. Because of the different fetal ferritin levels in the 2 pregnancies, it is possible that treatment of the mother with DF in the last weeks of pregnancy may have resulted in depletion of fetal iron stores.     

Influence of maternal diabetes mellitus on fetal iron status

OBJECTIVE: To determine the effects of maternal diabetes on fetal iron status using serum transferrin receptors (STfR) and their ratio to ferritin (TfR-F index) in cord blood. METHODS: Iron, ferritin, erythropoietin, STfR and haemoglobin concentration were measured and TfR-F index calculated in 97 maternal/cord blood pairs. Forty-nine women had type 1 diabetes (diagnosed before pregnancy) and these were compared with forty-eight non- diabetic controls. The women with type 1 diabetes were recruited consecutively from attendance at the joint antenatal endocrine clinic while the control group of women was recruited from consecutive attendance at the remaining antenatal clinics. RESULTS: The infants of the diabetic women had significantly lower levels of ferritin (47 vs 169 mug/l; p<0.01) and higher STfR (17.4 vs 12.9 mg/l; p<0.01) and TfR-F index (10.4 vs 5.8; p<0.01) than controls. They were also significantly more acidotic at birth (7.25 vs 7.30; p<0.01), were born at an earlier gestation (36.7 vs 39.7 weeks; p<0.01) and had higher z Scores for weight (0.53 vs 0.02; p = 0.016). CONCLUSIONS: Maternal diabetes causes depletion of fetal iron stores and is associated with higher fetal iron demands as indicated by higher STfR level and TfR-F index in cord blood.     

Smoking during pregnancy--hematological observations in the newborn

Hematological values were measured in 28 newborn infants of mothers smoking 10-20 cigarettes daily during pregnancy, and in 25 infants of non-smokers. Higher hematocrit levels were found on the 1st day of life in infants of smoking mothers (60.8 +/- 5.0%, mean +/- S.D.) compared to controls (57.5 +/- 4.8%) (p less than 0.05). The hematocrit levels correlated positively with the maternal smoking level (r = 0.318, p less than 0.05) and the maternal serum thiocyanate concentrations at delivery (r = 0.389, p less than 0.01). Cord serum values for erythropoietin, serum-iron, transferrin and ferritin showed no statistically significant difference between the two groups. A significant inverse correlation was found between the hematocrit value on the 1st day of life and the cord serum ferritin concentration (r = -0.495, p less than 0.005). The present results suggest that maternal smoking stimulates fetal erythropoiesis, probably through a hypoxic effect on the fetus, dose related to the maternal smoking level. Increased erythropoiesis may cause increased iron incorporation into erythrocytes at expense of iron storage in the bone marrow and reticuloendothelial system.     

Fetal leptin influences birth weight in twins with discordant growth

The objective of this study was to determine the plasma leptin concentrations in twin pregnancies in relation to chorionicity and discordant fetal growth. We studied 53 twin pregnancies of which 26 had growth discordance of > or =20% and 27 were concordant for growth (discordance of < or =10%). Paired maternal and fetal blood samples were obtained at birth. Plasma leptin concentrations were measured by RIA. In discordant monochorionic pregnancies, fetal plasma leptin concentrations in the intrauterine growth-restricted twins were lower than the co-twins with normal growth (mean difference, 3 ng/mL; 95% CI, 2.2 to 3.3 ng/mL; p < 0.001), whereas no such differences were present between concordant monochorionic twin pairs (mean difference, 0.1 ng/mL; 95% CI, -0.2 to 0.5 ng/mL; NS). Similarly, fetal plasma leptin concentrations in appropriate-for-gestational-age twins were higher than in the intrauterine growth-restricted twins of the discordant dichorionic pregnancies (mean difference, 2.4 ng/mL; 95% CI, 1.8 to 3.1 ng/mL; p < 0.001). No such differences were present between the concordant dichorionic twin pairs (mean difference, 0.2 ng/mL; 95% CI, -0.1 to 0.5 ng/mL; NS). Maternal plasma leptin concentrations were comparable among all four groups and were higher than the fetal levels. Fetal plasma leptin concentrations of the intrauterine growth-restricted twins of discordant monochorionic and dichorionic pregnancies were comparable. There was a positive association between cord plasma leptin concentrations and the birth weight of twin pairs (y = 0.002x - 0.32; r = 0.63; p < 0.001; n = 106). A significant positive association was also found between percent differences in birth weight and fetal delta plasma leptin concentrations of the discordant monochorionic and dichorionic twin pairs (y = 0.057x + 0.93; r = 0.60; p < 0.001, n = 26). In conclusion, irrespective of chorionicity, plasma leptin concentrations in intrauterine growth-restricted twins were 2-fold lower than their co-twins with normal growth. These differences may be attributed to placental factors.     

