Association of oral iron supplementation with birth outcomes in non-anaemic South Indian pregnant women

Effect of Prenatal Iron Supplementation Adapted to Hemoglobin Levels in Early Pregnancy on Fetal and Neonatal Growth-ECLIPSES Study

In this randomized clinical trial, we evaluated the effects of prenatal iron supplementation adapted to pregnant women's initial hemoglobin (Hb) levels on fetal growth parameters until birth in women from the Mediterranean coast of northern Spain. All (n = 791) women were iron-supplemented during pregnancy according to Hb levels at the 12th gestational week: stratum 1 (Hb: 110-130 g/L) received 40 or 80 mg iron daily; stratum 2 (Hb > 130 g/L) received 40 or 20 mg iron daily. Fetal biometric and anthropometric measurements were evaluated in the three trimesters and at birth, respectively. In stratum 1, using 80 mg/d instead of 40 mg/d increased the risk of fetal head circumference > 90th percentile (OR = 2.49, p = 0.015) at the second trimester and fetal weight (OR = 2.36, p = 0.011) and femur length (OR = 2.50, p = 0.018) < 10th percentile at the third trimester. For stratum 2, using 40 mg/d instead of 20 mg/d increased the risk of fetal head circumference > 90th percentile (OR = 3.19, p = 0.039) at the third trimester. A higher risk of delivering an LGA baby (OR = 2.35, p = 0.015) for birthweight was also observed in stratum 1 women receiving 80 mg/d. It is crucial to adjust the prenatal iron supplementation to each pregnant woman's needs, i.e., adapted to their initial Hb levels, to achieve optimal fetal development, since excessive iron doses appear to adversely influence fetal growth.

High Iron Exposure from the Fetal Stage to Adulthood in Mice Alters Lipid Metabolism

Iron supplementation is recommended during pregnancy and fetal growth. However, excess iron exposure may increase the risk of abnormal fetal development. We investigated the potential side effects of high iron levels in fetuses and through their adult life. C57BL/6J pregnant mice from 2 weeks of gestation and their offspring until 30 weeks were fed a control (CTRL, FeSO₄ 0 g/1 kg) or high iron (HFe, FeSO₄ 9.9 g/1 kg) diets. HFe group showed higher iron accumulation in the liver with increased hepcidin, reduced TfR1/2 mRNAs, and lowered ferritin heavy chain (FTH) proteins in both liver and adipose tissues despite iron loading. HFe decreased body weight, fat weight, adipocyte size, and triglyceride levels in the blood and fat, along with downregulation of lipogenesis genes, including PPARγ, C/EBPα, SREBP1c, FASN, and SCD1, and fatty acid uptake and oxidation genes, such as CD36 and PPARα. UCP2, adiponectin, and mRNA levels of antioxidant genes such as GPX4, HO-1, and NQO1 were increased in the HFe group, while total glutathione was reduced. We conclude that prolonged exposure to high iron from the fetal stage to adulthood may decrease fat accumulation by altering ferritin expression, adipocyte differentiation, and triglyceride metabolism, resulting in an alteration in normal growth.

Materno-fetal iron transfer and the emerging role of ferroptosis pathways

A successful pregnancy and the birth of a healthy baby depend to a great extent on the controlled supply of essential nutrients via the placenta. Iron is essential for mitochondrial energy supply and oxygen distribution via the blood. However, its high reactivity requires tightly regulated transport processes. Disturbances of maternal-fetal iron transfer during pregnancy can aggravate or lead to severe pathological consequences for the mother and the fetus with lifelong effects. Furthermore, high intracellular iron levels due to disturbed gestational iron homeostasis have recently been associated with the non-apoptotic cell death pathway called ferroptosis. Therefore, the investigation of transplacental iron transport mechanisms, their physiological regulation and potential risks are of high clinical importance. The present review summarizes the current knowledge on principles and regulatory mechanisms underlying materno-fetal iron transport and gives insight into common pregnancy conditions in which iron homeostasis is disturbed. Moreover, the significance of the newly emerging ferroptosis pathway and its impact on the regulation of placental iron homeostasis, oxidative stress and gestational diseases will be discussed.

