Impact of maternal anemia on the infant's iron status at 9 months of age

Is Anemia in Low Income Pregnant Women Related to Their Infants' Having Anemia? A Cohort Study of Pregnant Women-Infant Pairs in the United States

OBJECTIVE

Given evidence that anemia in the first year of life is associated with long-term cognitive, motor, and behavioral deficits, reducing infant anemia is important. The primary objective of this research is to examine whether anemia in low income pregnant women in the United States is associated with anemia in the women's infants.

METHODS

This cohort study linked Centers for Disease Control and Prevention surveillance data on pregnant women with incomes below 185% of the federal poverty level from 2010 and 2011 with data on 6-11 month olds from 2011, resulting in a sample of 21,246 uniquely matched mother-infant pairs. We examined bivariate and multivariate relationship between anemia severity in pregnant women and in their infants.

RESULTS

Seventeen percent of women had anemia (13.1% mild and 3.9% moderate to severe) and 20.1% infants had anemia (16.4% mild and 3.7% moderate to severe). For both women and infants, blacks had substantially higher anemia rates than whites. In bivariate analysis and multivariate analyses maternal anemia showed a dose-response relationship to infant anemia. In predicted probabilities from the multivariate models, 27.2% of infants born to pregnant women with moderate to severe anemia had anemia, compared to 23.3% for infants whose mothers had mild anemia, and 18.3% for infants whose mothers did not have anemia.

CONCLUSION

This study provides strong evidence of a relationship between maternal and infant anemia in the United States among people with low incomes. Efforts to reduce anemia during pregnancy may be an important strategy for minimizing childhood anemia.

Increase serum cortisol in young guinea pig offspring in response to maternal iron deficiency

Iron deficiency (ID) has been reported as a risk factor in the pathology of attention-deficit/hyperactivity disorder, although the mechanisms seem unclear. Previous results from our research group showed that guinea pig offspring born from ID dams were significantly more active in the Open Field Test than the controls. This behavior could potentially be associated to stress. We therefore hypothesized that maternal iron deficiency (MID) elevates the offspring serum cortisol, a biomarker of stress, during childhood and possibly at mature age. Twenty-four female guinea pigs were fed an iron-sufficient (IS) diet (114 mg/kg) or ID diet (11.7 mg/kg) during the gestation and lactation. Pups in both groups were weaned at postnatal day (PNd) 9 and given an IS diet. Hematocrit and serum cortisol levels were measured in dams at every trimester of gestation and in pups at PNd24 and 84. We found no impact of MID on dam's cortisol values. However, our findings indicate that MID increased cortisol secretion in the offspring during childhood, cortisol values being significantly elevated in ID than IS pups at PNd24 (P < .05). During adulthood (PNd84), both groups showed comparable cortisol levels. The elevated cortisol secretion observed in the offspring born from ID mothers during childhood may indicate increased stress reactivity which may have contributed to the higher level of activity when tested in a novel open environment. These findings suggest that MID can potentially act as internal stressor affecting the early development conceivably leading to increased stress levels in the children.

Impact of maternal iron deficiency on the auditory functions in the young and adult guinea pig

OBJECTIVES

The aim of this study was to evaluate the hearing function in the guinea pig offspring at post-natal day (PNd) 24 and PNd84 born from dams suffering from iron deficiency during pregnancy and lactation by using the auditory brainstem response (ABR).

METHOD

Female guinea pigs (n = 24 per dietary group) were fed an iron sufficient (IS) diet (114 mg/kg) or an iron deficient (ID) diet (11.7 mg/kg) during the gestation and lactation periods. Pups in both groups were weaned at PNd9 and given the IS diet. The hematocrit level was measured at every trimester of pregnancy and at the day of sacrifice in dams and at PNd24 and PNd84 in pups. The animal body weight was measured on every second day until the day of sacrifice. The ABR was used in pups to measure the hearing threshold using a broad range of stimulus intensities and latency at 100 and 80 dB in response to 2, 4, 8, 16, and 32 kHz tone pips at PNd24 and 84.

RESULTS AND DISCUSSION

No significant difference between dietary groups was measured in hearing threshold and absolute latencies in pups at PNd24 and PNd84. Although the ID offspring (n = 16) did not differ in brainstem transmission times (BTTs) at 80 dB compare to the IS siblings (n = 25) at PNd24, they showed significant delayed inter-peak latency (IPL) I-IV at 100 dB suggesting a delayed BTT. At PNd84, the latency of all peaks including IPL I-IV at 80 and 100 dB significantly decreased and was also similar in pups from both dietary groups suggesting a better brain maturation. This is the first study investigating the long-term impact of maternal iron deficiency on the auditory functions in the guinea pig offspring during early development to adulthood.

