Heavy metals (lead, cadmium and mercury) in maternal, cord blood and placenta of healthy women

Lead, cadmium and mercury were measured in placental tissue, umbilical cord and maternal blood samples of 1578 women who delivered at the Al-Kharj King Khalid Hospital between 2005 and 2006. The aim of this study was to evaluate the status of heavy metal exposure in mothers and their newborns and to identify predictors of maternal exposure. Lead was detected in all cord and maternal blood and in 96% of placental tissues. Only in 0.89% and 0.83% of cord and maternal blood samples were the levels of lead above the CDC threshold limit of 10 μg/dl. Maternal blood lead was also higher (2.3%) than the German Reference value in women of 7 μg/dl. Approximately 9.3% of women had a placental lead above the 95th percentile in the range of 0.83-78 μg/g dry wt., a level of possible developmental toxicity. Cadmium was detected in 94.8% and 97.9% of cord and maternal blood samples respectively, though only five newborns had a cadmium level above the OSHA threshold limit of 5 μg/l. Comparing our results to the newly revised German Reference value for nonsmokers, 48.6% of mothers had blood cadmium levels >1.0 μg/l. We found as well that 25% of women had placental cadmium in the >75th percentile, in the range of 0.048-4.36 μg/g dry wt., which is likely to affect fetal growth and development. Of the maternal and cord blood samples, 11.2% and 13%, respectively, had mercury levels >5.8 μg/l, which is the EPA reference dose. Nearly 49% of women had mercury levels >2.0 μg/l, the German Reference value for those who consume fish ≤3 times a month. Around 50% of the mothers had placental mercury in the range of 0.031-13.0 μg/g dry wt. Regression analyses indicated that the levels of metals in the blood and placenta were influenced by several factors. This study provides informative baseline biomonitoring data and reveals a substantial exposure to heavy metals in non-occupationally exposed Saudi mothers and their newborns that might jeopardize the health of both. Additional research is also urgently needed to explore factors such as environment, diet, lifestyle and/or cultural habits contributing to maternal and fetal exposures. Preventive measures to eliminate or minimize the unnecessary risk of fetus exposure to heavy metals or other pollutants during pregnancy should be initiated once these factors are identified.     

Maternal selenium status in Slovenia and its impact on the selenium concentration of umbilical cord serum and colostrum

OBJECTIVE: The aim of this study was to assess serum selenium (Se) level of Slovenian mothers at birth and to elucidate its impact on the Se content of umbilical cord serum of their newborns and of that of colostrum. SUBJECTS AND METHODS: In sera of 20 Slovenian mothers at delivery and in the corresponding umbilical cord sera of their newborns Se concentrations were determined by hydride generation atomic absorption spectrometry (HG-AAS). In addition Se levels in 10 healthy female blood donors were determined. Colostrum samples of 18 mothers collected on the second and third day post partum were also investigated for their Se content. RESULTS: Serum Se concentrations of mothers showed to be 62+/-15 microg/l. Umbilical cord sera had 34+/-7 microg/l, which amounts to 55% of the maternal content. Concentrations of Se in colostrum ranged from 17 to 48 microg/l with a mean of 29+/-10 microg/l. In the sera of female blood donors the mean was 66+/-15 microg/l. A significant correlation (P<0.002) between the Se content of maternal and umbilical sera could be established. No significant correlation was found between maternal serum Se concentration and that of colostrum. CONCLUSIONS: Our data show that dietary Se intake for pregnant women in Slovenia is borderline.     

Impact of maternal seafood diet on fetal exposure to mercury, selenium, and lead.