Iron Fortification through Universal Distribution of Double-Fortified Salt Can Increase Wages and Be Cost-Effective: An Ex-Ante Modeling Study in India

BACKGROUND

The alleviation of iron deficiency through iron supplementation has not effectively reduced anemia in India, mainly due to low compliance. Food fortification with iron is considered a viable alternative, and the provision of double-fortified salt (DFS; with iron and iodine) has been mandated in public health programs. Limited evidence exists on its benefit-cost ratio.

OBJECTIVE

In this study we sought to estimate the economic benefit in terms of increased wages in relation to introduction of DFS in reduction of anemia and the cost of doing so.

METHODS

The economic benefit of introducing DFS in India was derived using a series of mathematical, statistical, and econometric models using data from national surveys capturing earnings and dietary iron intake of the population. Anemia status was predicted from data on dietary intake, sanitation, and for women, menstrual losses. The impact of iron deficiency anemia (IDA) on wages was estimated using a Heckman Selection model and 2-stage least squares procedure. Benefit of DFS was estimated through increased wages attributed to anemia reduction compared with its cost.

RESULTS

Men and women with IDA had lower wages (by 25.9%, 95% CI: 11.3, 38.1; and by 3.9%, 95% CI: 0.0, 7.7, respectively) than those without IDA. Additional iron intake through DFS was predicted to reduce prevalence of IDA (from 10.6% to 0.7% in men and 23.8% to 20.9% in women). The economic benefit-cost ratio of introducing DFS at a national level was estimated to be 4.2:1.

CONCLUSIONS

Iron fortification delivered through DFS under a universal program can improve wages and be sufficiently cost-effective for its implementation at scale in India.

The relationship between markers of antenatal iron stores and birth outcomes differs by malaria prevention regimen-a prospective cohort study

BACKGROUND

Iron deficiency (ID) has been associated with adverse pregnancy outcomes, maternal anaemia, and altered susceptibility to infection. In Papua New Guinea (PNG), monthly treatment with sulphadoxine-pyrimethamine plus azithromycin (SPAZ) prevented low birthweight (LBW; <2500 g) through a combination of anti-malarial and non-malarial effects when compared to a single treatment with SP plus chloroquine (SPCQ) at first antenatal visit. We assessed the relationship between ID and adverse birth outcomes in women receiving SPAZ or SPCQ, and the mediating effects of malaria infection and haemoglobin levels during pregnancy.

METHODS

Plasma ferritin levels measured at antenatal enrolment in a cohort of 1892 women were adjusted for concomitant inflammation using C-reactive protein and α-1-acid glycoprotein. Associations of ID (defined as ferritin <15 μg/L) or ferritin levels with birth outcomes (birthweight, LBW, preterm birth, small-for-gestational-age birthweight [SGA]) were determined using linear or logistic regression analysis, as appropriate. Mediation analysis assessed the degree of mediation of ID-birth outcome relationships by malaria infection or haemoglobin levels.

RESULTS

At first antenatal visit (median gestational age, 22 weeks), 1256 women (66.4%) had ID. Overall, ID or ferritin levels at first antenatal visit were not associated with birth outcomes. There was effect modification by treatment arm. Amongst SPCQ recipients, ID was associated with a 81-g higher mean birthweight (95% confidence interval [CI] 10, 152; P = 0.025), and a twofold increase in ferritin levels was associated with increased odds of SGA (adjusted odds ratio [aOR] 1.25; 95% CI 1.06, 1.46; P = 0.007). By contrast, amongst SPAZ recipients, a twofold increase in ferritin was associated with reduced odds of LBW (aOR 0.80; 95% CI 0.67, 0.94; P = 0.009). Mediation analyses suggested that malaria infection or haemoglobin levels during pregnancy do not substantially mediate the association of ID with birth outcomes amongst SPCQ recipients.

CONCLUSIONS

Improved antenatal iron stores do not confer a benefit for the prevention of adverse birth outcomes in the context of malaria chemoprevention strategies that lack the non-malarial properties of monthly SPAZ. Research to determine the mechanisms by which ID protects from suboptimal foetal growth is needed to guide the design of new malaria prevention strategies and to inform iron supplementation policy in malaria-endemic settings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01136850 .