Dietary LC-PUFA in iron-deficient anaemic pregnant and lactating guinea pigs induce minor defects in the offsprings' auditory brainstem responses

OBJECTIVES

We previously demonstrated that a mild pre-natal/early post-natal iron-deficient anaemic (IDA) diet devoid of long-chain polyunsaturated fatty acids (LC-PUFA) affected development, neurophysiology, and cerebral lipid biochemistry of the guinea pigs' progeny. Impacts of dietary LC-PUFA on altered cerebral development resulting from pre-natal IDA are unknown. To address this health issue, impacts of mild gestational IDA in the presence of dietary LC-PUFA on the offsprings' neural maturation were studied in guinea pigs using auditory brainstem responses (ABRs) and assessments of brain fatty acids (FAs).

METHODS

Female guinea pigs (n = 10/group) were fed an iron sufficient (IS) or IDA diet (146 and 12.7 mg iron/kg, respectively) with physiological amounts of LC-PUFA, during the gestation and lactation periods. From post-natal day (PNd) 9 onwards, the IS + PUFA diet was given to both groups of weaned offspring. Cerebral tissue and offsprings' ABR were collected on PNd24.

RESULTS

There was no difference in peripheral and brainstem transmission times (BTTs) between IS + PUFA and IDA + PUFA siblings (n = 10/group); the neural synchrony was also similar in both groups. Despite the absence of differences in auditory thresholds, IDA + PUFA siblings demonstrated a sensorineural hearing loss in the extreme range of frequencies (32, 4, and 2 kHz), as well as modified brain FA profiles compared to the IS + PUFA siblings.

DISCUSSION

The present study reveals that siblings born from dams exposed to a moderate IDA diet including balanced physiological LC-PUFA levels during pregnancy and lactation demonstrate minor impairments of ABR compared to the control siblings, particularly on the auditory acuity, but not on neural synchrony, auditory nerve velocity and BTT.

Prenatal Iron Deficiency in Guinea Pigs Increases Locomotor Activity but Does Not Influence Learning and Memory

The objective of the current study was to determine whether prenatal iron deficiency induced during gestation in guinea pigs affected locomotor activity and learning and memory processes in the progeny. Dams were fed either iron-deficient anemic or iron-sufficient diets throughout gestation and lactation. After weaning, all pups were fed an iron-sufficient diet. On postnatal day 24 and 40, the pups’ locomotor activity was observed within an open-field test, and from postnatal day 25 to 40, their learning and memory processes were assessed within a Morris Water Maze. The behavioural and cognitive tests revealed that the iron deficient pup group had increased locomotor activity, but solely on postnatal day 40, and that there were no group differences in the Morris Water Maze. In the general discussion, we propose that prenatal iron deficiency induces an increase in nervousness due to anxiety in the progeny, which, in the current study, resulted in an increase of locomotor activity.

Molecular mechanisms of cognitive impairment in iron deficiency: alterations in brain-derived neurotrophic factor and insulin-like growth factor expression and function in the central nervous system

OBJECTIVE

The present review examines the relationship between iron deficiency and central nervous system (CNS) development and cognitive impairment, focusing on the cellular and molecular mechanisms related to the expression and function of growth factors, particularly the insulin-like growth factors I and II (IGF-I/II) and brain-derived neurotrophic factor (BDNF), in the CNS.

METHODS

Nutritional deficiencies are important determinants in human cognitive impairment. Among these, iron deficiency has the highest prevalence worldwide. Although this ailment is known to induce psychomotor deficits during development, the precise molecular and cellular mechanisms underlying these alterations have not been properly elucidated. This review summarizes the available information on the effect of iron deficiency on the expression and function of growth factors in the CNS, with an emphasis on IGF-I/II and BDNF.

RESULTS AND DISCUSSION

Recent studies have shown that specific growth factors, such as IGF-I/II and BDNF, have an essential role in cognition, particularly in processes involving learning and memory, by the activation of intracellular-signaling pathways involved in cell proliferation, differentiation, and survival. It is known that nutritional deficiencies promote reductions in systemic and CNS concentrations of growth factors, and that altered expression of these molecules and their receptors in the CNS leads to psychomotor and developmental deficits. Iron deficiency may induce these deficits by decreasing the expression and function of IGF-I/II and BDNF in specific areas of the brain.