Umbilical cord blood from 1,023 consecutive births in the Faroe Islands showed a median blood-mercury concentration of 121 nmol/l (24.2 micrograms/l); 250 of those samples (25.1%) had blood-mercury concentrations that exceeded 200 nmol/l (40 micrograms/l). Maternal hair mercury concentrations showed a median of 22.5 nmol/g (4.5 micrograms/g), and 130 samples (12.7%) contained concentrations that exceeded 50 nmol/g (10 micrograms/g). Frequent ingestion of whale meat dinners during pregnancy and, to a much lesser degree, frequent consumption of fish, and increased parity or age were associated with high mercury concentrations in cord blood and hair. Blood-mercury levels were slightly lower if the mother had occasionally ingested alcoholic beverages. Mercury in blood correlated moderately with blood selenium (median, 1.40 mumol/l). Increased selenium concentrations were associated with intake of whale meat, alcohol abstention, delivery after term, and high parity. Lead in cord blood was low (median, 82 nmol/l), particularly if the mothers had frequently had fish for dinner and had abstained from smoking.     

Correlation between maternal and cord blood lead levels

Whole blood lead levels were estimated by atomic absorption analysis in 226 blood samples from 113 mothers of 23 different nationalities. Samples were collected before delivery, and from cord blood from their respective neonates. The concentrations of blood lead were within the expected range of occupationally unexposed populations. Mean maternal blood lead levels were 0.72 0.10 mumol/l (14.9 2.14 mug/dl), range 0.32-1.34 mumol/l (6.6-27.8 mug/dl) and mean cord blood levels were 0.64 0.12 mumol/l (range 0.29-1.46 mumol/l). Sixteen percent of the mothers and nearly 10% cord blood samples were found to have blood lead level greater than 0.97 mumol/l (20 mug/dl). Very high levels, in excess of 1.21 mumol/l (25 mug/dl), were detected in 3.5% of mothers as compared to 2.6% of cord blood samples. Out of 113 infants, 65 (58%) were males with a mean cord blood lead level of 0.63 mumol/l and 48 (42%) were females with a mean level of 0.66 muol/l. The lowest maternal blood lead levels 0.68 mumol/l were observed in ages 20 to 25 years old, and lowest cord blood levels 0.58 mumol/l were seen in maternal age of less than 20 years old. On the other hand, the highest maternal and cord blood lead levels (0.82 and 0.75 mumol/l, respectively) were observed in maternal ages of greater than 35 years old. The results show a direct correlation of blood lead level between mothers and umbilical cord as seen in the linear regression distribution curve.     

孕妇及新生儿汞暴露水平及影响因素分析

目的调查大连、上海市孕妇及其新生儿汞暴露水平及其影响因素。方法整群抽取上海和大连市三甲医院妇产科病房待产的孕妇,对孕妇周围血及与其对应的新生儿脐带血进行血汞检测,并分析其影响因素。结果上海市孕妇血汞和新生儿脐带血汞中位数分别为1.35和2.29μg/L,大连市孕妇血汞和新生儿脐带血汞中位数分别为1.99和3.57μg/L,2地新生儿脐带血汞均明显高于母亲血汞(P0.01);大连市孕妇血汞中有3例(1.7%)、脐带血汞中有9例(8.4%)超过美国国家环保局推荐的国际标准(5.8μg/L);应用多重线性回归分析发现,上海市父亲吸烟、孕妇家中使用杀虫剂、大连市孕妇有被动吸烟史对2地孕妇血汞及新生儿脐带血汞的影响差异有统计学意义。结论对于非职业暴露人群相对工业环境污染、不良生活方式和居住环境因素等对血汞暴露水平的影响更为明显和直接。     

Lead, mercury, and organochlorine compound levels in cord blood in Québec, Canada