Serum ferritin in term and preterm infants

Serum ferritin levels were examined in maternal serum, In cord sera and at one, four, eight and twelve weeks in 19 term and 28 preterm infants. There was no correlation between maternal and cord ferritin levels. Mean serum ferritin concentration was lower in preterm infants, and both term and preterm Infants exhibited' an initial rise in serum ferritin concentration followed by a steady fall. Serum ferritin concentration showed a good correlation with calculated iron stores at twelve weeks of age suggesting that serum ferritin estimation is the method of choice for monitoring body iron stores in infants. No correlation was found between serum ferritin concentration and calculated iron intake at any age in either term or preterm infants. It is suggested that iron supplementation additional to that present in modified cow's milk is not necessary for the first twelve weeks of life in either term or preterm infants.     

Fetal iron status in maternal anemia

Hemoglobin, serum iron, transferrin saturation and ferritin were measured on paired maternal and cord blood samples in 54 anemic (hemoglobin < 110 g/L) and 22 non-anemic (hemoglobin ≥ 110 g/L) pregnant women at term gestation. The levels of hemoglobin, serum iron, transferrin saturation and ferritin were significantly low in the cord blood of anemic women, suggesting that iron supply to the fetus was reduced in maternal anemia. The linear relationships of these parameters with both maternal hemoglobin and maternal serum ferritin indicated that the fetus extracted iron in amounts proportional to the levels available in the mother. Infants of mothers with moderate and severe anemia had significantly lower cord serum ferritin levels and hence poor iron stores at birth. It is concluded that iron deficiency anemia during pregnancy adversely affects the iron endowment of the infant at birth.     

The risk of mortality or cerebral palsy in twins: a collaborative population-based study

The purpose of the paper was to describe demographic and clinical factors associated with fetal or neonatal death or cerebral palsy (CP) in twins. Vital statistics from five populations in the United States and Australia, which included information on CP diagnosed after 1 y of age. Information on zygosity was not available. In 1,141,351 births, 25,772 of whom were twins, significant secular trends from 1980 to 1989 included increasing prevalence of twins, increasing proportion of unlike-sex twins, and increasing maternal age. Overall, twins were at an approximately 5-fold increased risk of fetal death, 7-fold increased risk of neonatal death, and 4-fold increased risk of CP compared with singletons. However, at birth weight <2500 g, twins generally did better than singletons, both with respect to mortality and to CP rates. Second-born twins and twins from same-sex pairs were at increased risk of early death but not of CP. Twins from growth-discordant pairs and twins whose co-twin died were at increased risk of both mortality and CP. The highest rates of CP were in surviving twins whose co-twin was still-born (4.7%), died shortly after birth (6.3%) or had CP (11.8%). In this large data set spanning a 10-y period, overall rates of death or cerebral palsy were higher in twins than singletons, although small twins generally did better than small singletons. Co-twin death was a strong predictor of CP in surviving twins. This risk was the same for same- and different-sex pairs, and observed both for preterm and term infants.     

Gender difference in cord serum ferritin concentrations.

