Umbilical Cord Blood Lead Levels Research Articles

Multiple prenatal exposures and acute-care clinical encounters for asthma among children born to mothers living near a Superfund site.

Prenatal exposures are associated with childhood asthma, and risk may increase with simultaneous exposures. Pregnant women living in lower-income communities tend to have elevated exposures to a range of potential asthma risk factors, which may interact in complex ways. We examined the association between prenatal exposures and the risk of childhood acute-care clinical encounters for asthma (hospitalizations, emergency department visits, observational stays) using conditional logistic regression with a multivariable smoothing term to model the interaction between continuous variables, adjusted for maternal characteristics and stratified by sex. All births near the New Bedford Harbor (NBH) Superfund site (2000-2006) in New Bedford, Massachusetts, were followed through 2011 using the Massachusetts Pregnancy to Early Life Longitudinal (PELL) Data System to identify children aged 5-11 years with acute-care clinical asthma encounters (265 cases among 7787 children with follow-up). Hazard ratios (HRs) were higher for children living closer to the NBH site with higher umbilical cord blood lead levels than in children living further away from the NBH site with lower lead levels (P<.001). HRs were higher for girls (HR=4.17; 95% CI, 3.60-4.82) than for boys (HR=1.72; 95% CI, 1.46-2.02). Our results suggest that prenatal lead exposure in combination with residential proximity to the NBH Superfund site is associated with childhood asthma acute-care clinical encounters. This article is part of a Special Collection on Environmental Epidemiology.

Relationship between lead concentration in maternal and umbilical cord blood and some neonatal outcomes in primiparous opium-dependent mothers in Zahedan, Southeast of Iran in 2022

BackgroundThere are limited studies on maternal and umbilical cord blood lead levels and their relationship with each other and with pregnancy outcomes in women addicted to opium. The present study was conducted with the aim of investigating the relationship between lead concentrations in maternal blood and umbilical cord blood with some neonatal outcomes in primiparous opium-dependent mothers.MethodThe present study is a cross-sectional and analytical research. A total of 35 mothers addicted to opium and 35 women without addiction from Zahedan city of Iran participated in this study in 2022. Convenience sampling was done, lead levels were measured and pregnancy outcomes checked by a checklist to collect information. Data analysis was done by independent t-tests, Pearson’s correlation coefficient, Point-Biserial Correlation Coefficient, multivariate linear regression and multivariate logistic regression using SPSS version 26 software.ResultsThere was a significant difference in maternal blood lead levels (24.97 ± 8.45 in addicted mothers and 7.5 ± 4.25 in healthy mothers) and in umbilical cord blood lead concentrations (18.68 ± 6.95 in the addicted group and 5.7 ± 2.84 in the healthy group) between the two groups (P < 0.0001 and P < 0.0001, respectively).The lead concentration of all the samples in the addicted group was higher than the high-risk levels. Birth weight, Apgar score, admission to NICU and need for resuscitation were significantly different between the two groups (P < 0.0001, P < 0.0001, p = 0.03 and p = 0.04, respectively). Based on the results of multivariate linear regression test, only addiction can reversely predict the birth weight (Beta= -0.74, P < 0.0001), 1-minute Apgar score (Beta = -0.47, P = 0.004) and 5th minute (Beta= -0.62, P = 0.001). According to multivariate logistic regression test, OR of none of the predictor variables was significant with the outcomes. Maternal and umbilical cord blood lead concentrations were not predictors of pregnancy outcomes.ConclusionThe use of opium during pregnancy leads to an increase in the level of lead in maternal blood and umbilical cord blood. Addiction increased adverse pregnancy outcomes but lead concentration did not predict pregnancy complications. It is recommended that the addiction treatment program be included in pre-pregnancy and pregnancy care plans.

Prenatal blood lead levels and Birth Weight: a Meta-analysis study.

