Maternal Iron Research Articles

Iron status, anemia, and birth outcomes among pregnant women in urban Bloemfontein, South Africa: the NuEMI study

BackgroundDespite routine iron supplementation for pregnant women in South Africa, anaemia and iron deficiency (ID) in pregnancy remain a public health concern.ObjectiveTo determine the associations between iron status and birth outcomes of pregnant women attending antenatal clinic at a regional hospital in Bloemfontein.MethodsIn this cross-sectional study of 427 pregnant women, blood was taken to analyze biomarkers of anaemia (haemoglobin), iron status (ferritin and soluble transferrin receptor) and inflammation (C-reactive protein and α-1-acid glycoprotein). A questionnaire was used to collect information about birth outcomes (birth weight and gestational age at birth), HIV exposure, sociodemographics, iron supplement intake, and maternal dietary iron intake using a validated quantified food frequency questionnaire.ResultsThe median (Q1, Q3) weeks of gestation of participants was 32 (26, 36) at enrolment. Anaemia, iron deficiency (ID), ID anaemia (IDA) and ID erythropoiesis (IDE) were present in 42%, 31%, 19% and 9.8% of participants, respectively. Median (Q1, Q3) dietary and supplemental iron intake during pregnancy was 16.8 (12.7, 20.5) mg/d and 65 (65, 65) mg/d, respectively. The median (max-min) total iron intake (diet and supplements) was 81 (8.8-101.8) mg/d, with 88% of participants having a daily intake above the tolerable upper intake level of 45 mg/d. No significant associations of anaemia and iron status with low birth weight and prematurity were observed. However, infants born to participants in the third hemoglobin (Hb) quartile (Hb > 11.3–12.2 g/dL) had a shorter gestation by 1 week than those in the fourth Hb quartile (Hb > 12.2 g/dL) (p = 0.009). Compared to pregnant women without HIV, women with HIV had increased odds of being anaemic (OR:2.14, 95%CI: 1.41, 3.247), having ID (OR:2.19, 95%CI: 1.42, 3.37), IDA (OR:2.23, 95%CI: 1.36, 3.67), IDE (OR:2.22, 95%CI: 1.16, 4.22) and delivering prematurely (OR:2.39, 95%CI: 1.01, 5.64).ConclusionIn conclusion, anaemia, ID, and IDA were prevalent in this sample of pregnant women, despite the reported intake of prescribed iron supplements, with HIV-infected participants more likely to be iron deficient and anaemic. Research focusing on the best formulation and dosage of iron supplementation to enhance iron absorption and status, and compliance to supplementation is recommended, especially for those living with HIV infection.Graphical

Maternal ketone supplementation throughout gestation improves neonatal cardiac dysfunction caused by perinatal iron deficiency.

Iron deficiency (ID) is common during gestation and in early infancy and has been shown to adversely affect cardiac development and function, which could lead to lasting cardiovascular consequences. Ketone supplementation has been shown to confer cardioprotective effects in numerous disease models. Here, we tested the hypothesis that maternal ketone supplementation during gestation would mitigate cardiac dysfunction in ID neonates. Female Sprague-Dawley rats were fed an iron-restricted or iron-replete diet before and throughout pregnancy. Throughout gestation, iron-restricted dams were given either a daily subcutaneous injection of ketone solution (containing β-hydroxybutyrate [βOHB]) or saline (vehicle). Neonatal offspring cardiac function was assessed by echocardiography at postnatal days (PD)3 and 13. Hearts and livers were collected post-mortem for assessments of mitochondrial function and gene expression profiles of markers oxidative stress and inflammation. Maternal iron restriction caused neonatal anemia and asymmetric growth restriction at all time points assessed, and maternal βOHB treatment had no effect on these outcomes. Echocardiography revealed reduced ejection fraction despite enlarged hearts (relative to body weight) in ID offspring, resulting in impaired oxygen delivery, which was attenuated by maternal βOHB supplementation. Further, maternal ketone supplementation affected biochemical markers of mitochondrial function, oxidative stress and inflammation in hearts of neonates, implicating these pathways in the protective effects conferred by βOHB. In summary, βOHB supplementation confers protection against cardiac dysfunction in ID neonates and could have implications for the treatment of anemic babies.