We measured cord serum ferritin concentrations in a total of 255 infants (116 females and 139 males), and evaluated the association between these values and various neonatal as well as maternal characteristics. The mean ferritin concentration in females (166 +/- 110 microg/l) was significantly higher than that in male infants (123 +/- 77 microg/l). The gender differences in ferritin were significant within groups of infants with fetal growth restriction, those who weighed <3,000 g, those whose mothers were African Americans or <25 years old. Maternal serum ferritin concentrations at 36 weeks of gestation significantly correlated with cord serum ferritin of male infants (r = 0.32, p < 0.001), whereas the association was not significant for females (r = 0.09, p > 0.41). Although the mechanism of the gender difference is unknown, it may be important to consider the sex of neonates when evaluating their iron nutriture immediately after birth.     

Essential fatty acid status measured in umbilical vessel walls of infants born after a multiple pregnancy

The essential fatty acid (EFA) status of full-term infants born after an uneventful, singleton pregnancy has been reported to be marginal. If this low EFA status is caused by a limiting maternal EFA supply, the higher total fetal EFA demand associated with a multiple pregnancy would result in an even lower EFA status of the infants born after a multiple pregnancy. Therefore, we compared the EFA status at birth of 30 pairs of twins, seven sets of triplets, and one set of quintuplets with that of 94 infants (51 preterm, 43 full-term) born after a singleton pregnancy. Phospholipid-associated EFA profiles of the umbilical vessel walls, considered a longer-term reflection of the fetal EFA status, were studied. After correction for gestational age at birth, levels of n-6 and n-3 EFAs were generally lower, while levels of EFA-deficiency indicating n-9 polyunsaturated fatty acids were significantly higher both in the draining umbilical arteries and the supplying veins of infants born after a multiple pregnancy. EFA profiles of twins and triplets were similar, but the average EFA status of the set of quintuplets was lower than that of twins and triplets. In conclusion, the observation that the EFA status of infants born after a multiple pregnancy is lower than that of infants born after a singleton pregnancy supports the view that the maternal EFA supply to the fetus is limiting. Considering the importance of EFAs and their longer chain derivatives for proper growth and development, this finding warrants further studies of the adequacy of the maternal EFA intake during pregnancy.     

Impact of daily versus weekly hematinic supplementation on anemia in pregnant women

OBJECTIVE: To compare the effectivity of weekly versus daily iron therapy in reducing maternal anemia and to evaluate the association of maternal hemoglobin and fetal growth. DESIGN: Prospective. SETTING: Tertiary care teaching hospital in an urban metropolis. METHOD: 40 pregnant women received daily and 40 pregnant women received weekly oral therapy (335 mg of ferrous sulphate and 500 g folic acid) for a period of 14 weeks. The age of each pregnant woman and their baseline anthropometric data (weight, height and body mass index) were estimated. Hemoglobin and hematocrit estimations were carried out during follow period at 4 wks, 8 wks and 14 weeks. Serum ferritin values as a marker of iron status were also calculated in both the groups initially, at 14 weeks and at the time of delivery. Fetal anthropometric indices of 137 full term neonates delivered to mothers included in either of the supplementation groups or admitted to the hospital were also studied in relation to maternal hemoglobin concentration. RESULTS: Forty subjects each were initially randomized into groups I and II. The age of pregnant women along with their baseline anthropometric data were similar in both groups. A total of 29 pregnant women in group I and 27 pregnant women in group II could be regularly followed up. The increase in hemoglobin and hematocrit values were similar in daily and weekly supplemented mothers. An intention to treat analysis also showed similar results. The ferritin values were similar at the start of supplementation and after 14 wks of weekly or daily iron therapy. Birth weight, crown heel length, head circumference of the neonate and placental weight increased significantly with rise in maternal hemoglobin levels. CONCLUSION: Weekly iron supplementation is an effective mode of treating anemia among pregnant women and maternal anemia during pregnancy is adversely associated with fetal growth.     