Lead, a known toxic metal, causes several adverse reproductive effects, including low birth weight. Fortunately, the exposure level has sharply decreased during the recent decades, but a definitive safe level did not introduce for pregnant women yet. The current meta-analysis study aimed to conduct a quantitative estimation of maternal and umbilical cord blood lead effects on birth weight. Two researchers have independently searched the scientific literature for retrieving related studies using the PRISMA criteria for data extraction. Twenty-one full-text articles were selected from primary 5006 titles, limited by the English language and published between 1991 and 2020 on humans. The pooled mean of maternal and umbilical cord blood lead levels were 6.85µg/dL (95% CI: 3.36-10.34) and 5.41µg/dL (95%CI: 3.43-7.40), respectively. The correlation coefficient analysis showed a significant inverse association between the mean maternal blood lead level and birth weight, which was confirmed by Fisher Z-Transformation analysis (-0.374, 95% CI: -0.382, -0.365, p < 0.01). In addition, a significantly lower birth weight (∆: 229 gr, p < 0.05) was found in the relatively high level of maternal blood lead than in low-level exposure (> 5µg/dL vs. ≤ 5µg/dL, respectively). In short, the present study findings suggest an increasing maternal blood lead levels could be a potential risk factor for reducing birth weight. Thus, pregnant women should avoid lead exposure, as much as possible. The online version contains supplementary material available at 10.1007/s40201-022-00843-w.

A Study of Maternal and Umbilical Cord Blood Lead Levels in Pregnant Women.

Lead is a highly toxic element which can cross the placental barrier and enter the fetus during pregnancy. Parental lead exposure has adverse effect on infant as well as on maternal health. As part of our program to investigate the lead poisoning in human population we investigated the maternal blood lead levels (MBLL) and umbilical cord blood lead (UBLL) levels in 200 pregnant women and collected their socio-demographic details. In the study we found high lead levels in both maternal and umbilical cord blood samples. The results showed 47.5% maternal blood (n = 95) detected with lead while 38.5% umbilical cord blood (n = 77) samples had lead concentration higher than that of reference range of ≤ 5µg/dL. We also found that the Spearman's correlation coefficient (rs) revealed a strong positive correlation between the MBLL and UBLL (rs = 0.63). The results from socio-demographic questionnaire demonstrated that the recent home painting (p = 0.002) and residing close proximity to traffic congestion (p = 0.05) were significantly associated with MBLL. Education, mother age, fuel and water sources were not significantly associated with MBLL. Iron and calcium deficiency along with tiredness, lethargy, abdominal pain were also reported in women having high lead level > 5µg/dL. Concludingly, on the basis of results obtained it may be stated that we found elevated BLLs in both pregnant women as well as in umbilical cord blood. The prevalence of elevated lead levels in mothers will expose the fetus to lead through placental barriers mobilization and it can have long term adverse effects on the developing fetus. Therefore, it is recommended that screening of blood lead levels be carried out in high-risk women based on their social, occupational, environmental, and individual factors. In addition, stringent regulations on lead-based products are also required from government agencies/authorities to reduce environmental lead burden and toxicity. Moreover, public awareness programs should be organized on hazardous effect of lead.

Correlation between maternal and fetal umbilical cord blood lead concentrations in Libya.

People are exposed to lead from car exhaust fumes (leaded petrol), lead-based paints, plumbing systems, cigarette smoking, contaminated soil and dust, foods grown in polluted areas, and water sources. Among the vulnerable subpopulations are pregnant women, fetuses and infants. To estimate and correlate maternal and neonatal blood lead levels and compare these between neonates and their mothers in Tripoli and Ghadames. In this cross-sectional study, blood was collected from 120 and 116 mothers and their neonates from Tripoli and Ghadames, respectively. Lead levels were determined using atomic absorption spectrophotometry. A simple questionnaire was filled by the participants using face-to face interview. Data were analysed using SPSS version 20.0 and Excel. Mean blood and umbilical cord lead levels were 6.83 (standard deviation 4.96) and 6.05 (4.89) µg/dl in mothers and neonates from Tripoli, respectively, and 5.91 (4.02) and 4.54 (4.09) µg/dl from Ghadames. There was no significant difference in blood lead level between mothers from Tripoli and Ghadames. However, there was a significant correlation between maternal blood and umbilical cord blood in Tripoli and Ghadames. Linear regression revealed that neonatal umbilical cord blood lead levels reflected the levels in maternal blood. Blood lead in this study was higher than that reported in industrialized western countries. We detected moderate blood lead levels among pregnant women in Tripoli and Ghadames. It is important to detect the source of lead in the Libyan population to treat this problem effectively.