We conducted this study to evaluate blood levels of lead, mercury, and organochlorine compounds in newborns in the Province of Quebec. During 1993 to 1995, we carried out a survey in 10 hospitals located in southern Quebec. During that time, umbilical cord blood samples were obtained from 1109 newborns, and we analyzed each for lead, mercury, 14 polychlorinated biphenyl congeners, and 11 chlorinated pesticides. We used the geometric mean and 95% confidence interval (CI) to describe the results. Mean concentrations of lead and mercury in cord blood were 0.076 micromol/l (95% CI = 0.074, 0.079) and 4.82 nmol/l (95% CI = 4.56, 5.08), respectively. The mean concentrations of total polychlorinated biphenyls (Aroclor 1260) and dichlorodiphenyl dichloroethylene were 0.514 microg/I (95% CI = .493, 0.536) and 0.412 microg/l (95% CI = 0.390, 0.435), respectively. We observed a statistically significant relationship between maternal age and cord blood concentrations of (a) lead, (b) mercury, (c) polychlorinated biphenyls, and (d) dichlorodiphenyl dichloroethylene. In addition, maternal smoking during pregnancy was associated with cord blood lead levels. The cord blood concentrations of lead, mercury, polychlorinated biphenyls, and dichlorodiphenyl dichloroethylene we measured in our study were the lowest levels recently reported in industrialized countries. The results of this study underline the role of public health authorities in the evaluation of biological levels of environmental contaminants among children for the assessment of risk of adverse health effects.     

A comparison of organochlorine pesticide residues in maternal adipose tissue,maternal blood,cord blood,and human milk from mother/infant pairs

A total of 41 samples of maternal blood, milk, subcutaneous fat and umbilical cord blood were collected from mothers giving birth by Caesarean operation at Kenyatta National Hospital in Nairobi in 1986. The samples were analyzed for organochlorine contaminants. The main contaminants found in all the samples were p,p-DDT (100%), p,p-DDE (100%), o,p-DDT (59%), dieldrin (27%), transnonachlor (15%), -HCH (12%) and lindane (2%) of all the samples analyzed. Polychlorobiphenyl (PCB) residues were not detected in any of the samples.The mean levels (mg/kg fat) of sum of DDT were 5.9 in subcutaneous fat, 4.8 in mothers milk, 2.7 in maternal serum and 1.9 in umbilical cord serum. There was a significant correlation between the levels of sum DDT in subcutaneous fat and milk fat (r=0.963), subcutaneous fat and maternal serum fat (r=0.843), and maternal serum fat and maternal milk fat (r=0.868), indicating the coherence of DDT in the body.Hexachlorocyclohexane (-HCH) was found in subcutaneous fat and milk fat with the mean levels of 0.03 and 0.26 mg/kg fat, respectively. Dieldrin detected in mothers milk and subcutaneous fat could not be quantified.     

Fetal and maternal immune responses to methylmercury exposure: a cross-sectional study

Methylmercury (MeHg) is a ubiquitous environmental contaminant with known neurodevelopmental effects. In humans, prenatal exposures primarily occur through maternal consumption of contaminated fish. In this study, we evaluated the association between prenatal exposure to MeHg and titers of total immunoglobulins (Ig) and specific autoantibodies in both mothers and fetuses by analyzing maternal and cord blood serum samples. We examined multiple immunoglobulin isotypes to determine if these biomarkers could inform as to fetal or maternal responses since IgG but not IgM can cross the placenta. Finally, we evaluated serum cytokine levels to further characterize the immune response to mercury exposure.The study was conducted using a subset of serum samples (N=61 pairs) collected from individuals enrolled in a population surveillance of MeHg exposures in the Brazilian Amazon during 2000/2001. Serum titers of antinuclear and antinucleolar autoantibodies were measured by indirect immunofluorescence. Serum immunoglobulins were measured by enzyme-linked immunosorbent assay (ELISA) and BioPlex multiplex assay. Serum cytokines were measured by BioPlex multiplex assay.In this population, the geometric mean mercury level was within the 95th percentile for US populations of women of childbearing age but the upper level of the range was significantly higher. Fetal blood mercury levels were higher (1.35 times) than those in their mothers, but highly correlated (correlation coefficient [r]=0.71; 95% CI: 0.54, 0.89). Total IgG (r=0.40; 95% CI: 0.19, 0.62) and antinuclear autoantibody (odds ratio [OR]=1.05; 95% CI: 1.02, 1.08) levels in paired maternal and fetal samples were also associated; in contrast, other immunoglobulin (IgM, IgE, and IgA) levels were not associated between pairs. Total IgG levels were significantly correlated with both maternal (r=0.60; 95% CI: 0.25, 0.96) and cord blood mercury levels (r=0.61; 95% CI: 0.25, 0.97), but individual isotypes were not. Serum cytokines, interleukin-1β (r=0.37; 95% CI: 0.01, 0.73), interleukin-6 (r=0.34; 95% CI: 0.03, 0.65), and tumor necrosis factor-α (r=0.24; 95% CI: 0.015, 0.47), were positively correlated between maternal and fetal samples. Antinuclear and antinucleolar autoantibody titer and serum cytokine levels, in either maternal or cord blood, were not significantly associated with either maternal or cord blood mercury levels.These data provide further evidence that there are likely IgG biomarkers of mercury-induced immunotoxicity in this population since IgG levels were elevated with increased, and associated with, mercury exposure. However, unlike previous data from adult males and non-pregnant females, we found no evidence that antinuclear and antinucleolar autoantibody titer is a reliable biomarker of mercury immunotoxicity in this population.     