Relationship between newborn and maternal iron status and haematological indices.

The haemoglobin, mean corpuscular volume, mean corpuscular haemoglobin, haematocrit, serum iron and total iron binding capacity, and serum ferritin concentrations in umbilical cord blood samples taken from 96 appropriate-for-gestational age infants delivered at term were measured and compared to the respective maternal values measured at 36 weeks' gestation. All the values were higher in cord blood. Only maternal mean corpuscular volume and mean corpuscular haemoglobin were correlated with cord serum iron. Cord blood haematological indices were not correlated with either gestation at delivery or birth weight. However, newborn serum ferritin was positively correlated with gestation at delivery, while the maternal:newborn ferritin ratio was inversely correlated with gestation and birth weight. The results suggest that maternal haematological and iron indices are not predictive of the haemoglobin or iron status of the newborn, and that the fetus continues to take up iron from the mother until delivery.     

Perinatal aspects of iron metabolism

Iron sufficiency is critical for rapidly developing fetal and neonatal organ systems. The majority of iron in the third trimester fetus and the neonate is found in the red cell mass (as hemoglobin), with lesser amounts in the tissues as storage iron (e.g. ferritin) or functional iron (e.g. myoglobin, cytochromes). Iron is prioritized to hemoglobin synthesis in red cells when iron supply does not meet iron demand. Thus, non-heme tissues such as the skeletal muscle, heart and brain will become iron deficient before signs of iron-deficiency anemia. Gestational conditions that result in lower newborn iron stores include severe maternal iron deficiency, maternal hypertension with intrauterine growth retardation and maternal diabetes mellitus. Stable, very low birthweight premature infants are also at risk for early postnatal iron deficiency because they accrete less iron during gestation, grow more rapidly postnatally, are typically undertreated with enteral iron and receive fewer red cell transfusions. Conversely, iron overload remains a significant concern in multiply transfused sick preterm infants because they have low levels of iron-binding proteins and immature antioxidant systems. CONCLUSION: The highly variable iron status of preterm infants combined with their risk for iron deficiency and toxicity warrants careful monitoring and support in the newborn and postdischarge periods.     

Discordant amino acid profiles in monochorionic twins with twin-twin transfusion syndrome

To test the hypothesis that discordant growth in monochorionic (MC) twins occurs at least in part due to disparity in placental amino acid transporter function, we measured plasma amino acid levels by HPLC in maternal and fetal blood samples collected at birth from gestational age matched twins with (n = 12) and without (n = 12) twin-twin transfusion syndrome (TTTS). In the donor twin, fetal plasma concentrations and feto-maternal ratios of five essential amino acids-valine (p < 0.001), leucine (p < 0.001), iso-leucine (p < 0.05), histidine (p < 0.001) and L-arginine (p < 0. 001)-were lower than the recipient and non-TTTS twin pairs. Fetal concentrations of the nonessential amino acids taurine (p < 0.001), serine (p < 0.01), glycine (p < 0.001) and tyrosine (p < 0.05) were also markedly lower in the donor than the recipient and non-TTTS twin pairs. In contrast, the fetal alanine level in the donor twin was higher than the recipient (664 +/- 64 versus 396 +/- 23 microM; p < 0.001) and the non-TTTS twin pairs (p < 0.01). No such differences between amino acid profiles in non-TTTS MC twin pairs were found. Maternal plasma amino acid levels between TTTS and non-TTTS groups were comparable. This study provides the first evidence that certain amino acids in the donor twin of chronic TTTS differ significantly from those of the co-twin while others were comparable between twin pairs. These data, therefore, argue against inter-twin transfusion as the sole cause of growth restriction of the donor twin and suggests instead that impaired placental transport of amino acids may be a likely mechanism.     

