Effects of prenatal blood lead exposure lower than 100 μg/L on infant's neurobehavioral development

Abstract

Abstract: 【Objective】 To determine the effects of prenatal lead exposure(lower than 100 μg/L) on six-month-old infant's growth and development. 【Methods】 The study subjects were 6-month-old infants whose mothers' blood lead were lower than 100 μg/L both during the 1^st and 3^rd trimester of gestation in a cohort study. Bayley infant development scale was used to evaluate the infants' development. The differences in mental development index(MDI) and psychomotor development index(PDI) of infant were compared across different prenatal blood exposure levels, using the P25, P50 and P75 of the blood lead during pregnancy as the dividing value of groups, respectively. 【Results】 The MDI and PDI of 6-month-old infants tended to decrease as the increase of prenatal blood lead exposure level. The PDI of 6-month-old infants in the relative high lead level group was lower than that in the relative low lead group as the dividing value of groups was P25 and P50 of blood lead, and the difference were statistically significant(P<0.05). There were no significant differences in the MDI of 6-month-old infants across groups. Besides, multivariate analysis indicated that the PDI of the infants whose prenatal lead concentration higher than P50 was 4.48 point lower than that of infants below P50. Similarly, the PDI of the infants whose prenatal lead concentration higher than P25 was 6.51 point lower than that of infants below P25. The differences were statistically significant. 【Conclusion】 Low level prenatal lead exposure may exert an influence on infants' behavior development and such effect might be more significant at the low level of lead exposure, which merits further research.

Key words: blood lead, prenatal exposure, infant, development

摘要： 【目的】探讨出生前100 μg/L以下剂量铅暴露对婴儿6月龄时智力和行为发育的影响。【方法】以出生前孕早期和晚期孕妇血铅低于100 μg/L的婴儿为研究对象,在其6月龄时用Bayley婴幼儿发育量表评价智力发育和精神运动发育。根据孕早期和晚期血铅的P25、P50和P75为界值,将婴儿分为相对高、中、低铅组,比较不同组间智力(mental development index, MDI)和行为发育指数(psychomotor development index, PDI)差异。【结果】婴儿6月龄时MDI和PDI均随出生前血铅水平的升高呈现下降趋势。以P25和P50为界值分组时,相对高铅组婴儿PDI均低于相对低铅组,且差异具有统计学意义(P<0.05);以P75为界值时,组间婴儿PDI未见明显差异。各分组间婴儿MDI差异均无统计学意义(P>0.05)。纳入孕妇年龄、文化因素分析发现,孕早期和晚期血铅在P50(31.15 μg/L和37.58 μg/L)以上的婴儿其PDI较其他婴儿PDI低4.48分;孕早期和晚期血铅水平在P25(24.0 μg/L和29.8 μg/L)以上的婴儿,其PDI较其他婴儿PDI低6.51分,差异均有统计学意义。【结论】出生前100 μg/L剂量以下铅暴露对婴儿发育有影响,特别是对婴儿6月龄时PDI影响更为显著。

关键词: 血铅, 出生前, 婴儿, 发育

CLC Number:

R179

WANG Bo, SHAO Di-chu, XIANG Zhang-hua, NI Wei-min, YANG Shui-lian, WU Cui-e, LI Ping-jian, FU Hua. Effects of prenatal blood lead exposure lower than 100 μg/L on infant's neurobehavioral development[J]. journal1, 2011, 19(6): 505-508.

王波,邵迪初,项张华,倪为民,杨水莲,吴翠娥,李凭健,傅华. 出生前低于100 μg/L血铅暴露对婴儿发育的影响[J]. 中国儿童保健杂志, 2011, 19(6): 505-508.

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