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

Preconceptional micronutrient adequacy among women in Greece: a prospective epidemiological study

INTRODUCTION

The importance of micronutrient intake during the preconceptional and early pregnancy period for both maternal and fetal outcomes is well-known, however, relevant data are not available for Greek pregnant women. The aim of the present study is to delineate the nutritional status preceding conception among a representative cohort of Greek pregnant women.

METHODS

This was a prospective study of pregnant women from routine care, recruited at 11+0-13+6 gestational weeks, between December 2020 and October 2022, at the 3rd Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Greece. Eligible participants for the study included healthy pregnant women aged 20 years or older, possessing a proficient understanding of the Greek language, and not engaged in specific nutritional programs. A validated Food Frequency Questionnaire was applied to gather information regarding nutritional habits in the last 6 months prior to conception. The consumption of nutrients was compared to the reference intake levels suggested by the European Food Safety Authority. Further analyses between different participants' subgroups were performed.

RESULTS

Overall, 1100 pregnant women (mean age: 32.4 ± 4.9 years) were enrolled. Almost all examined micronutrients' intake was significantly different from dietary reference values. Furthermore, nutrient adequacy ratio was below 60% in 6 out of 22 micronutrients examined, and Mean Adequacy Ratio was 93%. However, Mean Adequacy Ratio is characterized by extreme variance between the examined values. Iodine, folic acid, potassium, and vitamin D intake levels were significantly lower than the recommended intake levels (p < .001 for all), while vitamin K and niacin (p < .001 for both) were consumed in great extent. Sodium median intake, without calculating extra salt addition also exceeded the reference value levels (p = .03). Notably, magnesium intake exceeded the upper safety limits in 12.4% of the sample.

CONCLUSION

Potential inadequacies in important micronutrients for uneventful pregnancy outcomes have been revealed.. Special attention is needed for magnesium to balance possible toxicity with evident benefits.

Maternal hemoglobin drop in multiple pregnancy is associated with higher gestational age at birth and birthweight

INTRODUCTION

This retrospective study investigated the hypothesis that maternal hemoglobin (Hb) levels in twin pregnancy fall between the first and second trimesters and that higher falls are associated with higher gestational age at birth and higher birthweight (BW).

MATERIAL AND METHODS

The study population was defined as pregnant women with twin pregnancies delivering two live, phenotypically normal neonates, after 24+0 weeks of gestation, between October 2009 and September 2021 at an inner London maternity unit. Maternal Hb and mean corpuscular volume (MCV), at ≤14+0 weeks of gestation (Hb1) and again at 20+0-30+0 weeks gestation (Hb2) were recorded from the Hospital's perinatal database. MCV was used as a possible indicator of iron deficiency anemia. The association of Hb drop, defined as [Hb1(adjusted for gestational age) - Hb2], and MCV values with gestational age at birth, BW of both twins and delivery of small for gestational age (SGA) neonates, defined as BW <10th percentile for gestation, was evaluated.

RESULTS

923 pregnant women with twin pregnancies were included. Maternal Hb1 did not correlate with any outcomes measured. However, a lower Hb2 and a larger Hb drop was associated with a higher gestational age at birth (p < 0.001), a larger BW of twin 1 and 2 (p < 0.001 for both) and a reduction in the incidence of delivering one or two SGA neonates (p < 0.001 for both). MCV values did not correlate significantly with these outcomes.

CONCLUSIONS

This study showed that in twin pregnancy, a larger maternal Hb drop from the first to the second trimester is associated with a higher gestational age at birth and a larger BW. This change may represent a larger plasma volume expansion.

The impact of hematology electronic consultations on the management of iron deficiency

OBJECTIVES

Delays in the evaluation and treatment of iron deficiency can lead to increased disease-related morbidity and mortality. Electronic consultation (e-consult) is a referral modality that allows providers quicker access to recommendations from a specialist based on electronic chart review. While the use of e-consult is expanding in classical hematology, gaps exist in the understanding of patient outcomes related to its use for iron deficiency.

METHODS

We randomly selected 200 e-consults and 200 traditional referrals from 3,336 hematology referrals for iron deficiency at a single center. The primary outcomes of the retrospective analysis were: time to completion of the referral, and time to treatment with intravenous iron. Secondary outcomes included recurrence of iron deficiency, need for repeat e-consult, conversion to in-person evaluation, and assessment of whether the etiology of iron deficiency was addressed.

RESULTS

E-consults significantly reduced the time from referral to intravenous iron repletion (e-consult, 33 days; traditional referral, 68 days; p < .05). Assessment of the underlying etiology occurred in 70.7% of the e-consult encounters compared to 92.5% of traditional referrals (p < .05).

CONCLUSIONS

These findings highlight advantages of e-consults in improving care delivery in iron deficiency, and identifying gaps that can be improved through practice standardization to ensure equitable, high-value care.

Pregnancy Outcomes After Bariatric Surgery: Importance of Maternal Ferritin on Birth Weight

PURPOSE

The risks carried by pregnancy after bariatric surgery (BS) include small-for-gestational age (SGA) newborn and prematurity. However, the underlying mechanisms are not yet fully understood in pregnant women after BS.

MATERIAL AND METHODS

This single-center retrospective observational cohort study includes all women with a first and single pregnancy after BS who completed at least one clinical and biological nutritional assessment during pregnancy between 2010 and 2016. The quarterly biological assessment comprised blood count, ferritin, calcium, 25OH vitamin D, parathyroid hormone, fasting glucose, albumin, prealbumin, vitamin A, vitamin B12, folic acid, and zinc.

RESULTS

Among 120 pregnancies analysed, two-thirds underwent gastric bypass (Roux-en-Y and one-anastomosis) and one-third a restrictive procedure (adjustable gastric band or sleeve gastrectomy). The median [Q1-Q3] preoperative BMI was 43.8 [41.1-47.7] kg/m2 and the mean age at pregnancy was 32.6 ± 5.3 years. Weight loss and time from surgery to pregnancy were 35.1 ± 15.4 kg and 2.9 [1.3-4.5] years, respectively. Ten women (8%) gave birth prematurely, and 22 newborns (19%) were SGA. Univariate analysis shows that ferritin was significantly higher in mothers with SGA than in those without SGA (35.5 [22.3-69.5] vs. 15 [10-32] ng/ml) at third trimester of pregnancy. Women who received pre-pregnancy nutritional assessment seemed less likely to give birth to a SGA newborn (32% vs. 54%, p = 0.07).

CONCLUSION

Iron supplementation should be carefully prescribed and closely monitored during pregnancy in women who have undergone BS.

The crosstalk between cell death and pregnancy related diseases: A narrative review

Programmed cell death is intricately linked to various physiological phenomena such as growth, development, and metabolism, as well as the proper function of the pancreatic β cell and the migration and invasion of trophoblast cells in the placenta during pregnancy. Traditional and recently identified programmed cell death include apoptosis, autophagy, pyroptosis, necroptosis, and ferroptosis. In addition to cancer and degenerative diseases, abnormal activation of cell death has also been implicated in pregnancy related diseases like preeclampsia, gestational diabetes mellitus, intrahepatic cholestasis of pregnancy, fetal growth restriction, and recurrent miscarriage. Excessive or insufficient cell death and pregnancy related diseases may be mutually determined, ultimately resulting in adverse pregnancy outcomes. In this review, we systematically describe the characteristics and mechanisms underlying several types of cell death and their roles in pregnancy related diseases. Moreover, we discuss potential therapeutic strategies that target cell death signaling pathways for pregnancy related diseases, hoping that more meaningful treatments will be applied in clinical practice in the future.

Differential dietary intake and contribution of ultra-processed foods during pregnancy according to nutritional status

Introduction

Frequent consumption of ultra-processed foods (UPFs) during pregnancy is linked to excess intake of added sugar, fat, and sodium and inadequacy of several micronutrients. Diet quality during pregnancy should be maximized as inadequate levels of key nutrients and excessive intake of energy and added sugar might influence mother-child health. We aimed to estimate the contribution (% of total calories) of ultra-processed products to the total energy intake by pre-gestational body mass index (BMI) categories and Hb status during pregnancy in participants from the MAS-Lactancia Cohort.

Methods

Pre-gestational weight, hemoglobin levels, 24-h dietary intake recall interviews, and sociodemographic data were collected during the second and third trimesters of pregnancy. Reported consumed foods were categorized using the NOVA classification, and the contribution of calories from each NOVA category was estimated using the Mexican Food Database. We estimated medians and interquartile ranges (p25 and p75) for dietary intake and energy contributions. The comparison of intake between the second and third trimesters was done using the Wilcoxon test. In addition, a quantile regression model with an interaction between pre-gestational BMI and Hb levels status in tertiles over the percentage of energy from UPFs was adjusted by age and socioeconomic status.

Results

The contribution to total energy intake from UPFs was 27.4% in the second trimester and 27% in the third trimester (with no statistical difference). The percentage of energy intake from UPFs was higher in women who started pregnancy with obesity and presented the lowest levels of Hb (1st tertile), 23.1, 35.8, and 44.7% for the 25th, 50th, and 75th percentiles, respectively, compared to those with normal BMI and the highest tertile of Hb levels: 18, 29.0, and 38.6% for the 25th, 50th, and 75th percentiles, respectively.

Conclusion

In conclusion, UPF intake in pregnant women is similar to the general population and was higher for those with pre-gestational obesity and the lowest tertile of Hb levels. UPF contributes also to sugar, saturated fat, and sodium, which may adversely affect the health of mothers and their offspring.