Iron Overdose in Pregnant Women and its Treatment

During pregnancy, Iron requirements increase significantly to support the growth of the foetus and placenta, as well as maternal erythropoietic expansion. Iron supplementation is universally recommended for a viable pregnancy, irrespective of maternal Iron status. A food fortification strategy delivering about 10mg Iron per day lowers the proportion of women under risk of Iron deficiency to the range of 6 per cent to 39 per cent in many states. Combining fortification with weekly supplementation would lower the risk to between 1 per cent and 5 per cent. Food fortification and supplementation would expose many women to Iron levels that exceed the tolerable upper level of 45mg per day, producing Iron overload which can be prove to be toxic. Large epidemiological studies show a U-shaped association between maternal ferritin, a marker of Iron stores, and risk of adverse outcomes of pregnancy such as low birthweight, stillbirth, preterm birth (<37 weeks), very preterm birth (<32 weeks’ gestation), and neonatal asphyxia.

Exploring the Relationships between Maternal Iron Status, HIV, and Placental Size in Uganda

Exploring the Relationships between Maternal Iron Status, HIV, and Placental Size in Uganda

Fetal bradycardia and acidosis during maternal parenteral iron: Case reports and literature review.

Iron deficiency anemia is an important problem among pregnant women, and intravenous (IV) iron infusions have been increasingly used. Whether fetal monitoring is required during infusion has been debated, with a recent guideline by Hematologists recommending against such. We report two cases of fetal bradycardia after iron isomaltoside (IIM), in women with otherwise good maternal and fetal health. Both developed dyspnea with desaturation minutes from infusion, followed by persistent fetal bradycardia. Both underwent category 1 CS, with cord arterial pH of 7.08 and 6.94 respectively. Upon literature review, only three case reports on fetal bradycardia in IV iron were identified. For older IV iron formulations, a case was reported after IV dextran test dose, while two cases after ferric gluconate were reported. For the new formulation IIM, only one case was reported so far, but in a woman with Crohn's disease and intrauterine growth restriction. IV iron in pregnancy carries risk of anaphylactic or hypersensitivity reactions, even with the newest formulations and in women with good maternal and fetal health. While rarely reported so far, fetal bradycardia is a possible consequence, commonly preceded by respiratory symptoms. Fetal monitoring should therefore be considered during infusion.

A Study of the Prevalence of Anemia in Children With Severe Acute Malnutrition at a Pediatric Tertiary Care Hospital in South India.

Introduction In developing countries such as India, severe acute malnutrition (SAM) has been a cause for great concern in the pediatric population. SAM is associated with significant morbidity and mortality in children less than 60 months of age and leaves them vulnerable to diseases due to a decrease in immunological response. Children with SAM are prone to infections, and due to nutritional deficiency, many have anemia whichmay be a direct or indirect cause of morbidity and mortality. They are affected by frequent respiratory and gastrointestinal infections. Methodology A cross-sectional study was conducted for a period of two months, from December 1,2023, to January 31, 2024, in children with SAM aged less than 60 months. A detailed history and demographic profile were taken and recorded in a predesigned proforma. Anthropometric measurements of the study subjects were recorded, and lab investigations included complete blood picture, serum iron, serum ferritin, serum folate, and serum vitamin B12 levels. The prevalence and severity of anemia were determined by assessing the hemoglobin levels. The data collected was analyzed in Excel sheets (Microsoft Corporation, Redmond, Washington, United States) and the results were depicted in the form of graphs. Results A total of 300 children were included in the study of which 22 children were aged less than six months and 278 children were in the age group of 6-60 months. The overall gender distribution was 124 (41.4%) males and 176 (58.6%) females. In the age group of <6 months, of the 22 children, six (27.27%) were females while 16 (72.72%) were male. In the age group of 6-60 months, of the 278 children, 170 (61%) were females while 108 (39%) were males. Of the total 300 children, 232 (77.3%) were found to be anemic, of which 54 (23.2%) had mild anemia, 162 (69.8%) had moderate anemia, and 16 (6.89%) had severe anemia. Low serum iron levels were detected in 134 (44.6%) with iron deficiency being more common in females; below-normal ferritin levels were seen in 153 (51%) cases. Folate levels were found to be deficient in 97 (32.3%) children while vitamin B12 levels were deficient in 186 (62%). Conclusion Anemia is a common occurrence in children with SAM. Prevention of anemia starts from the womb by improvement of maternal nutrition and iron, and folic acid supplementation during pregnancy. Exclusive breastfeeding up to six months of age and further continuation of breastfeeding coupled with initiation of home-available complementary feeding from the age of six months onwards go a long way in maintaining healthy nutrition status inchildren in the vulnerable age group of less than 60 months. Healthcare professionals should utilize thewell-baby and well-child visits to educate the parents and primary caretakers regarding the feeding practicesto prevent, detect, and treatanemia, which will help reduce the morbidity and mortality in children with SAM.