Iron Biofortification and Homeostasis in Transgenic Cassava Roots Expressing the Algal Iron Assimilatory Gene, FEA1

We have engineered the tropical root crop cassava (Manihot esculenta) to express the Chlamydomonas reinhardtii iron assimilatory gene, FEA1, in its storage roots with the objective of enhancing the root nutritional qualities. Iron levels in mature cassava storage roots were increased from 10 to 36 ppm in the highest iron accumulating transgenic lines. These iron levels are sufficient to meet the minimum daily requirement for iron in a 500 g meal. Significantly, the expression of the FEA1 gene in storage roots did not alter iron levels in leaves. Transgenic plants also had normal levels of zinc in leaves and roots consistent with the specific uptake of ferrous iron mediated by the FEA1 protein. Relative to wild-type plants, fibrous roots of FEA1 expressing plants had reduced Fe (III) chelate reductase activity consistent with the more efficient uptake of iron in the transgenic plants. We also show that multiple cassava genes involved in iron homeostasis have altered tissue-specific patterns of expression in leaves, stems, and roots of transgenic plants consistent with increased iron sink strength in transgenic roots. These results are discussed in terms of strategies for the iron biofortification of plants.

Prevalence of anemia among Quebec Cree infants from 2002 to 2007 compared with 1995 to 2000

OBJECTIVE

To determine if screening of infants for anemia at 9 months in the Cree region of Quebec should continue,by comparing the prevalence of anemia in the initial years of screening (1995 to 2000) with prevalence data from infants screened between 2002 and 2007.

DESIGN

Comparison of anemia prevalence from 2 cross-sectional surveys. Nonoverlapping 95% CIs were used to determine if results were significantly different.

SETTING

Nine Quebec Cree communities. Participants Infants screened for anemia between 1995 and 2000 (n = 716) or 2002 and 2007 (n = 1325). Main outcome measures Anemia was diagnosed based on hemoglobin concentration. An erythrocyte mean cell volume of less than 71 fL was used as a proxy for iron deficiency.

RESULTS

Hemoglobin concentration among infants screened from 2002 to 2007 was, on average, 7 g/L greater than among infants screened from 1995 to 2000 (mean [standard deviation] 121 [11] g/L vs 114 [11] g/L). The prevalence of anemia (hemoglobin < 110 g/L) from 1995 to 2000 was 31.7% (95% CI 28.3% to 35.1%), but from 2002 to 2007 it was significantly lower at 12.5% (95% CI 10.7% to 14.2%). Using a hemoglobin concentration more specific to iron deficiency anemia (IDA) (hemoglobin < 100 g/L), from 1995 to 2000 7.5% (95% CI 5.6% to 9.4%) of infants had IDA, whereas from 2002 to 2007 only 2.0% (95% CI 1.2% to 2.8%) had IDA. The prevalence of iron deficiency based on mean cell volume declined from 18.3% (95% CI 15.5% to 21.1%) from 1995 to 2000 to 4.2% (95% CI 3.1% to 5.3%) from 2002 to 2007.

CONCLUSION

The 12.5% prevalence of anemia (hemoglobin < 110 g/L) among Cree infants from 2002 to 2007 was much lower than the prevalence from 1995 to 2000 but somewhat higher than among nonaboriginal infants (8.0%). The low anemia prevalence among Quebec Cree infants after 2002 suggests that replacing universal screening with targeted screening of higher-risk infants needs to be considered following studies to identify risk factors for anemia.

Relationship between maternal DHA and iron status and infants' cognitive performance

PURPOSE

The dietary nutrients iron and long-chain polyunsaturated fatty acids are believed to play an important role in early brain development. We investigated the relationship between pregnant women's iron and docosahexaenoic acid (DHA) status and their infants' cognitive performance at age six months.

METHODS

Blood iron and DHA status were analyzed in pregnant women at 28 to 32 weeks of gestation. The women's dietary habits, sociodemographic background, and cognitive performance were assessed using questionnaires. At age six months, infants' blood hemoglobin was analyzed, feeding practices assessed, and weight, length, and head circumference recorded. Each infant's cognitive performance was assessed using the Brunet-Lézine Scale of Psychomotor Development of Early Childhood and the Bayley Scales of Infant Development. Sixty-three mother-infant dyads completed the study.

RESULTS

During pregnancy, 9.5% of pregnant women were anemic, 34.9% had low iron stores, and 3.2% suffered from iron deficiency anemia. The DHA represented 4.36% and 2.15% in erythrocyte and plasma total fatty acids, respectively. These levels were considered adequate. No significant relationship was observed between gestational iron or DHA status and infants' cognitive performance.

CONCLUSIONS

In this small group of infants born to mothers with relatively good feeding practices and a privileged socioeconomic background, cognitive testing with the instruments above was not associated with maternal iron and DHA levels at age six months.