Scientific opinion on the tolerable upper intake level for iron

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the tolerable upper intake level (UL) for iron. Systematic reviews were conducted to identify evidence regarding high iron intakes and risk of chronic diseases, adverse gastrointestinal effects and adverse effects of iron supplementation in infancy, young childhood and pregnancy. It is established that systemic iron overload leads to organ toxicity, but no UL could be established. The only indicator for which a dose-response could be established was black stools, which reflect the presence of large amounts of unabsorbed iron in the gut. This is a conservative endpoint among the chain of events that may lead to systemic iron overload but is not adverse per se. Based on interventions in which black stools did not occur at supplemental iron intakes of 20-25 mg/day (added to a background intake of 15 mg/day), a safe level of intake for iron of 40 mg/day for adults (including pregnant and lactating women) was established. Using allometric scaling (body weight0.75), this value was scaled down to children and adolescents and safe levels of intakes between 10 mg/day (1-3 years) and 35 mg/day (15-17 years) were derived. For infants 7-11 months of age who have a higher iron requirement than young children, allometric scaling was applied to the supplemental iron intakes (i.e. 25 mg/day) and resulted in a safe level of supplemental iron intake of 5 mg/day. This value was extended to 4-6 month-old infants and refers to iron intakes from fortified foods and food supplements, not from infant and follow-on formulae. The application of the safe level of intake is more limited than a UL because the intake level at which the risk of adverse effects starts to increase is not defined.

The Role of Fresh Beef Intake and Mediterranean Diet Adherence during Pregnancy in Maternal and Infant Health Outcomes

Beef is an excellent source of nutrients important for maternal health and fetal development. It is also true that the Mediterranean diet is beneficial for the health of both the mother and offspring; however, the relative value of fresh beef intake within Mediterranean diet patterns during pregnancy is unknown. The objective of this project was two-fold: (1) assess the relationship between beef intake and nutrient intake in a pregnant population; (2) assess the relationship between maternal beef consumption among varying degrees of Mediterranean diet adherence with maternal risk of anemia and infant health outcomes. This is a secondary analysis of an existing cohort of pregnant women (n = 1076) who participated in one of two completed clinical trials examining the effect of a docosahexaenoic acid supplementation on birth and offspring outcomes. Women were enrolled between 12 and 20 weeks of gestation and were followed throughout their pregnancies to collect maternal and infant characteristics, food frequency questionnaires [providing beef intake and Mediterranean diet (MedD) adherence], and supplement intake. Women with the highest fresh beef intake had the highest intake of many micronutrients that are commonly deficient among pregnant women. Fresh beef intake alone was not related to any maternal or infant outcomes. There was a reduced risk of anemia among women with medium to high MedD quality and higher fresh beef intake. Women in the medium MedD group had 31% lower odds of anemia, and women in the high MedD group had 38% lower odds of anemia with every one-ounce increase in fresh beef intake, suggesting that diet quality indices may be misrepresenting the role of fresh beef within a healthy diet. These findings show that beef intake increases micronutrient intake and may be protective against maternal anemia when consumed within a healthy Mediterranean diet pattern.

Association between maternal hemoglobin concentration and educational attainment in mid-childhood in a high-resource obstetric setting: a prospective cohort study

BACKGROUND

Although maternal hemoglobin levels during pregnancy are commonly associated with perinatal outcomes, their link to childhood neurodevelopment remains uncertain.

OBJECTIVE

This study aimed to examine the associations between maternal hemoglobin in early and late pregnancy and the educational attainment of offspring mid-childhood in a high-resource obstetric setting.

STUDY DESIGN

Pregnancy data from a prospective birth cohort (Pregnancy Outcome Prediction Study, Cambridge, United Kingdom, 2008-2012, N=3285) were linked to mid-childhood educational outcomes (Department for Education, United Kingdom). Regression models adjusted for maternal, child, and socioeconomic factors were used to determine associations between maternal hemoglobin, pregnancy complications, and offspring educational outcomes (aged 5-7 years).

RESULTS

No association was observed between maternal hemoglobin at 12 weeks and the likelihood of either adverse pregnancy outcomes or children meeting expected educational standards between ages 5-7 years. Higher maternal hemoglobin at 28 weeks was associated with an increased risk of small-for-gestational-age infants (adjusted odds ratio, 1.26 [95% confidence interval, 1.11-1.59]; P=.002) and preterm birth (adjusted odds ratio, 1.38 [95% confidence interval, 1.11-1.81]; P=.005). There were no adverse birth outcomes associated with anemia. However, children of mothers who were anemic at 28 weeks had ∼40% increased risk of not attaining expected educational standards at age 5 (adjusted odds ratio, 1.42 [95% confidence interval, 1.03-1.95]; P=.03). There was no association between maternal anemia at 28 weeks and educational performance at ages 6-7. No associations were found between high maternal hemoglobin concentrations (top decile) or change in hemoglobin concentrations between 12 and 28 weeks and childhood educational attainment.

CONCLUSION

Maternal anemia at 28 weeks of pregnancy is associated with reduced educational attainment at 5 years old but not at older ages (6-7 years old). A proactive approach to increasing maternal hemoglobin in high-resource settings is unlikely to impact long-term childhood educational attainment.

Relationship between prepregnancy BMI and the concentrations of iron, calcium, and magnesium in serum and hair during the first trimester of pregnancy in women

BACKGROUND

In women of childbearing age, a low dietary supply of iron, calcium, and magnesium is often observed. Minerals deficiency in pregnant women is often associated with abnormal body weight and may impact fetal development disorders. The aim of this study is to determine the relationship between prepregnancy body mass index (BMI) and the dietary intake of iron, calcium and magnesium and their concentrations in serum and hair in pregnant women.

METHOD

The study involved 97 Caucasian/white low-risk pregnant women at 12 weeks of gestation. The analysis of minerals in serum and hair samples was performed using atomic absorption spectrometry. Pre-pregnancy BMI was calculated based on self-reported weight. The study used a validated questionnaire and a 24-h recall nutrition interview, which were analyzed using Aliant software.

RESULTS

It was found that overweight and obese women exhibited higher magnesium concentration in serum, while iron content in serum and hair was markedly lower compared to women with normal body weight. The average total supply of iron was below the recommendation in pregnant women. Moreover, an inverse significant relationship was observed between BMI and iron concentration in hair and serum in the whole population.

CONCLUSION

In conclusion, being overweight or obese before pregnancy is associated with low dietary iron intake and low iron concentration in serum and hair during the first trimester of pregnancy in women.

Anemia in Pregnancy With CKD

Chronic kidney disease (CKD), anemia, and iron deficiency are global health issues affecting individuals in both high-income and low-income countries. In pregnancy, both CKD and iron deficiency anemia increase the risk of adverse maternal and neonatal outcomes, including increased maternal morbidity and mortality, stillbirth, perinatal death, preterm birth, and low birthweight. However, it is unknown to which extent iron deficiency anemia contributes to adverse outcomes in CKD pregnancy. Furthermore, little is known regarding the prevalence, pathophysiology, and treatment of iron deficiency and anemia in pregnant women with CKD. Therefore, there are many unanswered questions regarding optimal management with oral or i.v. iron and recombinant human erythropoietin (rhEPO) in these women. In this review, we present a short overview of the (patho)physiology of anemia in healthy pregnancy and in people living with CKD. We present an evaluation of the literature on iron deficiency, anemia, and nutritional deficits in pregnant women with CKD; and we evaluate current knowledge gaps. Finally, we propose research priorities regarding anemia in pregnant women with CKD.

Epigenetic modifications in the ferroptosis pathway in cord blood cells from newborns of smoking mothers and their influence on fetal growth

Maternal smoking during pregnancy increases oxidative stress and decreases antioxidant capacity in newborns. Uncontrolled oxidative stress plays a role in fetal development disorders and in adverse perinatal outcomes. In order to identify molecular pathways involved in low fetal growth, epigenetic modifications in newborns of smoking and non-smoking mothers were examined. Low birth weight newborns of mothers who smoked more than 10 cigarettes per day during the first trimester of pregnancy and normal birth weight newborns of mothers who did not smoke during pregnancy were included in the study. DNA was extracted from umbilical cord blood of term newborns. 125 differentially methylated regions were identified by MeDIP-Seq. Functional analysis revealed several pathways, such as ferroptosis, that were enriched in differentially methylated genes after prenatal smoke exposure. GPX4 and PCBP1 were found to be hypermethylated and associated with low fetal growth. These epigenetic modifications in ferroptosis pathway genes in newborns of smoking mothers can potentially contribute to intrauterine growth restriction through the induction of cell death via lipid peroxidation of cell membranes. The identification of epigenetic modifications in the ferroptosis pathway sheds light on the potential mechanisms underlying the pathophysiology of low birth weight in infants born to smoking mothers.

Anaemia in the first trimester and poor physiological plasma expansion during pregnancy negatively impact foetal weight and newborn anthropometrics: An observational cohort study in Tanzania

OBJECTIVES

Anaemia during pregnancy is a major health challenge affecting pregnancy outcome worldwide. The objectives of this study were to investigate the impact of severe-moderate anaemia in the first trimester, as well as changes in haemoglobin during pregnancy among non-anaemic women, on foetal weight, placental blood flow and newborn anthropometrics.

METHODS

In a prospective cohort study, 346 women residing in rural Tanzania were followed throughout pregnancy with serial ultrasound and newborn anthropometrics assessed within 24 h of delivery. Associations between placental blood flow, foetal weight and newborn anthropometrics with either first trimester severe-moderate anaemia (haemoglobin≤9.5 g/dL) or changes in haemoglobin from the first to the third trimester among non-anaemic women, were assessed by mixed model regression and multiple linear regression, adjusting for maternal and foetal co-variables. Foetal weights and birthweight were converted to z-scores using a population based sex-specific weight reference.

RESULTS

Severe-moderate anaemia in the first trimester was associated with significantly reduced foetal weight z-scores (adjusted mean difference (aMD) -0.44 (95% CI -0.81, -0.07)) and newborn anthropometric indices (birth weight z-score aMD -0.55 (-0.9, -0.13), abdominal circumference aMD -11 mm (95% CI -20, -3)). There were no association between first trimester severe-moderate anaemia and placental blood flow. Among women who were non-anaemic in the first trimester, women with the least reduction in haemoglobin (Δ ≥ -0.3 g/dL) delivered significantly smaller newborns (birthweight z-score aMD -0.55 (-0.91, -0.20), abdominal circumference aMD -10 mm (95% CI -17, -3), compared to women with the greatest reduction (Δ haemoglobin ≤ -1.4 g/dL)).