Ochratoxin a in maternal and foetal blood and in maternal milk

Ochratoxin A (OA) levels were measured in blood serum of mothers foetuses and in mothers' milk. The mean concentration of OA in maternal serum was 1.14 ng/ml and in umbilical cord blood serum it was 1.96 ng/ml. The mean ratio of OA concentrations in maternal and foetal blood serum was 1.96. In maternal milk OA was found in 5 out of 13 studied samples. The mean intake of OA with mother's milk was not exceeding the tolerable daily intake for adults, nevertheless it was near 60% of TDI. The OA concentration ratio in maternal blood serum versus that in milk was 0.0058 on average. These results confirm the correlation between OA concentration maternal and foetal blood serum, and between OA concentration in maternal serum and milk.     

Correlation between blood mercury levels in mothers and newborns in Itaituba, Pará State, Brazil

This study evaluated transplacental mercury transfer by measuring Hg in blood samples of mothers and newborns (umbilical cord) in hospitals in the municipality (county) of Itaituba, Pará State, Brazil. Epidemiological and mercury exposure data were collected, besides clinical birth data. Mercury tests were performed by cold-vapor atomic absorption spectrophotometry. A total of 1,510 women and an equal number of their newborns participated in the study. Mean blood mercury was 11.53 microg/L in mothers and 16.68 microg/L in newborns (umbilical cord). The highest Hg levels were in the 31-40-year maternal age group and their newborns, with 14.37 microg/L and 21.87 microg/L, respectively. However, in all age groups the mean mercury level was higher in newborns than in mothers. There was a strong positive correlation between Hg levels in newborns and mothers (r = 0.8019; p = 0.000), with a significant linear regression model (r = 0.5283; p = 0.000). The results highlight the importance of monitoring pregnant women exposed to mercury as part of public health surveillance.     

Effects of prenatal exposure to mercury on cognitive and psychomotor function in one-year-old infants: epidemiologic cohort study in Poland