Relationship of maternal and newborn (cord) serum ferritin concentrations measured by immunoradiometry

Serum ferritin concentration was determined by immunoradiometry in venous blood samples of 45 pregnant women at term, in their babies' cord blood samples, and blood specimens obtained from 43 infants aged 3-12 months. The concentration of ferritin was higher in cord serum than in respective maternal samples and infant specimens. Low values were found in more than half of the maternal venous samples. Iron stores of newborns delivered by mothers with low serum ferritin concentration were lower than in newborns of mothers having normal ferritin levels. Serum ferritin measurement is a sensitive method to determine iron deficiency in pregnancy.     

Effects of antenatal betamethasone administration on fetal heart rate and behavior in twin pregnancy

The efficacy of antenatal corticosteroid therapy in reducing the incidence of respiratory distress syndrome in twin pregnancy is controversial. The corticosteroid levels achieved with the current regimen might not be high enough to reach both siblings. In singleton fetuses, maternal betamethasone administration causes transient reductions in fetal heart rate (FHR), FHR variability, and body and breathing movements. We performed a prospective study to determine whether there are similar effects of betamethasone on FHR and behavior in preterm twin pregnancy and whether the effects occur similarly in both twin members. Eighteen women who were carrying twins received optimal corticosteroid treatment. Simultaneous recordings were made on twins before (day 0), during (days 1-2), and after (days 3-4) corticosteroid therapy using separate cardiotocography and ultrasound machines. Betamethasone administration was associated with significant transient decreases in basal FHR (day 1), FHR variability (days 2 and 3), and body and breathing movements (day 2). The overall changes in twins were similar to those previously found in singleton pregnancies. There was a high degree of association of response to betamethasone among individual members of twin pairs. The betamethasone-induced effects were unrelated to fetal sex, positioning, chorionicity, and discordance in size, but there was an effect of gestation on FHR. We conclude that the current regimen of antenatal corticosteroids used in preterm twin pregnancies results in observable physiologic and behavioral changes in twin pairs irrespective of their composition. This provides evidence that the achieved betamethasone levels are high enough to reach the compartment of either twin member.     

Developmental outcome of discordant premature twins at 3 years

BACKGROUND: There are numerous known or unknown maternal, fetal and intrauterine conditions that may lead to growth restriction. In addition to prematurity and growth restriction, developmental outcome may also be influenced by many genetic and environmental factors. AIM: To examine the impact of intrauterine growth restriction on development in premature discordant twins. STUDY DESIGN: Intra-pair control comparison. METHODS: Developmental outcome at age 3 years was examined in 21 pairs of discordant (>15% birth weight discordance) very low birth weight (VLBW) premature twins. RESULTS: None of the smaller twins had cerebral palsy and one larger twin had a mild diplegia. In paired comparisons, the smaller twins were somatically smaller and had a slight lower Griffiths' developmental quotient (GQ) than the co-twins without cerebral palsy [mean+/-S.D. 100+/-13, range 73-117, versus 104+/-12, 80-124, p=0.002]. The largest difference was in the locomotor subscale. There was a greater intra-pair GQ difference in the 12 twin pairs who had a discordance of greater than 30% (mean GQ=98 versus 105, p<0.001). The intra-pair GQ correlated well (r=0.90), a finding similar to that of a comparative group of 26 nondiscordant VLBW twin pairs (r=0.87). A multivariate analysis confirmed that gestation and percentage discordance were the important factors influencing GQ. CONCLUSION: There exists a strong influence of common intrauterine, genetic and environmental factors on developmental outcome. Despite an overall lack of adverse outcome in smaller twins, results indicated a small but significant influence of growth restriction.     