Association of newborn blood lead concentration with neurodevelopment outcome in early infancy

BackgroundIn utero exposure to toxic metal substances can cause severe neurodevelopmental deficits in developing fetus and infant. MethodsWe evaluated the association of newborn umbilical cord blood lead concentration with early neurodevelopmental performance (cognitive, receptive language, expressive language, fine motor, gross motor and social-emotional development). The Bayley Scale of Infants Developments-III (BSID-III) was used to perform neurodevelopment outcomes at an average age of 6.5 months. In this prospective study, total of 167 mother-child pairs were enrolled from Western Rajasthan, India. Association between risk factors of lead contamination and newborn umbilical cord blood lead levels was observed. Multivariate regression was performed to see the association of cord blood lead level with infant neurodevelopment outcome. ResultsThe obtained newborn umbilical cord blood lead concentration 5.0–10.5 μg/dL was negatively associated with the sub-scale score of gross motor development (β-coefficient with 95 % CI; −0.29 (−5.0–0.11), p = 0.04). However, no associations were found with the score of cognitive, language, gross motor, and social-emotional development. The umbilical cord blood lead concentration <5.0 μg/dL was also not associated with the BSID-III scores. The mother's regular intake of calcium supplements during the antenatal period was significantly associated with a lower umbilical cord blood lead level (p-value 0.031). ConclusionThe data suggest that newborn umbilical cord blood lead concentration 0.5–10.5 μg/dL has a negative association with early gross motor development during infancy.

Comparative analyses of umbilical cord lead concentration in term and IUGR complicated neonates

Background Lead as a toxic heavy metal can readily transfer through the placenta; this condition may increase the risk of lead toxicity for a developing fetus. Therefore, we undertook this study to evaluate the association between umbilical cord blood lead levels and the risk of intrauterine growth restriction (IUGR) occurrence. Methods A cross-sectional study was done at an academic hospital (Tehran, Iran, 2017). The population study was term and IUGR complicated neonates. Immediately after birth, 3-ml umbilical cord blood was collected in some tubes and sent to a laboratory to assay plasma lead levels. Demographic data related neonates and their mothers were gathered from the medical record. All recorded data were analyzed to compare the cord blood lead levels among normal term and IUGR neonates as the primary outcome. Results Totally 152 neonates, 76 in each group with inclusion criteria entered the study. Of all neonates, 71 subjects (47%) were male. The mean (±SD) cord blood lead levels was 6.5 ± 4.2 µg/l. Of all neonates, 102 (67.1%) had high cord blood lead levels (≥5 µg/dl) and 50 subjects (32.8%) had low cord blood lead levels (<5 µg/dl). The mean gestational age, birth weight and head circumference of term neonates were significantly higher than IUGR complicated neonates (p-value = .0001). On the other hand, no significant difference was observed between two groups regarding the mean cord blood lead concentrations (6.2 ± 2.2 and 6.8 ± 5.6 µg/dl; p-value = .855). ANOVA analyses showed no relationships between cord blood lead levels and all assessed qualitative variables except from mother’s educational status (in IUGR group; p-value = .048 and in term group; p-value = .010). Conclusion Our results highlighted that IUGR occurrence was not associated with fetal blood lead levels alone. Moreover, highly educated mothers had neonates with low blood lead levels, showing that maternal education may be a potentially protective factor against this toxin exposure in newborns. The majority of neonates in the present study had high blood lead concentrations that show a necessity for more efforts and strategies regarding protection against potential deleterious effects of lead toxicity.