PURPOSE: The aim of the study is to assess the cognitive and psychomotor status of 1-year-old infants whose mothers were exposed to low, but varying, amounts of mercury during pregnancy. METHODS: Mercury levels in cord and maternal blood at delivery were used to assess prenatal environmental exposure to mercury. Bayley Scales of Infant Development were used to assess neurobehavioral health outcomes. The cohort consisted of 233 infants who were born at 33 to 42 weeks of gestation between January 2001 and March 2003 to mothers attending ambulatory prenatal clinics in the first and second trimesters of pregnancy. Enrollment included only nonsmoking women with singleton pregnancies between the ages of 18 and 35 years who were free from chronic diseases. RESULTS: The geometric mean (GM) for maternal blood mercury level for the group of infants with normal neurocognitive performance was lower (GM = 0.52 mug/L; 95% confidence interval [CI], 0.46-0.58) than that observed in the group with delayed performance (GM = 0.75 mug/L; 95% CI, 0.59-0.94), and this difference was significant (p = 0.010). The GM of cord blood mercury level in the normal group also was lower (GM = 0.85 mug/L; 95% CI, 0.78-0.93) than that observed in the group with delayed performance (GM = 1.05 mug/L; 95% CI, 0.87-1.27), and this difference was of borderline significance (p = 0.070). The relative risk (RR) for delayed performance increased more than threefold (RR = 3.58; 95% CI, 1.40-9.14) if cord blood mercury level was greater than 0.80 mug/L. Risk for delayed performance in the group of infants with greater maternal mercury levels (>0.50 mug/L) also was significantly greater (RR = 2.82; 95% CI, 1.17-6.79) compared with children whose mothers had mercury levels less than 0.50 mug/L. CONCLUSIONS: The results may be of public health importance because delayed psychomotor or mental performance in infants is assumed to be an indicator of later neurocognitive development in children, which may persist into adult life.     

Effect of maternal lifestyle on cord blood IgE factor

During recent decades much interest has been focused on the possibility of predicting and preventing atopic diseases during pregnancy. The idea of being able to detect a predisposition early and take suitable environmental measures in order to avoid overt allergy is an attractive position. Elevated cord IgE of around 1.0 IU/ml has been proposed as a predictor in western children. However, there remains no information about the effect of maternal lifestyle during pregnancy on these levels. Total IgE levels were therefore determined using Pharmacia CAP system and PRIST, with sensitivities of 0.01 kU/l and 0.25 kU/l, respectively, from serum samples taken from 1138 Japanese pairs of cord blood and pregnant women responding to a questionnaire regarding 17 health practices, intake of 32 food allergens and 5 environmental factors. Of these, 28 (2.5%) pairs of samples were excluded from further analysis because of high contamination of IgA (> 15.4 mg/ml) in cord blood. Median cord blood IgE was 0.286 kU/l and geometric mean IgE was 66.25 kU/l in maternal sera using CAP system; there was no significant correlation between maternal log (IgE) and cord blood IgE. Similar results were obtained from PRIST, whose correlation with CAP system was significant (r = 0.884, p < 0.001 for maternal and r = 0.765, p < 0.001 for cord blood). Multiple logistic analysis demonstrated that avoidance of simultaneous exposure to hens' eggs and cow's milk (relative risk = 1.3, p < 0.05) as well as soy beans (relative risk = 2.8, p < 0.01) should be advised to mothers with positive allergic histories and/or high total IgE (> 400 IU/ml), especially in women aged more than 35 years who are pregnant with a male child. However, maintenance of healthy lifestyles, especially taking proper exercise and sleeping, and avoidance of inhalant allergens during late pregnancy may be a more important strategy for the reduction of cord blood IgE levels.     

Blood lead levels of both mothers and their newborn infants in the middle part of China