Perspective: When the cure might become the malady: the layering of multiple interventions with mandatory micronutrient fortification of foods in India

When public health programs with single nutrients are perceived to have a poor impact on the target health outcome, the policy response can be to supply more, by layering additional mandatory programs upon the extant programs. However, we argue for extreme caution, because nutrients (like medicines) are beneficial in the right dose, but potentially harmful when ingested in excess. Unnecessary motivations for the reactionary layering of multiple intervention programs emerge from incorrect measurements of the risk of nutrient inadequacy in the population, or incorrect biomarker cutoffs to evaluate the extent of nutrient deficiencies. The financial and social costs of additional layered programs are not trivial when traded off with other vital programs in a resource-poor economy, and when public health ethical dilemmas of autonomy, equity, and stigma are not addressed. An example of this conundrum in India is the perception of stagnancy in the response of the prevalence of anemia to the ongoing pharmacological iron supplementation program. The reaction has been a policy proposal to further increase iron intake through mandatory iron fortification of the rice provided in supplementary feeding programs like the Integrated Child Development Services and the School Mid-Day Meal. This is in addition to the ongoing pharmacological iron supplementation as well as other voluntary iron fortifications, such as those of salt and manufactured food products. However, before supplying more, it is vital to consider why the existing program is apparently not working, along with consideration of the potential for excess intake and related harms. This is relevant globally, particularly for countries contemplating multiple interventions to address micronutrient deficiencies. Supplying more by layering multiple nutrient interventions, instead of doing it right, without thoughtful considerations of social, biological, and ethics frameworks could be counterproductive. The cure, then, might well become the malady.

Iron status in late pregnancy is inversely associated with birth weight in Colombia

OBJECTIVE

Gestational anaemia (GA) is common in developing countries. This study assessed the relationship of late GA and negative perinatal outcomes in participants recruited in a reference maternity unit of the Caribbean region of Colombia.

DESIGN

Prospective analytical birth cohort study. Maternal Hb and serum ferritin (SF) levels were measured. GA was defined as Hb levels <6·82 mmol/l (<11 g/dl), SF depletion as SF levels <12 µg/l. Birth outcomes such as low birth weight (LBW), preterm birth (PB) and small for gestational age (SGA) were examined.

SETTING

Mothers in the first stage of labour, living in urban or rural areas of Bolívar, were enrolled in an obstetrical centre located in Cartagena, Colombia. Blood and stool samples were taken prior delivery. Maternal blood count, SF levels and infant anthropometric data were recorded for analysis.

PARTICIPANTS

1218 pregnant women aged 18-42 years and their newborns.

RESULTS

Prevalence of GA and SF depletion was 41·6 % and 41·1 %, respectively. GA was positively associated with poverty-related sociodemographic conditions. Prenatal care attendance lowered the risk of PB, LBW and SGA. Birth weight was inversely associated with Hb levels, observing a -36·8 g decrease in newborn weight per 0·62 mmol/l (or 1 g/dl) of maternal Hb. SF depletion, but not anaemia, was associated with PB. SGA outcome showed a significant association with anaemia, but not a significant relationship with SF depletion.

CONCLUSIONS

Birth weight and other-related perinatal outcomes are negatively associated with Hb and SF depletion. Prenatal care attendance reduced the risk of negative birth outcomes.

Association between maternal plasma ferritin level and infants' size at birth: a prospective cohort study in rural Bangladesh

Background: Iron supplementation in pregnancy is recommended by the WHO to prevent a major public health problem, namely, maternal iron deficiency and its consequences. There are gaps in the existing evidence regarding maternal and neonatal benefits and harms of universal iron supplementation.

Objective: To evaluate the association between maternal iron status during pregnancy and infant size at birth (birth weight and length).

Method: This present prospective cohort study was nested in a food and micronutrient supplementation trial conducted in Matlab (MINIMat study), rural Bangladesh. We randomly selected 573 women recruited into the MINIMat study from January – December 2002 who delivered singletons with available birth anthropometric information. The plasma ferritin of each mother was measured at gestational week 14 (GW14; before the start of micronutrient supplementation) and at week 30 (GW30).