Study of Umbilical Blood Lead Level and Its Relation with Pregnancy Outcome

مازال التعرض للرصاص يمثل مشكلة صحية تحتاج للاهتمام من الانظمة الصحية المختلفة. تم تصميم الدراسة الحالية لاستكشاف وجود علاقة بين التعرض الأمومي للرصاص ومستويات الرصاص في دم الحبل السري وتحديد العوامل المسببة المحتملة التي قد تؤثر على مستويات الرصاص في الدم السُري العالية وتأثيرها على نتائج الحمل. وقد شملت الدراسة مائة مولود حديث الولادة من أمهات حوامل أصحاء يحملن حملاً مفرداً. تم استخدام نموذج استبيان لجمع المعلومات من الأمهات المشاركات فيما يتعلق بالبيانات الديموجرافية وتاريخ الحمل وتم سحب عينة دم من الحبل السري لكل طفل حديث الولادة لتحديد مستوى الرصاص بها. كشفت الدراسة أن مستويات الرصاص العالية في دم الحبل السري كانت مع الأمهات الحوامل اللاتي يسكن أو يعملن بالقرب من الشوارع أو الطرق المزدحمة وأيضا العيش بالقرب من ورش الطلاء وأماكن حرق النفايات وأيضا شرب الشاي أو القهوة أو الشاي الأخضر. وأيضا الأمهات الحوامل اللاتي كانت نسبة الهيموجلوبين لديهن منخفضة. بينما كانت مستويات الرصاص المنخفضة في دم الحبل السري مع الأمهات الحوامل اللاتي يتناولن مكملات الحديد والكالسيوم. كما كشفت نتائج الدراسة أيضا أن هناك علاقة بين ارتفاع مستوى الرصاص في دم الحبل السري ونتائج الحمل متمثلة في انخفاض ملحوظ في القياسات البشرية (الوزن، الطول، ومحيط الرأس). أن وجود مستويات عالية من الرصاص في دم الحبل السري يعكس أضراراً جانبية على صحة الأم والجنين.

Determination of lead levels in maternal and umbilical cord blood at birth at the Lagos University Teaching Hospital, Lagos.

BackgroundLead toxicity is a cause of intellectual disability in children and majority of affected children live in developing countries. Its adverse effect on pregnancy outcome has also been documented.ObjectivesTo assess the relationship between maternal blood lead levels and umbilical cord blood lead levels in their corresponding newborn infants; to determine factors associated with high blood lead levels and the pregnancy outcome in participants.Materials and methodsThis was a cross-sectional descriptive study carried out at a tertiary Teaching Hospital, Lagos, Nigeria. Four hundred and forty pregnant women and their respective newborns delivered at the study centre. Blood samples were obtained from the mothers and umbilical cord of the newborns at delivery and analysed by atomic absorption spectrophotometry. Socio-demographic and obstetric data was obtained by questionnaires administered to the mothers. The anthropometric measurements of the babies were taken at birth and clinical data recorded. Main outcome measures were blood lead levels in mother and baby pair, socio-demographic factors, birth weight, gestational age, length, occipito-frontal circumference.ResultsThe median maternal and umbilical blood lead level was 64.3μg/dl and 39.2μg/dl respectively. The levels were above 5μg/dl in 75.6% and 66.8% of mothers and umbilical cord respectively. There was a strong positive correlation between the maternal and umbilical cord blood lead levels (rs = 0.80). Use of calcium supplements during pregnancy was significantly associated with a lower maternal blood lead level (p = 0.010) while recent painting and renovation of residential accommodation were associated with a higher umbilical cord blood lead level (p = 0.025). There were no statistically significant associations between the maternal and umbilical cord blood lead levels and the gestational age and anthropometry of the newborns at birth.ConclusionsThe blood lead levels in newborns of women residing in Lagos, Nigeria are high and administration of antenatal calcium is associated with lower blood lead levels.

High umbilical cord blood lead levels and "calabar chalk" consumption amongst pregnant women in two hospitals in Cameroon.

