Mohsen Vigeh

Blood manganese concentrations and intrauterine growth restriction

To assess the relationship between blood concentrations of manganese (Mn) and intrauterine growth restriction (IUGR), Mn levels in the umbilical cord blood (UCB) and the mother whole blood (MWB) samples were measured in apparently healthy mothers and their newborns. Measurement was conducted by an inductively coupled plasma mass spectrometry. Manganese concentrations in MWB were significantly lower (p<0.01) in IUGR cases than in appropriate for gestational age (AGA) cases (mean+/-S.D.; 16.7+/-4.8 and 19.1+/-5.9 microg/l, respectively). Conversely, UCB concentrations of Mn were significantly higher (p<0.05) in IUGR newborns than AGA newborns (44.7+/-19.1 and 38.2+/-13.1 microg/l, respectively). Logistic regression analysis demonstrated significant relationships of the mother whole blood and the umbilical cord blood concentrations of Mn in IUGR cases (OR=0.868, 1.044, respectively). The study suggests that manganese concentrations in MWB and UCB might induce different effects on birth weight in healthy mothers. Because intrauterine growth restriction is a multi-factorial problem, further epidemiological and clinical studies on larger numbers of subjects are needed to confirm the findings in the present study.

Blood lead at currently acceptable levels may cause preterm labour

Objectives Although occupational and environmental exposures to lead have been dramatically reduced in recent decades, adverse pregnancy outcomes have been observed at ‘acceptable’ levels of blood lead concentrations (≤10 μg/dl). Methodology Blood samples were collected from 348 singleton pregnant women, aged 16–35 years, during the first trimester of pregnancy (8–12 weeks) for lead measurement by inductively coupled plasma–mass spectrometry. Subjects were followed up and divided into two groups (preterm and full-term deliveries) according to duration of gestation. Results The average (range) and geometric means of blood lead levels were 3.8 (1.0–20.5) and 3.5 μg/dl, respectively. Blood lead level was significantly (p<0.05) higher in mothers who delivered preterm babies than in those who delivered full-term babies (mean±SD: 4.46±1.86 and 3.43±1.22 μg/dl, respectively). Logistic regression analysis demonstrated that a 1 unit increase in blood lead levels led to an increased risk of preterm birth (OR 1.41, 95% CI 1.08 to 1.84). Conclusion Adverse pregnancy outcomes may occur at blood lead concentrations below the current acceptable level.

Early pregnancy blood lead levels and the risk of premature rupture of the membranes

To clarify the effects of lead on fetal premature rupture of the membranes (PROM), blood lead concentrations were measured using inductively coupled plasma-mass spectrometry in 332 women, aged 16-35 years, during their early pregnancy period (8-12 weeks). Blood lead concentrations were significantly higher in the 36 PROM deliveries than in the 296 non-PROM deliveries (mean ± SD, 4.61 ± 2.37 and 3.69 ± 1.85 μg/dl, respectively; p<0.05). The logistic regression analysis revealed that a 1-unit increase in the logarithm of the blood lead level led to a several-fold increase in the risk of PROM (unit risk=17.98, 95% CI 1.6-198.6). Thus, it is suggested that lead can increase the risk of PROM in pregnant women with mean blood lead less than 5 μg/dl.

Relationship between Increased Blood Lead and Pregnancy Hypertension in Women without Occupational Lead Exposure in Tehran, Iran

This study was conducted to assess the relationship between blood lead levels and pregnancy-induced hypertension. Participants were 110 pregnant women, of whom 55 were hypertensive, 27 ± 5.6 yr of age (mean ± standard deviation) (range = 17-40 yr); the other 55 women were age- and gravidity-matched normotensive controls. Participants were selected on the basis of their medical history and the results of a questionnaire-based interview. Subjects were at gestational ages 37 ± 2.5 wk (range = 30-41 wk) and were not occupationally exposed to lead. Blood samples were collected within 24 hr after delivery, and blood lead levels were measured. For the hypertensive cases, blood lead levels were 5.7 ± 2 μg/dl (range = 2.2-12.6 μg/dl [0.27 ± 0.10 μmol/l; range = 0.11-0.60 μmol/I), which were significantly higher than those of the control group (i.e., 4.8 ± 1.9 μg/dl; range = 1.9-10.6 μg/dl [0.23 ± 0.09 μmol/I; range = 0.09-0.51 μmol/I]). There were no significant differences in blood lead concentrations among hypertensive subjects with proteinuria (n = 30) and those without proteinuria (n = 25). Results of this study indicated that low-level lead exposure may be a risk factor for pregnancy hypertension.

Low level prenatal blood lead adversely affects early childhood mental development.

The effect of prenatal lead exposure on child development has been a topic of public health concern for decades. To estimate prenatal lead exposure effects on early childhood development, maternal blood (n = 364) and umbilical cord blood (n = 224) samples were collected during pregnancy and at delivery. Mental development was assessed using the Harold Ireton Early Child Development Inventory from 174 children. Maternal whole blood lead levels in the first trimester were significantly higher in children with developmental scores <20% than in those with normal scores (mean ± standard deviation: 6.3 ± 1.9 vs 4.0 ± 2.4 µg/dL, respectively, P = .01). Maternal blood lead levels in the first trimester were also inversely associated with the development scores (r = –0.155, P = .041). Logistic regression analysis showed a significant relationship between increasing maternal blood lead levels in the first trimester with low development scores (odds ratio = 1.74, 95% confidence interval = 1.18-2.57, P = .005). The findings of the present study showed a relatively low level of prenatal lead exposure (mean < 6.5 µg/dL) associated with lower developmental scores in early childhood.