Results: Multivariable linear regression revealed no association between plasma ferritin at GW14 and birth weight. However, newborns of women in the highest tertile of plasma ferritin at GW30 (median = 29 µg/L) had on average a 93-gm lower birth weight (95% CI: −172, – 14; p = 0.021) than the newborns of women in the lowest tertile (median = 8 µg/L). Logistic regression showed that odds of low birth weight were approximately two times higher [odds ratio (OR) = 2.27; 95% CI: 1.40, 3.67] among those with mothers in the highest ferritin tertile than in the lowest tertile at GW30. No association was found between maternal plasma ferritin and birth length.

Conclusion: We observed an inverse association between high plasma ferritin in the last trimester (GW30) and birth weight but not birth length. The results suggested that elevated plasma ferritin in pregnancy could have an untoward effect on birth weight.

Association between Iron Supplementation, Dietary Iron Intake and Risk of Moderate Preterm Birth: A Birth Cohort Study in China

Background:

To evaluate the independent and collective effects of maternal iron supplementation and dietary iron intake upon the risk of moderate preterm birth and its subtypes.

Methods:

In this birth cohort study, 1019 pregnant women with moderate preterm birth and 9160 women with term birth were recruited at Gansu Provincial Maternity and Child Care Hospital from 2010–2012 in China. Unconditional logistic regression models were utilized to evaluate the association between maternal iron supplementation, dietary iron intake, and the risk of moderate preterm birth and its subtypes.

Results:

Compared with non-users, iron supplement users exerted a protective effect upon the overall (OR=0.54, 95%CI=0.40–0.72) and spontaneous moderate preterm birth (OR=0.39, 95%CI=0.33–0.83). Compared with the 25^th quartiles of dietary iron intake, either before or during pregnancy, it exerted a significantly protective effect upon those who had the highest quartiles of dietary iron intake (OR=0.87, 95%CI=0.82–0.95 for the highest quartiles of dietary iron intake before pregnancy OR=0.85, 95%CI=0.79–0.91). Positive association was observed between the additive scale and multiplicative scale for preterm birth, spontaneous preterm rather than medically indicated preterm.

Conclusion:

Iron supplements (60 mg/day) and high-iron intake (>25.86 mg/day before pregnancy, >30.46 mg/day during pregnancy) reduced the risk of moderate preterm birth. Positive correlation is found between the additive scale and multiplicative scale for preterm birth, spontaneous preterm birth.

Oxidative Stress at Birth Is Associated with the Concentration of Iron and Copper in Maternal Serum

Oxidative stress (OS) in the foetal and neonatal periods leads to many disorders in newborns and in later life. The nutritional status of pregnant women is considered to be one of the key factors that triggers OS. We investigated the relationship between the concentration of selected mineral elements in the blood of pregnant women and the concentration of 3′nitrotyrosine (3′NT) as a marker of OS in the umbilical cord blood of newborns. The study group consisted of 57 pregnant women and their newborn children. The concentrations of magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn) and copper (Cu) in maternal serum (MS) were measured by the flame atomic absorption/emission spectrometry (FAAS/FAES) method. The concentration of 3′NT in umbilical cord serum (UCS) of newborns was determined by the ELISA method. A positive correlation between MS Fe and UCS 3′NT in male newborns was shown (rho = 0.392, p = 0.053). Significantly higher UCS 3′NT was demonstrated in newborns, especially males, whose mothers were characterized by MS Fe higher than 400 μg/dL compared to those of mothers with MS Fe up to 300 μg/dL (p < 0.01). Moreover, a negative correlation between the MS Cu and UCS 3′NT in male newborns was observed (rho = −0.509, p = 0.008). Results of the study showed the need to develop strategies to optimize the nutritional status of pregnant women. Implementation of these strategies could contribute to reducing the risk of pre- and neonatal OS and its adverse health effects in the offspring.