CONCLUSIONS

Severe-moderate anaemia in early pregnancy was associated with smaller newborn anthropometrics which was reflected in smaller mean foetal weights in the second and third trimester. Furthermore, among women who were non-anaemic in the first trimester, there was an association between smaller newborn anthropometrics and limited haemoglobin decrease during pregnancy, possibly reflecting insufficient plasma expansion.

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.

Is It Time to Alter the Standard of Care for Iron Deficiency/Iron Deficiency Anemia in Reproductive-Age Women?

Two billion people worldwide suffer from anemia, with reproductive-age women being disproportionately affected. Iron plays a crucial role in cellular function and impacts cognition, physical function, and quality of life. Iron deficiency (ID) and iron deficiency anemia (IDA) are associated with adverse effects on pregnancy and fetal development. Oral iron supplementation has been the standard treatment for decades, often producing sub-optimal outcomes. Many babies are still being born with ID and suffer adverse sequelae due to inadequate iron levels in the mothers. Is it time to consider a broad scale-up of parenteral iron as a new standard of care?

Prevalence of and risk factors for iron deficiency among pregnant women with moderate or severe anaemia in Nigeria: a cross-sectional study

BACKGROUND

Anaemia during pregnancy causes adverse outcomes to the woman and the foetus, including anaemic heart failure, prematurity, and intrauterine growth restriction. Iron deficiency anaemia (IDA) is the leading cause of anaemia and oral iron supplementation during pregnancy is widely recommended. However, little focus is directed to dietary intake. This study estimates the contribution of IDA among pregnant women and examines its risk factors (including dietary) in those with moderate or severe IDA in Lagos and Kano states, Nigeria.

METHODS

In this cross-sectional study, 11,582 women were screened for anaemia at 20-32 weeks gestation. The 872 who had moderate or severe anaemia (haemoglobin concentration < 10 g/dL) were included in this study. Iron deficiency was defined as serum ferritin level < 30 ng/mL. We described the sociodemographic and obstetric characteristics of the sample and their self-report of consumption of common food items. We conducted bivariate and multivariable logistic regression analysis to identify risk factors associated with IDA.

RESULTS

Iron deficiency was observed among 41% (95%CI: 38 - 45) of women with moderate or severe anaemia and the prevalence increased with gestational age. The odds for IDA reduces from aOR: 0.36 (95%CI: 0.13 - 0.98) among pregnant women who consume green leafy vegetables every 2-3 weeks, to 0.26 (95%CI: 0.09 - 0.73) among daily consumers, compared to those who do not eat it. Daily consumption of edible kaolin clay was associated with increased odds of having IDA compared to non-consumption, aOR 9.13 (95%CI: 3.27 - 25.48). Consumption of soybeans three to four times a week was associated with higher odds of IDA compared to non-consumption, aOR: 1.78 (95%CI: 1.12 - 2.82).

CONCLUSION

About 4 in 10 women with moderate or severe anaemia during pregnancy had IDA. Our study provides evidence for the protective effect of green leafy vegetables against IDA while self-reported consumption of edible kaolin clay and soybeans appeared to increase the odds of having IDA during pregnancy. Health education on diet during pregnancy needs to be strengthened since this could potentially increase awareness and change behaviours that could reduce IDA among pregnant women with moderate or severe anaemia in Nigeria and other countries.

Dietary intakes of iron, folate, and vitamin B12 during pregnancy and correlation with maternal hemoglobin and fetal growth: findings from the ROLO longitudinal birth cohort study

PURPOSE

Dietary micronutrient intakes of iron, folate and vitamin B12 are known to influence hemoglobin. Low maternal hemoglobin (maternal anemia) has been linked to low birthweight and other adverse health outcomes in the fetus and infant. Our primary aim was to explore relationships between maternal dietary micronutrient intakes, maternal full blood count (FBC) parameters and fetal abdominal circumference (AC) and estimated fetal weight (EFW) growth trajectories. Secondarily, we aimed to assess relationships between maternal dietary micronutrient intakes, maternal hemoglobin values and placental weight and birthweight.

METHODS

Mother-child pairs (n = 759) recruited for the ROLO study were included in this analysis. Maternal dietary micronutrient intakes were calculated from food diaries completed during each trimester of pregnancy. FBC samples were collected at 13- and 28-weeks' gestation. Fetal ultrasound measurements were recorded at 20- and 34-weeks' gestation. Growth trajectories for AC and EFW were estimated using latent class trajectory mixture models.

RESULTS

Dietary intakes of iron and folate were deficient for all trimesters. Mean maternal hemoglobin levels were replete at 13- and 28-weeks' gestation. Dietary iron, folate and vitamin B12 intakes showed no associations with fetal growth trajectories, placental weight or birthweight. Lower maternal hemoglobin concentrations at 28 weeks' gestation were associated with faster rates of fetal growth and larger placental weights and birthweights.

CONCLUSION

The negative association between maternal hemoglobin at 28 weeks' gestation and accelerated fetal and placental growth may be due to greater consumption of maternal iron and hemoglobin by fetuses' on faster growth trajectories in addition to placental biochemical responses to lower oxygen states.

Maternal anaemia and birth weight: a cross-sectional study from Jiangxi Province, China

BACKGROUND

Association between maternal haemoglobin (Hb) and low birth weight (LBW) remains a controversial topic, and data in China were sparse.

AIMS

We aimed to investigate the association between maternal Hb and LBW among pregnant women in Jiangxi Province, China.

METHODS

In this cross-sectional study, 1,029 participants were enrolled. Anaemia was classified according to World Health Organization's definition of anaemia in pregnancy. Logistic regression analysis was performed to evaluate the association between maternal Hb and LBW. Generalized additive model and smooth curve fitting (penalized spline method) were conducted to explore the exact shape of curve between them.

RESULTS

The overall prevalence of anaemia was 58.2% in our study. A significantly higher risk of LBW was found in moderate anaemia subjects (odds ratio [OR] = 2.93; 95% confidence interval [CI]: 1.16-5.31) and severe anaemia subjects (OR = 63.86; 95% CI: 25.66-158.90) compared with maternal Hb concentration >100 g/L. The fully adjusted smooth curve fitting presented an L-shaped association between the maternal Hb and LBW, with a turning point at about 110 g/L. Subgroup analyses showed that stronger associations between maternal Hb and LBW were detected in pregnant women with high education, long duration of gestation and multiple antenatal visits (all P for interaction <0.05).

CONCLUSIONS

Anaemia in delivering women was associated with an elevated risk of LBW and the risk increased with the severity of anaemia, especially among pregnant women with high education, long duration of gestation and multiple antenatal visits from Jiangxi Province, China.

Ferroportin expression and regulation in human placenta/fetal membranes: Implications for ferroptosis and adverse pregnancy outcomes

Iron overload is associated with pregnancy complications. Ferroportin (FPN) is the only known iron exporter in mammalian cells. We hypothesize that FPN is functionally important in ferrotopsis, a process of iron-dependent non-apoptotic programmed cell death, and may have a critical role to play in pregnancy success. We investigated the expression of FPN in placenta/fetal membranes by immunohistochemistry in tissues collected from pregnancies with/without preeclampsia (PE) and spontaneous preterm birth (SPTB). FPN was highly expressed in both trophoblasts and decidual cells found in placenta/fetal membranes. Staining was significantly reduced in fetal membranes from SPTB versus healthy pregnancies (P = 0.046). FPN expression in immortalized human endometrial stromal cells (HESC) increased with in vitro decidualization induction using 1 μM of medroxyprogesterone acetate and 0.5 mM of dibutyryl-cAMP. In addition, both HESC cells and immortalized extravillous trophoblast SW71 cells with FPN knockdown showed significant sensitivity to ferroptosis inducer, erastin (P < 0.001 and P = 0.009, respectively). The survival of both HESC and SW71 cells was not negatively affected by iron supplementation with ferric ammonium citrate in the medium. However, SW71 cells were more sensitive than HESC cells to physiologic iron in the presence of a non-lethal dose of erastin (P < 0.001). Taken together, our data demonstrating increased sensitivity of FPN knockdown HESC and SW71 cells to erastin and increased sensitivity of trophoblasts to iron overload under ferroptotic stress support the hypothesis that FPN protects against ferroptosis during pregnancy.

Biology of Anemia: A Public Health Perspective

Our goal is to present recent progress in understanding the biological mechanisms underlying anemia from a public health perspective. We describe important advances in understanding common causes of anemia and their interactions, including iron deficiency (ID), lack of other micronutrients, infection, inflammation, and genetic conditions. ID develops if the iron circulating in the blood cannot provide the amounts required for red blood cell production and tissue needs. ID anemia develops as iron-limited red blood cell production fails to maintain the hemoglobin concentration above the threshold used to define anemia. Globally, absolute ID (absent or reduced body iron stores that do not meet the need for iron of an individual but may respond to iron supplementation) contributes to only a limited proportion of anemia. Functional ID (adequate or increased iron stores that cannot meet the need for iron because of the effects of infection or inflammation and does not respond to iron supplementation) is frequently responsible for anemia in low- and middle-income countries. Absolute and functional ID may coexist. We highlight continued improvement in understanding the roles of infections and inflammation in causing a large proportion of anemia. Deficiencies of nutrients other than iron are less common but important in some settings. The importance of genetic conditions as causes of anemia depends upon the specific inherited red blood cell abnormalities and their prevalence in the settings examined. From a public health perspective, each setting has a distinctive composition of components underlying the common causes of anemia. We emphasize the coincidence between regions with a high prevalence of anemia attributed to ID (both absolute and functional), those with endemic infections, and those with widespread genetic conditions affecting red blood cells, especially in sub-Saharan Africa and regions in Asia and Oceania.

Accuracy of HemoCue301 portable hemoglobin analyzer for anemia screening in capillary blood from women of reproductive age in a deprived region of Northern Peru: An on-field study

OBJECTIVE

We aim to assess the accuracy and effectiveness of the HemoCue 301, a point-of-care (POC) device for measuring hemoglobin levels, and detecting anemia among individuals living in Tumbes, a rural, underserved area in Northern Peru.