Introduction“Calabar chalk” is a lead-laden pica mostly consumed by pregnant women worldwide as a remedy for morning sickness. This clay material has been shown to have lead levels of up to 40mg per kilogram. Meanwhile blood lead levels, even at doses less than 10μg/dl will be toxic to humans and even worse-off to the fetus as it crosses the placenta. We, therefore, sort to determine the prevalence of “Calabar chalk” consumption amongst pregnant women and if it translates to higher umbilical cord blood lead levels.MethodsWe carried out a cross-sectional study by prospectively and consecutively enrolling 300 pregnant women from December 2014 through February 2015. A questionnaire was administered to ascertain “Calabar chalk” consumption. The levels of lead in the umbilical cord blood of 51 participants of each group of those who consumed and didn't consume “Calabar chalk” were measured by spectrometry and compared using the T-test (p<0.05).ResultsThe prevalence of “Calabar chalk” consumption was 43.33%. This was mostly consumed during pregnancy only (46.34%), with higher rates observed amongst primigravidas. The mean umbilical blood lead levels amongst those who consumed and those who did not consume “Calabar chalk” was 39.19μg/dl and 25.33μg/dl respectively (P=0.111).ConclusionThe prevalence of “Calabar chalk” consumption was high in the pregnant women population. The overall umbilical cord blood lead levels were extremely high in both consumers and non-consumers. We recommend health education and chelation therapy to be considered.

The Relationship between Maternal and Neonatal Umbilical Cord Blood Lead Levels and their Correlation with Neonatal Anthropometric Indices

Background: Lead is an element, which can cross the placenta and enter the fetus during pregnancy if present in the blood of the expectant mother. Therefore, in this study, the level of lead in maternal and umbilical cord blood of neonates was determined, and its relationship with weight at birth, gestational age, height, and head circumference was investigated. Methods: In this cross sectional study, a total of 70 pregnant women and their newborns were selected at Mousavi Hospital of Zanjan, Iran, based on the inclusion criteria. The level of lead in the umbilical cord blood of newborns and mothers was evaluated, and its correlation with birth weight, gestational age, height, and head circumference was assessed. Results: The average level of lead in the maternal and cord blood was 11.01 μg/dL and 9.54 μg/dL, respectively, which indicates a significant difference (P < 0.001). In addition, there was a significant inverse linear relationship between the level of lead in maternal blood and birth weight; therefore, an increase in the maternal blood lead level resulted in the lower weight of neonates at birth. However, there was no significant correlation between lead level and gestational age, height, or head circumference. Conclusions: In this study, the average lead level of pregnant women was 11.01 μg/dL in Zanjan, which is higher than the global standard (10 μg/dL). The birth weight of newborns, whose mothers had higher blood lead levels, was lower than that of other neonates. Therefore, more attention should be paid to the level of lead by the healthcare system in order to take effective measures and reduce lead pollution.

Lead Level in Umbilical Cord Blood and its Effects on Newborns Anthropometry.

High concentration of blood lead is accompanied by adverse health effects on growth of foetus and the newborn. The aim of this study was to determine umbilical cord blood lead level and its relationship with birth weight, length and head circumference of the newborns in Abadan, Iran. In this cross-sectional study, 3 ml blood was collected from the umbilical cord vein in 147 newborns, immediately after the birth. Blood lead was measured using atomic absorption spectrophotometry. Data collection instruments included demographic questionnaire (age of mother, gestational age, newborn gender, job and education of mother) and also data registration form (umbilical cord blood lead concentration, weight, length, and head circumference of newborn). Data was analyzed with SPSS software version 16.0. The mean of umbilical cord blood lead was determined 0.65±0.32 µg/dl (0.3-1.35 µg/dl). The decrease of birth weight with increased blood lead level was small and was not statistically significant. There was reverse significant correlation between umbilical cord blood lead level and birth length and head circumference. There was no significant correlation between blood lead and other variables such as age, weight, education and job of mother and gestational age. Umbilical blood lead level was determined <5 µg/ dl. Excess of umbilical cord blood lead caused decreasing birth weight, length and head circumference of the newborns.