Effect of hepcidin antagonists on anemia during inflammatory disorders

Iron is an essential element for the mammalian body however, its homeostasis must be regulated accurately for appropriate physiological functioning. Alterations in physiological iron levels can lead to moderate to severe iron disorders like chronic and acute iron deficiency (anemia) or iron overload. Hepcidin plays an important role in regulating homeostasis between circulating iron and stored iron in the cells as well as the absorption of dietary iron in the intestine. Inflammatory disorders restrict iron absorption from food due to increased circulating levels of hepcidin. Increased production of hepcidin causes ubiquitination of ferroportin (FPN) leading to its degradation, thereby retaining iron in the spleen, duodenal enterocytes, macrophages, and hepatocytes. Hepcidin inhibitors and antagonists play a consequential role to ameliorate inflammation-associated anemia. Many natural and synthesized compounds, able to reduce hepcidin expression during inflammation have been identified in recent years. Few of which are currently at various phases of clinical trial. This article comprises a comprehensive review of therapeutic approaches for the efficient treatment of anemia associated with inflammation. Many strategies have been developed targeting the hepcidin-FPN axis to rectify iron disorders. Hepcidin modulation with siRNAs, antibodies, chemical compounds, and plant extracts provides new insights for developing advanced therapeutics for iron-related disorders. Hepcidin antagonist's treatment has a high potential to improve iron status in patients with iron disorders, but their clinical success needs further recognition along with the identification and application of new therapeutic approaches.

Maternal iron-deficiency is associated with premature birth and higher birth weight despite routine antenatal iron supplementation in an urban South African setting: The NuPED prospective study

Background

Recent studies are suggesting a U-shaped relationship between antenatal iron exposure and birth outcomes. Little is known about the iron status and associated birth outcomes of pregnant women in South Africa. Our aim was to assess iron status at early, mid- and late pregnancy, and to determine associations with gestational age and birth weight in women in Johannesburg, South Africa.

Methods

In this prospective study of 250 pregnant women, we measured haemoglobin, biomarkers of iron status and inflammation at <18, 22 and 36 weeks of gestation, plus birth weight and gestational age at delivery. Associations of anaemia and iron status with birth outcomes were determined using regression models adjusted for confounders.

Results

At enrolment, the prevalence of anaemia, iron depletion (ID) and iron deficiency erythropoiesis (IDE) was 29%, 15% and 15%, respectively, and increased significantly with pregnancy progression. Anaemia and ID at 22 weeks, as well as IDE at 36 weeks were associated with higher birth weight (β = 135.4; 95% CI: 4.8, 266.1 and β = 205.4; 95% CI: 45.6, 365.1 and β = 178.0; 95% CI: 47.3, 308.7, respectively). Women in the lowest ferritin quartile at 22 weeks gave birth to babies weighing 312 g (95% CI: 94.8, 528.8) more than those in the highest quartile. In contrast, IDE at 22 weeks was associated with a higher risk for premature birth (OR: 3.57, 95% CI: 1.24, 10.34) and women in lower haemoglobin quartiles at <18 weeks had a shorter gestation by 7 days (β = -6.9, 95% CI: -13.3, -0.6) compared to those in the highest quartile.

Conclusion

Anaemia, ID and IDE prevalence increased during pregnancy despite routine iron supplementation. ID and anaemia at mid-pregnancy were associated with higher birth weight, while IDE was associated with premature birth. These results suggest that current antenatal screening and supplementation practices in South Africa need to be revisited.

The Impact of Iron Overload and Ferroptosis on Reproductive Disorders in Humans: Implications for Preeclampsia

Iron is an essential element for the survival of most organisms, including humans. Demand for iron increases significantly during pregnancy to support growth and development of the fetus. Paradoxically, epidemiologic studies have shown that excessive iron intake and/or high iron status can be detrimental to pregnancy and is associated with reproductive disorders ranging from endometriosis to preeclampsia. Reproductive complications resulting from iron deficiency have been reviewed elsewhere. Here, we focus on reproductive disorders associated with iron overload and the contribution of ferroptosis-programmed cell death mediated by iron-dependent lipid peroxidation within cell membranes-using preeclampsia as a model system. We propose that the clinical expressions of many reproductive disorders and pregnancy complications may be due to an underlying ferroptopathy (elemental iron-associated disease), characterized by a dysregulation in iron homeostasis leading to excessive ferroptosis.