The Effects of Prenatal Iron Supplementation on Offspring Neurodevelopment in Upper Middle- or High-Income Countries: A Systematic Review

Iron supplementation is commonly recommended for the prevention and treatment of maternal iron deficiency (ID) or iron deficiency anemia (IDA). However, the impacts of prophylactic of therapeutic prenatal iron supplementation on child neurodevelopment in upper middle-income (UMI) and high-income countries (HICs), where broad nutritional deficiencies are less common, are unclear. To investigate this, we conducted a systematic review, searching four databases (Medline, CINAHL, EMBASE, Cochrane Library) through 1 May 2023. Randomized controlled trials (RCTs) assessing oral or intravenous iron supplementation in pregnant women reporting on child neurodevelopment (primary outcome: age-standardized cognitive scores) were eligible. We included three RCTs (five publications) from two HICs (Spain and Australia) (N = 935 children; N = 1397 mothers). Due to clinical heterogeneity of the RCTs, meta-analyses were not appropriate; findings were narratively synthesized. In non-anemic pregnant women, prenatal iron for prevention of IDA resulted in little to no difference in cognition at 40 days post-partum (1 RCT, 503 infants; very low certainty evidence). Similarly, the effect on the intelligence quotient at four years was very uncertain (2 RCTs, 509 children, very low certainty evidence). No RCTs for treatment of ID assessed offspring cognition. The effects on secondary outcomes related to language and motor development, or other measures of cognitive function, were unclear, except for one prevention-focused RCT (302 children), which reported possible harm for children’s behavioral and emotional functioning at four years. There is no evidence from UMI countries and insufficient evidence from HICs to support or refute benefits or harms of prophylactic or therapeutic prenatal iron supplementation on child neurodevelopment.

Maintaining Normal Serum Ferritin Levels During Pregnancy: A Randomized Controlled Trial of Daily versus Weekly Ferrous Sulfate

Background: Serum ferritin is the most reliable indication of stored iron in pregnancy, offering a noninvasive way to detect iron deficiency anemia before it occurs. Therefore, this study aimed to determine serum ferritin levels among women receiving daily versus weekly iron supplementation, with a secondary focus on comparing the proportion developing iron deficiency anemia and compli-ance rates between the two groups.Methods: This non-blinded randomized control trial involved non-anaemic pregnant women attend-ing antenatal clinics at two Teaching Hospitals in Osun State. One hundred twenty-five subjects were recruited to receive 65mg in the control group, while another 125 subjects in the active group re-ceived three tablets (195mg) of ferrous sulfate (Fesulf) once weekly for 17 weeks from the 20th to 37th weeks of gestation. The primary outcome measure was comparing mean serum ferritin levels in both groups at 37 weeks.Results: Among the 240 subjects analyzed, the 37-week serum ferritin level was higher in the daily group (73.26±26.67μg/L) compared to the weekly group (63.04±30.71 μg/L), p value=0.006. Four (3.36%) and 10 (8.26%) of our subjects had Iron deficiency anaemia. Nine subjects (3.75%) reported dyspepsia as a side effect. Daily 65 mg of Felsulf proved more effective than weekly 195mg in main-taining normal blood ferritin levels during pregnancy.Conclusions: Daily iron supplementation with 65mg ferrous sulfate was more effective at main-taining adequate maternal iron concentration in this group of non-anaemic pregnant women. This dosage is recommended for routine iron supplementation in our environment.