Maternal iron deficiency alters essential fatty acid and eicosanoid metabolism and increases locomotion in adult guinea pig offspring

Iron deficiency (ID) is the most prevalent worldwide nutritional deficiency. Groups at risk of developing ID anemia are infants and pregnant women, even in industrialized countries. Our goal in this study was to evaluate the long-term consequences of maternal ID on the offspring's fatty acid and eicosanoid metabolism, behavior, and spatial memory. Female guinea pigs consumed iron-sufficient (IS) and -deficient (ID) diets for 14 d before mating and throughout pregnancy and lactation. Dietary iron restriction resulted in ID in pregnant females. On postnatal d 9, all offspring (ID and IS) were weaned to the IS diet and at 42 d, all offspring were iron replete. Locomotion was tested in pups on postnatal d 24 and 40 and spatial memory from d 25 to 40. Pups from the ID group were significantly more active in the open field at both times of testing, whereas spatial memory, tested in a Morris water maze, was comparable in both groups. On postnatal d 42, liver, RBC, and brain fatty acid composition were measured. Dihomogammalinolenic [20:3(n-6)], docosapentaenoic [22:5(n-3)], and docosahexaenoic [22:6(n-3)] acid contents were significantly higher in brain phospholipids of offspring born to ID dams. Prostaglandin E(2) and F(2alpha) concentrations were also significantly higher in brains of offspring born to ID dams. This demonstrates that moderate ID during gestation and lactation results in alterations of brain fatty acid and eicosanoid metabolism and perturbation in behavior in adult offspring.

Maternal iron deficiency and its effect on essential fatty acid and eicosanoid metabolism and spatial memory in the guinea pig offspring

Iron deficiency is prevalent among infants and pregnant women in industrialized country. The goal of this study was to evaluate the impact of moderate maternal iron deficiency on the offspring's fatty acid and eicosanoid metabolism and spatial memory in guinea pigs. An iron-sufficient (IS) or iron-deficient (ID) diet was fed 14 days before mating and throughout pregnancy and lactation. The pups were tested for spatial memory on post-natal days 4-7. On post-natal day 9, the biochemical analysis included the pup's brain fatty acid profiles, prostaglandin (PGE(2) and PGF(2alpha)) concentrations and cyclooxygenase II protein levels. Spatial memory and indices of eicosanoid metabolism were comparable in both dietary groups. However, n-3 fatty acids were significantly higher (p<0.05) in brain of pups from the ID group. The data suggest that maternal iron deficiency results in a modification of the fatty acid profile of the offspring's brain that is not associated with any spatial memory deficits during early development.

Iron deficiency anemia following prenatal nutrition interventions

PURPOSE

Iron deficiency anemia (IDA) during pregnancy and infancy is still common in developed countries, especially in low-income groups. We examined the prevalence of anemia and IDA in healthy low-income pregnant women participating in the Early Childhood Initiatives (ECI) program, and in their infants when they reached six months of age.

METHODS

Pregnant women were recruited by nutritionists. In mothers, hemoglobin (Hb), mean corpuscular volume, and serum ferritin (SF) were measured at 36 +/- 2 weeks of gestation. In infants, Hb, mean corpuscular volume, SF, serum iron, total iron binding capacity (TIBC), and transferrin saturation (TS) were measured at six months of age. Thirty-one mother-infant pairs participated.

RESULTS

Among the 31 pregnant women participating in the ECI program, six (19.4%) were anemic (Hb <110 g/L) and five (16.1%) suffered from IDA (Hb <110 g/L and SF <10 microg/L). Among infants, seven of 23 (30.4%) were anemic (Hb <110 g/L) and five of 23 (21.7%) suffered from IDA (Hb <110 g/L plus two of the following: TIBC >60 micromol/L, SF <10 microg/L, serum iron <5.3 micromol/L, TS < or = 15%).

CONCLUSIONS

The prevalence of anemia in this group of low-income pregnant women is comparable to that in privileged women. The prevalence of IDA in infants is comparable to that observed in other high-risk groups. Effective strategies are needed to prevent IDA in vulnerable groups.

Is there a link between postpartum anemia and discontinuation of breastfeeding?

PURPOSE

Factors associated with early cessation of breastfeeding were identified and patterns of infant feeding were examined. Feeding practices were compared with the 1998 guidelines in Nutrition for Healthy Term Infants and with recent Health Canada recommendations.

METHODS

To recruit participants, a letter was sent to every mother (n=424) who gave birth at Dr. Georges-L. Dumont Regional Hospital in Moncton from April 1998 to February 1999. Eighty-five mothers agreed to participate with their infants. Information on infant feeding patterns and socioeconomic background was gathered with semi-structured questionnaires. Only healthy infants from singleton pregnancies were included in this study.