Maternal iron intake during pregnancy and the risk of small for gestational age

Studies of iron and its association with the risk of small for gestational age (SGA) show inconsistent results. Consuming iron supplements during pregnancy is controversial because of possible risks. This study assessed the association between iron intake and the risk of having an SGA newborn and whether iron intake is associated with gestational diabetes. A case-control study of 518 pairs of Spanish women who were pregnant and attending five hospitals was conducted. Groups were matched 1:1 for age (±2 years) and hospital. Cases were women with an SGA newborn at delivery. Controls were women with normal-sized newborns at delivery. Data were gathered on demographic characteristics, socio-economic status, adverse habits (like smoking), and diet. A 137-item food frequency questionnaire was completed. Iron intakes were categorized in quintiles (Q1-Q5). Crude odds ratios (ORs) and adjusted ORs (aORs) with 95% confidence intervals (CIs) were estimated by conditional logistic regression. No significant relationship was found between dietary iron intake and SGA. A protective association was found for women receiving iron supplementation >40 mg/day and SGA versus women not taking supplements (aOR = 0.64, 95% CI [0.42, 0.99]). This association was identified in mothers both with (aOR = 0.57, 95% CI [0.40, 0.81]) and without (aOR = 0.64, 95% CI [0.64, 0.97]) anaemia. In women in the control group without anaemia, iron supplementation >40 mg/day was positively associated with gestational diabetes (aOR = 6.32, 95% CI [1.97, 20.23]). Iron supplementation in pregnancy may prevent SGA independently of existing anaemia but may also increase the risk of gestational diabetes.

Estimation of protein requirements in Indian pregnant women using a whole-body potassium counter

BACKGROUND

The 2007 World Health Organization/Food and Agriculture Organization/United Nations University (WHO/FAO/UNU) recommendation for the Estimated Average Requirement (EAR) of additional protein during pregnancy for a gestational weight gain (GWG) of 12 kg (recalculated from a GWG of 13.8 kg) is 6.7 and 21.7 g/d in the second and the third trimester, respectively. This EAR is based on measurements of potassium accretion in high-income country (HIC) pregnant women. It is not known if low- to middle-income country, but well-nourished, pregnant women have comparable requirements.

OBJECTIVE

We aimed to estimate total body potassium (TBK) accretion during pregnancy in Indian pregnant women, using a whole-body potassium counter (WBKC), to measure their additional protein EAR.

METHODS

Well-nourished pregnant women (20-40 y, n = 38, middle socioeconomic stratum) were recruited in the first trimester of pregnancy. Anthropometric, dietary, and physical activity measurements, and measurements of TBK using a WBKC, were performed at each trimester and at birth.

RESULTS

The mid-trimester weight gain was 2.7 kg and 8.0 kg in the second and the third trimester, respectively, for an average 37-wk GWG of 10.7 kg and a mean birth weight of 3.0 kg. Protein accretion was 2.7 and 5.7 g/d, for an EAR of 8.2 and 18.9 g/d in the second and the third trimester, respectively. The additional protein EAR, calculated for a GWG of 12 kg, was 9.1 and 21.2 g/d in the second and the third trimester, respectively.

CONCLUSION

The additional protein requirements of well-nourished Indian pregnant women for a GWG of 12 kg in the second and third trimesters were similar to the recalculated 2007 WHO/FAO/UNU requirements for 12 kg.

Association between violence during pregnancy and preterm birth and low birth weight in Colombia: Analysis of the demographic and health survey

To explore the association between low birth weight and preterm birth with violence during pregnancy, we conducted a cross-sectional study by using the 2010 Colombian Demographic and Health Survey. We conducted bivariate analyses, binomial logistic regression, and stratified models by age, and 14,520 women were included. There was no association between violence and low birth weight. Nonetheless, an association with preterm birth in women aged over 35 was observed (OR 1.98, 95%CI 1.23, 3.17). Prenatal care appeared to be a protective factor for both outcomes. This research unexpectedly showed that supplementation with folic acid and iron was associated with preterm birth.