Statement of Retraction: Impact of maternal iron deficiency anaemia on the expression of the newly discovered multi-copper ferroxidase, Zyklopen, in term placentas

Statement of Retraction: Impact of maternal iron deficiency anaemia on the expression of the newly discovered multi-copper ferroxidase, Zyklopen, in term placentas

Maternal hemoglobin and iron status in early pregnancy and childhood cardiac outcomes

Background & aimsDysregulation of iron homeostasis is associated with cardiac alterations in a sex-dependent manner in adults. It is unknown whether iron status during pregnancy has long-term impact on cardiovascular health, and if this association is influenced by sex. Therefore, the study aimed to evaluate sex-specific association between maternal iron status during early pregnancy and cardiac outcomes in children aged 10 years. MethodsIn a population-based cohort study among 1972 mother-child pairs, hemoglobin and ferritin were measured in early pregnancy (<18 weeks) and categorized into anemia (hemoglobin<11g/dL), elevated hemoglobin (hemoglobin≥13.2g/dL), iron deficiency (ferritin<15 μg/L), and iron overload (ferritin>150 μg/L). At 10 years of age, cardiac MRI was performed to measure right and left cardiac outcomes of function (ventricular end-diastolic volume (RVEDV and LVEDV) and ejection fraction (RVEF and LVEF)), and structure (left ventricular mass (LVM), and left ventricular mass-to-volume ratio (LMVR)). Results are presented for boys and girls separately and models were adjusted for confounders and multiple testing. ResultsIn boys, one standard deviation score (SDS) increase in maternal hemoglobin was associated with lower RVEDV and LVEDV (difference (95%CI) -0.10 (-0.17, -0.03) SDS and -0.09 (-0.16, -0.03) SDS, respectively). In boys, maternal anemia, as compared to normal hemoglobin levels, was associated with higher LVEDV (difference 0.34 (0.10, 0.59) SDS).No associations were observed for other cardiac outcomes and for ferritin in boys. No associations were observed in girls. ConclusionIn boys, dysregulated iron status during early pregnancy might permanently alter cardiovascular RVEDV and LVEDV function. Underlying mechanisms need further study.

Statement of Retraction: Effect of Maternal Iron Deficiency Anaemia on the Expression of Iron Transport Proteins in the Third Trimester Placenta

Statement of Retraction: Effect of Maternal Iron Deficiency Anaemia on the Expression of Iron Transport Proteins in the Third Trimester Placenta

The association of umbilical cord blood oxidative stress with maternal iron deficiency anemia: A tertiary center experience.

To compare the levels of oxidative stress markers in the umbilical cord blood between pregnant women diagnosed with iron deficiency anemia (IDA) and low-risk controls. The sample consisted of 131 patients, including 55 pregnant women with IDA and 76 controls with similar demographic characteristics. Participants were selected from patients delivered at ≥37 weeks. We compared the two groups in terms of the native thiol, total thiol, disulfide, and ischemia-modified albumin (IMA) levels measured in pregnant women's umbilical cord venous blood. The native thiol and total thiol values were statistically significantly lower in the anemia group, and the disulfide and IMA values were statistically significantly higher in the IDA group (P < 0.001). Perinatal outcomes were similar between the groups. In the present study, pregnant women with IDA had lower native and total thiol values and higher disulfide and IMA values in umbilical cord blood. Iron deficiency anemia in pregnancy may be a potential cause of increased oxidative stress.

The Effects of Maternal Iron and Folate Supplementation on Pregnancy and Infant Outcomes in Africa: A Systematic Review.