Increase in blood manganese induces gestational hypertension during pregnancy

Objective: Pregnancy hypertension can lead to many pregnancy complications and increases the risk of maternal morbidity and mortality. Methods: To investigate the effects of blood manganese (Mn) on the development of pregnancy hypertension, 364 healthy women were examined during early pregnancy until delivery. Results: At the first and second trimesters of pregnancy, concentrations of Mn in maternal blood were significantly higher in the hypertensive pregnant women than in the normotensive women. The logistic regression analysis demonstrated significant relationships between Mn concentrations in maternal blood for the first and second trimesters of pregnancy with gestational hypertension [OR (95% CI) = 47.0 (4.0–556.4) and 5.5 (1.1–29.0), respectively]. Conclusion: The present study thus suggested that increased Mn during pregnancy might be a potential risk factor for inducing pregnancy hypertension.

Relationship between maternal thyroid-stimulating hormone (TSH) elevation during pregnancy and low birth weight: A longitudinal study of apparently healthy urban Japanese women at very low risk

OBJECTIVE Thyroid hormones cross the placenta and promote fetal development and growth. The present study investigated whether an increase in maternal thyroid-stimulating hormone (TSH) concentration between the first and third trimesters is a determinant of birth weight during normal pregnancy. METHODS Maternal thyroid hormones and TSH were longitudinally measured at 12, 25, and 36weeks of pregnancy in 163 healthy pregnant women. Low birth weight (LBW) was defined as less than 2500g. ∆TSH12-36W was calculated as the difference in TSH concentrations between 12 and 36weeks of pregnancy. RESULTS Of the 163 neonates, 10 (6.1%) were LBW neonates. Free triiodothyronine and free thyroxine levels were similar at all gestational ages in the normal birth weight (Normal) and LBW groups. However, the median ∆TSH12-36W value was higher in the LBW than the Normal group (1.67 vs. 0.54mIU/L, P=0.008). Multivariate linear regression analysis showed that ∆TSH12-36 was inversely correlated with birth weight (β=-0.179, P=0.008). CONCLUSION An increase in maternal TSH concentration between the first and third trimesters is an independent determinant of birth weight in normal pregnancy.

Increased prenatal blood manganese may induce gestational blood pressure

ABSTRACT Objective: Pregnancy hypertension is the most common gestational complication and poses a critical risk for mother and fetus. Whether environmental factors may play an important role in disease occurrence is not fully determined. Methods: To investigate the effects of prenatal manganese (Mn) exposure on gestational blood pressure, 386 women were examined. Results: Early pregnancy blood Mn was significantly (p < 0.05) correlated with blood pressure through gestation. A significant association between odds of pre-hypertension with blood Mn was shown (OR:1.150, 95% CI:1.052–1.258). Conclusion: The current study results might suggest the blood Mn level during early stage of pregnancy as a potential risk factor for increasing the risk of gestational blood pressure.

The Relation of Maternal Blood Arsenic to Anemia During Pregnancy

To clarify the relationship of prenatal arsenic exposure to hemoglobin concentrations and anemia during pregnancy, a longitudinal study was conducted of 364 participants during early pregnancy from October 2006 to March 2011 in Tehran, Iran. Maternal whole blood (taken between 8–12 and 20–24 weeks of gestation, and at delivery) and umbilical cord blood samples were collected for arsenic measurement. The mean concentration of maternal blood arsenic in the first trimester of pregnancy was significantly lower in anemic women compared with non-anemic participants (mean ± SD: 12.4 ± 3.4 versus 14.8 ± 4.0 μg/L, respectively, p < 0.001). Maternal whole blood arsenic levels in the first and third trimesters were significantly (p < 0.05) correlated with hemoglobin concentrations measured throughout gestation (r = 0.312, 0.424, and 0.183). Multiple logistic regression analysis demonstrated that increased maternal blood arsenic levels in the first trimester were significantly negatively associated to anemia during pregnancy (OR = 0.85, CI: 0.77–0.94, p < 0.01). The present study showed that prenatal blood arsenic exposure was not a risk factor for the occurrence of anemia.

226 Prenatal blood lead level and childhood neurobehavioral deficit

Objectives Lead is one of the oldest known toxic metals. For decades, its effects on child development has been remained a topic of concern with an increased interest in ‘what prenatal blood lead levels should be considered toxic’. Many resent studies have shown the impacts of increased blood lead on different aspects of infants’ development at ‘acceptable’ levels (≤100μg/L). Methods To investigate the effects of prenatal lead exposure on children mental development, we have conducted a longitudinal study. Pregnant women (n = 364) who referred to hospitals for prenatal care at the first trimester of pregnancy were asked to participate in the survey. Maternal whole blood (MWB) samples, one for each pregnancy trimesters (3 times), and the umbilical cord blood samples, at the time of delivery, were collected and subjected to ICP-MS analysis for measurement of lead concentrations. We invited the mothers and their children to the research hospitals when the children were between 20 and 36 months of age and assessed mental development using Early Child Development Inventory (ECDI). The inventory included 60 items, which cover seven different development areas. Results MWB lead followed a U-shaped pattern over the course of pregnancy with lowest level during the second trimester. The ECDI score was inversely related to the first trimester blood lead concentrations (r = -0.15, p<0.05). The logistic regression analysis demonstrated significant relationships between increasing the first trimester lead concentrations (loge) with low score of ECDI, adjusting for multiple covariates (Unit risk: 5.7, 95% CI: 1.1 - 30.7, p <0.001). Conclusions Increased prenatal lead concentrations, even at “acceptable” level, adversely affects ECDI scores. Therefore, a reappraisal of lead exposure standards for female workers is a critical public health concern.