Iron supplementation during pregnancy - a cross-sectional study undertaken in four German states

Background

Iron deficiency but also iron overload during pregnancy has been associated with unwanted health effects. In Germany, iron supplements are only recommended for pregnant women with diagnosed iron deficiency/anaemia. Prevalence of anaemia among pregnant women was reported at 24.4% in 2011. However, limited data suggest that more than 60% of women in Germany use iron supplements during gestation. Against this background, we investigated the prevalence of iron supplement intake among pregnant women and explored determining factors in order to assess whether women are following the advice to only supplement iron in case of a diagnosed iron deficiency/anaemia.

Methods

A cross-sectional study was carried out in four German states in 2015 where, with the help of midwives, women in childbed were asked to retrospectively answer a questionnaire about iron intake from various sources and reasons for supplementing iron during their recent pregnancy. We used Chi-square-tests and logistic regression analysis to evaluate associations between iron supplementation and other nutritional, sociodemographic and maternal variables and to assess attitudes of women meeting versus not meeting the official recommendation on iron supplement intake during pregnancy.

Results

Of 207 participants, 65.2% had supplemented iron. 84.4% reported to have done this because of a diagnosed iron deficiency/anaemia. Iron intake ranged from 5 to 200 mg/day, and duration of supplementation varied between two weeks and throughout gestation. Of women who reported to have been diagnosed with iron deficiency/anaemia, 47.5% had supplemented ≥80 mg/day iron, while 26.2% had taken iron in lower amounts ≤40 mg/day. Six percent of the participating women had not supplemented iron in spite of a diagnosed iron deficiency/anaemia, whereas 19.7% of women without iron deficiency/anaemia still had supplemented iron (range: 7 to 80 mg/day).

Conclusion

The majority of pregnant women used iron supplements in case of a diagnosed iron deficiency/anaemia. However, not all women with iron deficiency/anaemia supplemented (sufficient amounts of) iron, while there was also indiscriminate use of iron supplements in women without iron deficiency/anaemia. Further research is warranted to confirm these findings in representative samples.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-2130-5) contains supplementary material, which is available to authorized users.

U-shaped curve for risk associated with maternal hemoglobin, iron status, or iron supplementation

Both iron deficiency (ID) and excess can lead to impaired health status. There is substantial evidence of a U-shaped curve between the risk of adverse birth outcomes and maternal hemoglobin concentrations during pregnancy; however, it is unclear whether those relations are attributable to conditions of low and high iron status or to other mechanisms. We summarized current evidence from human studies regarding the association between birth outcomes and maternal hemoglobin concentrations or iron status. We also reviewed effects of iron supplementation on birth outcomes among women at low risk of ID and the potential mechanisms for adverse effects of high iron status during pregnancy. Overall, we confirmed a U-shaped curve for the risk of adverse birth outcomes with maternal hemoglobin concentrations, but the relations differ by trimester. For low hemoglobin concentrations, the link with adverse outcomes is more evident when hemoglobin concentrations are measured in early pregnancy. These relations generally became weaker or nonexistent when hemoglobin concentrations are measured in the second or third trimesters. Associations between high hemoglobin concentration and adverse birth outcomes are evident in all 3 trimesters but evidence is mixed. There is less evidence for the associations between maternal iron status and adverse birth outcomes. Most studies used serum ferritin (SF) concentrations as the indicator of iron status, which makes the interpretation of results challenging because SF concentrations increase in response to inflammation or infection. The effect of iron supplementation during pregnancy may depend on initial iron status. There are several mechanisms through which high iron status during pregnancy may have adverse effects on birth outcomes, including oxidative stress, increased blood viscosity, and impaired systemic response to inflammation and infection. Research is needed to understand the biological processes that underlie the U-shaped curves seen in observational studies. Reevaluation of cutoffs for hemoglobin concentrations and indicators of iron status during pregnancy is also needed.

Effects of different regimens of iron prophylaxis on maternal iron status and pregnancy outcome: a randomized control trial

PURPOSE

Iron supplementation is associated with side effects and overload risk. We compared different regimens of iron supplementation on maternal hematological status and pregnancy outcome in a cohort of healthy pregnant women.