Iron and folate deficiency are prevalent in pregnant women in Africa. However, limited research exists on the differential effect of oral iron-only, folate-only, or Iron Folic Acid (IFA) supplementation on adverse pregnancy and infant outcomes. This systematic review addresses this gap, focusing on studies conducted in Africa with limited healthcare access. Understanding these differential effects could lead to more targeted and potentially cost-effective interventions to improve maternal and child health in these settings. A systematic review was conducted following PRISMA guidelines. The primary exposures were oral iron-only, folate-only, or IFA oral supplementation during pregnancy, while the outcomes were adverse pregnancy and infant outcomes. A qualitative synthesis guided by methods without meta-analysis was performed. Our qualitative synthesis analysed 10 articles reporting adverse pregnancy (adverse birth outcomes, stillbirths, and perinatal mortality) and infant outcomes (neonatal mortality). Consistently, iron-only supplementation demonstrated a reduction in perinatal death. However, evidence is insufficient to assess the relationship between iron-only and IFA supplementation with adverse birth outcomes, stillbirths, and neonatal mortality. Findings suggested that iron-only supplementation during pregnancy may reduce perinatal mortality in African women. However, evidence remains limited regarding the effectiveness of both iron-only and IFA supplementation in reducing stillbirths, and neonatal mortality. Moreover, additional primary studies are necessary to comprehend the effects of iron-only, folate-only, and IFA supplementation on pregnancy outcomes and infant health in the African region, considering rurality and income level as effect modifiers.

Compliance with Iron Supplementation Consumption in Pregnant Women on Hematological Profiles and Ret-He

Fetal growth will increase the mass of maternal and fetal erythrocytes resulting in an increase in iron requirements, causing a decrease in maternal iron stores.A decrease in iron in the body will disrupt the formation of hemoglobin, because one of the components that forms it is heme which contains iron. the aim of our research is to study the compliance of pregnant women in consuming iron supplements regarding hematological features and body iron reserves through the Ret-He examination. This research is a cross-sectional study in 30 pregnant women for complete blood count (CBC), Ret-He and estradiol. There were differences in the concentrations of Hgb and MCHC (P-value &lt; 0.05) and there were no differences in the concentrations of Hct, RBC, MCV, MCH, RDW, Ret-He and estradiol (P-value &gt; 0.05). It was found that there was a relationship between estradiol and Hgb (P-value = 0.047; r = 0.366). Pregnant women who do not comply with taking iron supplements experience a decrease in Hgb and MCHC. The decrease in Hgb levels is strongly correlated with E2 levels in pregnant women who adhere and do not comply with iron supplementation.

Association between maternal iron status and the risk of pre-eclampsia: a case-control study.

This study aimed to assess the associations of maternal iron status and placental iron transport proteins expression with the risk of pre-eclampsia (PE) in Chinese pregnant women. A total of 94 subjects with PE and 112 healthy pregnant women were enrolled. Fasting blood samples were collected to detect maternal iron status. The placenta samples were collected at delivery to detect the mRNA and protein expression of divalent metal transporter 1 (DMT1) and ferroportin-1 (FPN1). Logistic analysis was used to explore the associations of maternal iron status with PE risk. The associations of placental iron transport proteins with maternal iron status were explored. After adjusting for covariates, dietary total iron, non-heme iron intake and serum hepcidin were negatively associated with PE, with adjusted ORs (95%CIs) were 0.40 (0.17, 0.91), 0.42 (0.18, 0.94) and 0.02 (0.002, 0.13) for the highest versus lowest tertile, respectively. For the highest tertile versus lowest tertile, serum iron (4.08 (1.58, 10.57)) and ferritin (5.61 (2.36, 13.31)) were positively associated with PE. The mRNA expressions and protein levels of DMT1 and FPN1 in placenta were up-regulated in the PE group (p < 0.05). The mRNA expressions of DMT1 and FPN1 in placenta showed a negative correlation with the serum hepcidin (r = -0.71, p < 0.001; r = -0.49, p < 0.05). In conclusion, the maternal iron status were closely associated with PE risk, placental DMT1 and FPN1 were upregulated in PE which may be a promising target for the prevention of PE.

How does maternal anemia affect the levels of umbilical cord brain-derived neurotrophic factor?