METHODS

Baseline analysis of a clinical trial aimed at assessing the effect of multi-fortified bread (NCT05103709). Adult women with capillary blood HemoCue 301 readings below 12 g/dL were recruited in coastal city of Tumbes, Peru. A total of 306 women took part of the study, venous blood samples were taken and analyzed with an automated hematology analyzer. Serum samples were used to measure ferritin, serum iron and C reactive protein.

RESULTS

Capillary blood measured by the Hemocue 301 has a bias of 0.36 ± 0.93 g/dL respect to the automated Hb. More than 50% of women with normal ferritin values were classified as anemics according to the HemoCue 301. Automated Hb cut-off of 10.8 g/dL [AUC 0.82 (0.77-0.88)] had a specificity of 0.817 and a sensitivity 0.711 while with the HemoCue 301 cut-off of 11.1 g/dL [AUC 0.71 (0.62-0.79)] had a specificity of 0.697 and a sensitivity 0.688. The performance of the automated Hb cut-off was significantly better than the HemoCue (p<0.001).

CONCLUSION

Caution must be taken when using POC devices, especially with values around the threshold. Cut-off values found in our study could be used as surrogate means when no confirmatory tests are available. Clinical outcomes should be prioritized when diagnosing iron deficiency anemia in women of reproductive age to ensure proper diagnosis.

The Associations of Maternal Blood Hemoglobin and Serum Triglyceride Levels and the Risk of Preterm Delivery

The abnormal hemoglobin (HGB) and serum lipid concentrations during pregnancy will increase the risk of preterm delivery. Our study aimed to explore the correlation between prenatal HGB and serum lipid levels and preterm delivery. We enrolled 215 mother-infant pairs in a pilot cohort study. The logistic regression model and Restricted Cubic Spline model (RCS) were used to investigate the levels of prenatal blood HGB and serum lipid such as triglyceride (TG), total cholesterol, high-density lipoprotein, low density lipoprotein and preterm delivery. The results showed that moderate levels of prenatal blood HGB (OR=0.28; 95%CI: 0.10, 0.75, p-trend=0.018) and high level of serum TG (OR=0.29; 95%CI: 0.10, 0.84, p-trend=0.022) level were negatively associated with the risk of preterm delivery. The joint effect results showed that compared with lower level of prenatal blood HGB (≤123.13 g/l) and TG (≤3.7 mmol/l), we found that high levels prenatal blood HGB and serum TG (OR=0.32, 95%CI: 0.12, 0.89) had a negative association with the risk of preterm delivery. Moreover, prenatal blood HGB and serum TG levels had negative linear dose-effect relationships with the risk of preterm delivery in overall and girl group (p<0.05). Moderate levels of prenatal blood HGB and high level of serum TG were negatively associated with the risk of preterm delivery. The joint effect of high levels prenatal HGB and prenatal serum TG in the normal range were negatively correlated with preterm delivery. Moreover, the underlying mechanisms should be clarified in future studies.

Maternal gestational iron status and infant haematological and neurodevelopmental outcomes

Prevention of iron deficiency (ID), the most common micronutrient deficiency in infants and children, begins prenatally by ensuring adequate fetal loading. Adequate intrauterine iron status is crucial for normal fetal brain development, postnatal brain performance and prevention of early postnatal iron deficiency, particularly in infants fed exclusively human milk. Adequate fetal loading may be achieved in some cases through adequate maternal iron levels prior to pregnancy and oral iron supplementation during pregnancy. However, because so many women are iron-deficient leading up to pregnancy, coupled with the negative iron balance induced by pregnancy, a large number of women remain iron-deficient during pregnancy. More consistent iron-specific early screening and more effective iron delivery approaches are needed to solve this global problem.

Trace Elements Levels in Major Depressive Disorder-Evaluation of Potential Threats and Possible Therapeutic Approaches

The multifactorial etiology of major depressive disorder (MDD) includes biological, environmental, genetic, and psychological aspects. Recently, there has been an increasing interest in metallomic studies in psychiatry, aiming to evaluate the role of chosen trace elements in the MDD etiology as well as the progression of symptoms. This narrative review aims to summarize the available literature on the relationship between the concentration of chosen elements in the serum of patients with MDD and the onset and progression of this psychiatric condition. The authors reviewed PubMed, Web of Science, and Scopus databases searching for elements that had been investigated so far and further evaluated them in this paper. Ultimately, 15 elements were evaluated, namely, zinc, magnesium, selenium, iron, copper, aluminium, cadmium, lead, mercury, arsenic, calcium, manganese, chromium, nickel, and phosphorus. The association between metallomic studies and psychiatry has been developing dynamically recently. According to the results of current research, metallomics might act as a potential screening tool for patients with MDD while at the same time providing an assessment of the severity of symptoms. Either deficiencies or excessive amounts of chosen elements might be associated with the progression of depressive symptoms or even the onset of the disease among people predisposed to MDD.

The Associated Factors of Low Birthweight Among Term Singletons in Japan: A Pregnancy Birth Registry Analysis

BACKGROUND

Progress in reducing the global low birthweight (LBW) has been insufficient. Although the focus has been on preventing preterm birth, evidence regarding LBW in term births is limited. Despite its low preterm birth prevalence, Japan has a higher LBW proportion than other developed countries. This study aimed to examine the prevalence of LBW in term singleton births and its associated factors using a national database.

METHODS

We retrospectively analyzed the data of neonates registered in the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System who were born 2013-2017. Exclusion criteria included stillbirths, delivery after 42 gestational weeks, and missing data. Logistic regression analyses were performed to investigate the maternal and perinatal factors associated with LBW in term singletons using the data of 715,414 singleton neonates.

RESULTS

The overall prevalence of LBW was 18.3%, and 35.7% of LBWs originated from singleton term pregnancies. Multiple logistic regression analyses indicated that both modifiable and non-modifiable factors were independently associated with LBW in term neonates. The modifiable maternal factors included pre-pregnancy underweight, inadequate gestational weight gain, and smoking during pregnancy, while the non-modifiable factors included younger maternal age, nulliparity, hypertensive disorders of pregnancy, cesarean section delivery, female offspring, and congenital anomalies.

CONCLUSION

Using the Japanese pregnancy birth registry data, more than one-third of LBWs were found to originate from singleton term pregnancies. Both modifiable and non-modifiable factors were independently associated with LBW in term neonates. Prevention strategies on modifiable risk factor control will be effective in reducing LBW worldwide.

Association between maternal haemoglobin concentrations and maternal and neonatal outcomes: the prospective, observational, multinational, INTERBIO-21st fetal study

BACKGROUND

Anaemia in pregnancy is a global health problem with associated maternal and neonatal morbidity and mortality. We aimed to investigate the association between maternal haemoglobin concentrations during pregnancy and the risk of adverse maternal and neonatal outcomes.

METHODS

In this prospective, observational, multinational, INTERBIO-21st fetal study conducted at maternity units in Brazil, Kenya, Pakistan, South Africa, and the UK, we enrolled pregnant women (aged ≥18 years, BMI <35 kg/m2, natural conception, and singleton pregnancy) who initiated antenatal care before 14 weeks' gestation. At each 5±1 weekly visit until delivery, information was collected about the pregnancy, as well as the results of blood tests taken as part of routine antenatal care, including haemoglobin values. The outcome measures were maternal (gestational diabetes, pregnancy-induced hypertension, and preterm premature rupture of membranes) and neonatal outcomes (small for gestational age, preterm birth, and acute respiratory distress syndrome).

FINDINGS

Between Feb 8, 2012, and Nov 30, 2019, 2069 women (mean age 30·7 years [SD 5·0]) had at least one routinely haemoglobin concentration measured at 14-40 weeks' gestation, contributing 4690 haemoglobin measurements for the analysis. Compared with a haemoglobin cutoff of 110 g/L, the risk was increased more than two-fold for pregnancy-induced hypertension at haemoglobin concentrations of 170 g/L (risk ratio [RR] 2·29 [95% CI 1·19-4·39]) and higher, for preterm birth at haemoglobin concentrations of 70 g/L (RR 2·04 [95% CI 1·20-3·48]) and 165 g/L (RR 2·06 [95% CI 1·41-3·02]), and for acute respiratory distress syndrome at haemoglobin concentrations of 165 g/L (RR 2·84 [95% CI 1·51-5·35]). Trimester-specific results are also presented.

INTERPRETATION

Our data suggests that the current WHO haemoglobin cutoffs are associated with reduced risk of adverse maternal and neonatal outcomes. The current haemoglobin concentration cutoffs during pregnancy should not only consider thresholds for low haemoglobin concentrations that are associated with adverse outcomes but also define a threshold for high haemoglobin concentrations given the U-shaped relationship between haemoglobin concentration and adverse neonatal and maternal outcomes.

FUNDING

Bill & Melinda Gates Foundation.

Maternal Iron Status Is Dynamic Throughout Pregnancy and Might Predict Birth Outcomes in a Sex Dependent Manner: Results from the Alberta Pregnancy Outcomes and Nutrition (APrON) Cohort Study

BACKGROUND

Developmental responses to nutrient deprivation may differ by fetal sex. Despite this, relationships between maternal prenatal iron biomarkers and birth outcomes when stratifying by offspring sex are poorly described, especially in healthy cohorts.

OBJECTIVES

This study aimed to determine associations between maternal iron biomarkers and birth weights (BWs) and birth head circumferences (BHCs) among female and male newborns to assess whether the potential predictive ability of iron biomarkers on birth outcomes differs by offspring sex.

METHODS

The Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study recruited 2189 pregnant individuals from Calgary and Edmonton, Canada. Maternal blood was drawn at each trimester and 3 mo postpartum. Maternal serum ferritin (SF) concentrations were measured using chemiluminescent immunoassays and erythropoietin (EPO), hepcidin, and soluble transferrin receptor (sTfR) using enzyme-linked immunosorbent assays. Ratios of sTfR:SF and hepcidin:EPO were calculated and birth outcomes accessed through delivery records. Directed acyclic graphs informed multivariate regression models.