Stunting is associated with blood lead concentration among Bangladeshi children aged 2-3 years.

BackgroundLead toxicity is of particular public health concern given its near ubiquitous distribution in nature and established neurotoxicant properties. Similar in its ubiquity and ability to inhibit neurodevelopment, early childhood stunting affects an estimated 34 % of children under 5 in low- and middle-income countries. Both lead and stunting have been shown to be associated with decreased neurodevelopment, although the relationship between these childhood burdens is underexplored. The association between lead exposure and stunting has been previously established, yet limited data are available on susceptibility windows.MethodsWhole blood lead samples were collected from rural Bangladeshi children at delivery (umbilical cord blood) and at age 20–40 months (fingerstick blood). Stunting was determined using the Child Growth Standards developed from the World Health Organization Multicentre Growth Reference Study. Children with height for age < -2 z-scores below the median of the WHO Child Growth Standards were classified as stunted in all analyses.ResultsMedian (IQR) umbilical cord and fingerstick blood lead levels were 3.1 (1.6–6.3) μg/dl and 4.2 (1.7–7.6) μg/dl, respectively. In adjusted multivariable regression models, the odds of stunting at 20–40 months increased by 1.12 per μg/dl increase in blood lead level (OR = 1.12, 95 % CI: 1.02–1.22). No association was found between cord blood lead level and risk of stunting (OR = 0.97, 95 % CI: 0.94–1.00).ConclusionsThere is a significant association between stunting and concurrent lead exposure at age 20–40 months. This association is slightly attenuated after controlling for study clinic site. Additional research including more precise timing of lead exposure during these critical 20–40 months is needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12940-016-0190-4) contains supplementary material, which is available to authorized users.

Placental biomarkers of PAH exposure and glutathione-S-transferase biotransformation enzymes in an obstetric population from Tijuana, Baja California, Mexico

Environmental exposures along the US-Mexico border have the potential to adversely affect the maternal-fetal environment. The purpose of this study was to assess placental biomarkers of environmental exposures in an obstetric population at the California-Baja California border in relation to detoxifying enzymes in the placenta and nutritional status. This study was conducted on consenting, full-term, obstetric patients (n=54), delivering in a hospital in Tijuana, Baja California (BC), Mexico. Placental polyaromatic hydrocarbon (PAH)-DNA adducts were measured in addition to placental glutathione-S-transferase (GST) activity and genotype, maternal serum folate, and maternal and umbilical cord blood lead and cadmium levels. A questionnaire was administered to the mothers to determine maternal occupation in a maquiladora, other exposures, and obstetric indicators. In univariate analysis, maternal serum folate levels were inversely correlated with total PAH-DNA adducts (rho=−0.375, p=0.007); adduct #1 (rho=−0.388, p=0.005); and adduct #3 (rho =−0.430, p=0.002). Maternal lead levels were significantly positively correlated with cord blood lead levels (rho=0.512, p<0.001). Cadmium levels were generally very low but significantly higher in mothers exposed to environmental tobacco smoke (ETS) (either at work or at home, n=10). In multivariate analysis, only maternal serum folate levels remained as a significant negative predictor of total DNA-PAH adducts levels in placenta. These findings affirm that placental tissue is a valuable and readily available source of human tissue for biomonitoring; and indicate that further study of the role of nutrition in detoxification and mitigation of environmental exposures in pregnant women is warranted.

Is Prenatal Lead Exposure a Concern in Infancy? What Is the Evidence?