A cross-sectional investigation on maternal and umbilical blood lead levels in an urban area, an industrial town and a rural area of middle China is reported. Blood samples from 89 mothers during delivery, from the umbilical cords and from 105 non-pregnant women were collected. Self-administered questionnaires including the medical history and the pregnancy-related complaints were performed. After acid digestion, the whole blood lead levels were determined by a 180-80 flame atomic absorption spectrometer. The geometric mean for lead levels in blood of non-pregnant women was 66.9 microg/l (range: 25.0-201.0 microg/l) in the urban, 66.9 microg/l (range: 30.5-198.8 microg/l) in the industrial town, and 53.3 microg/l (range: 16.0-170.5 microg/l) in the rural area. The geometric mean of lead levels in blood of pregnant women at delivery both in the rural area (74.4 microg/l, range: 35.2-245.6 microg/l) and industrial town (65.9 micro/l, range: 20.0-172.0 microg/l) were higher than in the urban region (54.3 microg/l, range: 27.9-187.0 microg/l; p < 0.05). Compared with non-pregnant women at the same area, the blood lead levels of pregnant women was lower in urban (p < 0.05), but higher in rural areas (p < 0.05). The geometric mean for lead level in umbilical cord blood was significantly higher in rural (84.1 microg/l, range: 28.0-185.0 microg/l) than in the other areas (53.5 microg/l, range: 23.5-156.7 microg/l in the urban; 60.1 microg/l, range: 12.5-168.3 microg/l in the industrial town). The total geometric mean for lead level in cord blood was 69.0 microg/l (range: 12.5-185.0 microg/l), and 17.8% samples were above the blood lead threshold of health concern (> or =100 microg/l) for children (CDC, 1991), but the body weight and length of newborn babies have not been affected. The correlation between maternal and cord blood was 0.6805 (p < 0.01). Most of the pregnant women did not take the calcium supplements recommended during pregnancy. In conclusion, there were some lead burdens on both the mothers and their newborn babies in these areas. All possible measures should be taken to reduce the environmental lead exposure. It is also crucial that maternal nutrient intake, particularly calcium, should be sufficient.     

Maternal amalgam dental fillings as the source of mercury exposure in developing fetus and newborn

Dental amalgam is a mercury-based filling containing approximately 50% of metallic mercury (Hg(0)). Human placenta does not represent a real barrier to the transport of Hg(0); hence, fetal exposure occurs as a result of maternal exposure to Hg, with possible subsequent neurodevelopmental disabilities in infants. This study represents a substudy of the international NIH-funded project "Early Childhood Development and polychlorinated biphenyls Exposure in Slovakia". The main aim of this analysis was to assess the relationship between maternal dental amalgam fillings and exposure of the developing fetus to Hg. The study subjects were mother-child pairs (N=99). Questionnaires were administered after delivery, and chemical analyses of Hg were performed in the samples of maternal and cord blood using atomic absorption spectrometry with amalgamation technique. The median values of Hg concentrations were 0.63 microg/l (range 0.14-2.9 microg/l) and 0.80 microg/l (range 0.15-2.54 microg/l) for maternal and cord blood, respectively. None of the cord blood Hg concentrations reached the level considered to be hazardous for neurodevelopmental effects in children exposed to Hg in utero (EPA reference dose for Hg of 5.8 microg/l in cord blood). A strong positive correlation between maternal and cord blood Hg levels was found (rho=0.79; P<0.001). Levels of Hg in the cord blood were significantly associated with the number of maternal amalgam fillings (rho=0.46, P<0.001) and with the number of years since the last filling (rho=-0.37, P<0.001); these associations remained significant after adjustment for maternal age and education. Dental amalgam fillings in girls and women of reproductive age should be used with caution, to avoid increased prenatal Hg exposure.     

Mercury exposures and symptoms in smelting workers of artisanal mercury mines in Wuchuan, Guizhou, China

Mercury exposures to smelting workers of artisanal mercury mines in Wuchuan, Guizhou, China were evaluated by urine and hair mercury survey. The mean urinary mercury (U-Hg), hair total mercury (T-Hg), and hair methyl mercury (Me-Hg) for smelting workers was 1060 microg/g creatinine (microg/g Cr), 69.3 and 2.32 microg/g, respectively. The results were significantly higher than that of control group, which is 1.30 microg/g Cr, 0.78 and 0.65 microg/g, correspondingly. The average urinary beta2-microglobulin (beta2-MG) was 248 microg/g Cr for the exposed group contrasting to 73.5 microg/g Cr for the control group and the data showed a serious adverse effect on renal system for the smelting workers. The workers were exposed to mercury vapor through inhalation, and the exposure route of Me-Hg may be through intake of polluted diet. The results indicate that age, alcohol drinking, and smoking are not crucial factors controlling the urine and hair mercury levels for the exposed and the control group. Clinical symptoms including finger and eyelid tremor, gingivitis, and typical dark-line on gums were observed in six workers. This study indicated that the smelting workers in Wuchuan were seriously exposed to mercury vapor.     