ObjectiveIn this study, we aimed to evaluate the effect of maternal iron deficiency anemia on the umbilical cord level of brain-derived neurotrophic factor (BDNF), which plays a very important role in the central nervous system. MethodsOur research was planned as a quantitative, prospective, and analytical type of study. A total of 90 volunteers, term, singleton pregnant hospitalized in the Health Sciences University Ümraniye Training and Research Hospital Gynecology and Obstetrics Clinic between September 2021 and August 2022 were included in this study. While 45 of these pregnants were pregnant women with iron deficiency anemia (hemoglobin ≤ 110 g/L and serum ferritin level ≤ 12 μg/L), 45 cases were in the control group without iron deficiency anemia (hemoglobin > 110 g/L, serum ferritin > 12 μg/L). When pregnant were admitted to the hospital, blood samples were taken to analyze hemoglobin, mean cell volume (MCV), iron, unsaturated iron binding capacity, total iron binding capacity, serum ferritin, transferrin, and CRP levels. Also, we noted the maternal age, gravida, parity, birth weight, head circumference, type of birth, 1. minute Apgar score, and 5. minute Apgar score. During the delivery; after the umbilical cord had been clamped and cut, we took 5 cc of umbilical cord blood. Then, we put it in the serum-separating laboratory tubes. After we centrifuged these blood samples, we put the serum parts in the Eppendorf tubes to be stored at −80 degrees Celsius. At the end of the study, we calculated the level of BDNF using special human brain-derived neurotrophic factor ELISA kits. The umbilical cord BDNF levels of the maternal iron deficiency anemia group and the control group were compared statistically. ResultsWhen we evaluated the fetal umbilical cord BDNF values of 90 participants, the median value BDNF in the babies of 45 anemic mothers was 3.16 (IQR 0.73), and the median BDNF value of the babies of 45 healthy mothers was 5.37 (IQR 1.02). We found a statistical difference between BDNF and hemoglobin, hematocrit, MCV, and iron values between these two groups. ConclusionIn conclusion, the BDNF value of the babies of healthy individuals is higher than that of anemic individuals. Our study showed that the amount of BDNF in the umbilical cord blood was significantly affected by maternal iron deficiency anemia.

Chromatin accessibility and H3K9me3 landscapes reveal long-term epigenetic effects of fetal-neonatal iron deficiency in rat hippocampus

BackgroundIron deficiency (ID) during the fetal-neonatal period results in long-term neurodevelopmental impairments associated with pervasive hippocampal gene dysregulation. Prenatal choline supplementation partially normalizes these effects, suggesting an interaction between iron and choline in hippocampal transcriptome regulation. To understand the regulatory mechanisms, we investigated epigenetic marks of genes with altered chromatin accessibility (ATAC-seq) or poised to be repressed (H3K9me3 ChIP-seq) in iron-repleted adult rats having experienced fetal-neonatal ID exposure with or without prenatal choline supplementation.ResultsFetal-neonatal ID was induced by limiting maternal iron intake from gestational day (G) 2 through postnatal day (P) 7. Half of the pregnant dams were given supplemental choline (5.0 g/kg) from G11–18. This resulted in 4 groups at P65 (Iron-sufficient [IS], Formerly Iron-deficient [FID], IS with choline [ISch], and FID with choline [FIDch]). Hippocampi were collected from P65 iron-repleted male offspring and analyzed for chromatin accessibility and H3K9me3 enrichment. 22% and 24% of differentially transcribed genes in FID- and FIDch-groups, respectively, exhibited significant differences in chromatin accessibility, whereas 1.7% and 13% exhibited significant differences in H3K9me3 enrichment. These changes mapped onto gene networks regulating synaptic plasticity, neuroinflammation, and reward circuits. Motif analysis of differentially modified genomic sites revealed significantly stronger choline effects than early-life ID and identified multiple epigenetically modified transcription factor binding sites.ConclusionsThis study reveals genome-wide, stable epigenetic changes and epigenetically modifiable gene networks associated with specific chromatin marks in the hippocampus, and lays a foundation to further elucidate iron-dependent epigenetic mechanisms that underlie the long-term effects of fetal-neonatal ID, choline, and their interactions.