Exposure to unhealthy and unsafe environments cause 1 in 4 deaths in childhood each year. Early exposure to lead beginning prenatally and continuing throughout childhood is one of the mechanisms associated with unhealthy and unsafe environments, particularly in industrial countries and urban communities. Lead is a known heavy metal that crosses the placenta and blood-brain barrier depositing in fetal tissues. The purpose of this integrative review was to determine which maternal-fetal dyads were at high risk for elevated umbilical cord lead (Pb) levels and to examine the consequences associated with elevated umbilical cord Pb levels. PubMed was searched to obtain English language publications from 2005 to March 2015 for studies examining the effects of prenatal lead exposure on infant outcomes using key terms "lead" combined with "infant." A total of 17 articles were retained for analysis. Infants with elevated umbilical cord blood lead levels were associated with maternal demographic factors and country of origin. Maternal-specific exposure to lead products prior to or during pregnancy was associated with elevated umbilical cord blood lead levels. The consequences of prenatal lead exposure to the infant at birth anthropometrically were mixed. The evidence on neurological consequences of prenatal exposure to lead appears to reflect changes in cognitive impairment; however, it needs further study. The major recommendation is primary prevention of lead exposure across the life span. Implementation of policies that reduce the availability of leaded products to reduce leaded products, especially ones aimed at children and women of childbearing age. Research needs to be focused in 2 directions: (1) prevention of lead exposure during pregnancy and (2) prevention of lead leaching from bones for all women of childbearing age.

Maternal hemochromatosis gene H63D single-nucleotide polymorphism and lead levels of placental tissue, maternal and umbilical cord blood

Human hemochromatosis protein (HFE), a major histocompatibility complex class I-like integral membrane protein, participates in the down regulation of intestinal iron absorption by binding to transferrin receptor (TR). HFE competes with transferrin-bound iron for the TR and thus reduces uptake of iron into cells. On the other hand, a lack of HFE increases the intestinal absorption of iron similarly to iron deficiency associated with increasing in absorption and deposition of lead. During pregnancy, placenta cannot prevent transfer lead to the fetus; even low-level lead poisoning causes neurodevelopmental toxicity in children. The aim of this study was to determine the association between the maternal HFE H63D single-nucleotide polymorphism and lead levels in placental tissue, maternal blood and umbilical cord bloods. The study population comprised 93 mother–placenta pairs. Venous blood from mother was collected to investigate lead levels and HFE polymorphism that was detected by standard PCR–RFLP technique. Cord bloods and placentas were collected for lead levels which were analyzed by dual atomic absorption spectrometer system. The HFE H63D genotype frequencies of mothers were found as 75.3% homozygote typical (HH), 23.6% heterozygote (HD) and 1.1% homozygote atypical (DD). Our study results showed that the placental tissue, umbilical cord and maternal blood lead levels of mothers with HD+DD genotypes were significantly higher than those with HH genotype (p<0.05). The present study indicated for the first time that mothers with H63D gene variants have higher lead levels of their newborn's placentas and umbilical cord bloods.

Maternal iron metabolism gene variants modify umbilical cord blood lead levels by gene-environment interaction: a birth cohort study.

BackgroundGiven the relationship between iron metabolism and lead toxicokinetics, we hypothesized that polymorphisms in iron metabolism genes might modify maternal-fetal lead transfer. The objective of this study was to determine whether maternal and/or infant transferrin (TF) and hemochromatosis (HFE) gene missense variants modify the association between maternal blood lead (MBL) and umbilical cord blood lead (UCBL).MethodsWe studied 476 mother-infant pairs whose archived blood specimens were genotyped for TF P570S, HFE H63D and HFE C282Y. MBL and UCBL were collected within 12 hours of delivery. Linear regression models were used to examine the association between log-transformed MBL and UCBL, examine for confounding and collinearity, and explore gene-environment interactions.ResultsThe geometric mean MBL was 0.61 μg/dL (range 0.03, 3.2) and UCBL 0.42 (<0.02, 3.9). Gene variants were common with carrier frequencies ranging from 12-31%; all were in Hardy-Weinberg equilibrium. In an adjusted linear regression model, log MBL was associated with log UCBL (β = 0.92, 95% CI: 0.82, 1.03; p < 0.01) such that a 1% increase in MBL was associated with a 0.92% increase in UCBL among infants born to wild-type mothers. In infants born to C282Y variants, however, a 1% increase in MBL is predicted to increase UCBL 0.65% (βMain Effect = −0.002, 95% CI: −0.09, −0.09; p = 0.97; βInteraction = −0.27, 95% CI: −0.52, −0.01; p = 0.04), representing a 35% lower placental lead transfer among women with MBL 5 μg/dL.ConclusionsMaternal HFE C282Y gene variant status is associated with greater reductions in placental transfer of lead as MBL increases. The inclusion of gene-environment interaction in risk assessment models may improve efforts to safeguard vulnerable populations.Electronic supplementary materialThe online version of this article (doi:10.1186/1476-069X-13-77) contains supplementary material, which is available to authorized users.