Associations of Prenatal Mercury Exposure From Maternal Fish Consumption and Polyunsaturated Fatty Acids With Child Neurodevelopment: A Prospective Cohort Study in Italy

Background

Mercury is a neurotoxin, and limited prenatal exposure to it can affect long-term child neurodevelopment. However, results of epidemiologic studies of such exposure have been inconsistent. We examined the association of prenatal mercury exposure from maternal fish consumption with child neurodevelopment in northern Italy.

Methods

A population-based cohort of 606 children and their mothers was studied from pregnancy to age 18 months. Mercury levels were measured in maternal hair and blood during pregnancy and in umbilical cord blood and breast milk. Levels of polyunsaturated fatty acids (PUFAs) were measured in maternal serum. Maternal and child intakes of fish were assessed by using a food frequency questionnaire. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) was used to evaluate child neurodevelopment. Multivariate linear regression was used to examine the association of mercury exposure with BSID-III scores, after controlling for maternal fish intake, PUFAs during pregnancy, and several other confounders.

Results

Mean weekly fish intake during pregnancy was less than 2 servings. Mercury concentrations in biological samples were low (mean, 1061 ng/g in hair) and moderately correlated with fish intake, particularly of carnivorous species. Maternal ω-3 PUFA concentrations were poorly correlated with fish intake. Maternal intelligence quotient (IQ) and child intake of fish were significantly associated with neurodevelopment scores. In multivariate models, the level of Hg exposure was not associated with neurodevelopmental performance at 18 months.

Conclusions

In this Italian population, neurodevelopment at 18 months was associated with child intake of fresh fish and maternal IQ rather than with mercury exposure. The expected beneficial effect of maternal fish intake (from maternal ω-3 PUFAs) was not found.Key words: mercury, polyunsaturated fatty acids, nervous system development, fish, Bayley Scales of Infant and Toddler Development     

Carotenoid Profile in Maternal/Cord Plasma and Changes in Breast Milk along Lactation and Its Association with Dietary Intake: A Longitudinal Study in a Coastal City in Southern China

In this study, changes of carotenoids in breast milk were observed longitudinally for up to one year. Our study aimed to analyze the profile of carotenoids in breast milk and maternal/cord plasma and its correlation with dietary intake in Guangzhou. Plasma and breast milk samples of five stages during lactation (i.e., colostrum; transitional milk; and early, medium, and late mature milk) were collected from lactating mothers. The food frequency questionnaire (FFQ) was used for collecting data on dietary intake in the corresponding stages. Levels of lutein, zeaxanthin, β-cryptoxanthin, β-carotene, and lycopene were analyzed by high-performance liquid chromatography. We found that the total carotenoid level decreased gradually with the extension of lactation and eventually stabilized. Among them, the content of lutein increased from colostrum to transitional milk and decreased thereafter until it plateaued in the mature milk. Furthermore, lutein was reported as the dominant nutrient in maternal plasma, cord plasma, transitional milk, and mature milk at up to 400 days postpartum, while beta-carotene was predominant in colostrum. The content of β-carotenoid in middle and late mature breast milk was related to dietary intake (r = 1.690, p < 0.05). Carotenoid level in cord blood was lower than that in the mother’s plasma and was related to the carotenoid intake in the mother’s diet. Correlation of carotenoids between maternal and umbilical cord blood, breast milk, and maternal blood could well reflect the transport of carotenoids. These findings may help to guide mothers’ diets during breastfeeding.     