Causal relationship between iron status and preeclampsia-eclampsia: a Mendelian randomization analysis

ABSTRACT Background Preeclampsia/eclampsia is a severe pregnancy-related disorder associated with hypertension and organ damage. While observational studies have suggested a link between maternal iron status and preeclampsia/eclampsia, the causal relationship remains unclear. The aim of this study was to investigate the genetic causality between iron status and preeclampsia/eclampsia using large-scale genome-wide association study (GWAS) summary data and Mendelian randomization (MR) analysis. Methods Summary data for the GWAS on preeclampsia/eclampsia and genetic markers related to iron status were obtained from the FinnGen Consortium and the IEU genetic databases. The “TwoSampleMR” software package in R was employed to test the genetic causality between these markers and preeclampsia/eclampsia. The inverse variance weighted (IVW) method was primarily used for MR analysis. Heterogeneity, horizontal pleiotropy, and potential outliers were evaluated for the MR analysis results. Results The random-effects IVW results showed that ferritin (OR = 1.11, 95% CI: .89–1.38, p = .341), serum iron (OR = .90, 95% CI: .75–1.09, p = .275), TIBC (OR = .98, 95% CI: .89–1.07, p = .613), and TSAT (OR = .94, 95% CI: .83–1.07, p = .354) have no genetic causal relationship with preeclampsia/eclampsia. There was no evidence of heterogeneity, horizontal pleiotropy, or possible outliers in our MR analysis (p > .05). Conclusions Our study did not detect a genetic causal relationship between iron status and preeclampsia/eclampsia. Nonetheless, this does not rule out a relationship between the two at other mechanistic levels.

Abnormal umbilical cord coiling and association with pregnancy factors.

The umbilical cord, as a connecting bridge between two lives, plays an important role in fetal development. Though studies on the umbilical cord date back many years, extensive studies on certain umbilical cord characteristics, such as umbilical cord coiling, are rare. Cord coiling, measured by the umbilical coiling index, is a physiological phenomenon that offers resistance to external pressures. Umbilical cord coiling is a result of several factors, both environmental and genetic. However, umbilical cords sometimes coil abnormally, resulting in hypocoiling, hypercoiling, or non-coiling which have significant associations with adverse perinatal outcomes. An all-language literature search was conducted on Medline from 1970 to 2023. The following search terms were used; umbilical cord; umbilical coiling; coiling index; abnormal coiling; perinatal outcomes, and cross-referencing yielded further information. We comprehensively reviewed the literature on umbilical cord coiling, factors contributing to coiling, abnormal coiling of the umbilical cord, and the association with several factors including maternal age, gravida, gestational diabetes mellitus, pre-eclampsia, abruption, birth weight, intrauterine growth retardation, maternal iron status, small for gestational age, fetal heart rate variations, ponderal index, and sought possible explanations.

Associations of maternal serum concentration of iron-related indicators with birth outcomes in Chinese: a pilot prospective cohort study

BackgroundPrevious studies of maternal iron and birth outcomes have been limited to single indicators that do not reflect the comprehensive relationship with birth outcomes. We aimed to investigate the relationship between maternal iron metabolism and neonatal anthropometric indicators using comprehensive iron-related indicators.MethodsA total of 914 Chinese mother-child dyads were enrolled in this prospective study. Subjects’ blood samples were collected at ≤ 14 weeks of gestation. Serum concentrations of iron-related indicators were measured by enzyme-linked immunosorbent assay (ELISA). Femur length was measured by B-ultrasound nearest delivery. Neonatal anthropometric indicators were collected from medical records.ResultsAfter adjustment for potential covariates, higher iron (per one standard deviation, SD increase) was detrimentally associated with − 0.22 mm lower femur length, whereas higher transferrin (per one SD increase) was associated with 0.20 mm higher femur length. Compared with normal subjects (10th-90th percentiles), subjects with extremely high (> 90th percentile) iron concentration were detrimentally associated with lower femur length, birth weight, and chest circumference, and a higher risk of low birth weight, LBW (HR: 3.92, 95%CI: 1.28, 12.0). Subjects with high concentration of soluble transferrin receptor, sTFR and transferrin (> 90th percentile) were associated with higher femur length. Subjects with low concentration of iron and ferritin concentrations (< 10th percentile) were associated with a higher risk of LBW (HR: 4.10, 95%CI: 1.17, 14.3) and macrosomia (HR: 2.79, 95%CI: 1.06, 7.35), respectively.ConclusionsMaternal iron overload in early pregnancy may be detrimentally associated with neonatal anthropometric indicators and adverse birth outcomes.