RESULTS

At birth, almost 83% of infants were breastfed. The proportions of infants breastfed for at least four, six, and nine months were 43%, 22%, and 9%, respectively. As many as 34% of infants were introduced to baby cereals before age four months, and 21% were introduced to cow's milk before age nine months. Lower family income, lower level of parental education, and reduced postpartum hemoglobin level (below 95 g/L) were associated with discontinuation of breastfeeding before infants were four months old.

CONCLUSIONS

Early postpartum nutrition interventions may be effective in ensuring follow-up care for mothers with compromised iron status, in supporting breastfeeding for at least six months, and in promoting better infant feeding practices.

Does inadequate maternal iron or DHA status have a negative impact on an infant's functional outcomes?

Marginal intake of iron and omega-3 long-chain fatty acids (DHA) is prevalent among pregnant women. It is not clear to what extent poor iron or DHA status during pregnancy impacts on an infant's functional outcomes. A few studies suggest that inadequate maternal iron or DHA status may be associated with suboptimal functional outcomes in infants. In addition, there is a lack of prospective studies using randomized, double-blind design or experimental studies with appropriate animal models. Although both nutrients are involved in early brain development and their metabolism is interrelated, no study has examined the interaction between iron and omega-3 fatty acids during pregnancy.

CONCLUSION

Long-term studies on large cohorts of pregnant women and their infants are needed to determine whether inadequate iron or DHA status during pregnancy is detrimental to infant neurodevelopment.

Iron bioavailability in prenatal multivitamin supplements with separated and combined iron and calcium

OBJECTIVE

To compare iron absorption of a prenatal multivitamin supplement containing both iron and calcium (HICA) to that of another multivitamin containing a lower iron dose and no calcium (LI).

METHODS

In a crossover study, serum iron was measured in 12 healthy women administered HICA and LI separately on 2 different occasions. Blood samples were taken at 0, 1, 2, 3, 4, 6, and 8 hours after administration of each supplement.

RESULTS

The values of the area under the concentration-time curve (AUC) were not significantly different between LI (79.1 +/- 36.0 micro M*h) and HICA (91.4 +/- 50.4 micro M*h) (P =.37). After standardizing the AUC for dose, the relative absorption over the 8-hour time period was significantly higher for LI (2.3 +/-.0 micro M*h/mg) than for HICA (1.5 +/- 0.8 micro M*h/mg) (P =.021).

CONCLUSION

The absorption of iron from a low-iron-containing supplement was similar to that from a supplement with almost twice the amount of iron, due possibly to the exclusion of calcium in the LI product. Thus, while offering similar amounts of iron, the LI supplement may be better tolerated by women who are sensitive to iron-induced adverse effects.

Iron, ferritin, and nutrition

Ferritin, a major form of endogenous iron in food legumes such as soybeans, is a novel and natural alternative for iron supplementation strategies where effectiveness is limited by acceptability, cost, or undesirable side effects. A member of the nonheme iron group of dietary iron sources, ferritin is a complex with Fe3+ iron in a mineral (thousands of iron atoms inside a protein cage) protected from complexation. Ferritin illustrates the wide range of chemical and biological properties among nonheme iron sources. The wide range of nonheme iron receptors matched to the structure of the iron complexes that occurs in microorganisms may, by analogy, exist in humans. An understanding of the chemistry and biology of each type of dietary iron source (ferritin, heme, Fe2+ ion, etc.), and of the interactions dependent on food sources, genes, and gender, is required to design diets that will eradicate global iron deficiency in the twenty-first century.

Haematological problems in pregnancy

PURPOSE OF REVIEW

Haematological disorders of pregnancy are common reasons for referral. It is reasonable then to devote a review to recent publications on these issues.

RECENT FINDINGS

Several narrative reviews on the management of venous thromboembolic disease in pregnancy provide exceptional guidance. They highlight, however, that most of what is done is still based on opinions from highly qualified people, extrapolated from the non-pregnant literature but not involving randomized trials on pregnant patients. It is apparent that a consensus is nearing on the management of both pregnancy-related thrombocytopenia and idiopathic (immune) thrombocytopenic purpura. Several randomized controlled trials are reported on the treatment of non-deficiency anaemia, using oral iron, intravenous iron and erythropoietin, which contribute to the debate on the appropriate and best intervention for this common problematic issue.

SUMMARY

This review demonstrates the need for appropriately sized randomized trials on haematological issues in pregnancy. With heparin becoming the most common medication being administered prophylactically and therapeutically in pregnancy, it is important that quality trials are performed to guide its sensible utilization.