RESULTS

The risk of maternal iron deficiency increased throughout pregnancy because ∼61% showed depleted iron stores (SF < 15 μg/L) by the third trimester. Maternal hepcidin, SF, sTfR, and sTfR:SF concentrations changed across time (P < 0.01), and participants carrying female fetuses consistently (across 6 biomarkers) showed a lower iron status during the third trimester compared with those with male fetuses (P < 0.05). Higher maternal SF and hepcidin:EPO during the third trimester was associated with lower BWs in males (P = 0.006 for SF; P = 0.03 for hepcidin:EPO) and females (P = 0.02 for SF; P = 0.02 for hepcidin:EPO). There were additional inverse associations between BWs and third trimester maternal hepcidin (P = 0.03) and hemoglobin (P = 0.004) and between BHCs and maternal SF (second trimester; P < 0.05) and Hb (third trimester P = 0.02) but only in males.

CONCLUSIONS

Relationships between maternal iron biomarkers and BWs and BHCs may depend on the timing of pregnancy and offpsring sex. There was a high risk of third trimester iron storage depletion among generally healthy pregnant individuals.

Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis

INTRODUCTION

Effects of daily iron supplementation in iron replete pregnancy are unclear. This systematic review aimed to assess benefits and harms of oral iron supplements in pregnant women without anemia and iron deficiency.

MATERIAL AND METHODS

We predefined and registered a protocol in PROSPERO (CRD42020186210) and performed the review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. We searched for randomized clinical trials (RCTs) and observational studies comparing daily oral iron supplementation with no iron supplements in non-anemic iron replete pregnant women. Searches were conducted in MEDLINE (by PubMed), EMBASE (by OVID), Cochrane Library, and ClinicalTrials.gov from inception to September 2022 without language restrictions. Two authors independently screened records, extracted data, and assessed risk of bias using the revised Cochrane risk of bias tool (RoB2). One author read full-texts, assessed certainty of evidence by GRADE and conducted meta-analyses using a random-effects model. Primary outcomes included iron deficiency anemia, iron deficiency, hemoglobin >130 g/L, elevated iron status, small for gestational age newborns, low birthweight newborns, preterm birth, and congenital anomalies.

RESULTS

Eight RCTs (2822 women) but no observational studies were eligible for inclusion. Daily oral iron supplementation in pregnancy probably reduces iron deficiency anemia at term (risk ratio [RR]: 0.51, 95% confidence interval [CI]: 0.38-0.70; 4 RCTs, 1670 women; I2  = 13%; moderate-certainty evidence) and the incidence of low birthweight babies (RR: 0.30, 95% CI: 0.13-0.68; 2 RCTs, 361 infants; I2  = 0%; moderate-certainty evidence). In addition, it may reduce iron deficiency at term (RR: 0.74, 95% CI: 0.60-0.92; 4 RCTs, 1663 women; I2  = 58%; low-certainty evidence) and the incidence of small for gestational age babies (RR: 0.39, 95% CI: 0.17-0.86; 1 RCT, 213 infants; I2 not estimable; low-certainty evidence).

CONCLUSIONS

Daily iron supplementation in iron replete non-anemic pregnant women probably reduces the risk of maternal iron deficiency anemia at term and low birthweight.

Maternal hemoglobin and iron status in early pregnancy and risk of respiratory tract infections in childhood: A population-based prospective cohort study

BACKGROUND

Maternal hemoglobin and iron status measures during pregnancy might affect the developing fetal respiratory system leading to adverse respiratory conditions. Our aim was to assess the associations of maternal hemoglobin and iron status measures during pregnancy with the risk of respiratory tract infections in children until 10 years of age.

METHODS

In a population-based cohort study among 5134 mother-child pairs, maternal hemoglobin and iron status including ferritin, transferrin, and transferrin saturation were measured during early pregnancy. In children, physician-attended respiratory tract infections from age 6 months until 10 years were assessed by questionnaires. Confounder-adjusted generalized estimating equation modeling was applied.

RESULTS

After taking multiple testing into account, high maternal ferritin concentrations and low maternal transferrin saturation during pregnancy were associated with an overall increased risk of upper, not lower, respiratory tract infections until age 10 years of the child [OR (95% CI: 1.23 (1.10, 1.38) and 1.28 (1.12, 1.47), respectively)]. High maternal transferrin saturation during pregnancy was associated with a decreased and increased risk of upper respiratory tract infections at 1 and 6 years, respectively, [OR (95% CI: 0.60 (0.44, 0.83) and 1.54 (1.17, 2.02))]. Observed associations were suggested to be U-shaped (p-values for non-linearity ≤.001). Maternal hemoglobin and iron status measures during pregnancy were not consistently associated with child's gastroenteritis and urinary tract infections, as proxies for general infection effects.

CONCLUSION

High maternal ferritin and low transferrin saturation concentrations during early pregnancy were most consistently associated with an overall increased risk of child's upper, not lower, respiratory tract infections.

Cord Blood FGF-21 and GDF-15 Levels Are Affected by Maternal Exposure to Moderate to Severe Anemia and Malaria

Context

Anemia and malaria are global health problems affecting >50% of pregnant women in sub-Saharan Africa and are associated with intrauterine growth restriction. The hormones fibroblast growth factor 21 (FGF-21) and growth differentiation factor 15 (GDF-15) are involved in metabolic regulation and are expressed in the placenta. No studies exist on FGF-21 and GDF-15 responses to exposures of malaria and anemia in pregnancy.

Objective and Methods

Using a prospective, longitudinal pregnancy and birth cohort of women with an average age of 26 years from a rural region in northeastern Tanzania, we examined if FGF-21 and GDF-15 levels in maternal blood at week 33 ± 2 (n = 301) and in cord blood at birth (n = 353), were associated with anemia and malaria exposure at different time points in pregnancy and with neonatal anthropometry.

Results

Among mothers at gestation week 33 ± 2, lower FGF-21 levels were observed after exposure to malaria in the first trimester, but not anemia, whereas GDF-15 levels at week 33 ± 2 were not associated with malaria nor anemia. In cord blood, moderate to severe anemia at any time point in pregnancy was associated with higher levels of FGF-21, whereas malaria exposure in the third trimester was associated with lower FGF-21 levels in cord blood. Negative associations were observed between cord blood FGF-21 and GDF-15 levels and neonatal skinfold thicknesses and birthweight.

Conclusion

Our results suggest that moderate to severe anemia throughout pregnancy associates with higher FGF-21 levels, and malaria in last trimester associates with lower FGF-21 levels, in the neonates, thereby potentially affecting the future cardiometabolic health of the child.

[Analysis on the iron status and associated factors during the first trimester of pregnancy]

OBJECTIVE

To investigate the impact of dietary and underlying factors on the iron status of women in early pregnancy and to provide evidence for preventing iron deficiency and iron deficiency anemia, thereby reducing the incidence of associated adverse outcomes.

METHODS

From November to December 2018, women in the first trimester of pregnancy (< 12 weeks gestation) who established prenatal records at the Shunyi District Maternal and Child Health Hospital, Beijing, were enrolled in this study, in which 388 participants were accessed for data including demographic characteristics, anthropometric measurements, parity, biomarkers reflecting iron status, and food-frequency questionnaire. SPSS 26.0 were used for statistical analysis. Dietary patterns were extracted using principal component analysis, and factor scores of each dietary pattern were calculated. Two-sided Fisher exact probability test and one-way ANOVA were conducted to access differences in iron status among the groups, and the differences were significant if P < 0.05. Iron deficiency was defined as serum ferritin(SF) < 30 μg/L. To analyze the potential role of dietary factors on iron deficiency during the first trimester, the collected data listed above were adopted as independent factors for the cross-sectional Logistic regression. We used Logistic regression to analyze the potential effects of baseline characteristics and dietary factors on iron status.

RESULTS

Among the 388 participants included in the analysis, 121 (32.2%) were iron deficient, in which 107 (27.6%) were iron depletion (ID), 8 (2.1%) were iron deficiency erythropoiesis (IDA), 6(1.5%) were iron deficiency anemia. The mean SF concentration was (50.4±35.3) μg/L. Multiparity(OR=3.9, 95%CI: 1.81-8.42, P=0.001)was a risk factor for iron deficiency during early pregnancy. No significant iron status differences were found among the participants with different educational levels and anthropometric measurements. In contrast, age (OR =0.96, 95%CI: 0.94-0.97, P < 0.001) was a protective factor. For multiparas, taking iron-containing supplements might have a protective effect for iron deficiency (OR=0.27, 95%CI: 0.09-0.83, P=0.022). The balance-diet pattern (OR=0.81, 95%CI: 0.66-1.00, P=0.054) only showed a marginally significant effect.

CONCLUSION

Increasing attention should be paid to the iron status of pregnant multiparas and young pregnant women. For those women of reproductive age with the risk factors listed above, especially for multiparas, iron-containing supplements should be recommended to prevent gestational iron deficiency. The effect of the "balance" dietary pattern on iron status in the first trimester and following requires further research and discussion.

The Interactions between Maternal Iron Supplementation and Iron Metabolism-Related Genetic Polymorphisms on Birth Outcomes: A Prospective Study in Chinese

BACKGROUND

The effect of iron supplementation during pregnancy on birth outcomes may vary with maternal genetic background and needs more investigation.

OBJECTIVES

This prospective study aimed to evaluate the interactions between maternal iron supplementation and iron metabolism-related genetic polymorphisms on birth outcomes.

METHODS

This was a substudy from a community-based randomized control trial conducted in Northwest China, which included 860 women from the 2 micronutrient supplementation groups (folic acid [FA] and FA + iron group). Maternal peripheral blood, sociodemographic and health-related information, and neonatal birth outcomes were collected. Six single nucleotide polymorphisms in iron metabolism-related genes were genotyped. The alleles associated with decreased iron/hemoglobin status were used as the effect alleles. The genetic risk score (GRS) that reflected the genetic risk of low iron/hemoglobin status was estimated using the unweighted and weighted methods. Generalized estimating equations with small-sample corrections were applied to evaluate the interactions between iron supplementation and SNPs/GRS on birth outcomes.