Methyl mercury and inorganic mercury in Swedish pregnant women and in cord blood: influence of fish consumption

We studied exposure to methyl mercury (MeHg) in Swedish pregnant women (total mercury [T-Hg] in hair) and their fetuses (MeHg in cord blood) in relation to fish intake. The women were recruited at antenatal care clinics in late pregnancy to participate in an exposure study of environmental pollutants. Fish consumption was evaluated using food frequency questionnaires including detailed questions on fish consumption. In addition, we determined inorganic mercury (I-Hg) and selenium (Se) in cord blood. On average, the women consumed fish (all types) 6.7 times/month (range 0-25 times/month) during the year they became pregnant. They reported less consumption of freshwater fish--species that might contain high concentrations of MeHg--during than before pregnancy. T-Hg in maternal hair (median 0.35 mg/kg; range 0.07-1.5 mg/kg) was significantly associated (R2 = 0.53; p < 0.001) with MeHg in cord blood (median 1.3 microg/L; range 0.10-5.7 microg/L). Both hair T-Hg and cord blood MeHg increased with increasing consumption of seafood (r = 0.41; p < 0.001 and r = 0.46; p < 0.001, respectively). Segmental hair analysis revealed that T-Hg closer to the scalp was lower and more closely correlated with MeHg in cord blood than T-Hg levels in segments corresponding to earlier in pregnancy. We found a weak association between Se (median 86 microg/L; range 43-233 microg/L) and MeHg in cord blood (r = 0.26; p = 0.003), but no association with fish consumption. I-Hg in cord blood (median 0.15 microg/L; range 0.03-0.53 microg/L) increased significantly with increasing number of maternal dental amalgam fillings.     

Prevalence of hepatitis B surface antigen in pregnant mothers and its perinatal transmission

1000 pairs of maternal and cord blood samples were collected simultaneously at the time of delivery. 23 (2.3%) of the maternal samples were positive for HBsAg by enzyme-linked immunosorbent assay. HBeAg was detected in 11 (47%) of the 23 HBsAg positive mothers and anti-HBeAg was detected in another 5 samples. HBsAg and HBeAg were detected in 7 (30%) of the 23 cord blood samples from HBsAg-positive mothers, and anti-HBeAg was detected in one of these samples. At follow-up (6-18 months), antigenaemia had persisted in 17 (85%) of the 20 HBsAg-positive mothers and in 9 (45%) of 20 babies born to HBsAg-positive mothers. Seven of the 10 babies (70%) born to mothers positive for both HBsAg and HBeAg had persistent HBsAg in their blood, in contrast to 2 of the 10 babies (20%) born to mothers positive for HBsAg only. However, none of these mothers or their babies were found to have anti-HBeAg at follow-up. We conclude that the presence of HBeAg in mothers' blood enhances vertical transmission of hepatitis B virus infection to their babies.     

舟山海岛地区孕妇及新生儿内环境汞暴露现状调查研究

目的调查研究舟山地区孕妇及新生儿汞暴露现状,为相关防治措施的制定提供科学依据。方法选择2006年3月～2007年7月在舟山市妇幼保健医院分娩的舟山本地户籍孕妇及其新生儿作为本次研究对象,对孕妇尿、血、头发及其新生儿脐带血进行汞含量测定,并进行书面问卷调查。结果本研究共测定孕妇尿汞样2 190份,算术平均值为2.58μg/L;发汞3 109份,算术平均值为1.27 mg/kg;血汞3 337份,算术平均值为5.40μg/L;新生儿脐带血汞样本2 998份,算术平均值为7.71μg/L;获得孕妇尿汞、发汞、血汞及新生儿脐带血汞相对应样本及问卷1 554份,研究显示孕妇的尿汞值、发汞值、血汞值、新生儿脐血汞值存在关联性,其中孕妇血汞值与脐血汞值关联性最强（r=0.600,P〈0.01）,其他的相关系数均小于0.20。孕妇吃鱼次数与尿汞、血汞和新生儿脐带血汞水平相关。结论舟山地区孕妇尿、血和脐带血汞量与孕妇吃鱼次数有关,有很大比例的孕妇和新生儿有潜在的汞危害,需要进一步采取措施进行干预。