MATERIALS AND METHODS

Eighty non-anemic women with a normal singleton pregnancy were recruited at 11-13 weeks and randomized into controls (C; n = 20) and groups supplemented with ferrous iron 30 mg (FI; n = 20), liposomal iron 14 mg (Sideral® Pharmanutra, Pisa PI, Italy) (LI14; n = 20) and liposomal iron 28 mg/daily (LI28; n = 20) up to 6 weeks post-partum. Longitudinal maternal blood samples for iron markers were collected. Data on birth outcome were recorded. The treatment effect was evaluated using a mixed-effect regression model.

RESULTS

Both LI28 and LI14 groups showed significantly higher hemoglobin and ferritin concentrations compared with controls. Birth weight showed a trend to increase with supplementation, resulting in higher birth weight in the LI28 group compared with controls (3499 ± 464.1 g and 3092 ± 469.5 g, respectively, p < 0.01).

CONCLUSIONS

Our data show the effectiveness of 28 mg and 14 mg LI on maternal anemia prevention, as previously reported with FI 40 mg. LI has similar effects of higher doses of ferrous iron on maternal hematological parameters, thus allowing to reduce iron doses and side effects.

Oxidative stress during early pregnancy and birth outcomes

Objective

Routine high-dose Fe supplementation in non-anaemic pregnant women may induce oxidative stress and eventually affect birth outcomes. The aim of the present study was to measure oxidative stress markers in pregnant women with low/normal and high Hb values in trimester 1 (Hb1) and to relate these to birth weight.

Design

A cross-sectional study where selected oxidative stress markers were analysed in both maternal (trimester 1; T1) and cord blood samples and correlated with birth weight.

Setting

A tertiary hospital in urban South India.

Subjects

One hundred women were chosen based on their Hb1 values (forty women with low/normal Hb1 (<110 g/l) and sixty women with high Hb1 (≥120 g/l)).

Results

In T1, women with high Hb1 values were found to have lower paraoxonase-1 (PON-1) activity (424·7 (sd 163·7) v. 532·9 (sd 144·7) pmol p-nitrophenol formed/min per ml plasma, P=0·002) and higher lipid peroxides compared with women with low/normal Hb1. Routine supplementation of Fe to these women resulted in persistent lower PON-1 activity in cord blood (P=0·02) and directionally lower (P=0·142) birth weights. Furthermore, women with high Hb1 who delivered low-birth-weight babies were observed to have lowest PON-1 activity in T1. No changes were observed in other markers (myeloperoxidase activity and total antioxidant levels).

Conclusions

Routine Fe supplementation in pregnant women with high Hb1 associated with increased oxidative stress, as reflected by low PON-1 activity in T1, could potentially lead to deleterious effects on birth weight.

Rankings of iron, vitamin D, and calcium intakes in relation to maternal characteristics of pregnant Canadian women

Iron, vitamin D, and calcium intakes in the prenatal period are important determinants of maternal and fetal health. The objective of this study was to examine iron, vitamin D, and calcium intakes from diet and supplements in relation to maternal characteristics. Data were collected in a subsample of 1186 pregnant women from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a cohort study including pregnant women recruited from 10 Canadian sites between 2008 and 2011. A food frequency questionnaire was administered to obtain rankings of iron, calcium, and vitamin D intake (16-21 weeks of pregnancy). Intakes from supplements were obtained from a separate questionnaire (6-13 weeks of pregnancy). Women were divided into 2 groups according to the median total intake of each nutrient. Supplement intake was an important contributor to total iron intake (median 74%, interquartile range (IQR) 0%-81%) and total vitamin D intake (median 60%, IQR 0%-73%), while the opposite was observed for calcium (median 18%, IQR 0%-27%). Being born outside of Canada was significantly associated with lower total intakes of iron, vitamin D, and calcium (p ≤ 0.01 for all). Consistent positive indicators of supplement use (iron, vitamin D, and calcium) were maternal age over 30 years and holding a university degree. In conclusion, among Canadian women, the probability of having lower iron, vitamin D, and calcium intakes is higher among those born outside Canada; supplement intake is a major contributor to total iron and vitamin D intakes; and higher education level and age over 30 years are associated with supplement intake.