RESULTS

There were significant interactions between maternal iron supplementation and rs7385804 (P = 0.009), rs149411 (P = 0.035), rs4820268 (P = 0.031), the unweighted GRS (P = 0.018), and the weighted GRS (P = 0.009) on birth weight. Compared with FA supplementation only, FA + iron supplementation significantly increased birth weight among women with more effect alleles in rs7385804 (β: 88.8 g, 95% CI: 9.2, 168.3) and the GRSs (the highest unweighted GRS, β: 135.5 g, 95% CI: 7.7, 263.4; the highest weighted GRS, β: 145.9 g, 95% CI: 43.4, 248.5); it had a trend of decreasing birth weight and increasing low birth weight risk among women with fewer effect alleles.

CONCLUSIONS

In our population, maternal genetic background related to iron metabolism plays a significant role in determining the efficacy of iron supplementation. Routine iron supplementation could be more beneficial to fetal weight growth among mothers with higher genetic risk for low iron/hemoglobin status.

The importance of iron deficiency in pregnancy on fetal, neonatal, and infant neurodevelopmental outcomes

The role of iron in neurodevelopment has long been recognized, and the adverse effects of early-life iron deficiency on brain development and subsequent function across the lifespan continue to be a subject of research. A greater appreciation of the contribution of maternal preconceptional iron status and fetal iron accretion to offspring, postnatal iron status, and brain health across the lifespan has occurred over the past decade. This paradigm shift in thinking links two previously relatively siloed literatures: neonatal iron deficiency and postnatal iron deficiency. The understanding that iron accretion during the fetal period strongly influences postnatal iron balance has led to an appreciation of the importance and value of ensuring proper fetal iron loading. This article reviews the dynamics of fetal iron metabolism, the role of iron in the developing fetal brain, the short- and long-term neurobehavioral consequences of fetal iron underloading, and the potential mechanisms that account for the long-term effects of fetal/neonatal iron deficiency.

The Role of Ferroptosis in Placental-Related Diseases

Ferroptosis is a recently identified form of programmed cell death which is different from apoptosis, pyroptosis, necrosis, and autophagy. It is uniquely defined by redox-active iron-dependent hydroxy-peroxidation of polyunsaturated fatty acid (PUFA)-containing phospholipids and a loss of lipid peroxidation repair capacity. Ferroptosis has recently been implicated in multiple human diseases, such as tumors, ischemia-reperfusion injury, acute kidney injury, neurological diseases, and asthma among others. Intriguingly, ferroptosis is associated with placental physiology and trophoblast injury. Circumstances such as accumulation of lipid reactive oxygen species (ROS) due to hypoxia-reperfusion and anoxia-reoxygenation of trophoblast during placental development, the abundance of trophoblastic iron and PUFA, physiological uterine contractions, or pathological placental bed perfusion, cause placental trophoblasts' susceptibility to ferroptosis. Ferroptosis of trophoblast can cause placental dysfunction, which may be involved in the occurrence and development of placenta-related diseases such as gestational diabetes mellitus, preeclampsia, fetal growth restriction, preterm birth, and abortion. The regulatory mechanisms of trophoblastic ferroptosis still need to be explored further. Here, we summarize the latest progress in trophoblastic ferroptosis research on placental-related diseases, provide references for further understanding of its pathogenesis, and propose new strategies for the prevention and treatment of placental-related diseases.

Maternal hemoglobin change from early pregnancy to second trimester is associated with risk of gestational diabetes mellitus: a retrospective cohort study

Introduction

The accrual of iron that is reflected in high maternal hemoglobin (Hb) status is increasingly recognized as a risk factor for gestational diabetes mellitus (GDM). Changes in maternal Hb level could also implicate glycemic status in pregnancy. This study aimed to determine the associations between maternal Hb levels and their changes with GDM.

Methods

In this retrospective cohort study, a total of 1,315 antenatal records of mothers with singleton pregnancies from eight health clinics of a district in the northern region of Peninsular Malaysia who delivered between 1st January 2016-31st December 2017 were analyzed. Data extracted from the records were socio-demographic, anthropometric, obstetrical, and clinical data. Hb levels were extracted at booking (<14 weeks) and second trimester (14-28 weeks). Change in Hb was determined by subtracting the Hb level in the second trimester from the booking Hb level and was categorized as decreased, unchanged, and increased Hb. The associations between maternal Hb levels and their changes with GDM risk were analyzed using multiple regression, adjusting for covariates in four different models. Model 1: maternal age and height. Model 2: covariates of Model 1 added with parity, history of GDM, and family history of diabetes. Model 3: covariates of Model 2 added with iron supplementation at booking. Model 4: covariates of Model 3 added with Hb level at booking.

Results and Discussions

Unchanged Hb level from booking to second trimester was significantly associated with GDM risk in Model 1 (AOR: 2.55; 95% CI: 1.20, 5.44; p < 0.05), Model 2 (AOR: 2.45, 95% CI: 1.13, 5.34; p < 0.05) Model 3 (AOR: 2.42; 95% CI: 1.11, 5.27; p < 0.05), and Model 4 (AOR: 2.51; 95% CI: 1.15, 5.49; p < 0.05). No significant associations were observed between maternal Hb levels and GDM in the study.

Conclusion

Unchanged Hb levels from the booking (<14 weeks of gestation) to the second trimester (14-28 weeks) increased GDM risk. Further investigation is warranted to evaluate the associations between changes in maternal Hb and GDM risk and to identify potential factors influencing this relationship.

Nutrition and Metabolism in the First 1000 Days of Life

The first 1000 days of life are a critical window period for rapid growth and development during which individuals are more sensitive to the stimulation of environmental factors [...].

Effect of Adherence to the Mediterranean Diet on Maternal Iron Related Biochemical Parameters during Pregnancy and Gestational Weight Gain

Gestation is a crucial life stage for both women and offspring, and outcomes are affected by many environmental factors, including diet. The Mediterranean dietary pattern (MD) is considered a healthy eating pattern that can provide the nutritional requirements of pregnancy. Meanwhile, iron deficiency anemia is one of the most frequent complications related to pregnancy. This study aimed to evaluate how the level of adherence to the MD influences maternal gestational weight gain and specific iron-related maternal biochemical parameters during the pregnancy. Accordingly, an observational, population-based study using data from pregnant women conducted over the entire course of their pregnancy was carried out. Adherence to the MD was assessed once using the MEDAS score questionnaire. Of the 506 women studied, 116 (22.9%) were classified as demonstrating a high adherence, 277 (54.7%) a medium adherence, and 113 (22.3%) a low adherence to the MD. No differences were observed in gestational weight gain among the MD adherence groups but the adequacy of weight gain did vary among the groups, with the proportions of inadequate (insufficient or excessive) weight gain presenting the most notable differences. Total anemia prevalence was 5.3%, 15.6%, and 12.3%, respectively, during the first, second, and third trimesters. For iron-related biochemical parameters, no differences are observed among the adherence groups during pregnancy. With high adherence to the MD as the reference group, the crude odds of iron deficiency diagnosis are significant in the first trimester for both the medium [OR = 2.99 (1.55-5.75)] and low [OR = 4.39 (2.15-8.96)] adherence groups, with deficient adherence to the Mediterranean dietary pattern being responsible for 66.5% (35.5-82.6) and 77.2% (53.5-88.8) of the risk of iron deficiency diagnosis for medium and low adherence, respectively. However, adjusted odds ratios were not significant, possibly due to the small sample size. Our data suggest that MD adherence could be related to gestational weight gain adequacy and that optimal adherence could reduce iron deficiency and/or anemia during pregnancy in the studied population.

Association of arsenic exposure and clinical hematological changes during pregnancy: Findings from a prospective Wuhan birth cohort study

BACKGROUND

Animal studies have reported arsenic-induced disturbed erythropoiesis parameters. However, the effects of exposure to arsenic on hematological parameters among pregnant women are unclear.

OBJECTIVES

We aimed to evaluate trimester-specific associations between arsenic metabolites and erythropoietic parameters measured repeatedly during pregnancy.

METHODS

A total of 1945 pregnant women from a birth cohort study were included. We detected arsenic species in urine sampled at each trimester and extracted erythropoietic parameters in different trimesters from the medical records. We used linear regressions with generalized estimating equations (GEEs) to examine the relationship between arsenic metabolites concentrations at different trimesters and erythropoietic parameters. We utilized GEEs to calculate the odds ratio (OR) for anemia during pregnancy.

RESULTS

Adjusted trimester-specific analysis showed that higher monomethylated arsenic (MMA) and %MMA were related to remarkably reduced hemoglobin (Hb) and mean corpuscular hemoglobin (MCH). Additionally, elevated urinary MMA concentration and %MMA in the early trimester were associated with an increased risk of microcytic anemias in the late trimester.

CONCLUSIONS

Our study demonstrated a significant inverse relationship between gestational arsenic exposure and Hb and MCH. Notably, higher MMA and lower methylation capacity to metabolize inorganic arsenic (iAs) in early pregnancy might increase the likelihood of microcytic anemia among pregnant women in late pregnancy.

Maternal low and high hemoglobin concentrations and associations with adverse maternal and infant health outcomes: an updated global systematic review and meta-analysis

BACKGROUND

Growing evidence suggests low and high maternal hemoglobin (Hb) concentrations may have adverse consequences for maternal and child health. There remain questions on specific Hb thresholds to define anemia and high Hb as well as how cutoffs may vary by anemia etiology and timing of assessment.

METHODS

We conducted an updated systematic review (using PubMed and Cochrane Review) on low (< 110 g/L) and high (≥ 130 g/L) maternal Hb concentrations and associations with a range of maternal and infant health outcomes. We examined associations by timing of Hb assessment (preconception; first, second, and third trimesters, as well as at any time point in pregnancy), varying cutoffs used for defining low and high hemoglobin concentrations and performed stratified analyses by iron-deficiency anemia. We conducted meta-analyses to obtain odds ratios (OR) and 95% confidence intervals.

