新生儿神经行为发育与脐血及胎粪铅含量的关系(英文)

Relationship between neonatal neurobehavioral development and lead level in umbilical cord blood and meconium

背景以往大量研究都是以生产时一次性脐血铅的浓度来进行研究的,但生产时一次性脐血铅的浓度并不能很好的代表在整个妊娠期间铅对胎儿神经系统的累积损伤。胎粪中的铅主要来源于胎儿消化道分泌的消化液、新生儿肠道脱落的上皮细胞、胎儿吞咽下的羊水、皮脂,是从妊娠一开始直至新生儿出生后24h内排出,它反映的是整个妊娠过程中铅在新生儿胃肠道中的蓄积量。目的探讨在宫内低水平铅暴露状态下,比较新生儿脐血铅含量及胎粪铅含量与新生儿神经行为发育的相关性。设计以脐血铅和胎粪铅含量作为新生儿宫内铅暴露的指标,新生儿神经行为发育评分作为效应指标,采用描述性分析方法评价其相关关系。单位武汉科技大学,华中科技大学同济医学院职业病流行病学实验室,武汉第一冶金建筑总公司职工医院。对象选择武汉市新型工业区的青山区第一冶金建筑总公司职工医院妇产科1999-01/10出生的足月、健康新生儿103例作为观察对象。家属同意参加课题研究并填写问卷调查,提供新生儿胎粪,按时进行新生儿测试。方法①样本的采集及测定采取脐血5m L,于-4℃冰箱中冷藏保存。收集出生24h内的胎便,干重5～10g,用石墨炉原子吸收光谱法测定脐血铅与胎粪铅的含量。②分组以脐血铅0.483μm ol/L为分界值,将新生儿分成高铅组与低铅组。以127.78m g/kg作为胎粪铅的分界点,并将观察对象分为高铅组与低铅组。③新生儿神经行为发育检查采用新生儿神经行为发育检查法,于分娩第3天进行检查。同时采用自行设计的问卷对产妇进行调查。主要观察指标①新生儿脐血与胎粪中铅含量。②不同浓度脐血铅和胎粪铅的新生儿神经行为发育评分。结果103例新生儿均进入结果分析。①脐血高铅组与低铅组仅在新生儿神经行为发育总评分、生物视听定向反应得分上差异有显著性意义(P<0.05),但脐血铅含量与新生儿神经行为发育总评分、非生物听定向反应、非生物视定向反应、生物视听定向反应之间不存在等级相关关系。②胎粪高铅组与低铅组在新生儿神经行为发育总评分、非生物听定向反应、非生物视定向反应、生物视听定向反应4项评分上,两组差异有显著性和非常或极显著性意义(P<0.05～0.01)。胎粪铅含量与新生儿神经行为发育总评分、非生物视定向反应、生物视听定向反应3项神经评分有明确的等级负相关关系。结论胎粪铅含量与新生儿神经行为发育评分更为密切,胎粪铅含量可作为妊娠期胎儿体内铅蓄积的指标。

BACKGROUND： In the past, a lot of researches used one-time lead level in umbilical cord blood at birth for investigations,however, one-time lead level in umbilical cord blood at birth can not represent lead caused cumulative injury to neonatal nervous system during the whole period of pregnancy. Lead in meconium is mainly from digestive juice secreted by fetal alimentary tract, exfoliative epithelia from neonatal intestinal tract and amniotic fluid and sebum cutaneum swallowed by fetus, which is excreted from the very start of pregnancy to 24 hours after birth of neonates and refleets the lead deposit in neonatal intestinal tract during the whole period of pregnancy. OBJECTIVE： To explore the relationship between neurobehavioral development in neonates with intrauterine exposure to lead at low level and the lead level in umbilical cord blood （CBPb） and mecouium （MPb）. DESIGN： Take lead levels in umbilical cord blood and meconium as neonatal intrauterine exposure indicators and scores of neonatal neurobehavioral development as effect indicators, and descriptive analysis is used to evaluate the correlativity. SETTING： Wuhan University of Science and Technology; Laboratory of Occupation Disease and Epidemiology, Tongji Medical College; Huazhong University of Science and Technology; Wuhan First Metallurgical Con- struction Company Hospital for Workers and Staff. PARTICIPANTS： A total of 103 cases of full-term and healthy neonates were selected as objects of observation. The neonates were born in Departmeut of Gynecology and Obstetrics, Wuhan First Metallurgical Constretion Company Hospital, Qingshan District of New Industrial District of Wuhan from January to October 1999. Their parents were agreed to participate in the study and filled in the questionnaire, and provided neonatal meconium and performed neonatal tests on schedule. METHODS： （1） Collection and assay of sample： 5 mL umbilical cord blood were collected and reserved in refrigerator at -4℃. Meconium within 24 hours after birth, with dry weight between 5 to 10 g was collected, the lead levels in umbilical cord blood and meconium were assayed with the method of graphite furnace atomic absorption spectroscopy. （2） Grouping： The neonates were divided into two groups with high and low-exposure to lead based on the cutoff value of CBPb of 0.483 μmol/L and MPb of 127.78 mg/kg. （3） Neonatal neurobohavioral development examination： Neonatal neurobohavioral development examination method was used for examination 3 days before delivery. Meanwhile, self-designed questionnaire was used to conduct a survey in puerperas. MAIN OUTCOME MEASURES： （1） Lead levels in neonatal umbilical cord blood and meconium. （2） Scores of neurobehavioral development of neonates with different lead levels of umbilical cord blood and meconium. RESULTS： All the 103 cases of neonates entered results analysis. （1） There was significant difference only in scores of neonatal behavioral neurological assessment （NBNA） and biological, visual and auditory orientation reaction （BVAOR）between groups with high and low-exposure to lead in umbilical cord blood （P 〈 0.05）. However, there was no rank correlativity between lead level in umbilical cord blood and scores of NBNA, non-biological auditory orientation reaction （NBAOR）, non-biological visual orientation reaction （NBVOR） and biological visual and auditory orientation reaction （NBVOR）. （2）There was significant difference in scores of NBNA, NBAOR, NBVOR and BVAOR between groups with high and low-exposure to lead in meconium （P 〈 0.05-0.01）. The lead level in meconium clearly correlated reyersely with scores of NBNA, NBVOR and BVAOR. CONCLUSION： Lead level in meconium is more sensitively related to the scores of neonatal neurobehavioral development, which could be used as indicator for lead deposit in the fetal body during the period of pregnancy.