Prenatal and postnatal lead exposure and cognitive development of infants followed over the first three years of life: A prospective birth study in the Pearl River Delta region, China

PurposeOur pilot studies showed that there was a significant relationship between low cord blood levels and scores of neonatal behavioral neurological assessment. The study was further to probe the adverse cognitive effects induced by low-level lead exposure during prenatal and postnatal period. MethodTotally 362 mothers with their infants located the PRD, Guangdong, China participated in the study during their stay in these center: 141 in the high lead group [umbilical-cord blood lead levels (UCBLLs)≥3.92μg/dl] and 102 in the low lead group (UCBLLs≤1.89μg/dl). The other 137 subjects failed to complete the study for a variety of reasons. Blood Lead levels (BLLs) were measured by atomic absorption spectrophotometry, equipped with a graphite furnace. The developmental functioning of infants and children was assessed with BSID-II. The children's birth outcome and the rest of information were obtained from their medical records or a comprehensive questionnaire from their parents, which contained demographic characteristics, lifestyle, mother's IQ and environmental lead sources, etc. ResultsOf 380, 243 newborns (63.95%) had complete data collection for all variables included at 6, 12, 24 and 36 months of age. The mean UCBLLs for high and low lead group were 5.63±0.32μg/dl and 1.35±0.26μg/dl, respectively. Significant inverse associations have been found between the UCBLLs and the MDI and the PDI. The associations might attenuate over subsequent years. BLLs at 24 months were significantly associated, in an inverse direction, with MDI at 24 and 36 months. The observed trend of cognitive deficit beginning at 6 months of life might persist, and even develop over the coming years. A positive significant effect of home nurture environment was observed on MDI scores at 12, 24, 36 months of age and PDI scores at 24 and 36 months of age. ConclusionOur study demonstrates that prenatal and postnatal lead exposure as low as 5μg/dl has an adverse effect on neurodevelopment, best arrested by measuring UCBLLs and BLLs at 24 months of age, and suggest a reference for a blood lead critical value below 5μg/dL. The collective evidence indicate that low lead exposure must be addressed appropriately by health policy makers and argues for an improvement of home nurture environment, i.e., reduce the burden of Pb on children and, strengthen the training of cognitive ability.

Umbilical cord blood lead levels

Umbilical cord blood lead levels

Prenatal low-level lead exposure on neonatal neurological, physical, hearing the impact of development

Objective To investigate the prenatal low-level lead exposure neonatal nerve, physical,hearing and development impact. Methods 235 pregnant women in the delivery of umbilical cord blood of 1mL, using graphite furnace atomic absorption spectrometry determination of lead content in umbilical cord blood; on neonatal birth weight, length, head circumference measurements, using 20 neonatal behavioral neurological assessment Detection of neural behavior; teoae methods used to conduct hearing screening for newborns. According to umbilical cord blood lead levels, will study the subjects were divided into low-lead group, in the lead group, the high lead group 3 group, a comparative analysis between the different groups of nerves, physical, hearing and development level. Conclusion prenatal low-level lead exposure on neonatal neurobehavioral development have an adverse effect, but did not result in significant differences; on neonatal physical development and hearing development did not cause significant impact. Key words: Newborn; Umbilical cord blood lead; Neural behavior; Physical development; Hearing development