RESULTS

The updated systematic review included 148 studies. Low maternal Hb at any time point in pregnancy was associated with: low birthweight, LBW (OR (95% CI) 1.28 (1.22-1.35)), very low birthweight, VLBW (2.15 (1.47-3.13)), preterm birth, PTB (1.35 (1.29-1.42)), small-for-gestational age, SGA (1.11 (1.02-1.19)), stillbirth 1.43 (1.24-1.65)), perinatal mortality (1.75 (1.28-2.39)), neonatal mortality (1.25 (1.16-1.34), postpartum hemorrhage (1.69 (1.45-1.97)), transfusion (3.68 (2.58-5.26)), pre-eclampsia (1.57 (1.23-2.01)), and prenatal depression (1.44 (1.24-1.68)). For maternal mortality, the OR was higher for Hb < 90 (4.83 (2.17-10.74)) than for Hb < 100 (2.87 (1.08-7.67)). High maternal Hb was associated with: VLBW (1.35 (1.16-1.57)), PTB (1.12 (1.00-1.25)), SGA (1.17 (1.09-1.25)), stillbirth (1.32 (1.09-1.60)), maternal mortality (2.01 (1.12-3.61)), gestational diabetes (1.71 (1.19-2.46)), and pre-eclampsia (1.34 (1.16-1.56)). Stronger associations were noted earlier in pregnancy for low Hb and adverse birth outcomes while the role of timing of high Hb was inconsistent. Lower Hb cutoffs were associated with greater odds of poor outcomes; for high Hb, data were too limited to identify patterns. Information on anemia etiology was limited; relationships did not vary by iron-deficiency anemia.

CONCLUSION

Both low and high maternal Hb concentrations during pregnancy are strong predictors of adverse maternal and infant health outcomes. Additional research is needed to establish healthy reference ranges and design effective interventions to optimize maternal Hb during pregnancy.

Iron deficiency and iron overload in men and woman of reproductive age, and pregnant women

Iron is an essential micronutrient for human biology and health, but high iron levels can be dangerous. Both iron deficiency and iron overload have been linked to reproductive health. This review summarizes the effects of iron deficiency and iron overload on men of reproductive age, women of reproductive age, and pregnant women. In addition, appropriate iron levels and the need for iron and nutritional supplements at different stages of life and pregnancy are discussed. In general, men should be aware of the risk of iron overload at any stage of life; women should take appropriate iron supplements before menopause; postmenopausal women should pay attention to the risk of iron overload; and pregnant women should receive reasonable iron supplementation in middle and late pregnancy. By summarizing evidence on the relationship between iron and reproductive health, this review aims to promote the development of strategies to optimize reproductive capacity from the perspective of nutrition. However, additional detailed experimental investigations and clinical studies are needed to assess the underlying causes and mechanisms of the observed associations between iron and reproductive health.

Variation Patterns of Hemoglobin Levels by Gestational Age during Pregnancy: A Cross-Sectional Analysis of a Multi-Center Retrospective Cohort Study in China

Background: Pregnancy anemia is a global health concern. However, to our knowledge, there still has little consensus on the reference value of hemoglobin levels. Particularly, little evidence from China was accessible in most existing guidelines. Objective: To evaluate hemoglobin levels and anemia prevalence of pregnant women in China and offer evidence for anemia and its reference values in China. Methods: A multi-center retrospective cohort study was conducted among 143,307 singleton pregnant women aged 15–49 at 139 hospitals in China, with hemoglobin concentrations routinely tested at each prenatal visit. Subsequently, a restricted cubic spline was performed to reveal a non-linear variation of hemoglobin concentrations during the gestational week. The Loess model was used to describe the changes in the prevalence of different degrees of anemia with gestational age. Multivariate linear regression model and Logistic regression model were applied to explore influencing factors of gestational changes in hemoglobin level and anemia prevalence, respectively. Results: Hemoglobin varied nonlinearly with gestational age, and the mean hemoglobin levels decreased from 125.75 g/L in the first trimester to 118.71 g/L in the third trimester. By analyzing hemoglobin levels with gestational age and pregnancy period, we proposed new criteria according to 5th percentile hemoglobin concentration in each trimester as a reference for anemia, with 108 g/L, 103 g/L, and 99 g/L, respectively. According to WHO’s criteria, the prevalence of anemia sustainably increased with gestational age, with 6.2% (4083/65,691) in the first trimester, 11.5% (7974/69,184) in the second trimester and 21.9% (12,295/56,042) in the third trimester, respectively. In subsequent analysis, pregnant women in non-urban residents, multiparity, and pre-pregnancy underweight tended to have lower hemoglobin levels. Conclusions: This research, the first large-sample study to present a set of gestational age-specific reference centiles for hemoglobin levels in China, could be used to obtain a better understanding of the overall levels of hemoglobin in Chinese healthy pregnant women and ultimately offer clues for a more precise hemoglobin reference value of anemia in China.

Maternal hemoglobin levels and adverse pregnancy outcomes: individual patient data analysis from 2 prospective UK pregnancy cohorts

BACKGROUND

Hemoglobin (Hb) is a modifiable risk factor for adverse pregnancy outcomes. Studies have reported conflicting associations between maternal Hb levels and adverse pregnancy outcomes, including preterm birth (PTB), low birth weight (LBW), and perinatal mortality.

OBJECTIVE

In this study, we aimed to estimate the shape and magnitude of associations between maternal Hb levels in early (7-12 wk gestation) and late pregnancy (27-32 wk gestation) and pregnancy outcomes in a high-income setting.

METHODS

We used data from 2 UK population-based pregnancy cohorts: the Avon Longitudinal Study of Parents and Children (ALSPAC) and Pregnancy Outcome Prediction Study (POPS). We used multivariable logistic regression models to examine the relationship between Hb and pregnancy outcomes, adjusting for maternal age, ethnicity, BMI, smoking status, and parity. Main outcome measures were PTB, LBW, small for gestational age (SGA), pre-eclampsia (PET), and gestational diabetes mellitus (GDM).

RESULTS

Mean Hb in ALSPAC were 12.5 g/dL (SD = 0.90) and 11.2 g/dL (SD = 0.92) in early and late pregnancy, respectively, and 12.7 g/dL (SD = 0.82) and 11.4 g/dL (SD = 0.82) in POPS. In the pooled analysis, there was no evidence of associations between a higher Hb in early pregnancy (7-12 wk gestation) and PTB (OR per 1 g/dL of Hb: 1.09; 95% CI: 0.97, 1.22), LBW (1.12: 0.99, 1.26), and SGA (1.06; 0.97, 1.15). Higher Hb in late pregnancy (27-32 wk gestation) was associated with PTB (1.45: 1.30, 1.62), LBW (1.77: 1.57, 2.01), and SGA (1.45: 1.33, 1.58). Higher Hb in early and late pregnancy was associated with PET in ALSPAC (1.36: 1.12, 1.64) and (1.53: 1.29, 1.82), respectively, but not in POPS (1.17:0.99, 1.37) and (1.03: 0.86, 1.23). There was an association with a higher Hb and GDM in ALSPAC in both early and late pregnancy [(1.51: 1.08, 2.11) and (1.35: 1.01, 1.79), respectively], but not in POPS [(0.98: 0.81, 1.19) and (0.83: 0.68, 1.02)].

CONCLUSIONS

Higher maternal Hb may identify the risk of adverse pregnancy outcomes. Further research is required to investigate if this association is causal and to identify the underlying mechanisms.

Shooting shadows: India's struggle to reduce the burden of anaemia

Despite several efforts by the Government of India, the national burden of anaemia remains high and its growing prevalence (between 2015-2016 and 2019-2021) is concerning to India's public health system. This article reviews existing food-based and clinical strategies to mitigate the anaemia burden and why they are premature and insufficient. In a context where multiple anaemia control programmes are in play, this article proposes a threefold strategy for consideration. First, except the Comprehensive National Nutrition Survey, 2016-2018, which measured Hb concentration among children and adolescents aged 1-19 years using venous blood samples, all national surveys use capillary blood samples to determine Hb levels, which could be erroneous. The Indian government should prioritise conducting a nationwide survey for estimating the burden of anaemia and its clinical determinants for all age groups using venous blood samples. Second, without deciding the appropriate dose of Fe needed for an individual, food fortification programmes that are often compounded with layering of other micronutrients could be harmful and further research on this issue is needed. Same is true for the pharmacological intervention of Fe tablet or syrup supplementation programmes, which is given to individuals without assessing its need. In addition, there is a dire need for robust research to understand both the long-term benefit and side effects of Fe supplementation programmes. Third and final, the WHO is in process of reviewing the Hb threshold for defining anaemia, therefore the introduction of new anaemia control programmes should be restrained.

Establishing pregnancy-specific haematological reference intervals in Ghana; a three-center cross-sectional study

BACKGROUND

Abnormal intra-pregnancy haematological variables are associated with adverse feto-maternal outcomes. However, the reference intervals (RIs) employed in sub-Saharan Africa to inform clinical decisions are generally imported. Since RIs are influenced by age, geographical location, and race, we hypothesized that context specific RIs should be established in Ghana to contextualize intra-pregnancy decision making.

METHODS

This cross-sectional study retrospectively retrieved data of 333 pregnant women with no known clinically determined intra-pregnancy complications; 22 participants in their first trimester (T1; 1-13 weeks), 177 in their T2 (14-27 weeks), and 132 in T3 (28-41 weeks). RIs for haematological parameters were non-parametrically determined at 2.5th and 97.5th percentiles in accordance with CLSI guidance document EP28-A3c. Two-sample comparisons were undertaken using Wilcoxon rank-sum tests whereas more than two-sample comparisons were undertaken using Kruskal-Wallis test. Statistical significance was set at p <0.05 under the two-tailed assumptions.