Iron status in the first year of life

The iron status of babies of different race born at term to mothers in an inner city area was studied at birth and during the first year of life and related to maternal iron status. Haemoglobin and ferritin were measured in the mother at term (n = 81) and in the baby in cord blood (n = 81), at 6 months (n = 55), and at 1 year (n = 51). No relationship was found between the iron status of mothers and their babies at birth. However, iron stores at birth did affect later iron status, cord ferritin being significantly related to ferritin at 6 months (r = 0.42, p less than 0.01) and 1 year (r = 0.55, p less than 0.01) but not to haemoglobin at these ages. No relationship was found between haemoglobin iron at birth and subsequent iron status. Introduction of full cow's milk before the age of 6 months was associated with iron deficiency at this age and at 1 year. By the age of 1 year, iron deficiency was also associated with feeding greater than 900 ml whole cow's milk a day, inadequate feeding with solids, and higher weight gain. No stool parasites were found at the age of 1 year, and the presence of occult blood in stools did not significantly affect iron status at this age. At 1 year of age, 49% of these infants had low iron stores, including 20% with iron deficiency anaemia. Considerable improvement could result from simple changes in dietary practices.     

Differential effects of fetal number and maternal nutrition in late gestation on prolactin receptor abundance and adipose tissue development in the neonatal lamb

The present study examined the extent to which abundance of the prolactin receptor (PRLR) and a range of primary mitochondrial proteins are influenced by either maternal nutrition and/or fetal number in adipose tissue. Pregnant sheep were control fed [consuming 100% of total metabolizable energy (ME) requirements (taking into account requirements for both ewe maintenance and growth of the conceptus to produce a 4.5-kg lamb at term) for that stage of gestation] or were nutrient restricted (consuming 60% of total ME requirements). All ewes lambed normally at term and both perirenal adipose and hepatic tissues were sampled within 6 h of birth. Plasma membranes and mitochondria were prepared and analyzed using immunoblotting for abundance of PRLR and/or cytochrome c, voltage-dependent anion channel (VDAC), and uncoupling protein-1 (UCP1). Irrespective of maternal nutrition, abundance of specific isoforms of PRLR were significantly higher in adipose tissue sampled from twins compared with singletons and total UCP1 concentration per milligram of tissue was increased (p < 0.05). There was no effect of fetal number on PRLR abundance in the liver. Maternal nutrient restriction resulted in an increased abundance of both cytochrome c (p < 0.001) and VDAC in adipose tissue of twins but not singletons. This occurred despite maternal nutrition having no effect on either lamb body or adipose tissue weights, although both were lower (p < 0.05) in twins compared with singletons. In conclusion, fetal adipose tissue development is highly sensitive to nutritionally mediated changes in late gestation. An increase in fetal number results in greater PRLR abundance, which, in conjunction with a decrease in maternal nutrition, results in up-regulation of specific mitochondrial proteins.     

Does maternal iron supplementation during the lactation period affect iron status of exclusively breast-fed infants?

Iron deficiency anemia (IDA) causes growth and developmental retardation in infants. Iron supplementation from the 4th month of age may prevent IDA, but side effects of oral iron supplementation limit its usage. The aim of this study was to investigate the effect of maternal iron supplementation on the iron status of mothers and their exclusively breast-fed infants. In a prospective, placebo-controlled, double-blinded randomized study, healthy mothers (Hb > or = 11 g/dl) and their 10-20-day-old healthy term infants who were admitted to Hacettepe University for neonatal screening were enrolled. The mothers who were intending to exclusively breast-feed at least up to four months were included. Iron supplementation (n = 82, 80 mg elementary iron) and placebo (n = 86) were given to the mothers randomly for four months. The anthropometrical measurements of infants were recorded monthly. Of all, 69 mothers and their infants in the iron group and 63 in the placebo group completed the study. At the end of the study period, blood samples (complete blood count, serum iron, iron binding capacity and serum ferritin) were drawn from the mothers and their infants. After adjustment for baseline hemoglobin value, the mean levels of hemoglobin, serum iron and ferritin were similar in the two groups at the end of the study; however, serum iron binding capacity was significantly lower in the iron group than in the placebo group. Giving maternal iron supplementation during the first four months of the lactation period had no effect on the serum iron and ferritin levels of mothers and infants. This could be due to the relatively short duration of the follow-up period. A longer follow-up period is recommended to detect the effect of the maternal iron supplementation during lactation.