RESULTS

In accordance with WHO trimester-specific haemoglobin cutoffs, anaemia prevalence was a moderate (T1: 36.4%; 8/22 & T2: 31.6%; 56/177) to severe (T3:68.0%; 90/132) public health problem. Additionally, 9.3% (31/333) individuals had high gestational haemoglobin levels (Hb >13.0 g/dL). Moreover, haemoglobin (T2: 8.6-14.3 vs T3: 7.5-13.6 g/dL), MCH (T2: 22.5-69.8 vs T3: 21.6-31.9 pg), MCHC (T2: 30.2-51.8 g/L vs T3: 30.5-37.9 g/L), TWBC (T2: 4.0-13.4 vs T3: 4.1-13.0 x 109/L) required trimester specific RIs, compared to RBC (2.8-5.1 x 1012/L), MCV (66.2-100.2 fL), and platelet counts (106.3-388.3 x 109/L) that each required combined reference intervals.

CONCLUSIONS

The intra-pregnancy haematological RIs determined have appreciable lower limits; there is the need to determine context-specific thresholds for haematological variables predictive of positive and/or adverse maternal and infant health outcomes.

Impact of iron supplementation on gestational diabetes mellitus: A literature review

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, affecting 14% of pregnancies worldwide, and the prevention of pathological hyperglycaemia during pregnancy is meaningful for global public health. The role of iron supplementation in the progression of GDM has been of significant interest in recent years. Iron is a micronutrient that is vital during pregnancy; however, given the toxic properties of excess iron, it is probable that prophylactic iron supplementation will increase the risk of adverse pregnancy outcomes, including GDM. It is critical to clarify the effect of iron supplementation on the risk of GDM. Therefore, in this review, we comprehensively assess the role of iron in pregnancy. This review aimed to analyse the necessity of iron supplementation and maintenance of iron homeostasis during pregnancy, particularly reviewing the role and function of iron in beta cells and examining the mechanisms of excess iron contributing to the pathogenesis of GDM. Moreover, we aimed to discuss the association of haemoglobin and ferritin with GDM and identify priority areas for research.

Polymorphisms of haptoglobin modify the relationship between dietary iron and the risk of gestational iron-deficiency anemia

PURPOSE

To assess whether polymorphisms of haptoglobin (Hp) modify the relationship between dietary iron and the risk of gestational iron-deficiency anemia (IDA).

METHODS

This study analyzed 1430 singleton pregnant women aged 20 ~ ≤ 48 years from the 2017-2019 National Nutrition and Health Survey of Pregnant Women in Taiwan. Sociodemographic, blood biochemical, Hp phenotype, and 24-h dietary recall data were collected. Erythropoiesis-related total prenatal supplementation was defined as the reported use of multivitamins and minerals, vitamin B complex, folate, and iron.

RESULTS

Distributions of the Hp 1-1, Hp 2-1, and Hp 2-2 phenotypes were 13.6, 39.8, and 46.5%, respectively. Women with the Hp 1-1 phenotype had the lowest mean levels of serum ferritin (p-trend = 0.017), the highest prevalence of gestational ID (p-trend = 0.033) as well as the highest prevalence of gestational IDA (did not reach statistical differences, p-trend = 0.086). A gene-diet interaction on serum ferritin was observed between the Hp 1 and Hp 2 (2-1/2-2) alleles (p < 0.001). An adjusted multivariate logistic regression showed that compared to those with a normal blood iron status and who reported using erythropoiesis-related total prenatal supplements, those who did not had a 4.05-fold [odds ratio (OR) = 4.05 (95% confidence interval (CI) 2.63-6.24), p < 0.001] increased risk of gestational IDA. The corresponding ORs for carriers of the Hp 1 and Hp 2 alleles were 4.78 (95% CI 1.43-15.99) and 3.79 (95% CI 2.37-6.06), respectively.

CONCLUSION

Pregnant women who are Hp 1 carriers are at increased risk for developing IDA if they do not meet the recommended dietary allowance for iron or use erythropoiesis-related prenatal supplements.

Maternal hemoglobin concentrations across pregnancy and child health and development from birth through 6-7 years

Background

The role of changes in maternal hemoglobin (Hb) across pregnancy on child health and development (CHD) remains unclear.

Objective

We examined the association between maternal Hb trajectories and CHD outcomes: (a) birth outcomes (birth weight, length, gestational age, preterm, and small for gestational age); (b) child Hb at 3, 6, 12, and 24 months; and (c) motor and mental development at 12 and 24 months and cognitive functioning at age 6-7 years.

Methods

We used data from a randomized controlled trial (PRECONCEPT) conducted in Vietnam (N = 1,175 women enrolled during preconception with offspring follow-up through 6-7 years). Maternal Hb trajectories were developed using latent class analysis with Hb data at preconception, early (≤20 weeks), mid (21-29 weeks), and late (≥30 weeks) pregnancy. Multivariable linear and logistic regression models were used to assess the association between maternal Hb trajectories on CHD outcomes, adjusting for confounding variables at the maternal, child and household levels.

Results

Four distinct maternal Hb trajectories were identified. Track 1 (low initial Hb-decline) was associated with lower child Hb at 3 months (β [95% CI] -0.52 [-0.87, -0.16]), 6 months (-0.36 [-0.68, -0.05]), 12 months (-0.46 [-0.79, -0.13]), and 24 months (-0.44 [-0.72, -0.15]) and motor development at 12 months (-3.58 [-6.76, -0.40]) compared to track 4 (high initial Hb-decline). After adjustment for multiple testing, relationships remained robust with the exception of associations with child Hb at 6 months and motor development at 12 months. Track 2 (low initial Hb-improve) was the only Hb trajectory to increase across pregnancy; however, it was insufficiently powered. Track 3 (mid Hb-decline) was associated with lower child Hb at 12 months (-0.27 [-0.44, -0.10]) and 24 months (-0.20 [-0.34, -0.05]) compared to track 4 (high initial Hb-decline). Maternal Hb trajectories were not associated with birth outcomes or child development at 24 months or 6-7 years.

Conclusion

Maternal Hb trajectories during pregnancy are associated with child Hb concentrations across the first 1,000 days, but not with birth outcomes or later cognitive functioning. More work is needed to better understand and interpret changes in Hb levels during pregnancy especially in resource poor settings.

Non-linear connections between maternal hemoglobin during the third trimester of pregnancy and birth weight outcomes in full-term newborns: Estimating the breakpoints

Objective

Anemia is still an unfinished global health problem, and adverse birth weight outcomes have everlasting influences on the health of later life. However, the non-linear connections and breakpoints of maternal hemoglobin with birth weight outcomes are still needed to be further elucidated. We aimed to reveal the non-linear connections between maternal hemoglobin during the third trimester of pregnancy and birth weight, low birth weight (LBW), macrosomia, small for gestational age (SGA), and large for gestational age (LGA) in full-term newborns and elucidate the breakpoints of the connections.

Methods

A total of 11,411 singletons, full-term, and live newborns, whose mothers conducted the examination of hemoglobin concentration before delivery, were included in this study. A generalized additive model was used to identify and visualize the non-linear connections between maternal hemoglobin and birth weight outcomes. Piecewise linear regression model was adopted to estimate the breakpoints of the connections and report the non-linear connections in detail.

Results

There were inverted "U"-shaped exposure-response connections between maternal hemoglobin concentration and birth weight and the risk of macrosomia. There was an increasing trend of the risk of LBW and a decreased trend of LGA with the increase in maternal hemoglobin concentration. The breakpoints of maternal hemoglobin for birth weight were 100 and 138 g/L, and those for SGA were 97 and 138 g/L. The breakpoints of maternal hemoglobin were 119 g/L for LBW, 105 g/L for macrosomia, and 106 g/L for LGA. When maternal hemoglobin concentration ranged from 100 to 138 g/L, maternal hemoglobin concentration increased per 1 g/L, and birth weight significantly decreased by 2.58 g (95% CI: -3.33, -1.83). When maternal hemoglobin concentration ranged from 97 to 138 g/L, maternal hemoglobin concentration increased per 1 g/L, and the risk of SGA significantly increased by 2% (95% CI: 1%, 3%). When maternal hemoglobin concentration was equal to or lower than 119 g/L, maternal hemoglobin concentration increased per 1 g/L, and the risk of LBW significantly increased by 3% (95% CI: 0%, 5%). When maternal hemoglobin concentration was higher than the breakpoints, the risks of macrosomia (OR = 0.99, 95% CI: 0.98, 0.99) and LGA (OR = 0.99, 95% CI: 0.98, 1.00) declined as the increase of maternal hemoglobin concentration.

Conclusions

There were non-linear connections between maternal hemoglobin and birth weight outcomes, and there are breakpoints in the connections. Cost-effective interventions targeting pregnant women in the prevention of abnormal maternal hemoglobin concentration should be taken to reduce the incidence of adverse birth weight outcomes.

The Association between Iron and Folic Acid Supplementation and Malaria Prophylaxis and Linear Growth among Children and Neonatal Mortality in Sub-Saharan Africa—A Pooled Analysis

The majority of research on linear growth among children is confined to South Asia and focuses on iron and folic acid (IFA) supplementation during pregnancy, without considering malaria prophylaxis. Similarly, there is limited evidence on the association of antenatal IFA supplementation and malaria prophylaxis with neonatal mortality in sub-Saharan Africa (SSA). This study aims to address these gaps. A pooled analysis of demographic and health survey (DHS) data from 19 countries in SSA was conducted to study the association between IFA supplementation and malaria prophylaxis and linear growth and neonatal mortality. Multivariate logistic and linear regression models were used. Malaria prophylaxis was significantly associated with stunting, height-for-age Z scores (HAZ scores), and neonatal mortality, but IFA supplementation was not associated with these outcomes. When women’s height and body mass index (BMI) were introduced in the model, a significant association between combined malaria prophylaxis and IFA supplementation was found with HAZ scores only. For severe stunting, no significant association was found with either in the two models. In conclusion, this study underscores the importance of antenatal malaria prophylaxis as a potential intervention for nutrition outcomes (linear growth) and neonatal mortality, as well as the importance of coordinating efforts between malaria and the health and nutrition sectors to improve these outcomes in the countries of SSA.