[ 摘要 ]

胎便（meconium）是嬰兒出生24小時後，第一次排泄物，胎便的組成包括胃腸道中的表皮細胞、胎毛、胎脂、羊水，因此胎便可以反應出胎兒在子宮內腸胃道中的金屬的累積量。本研究採橫斷性的研究設計，以新生兒胎便中鉛、鎘、汞、砷濃度作為其在母親子宮內金屬累積暴露之生物指標，探討胎便金屬濃度與新生兒生長狀況之相關性，並評估母親的基本人口學特徵、生活型態、飲食習慣對胎便中鉛、鎘、汞、砷濃度與新生兒生長狀況之影響。研究期間為2006年12月至2007年4月，於新竹某醫院進行收樣，個案為母親及新生兒配對共198對，均為自願且懷孕期間無併發症者，進行母親基本資料蒐集與問卷訪視，收集新生兒出生第一天的胎便及紀錄生長狀況，並分析胎便中鉛、鎘、汞、砷濃度，其中胎便鉛、鎘、砷濃度使用感應耦合電漿質譜儀(Inductively Coupled Plasma Mass Spectrometry; ICP-MS)分析，胎便汞濃度使汞分析儀(Mercury Analysis System)分析。結果發現，新生兒胎便中鉛、鎘、汞、砷的幾何平均濃度分別為11.69±2.10 ppb dry weight (wt)、13.59±7.65 ppb dry wt、79.21±7.33 ppb dry wt、23.45±50.50 ppb dry wt。母親生產胎次為第一胎、籍貫為原住民者其新生兒胎便鉛濃度顯著較高；懷孕前有吃生魚片習慣者其胎便汞濃度顯著較高。複廻歸模式中發現母親喝酒、懷孕期間魚攝取量(克/餐)會顯著降低新生兒的出生體重；母親有喝酒習慣與職業暴露則新生兒的出生頭圍比沒有者顯著較小；母親有喝酒習慣、年齡越大則新生兒生產週數顯著較長。此外，調整新生兒胎便汞濃度與母親職業暴露後，胎便砷濃度每增加10 ppb，則新生兒出生頭圍異常(<32公分)的危險對比值就提高4.46倍(95% C.I=1.086-18.38)；調整新生兒胎便汞濃度與砷濃度後，有職業暴露的母親，其新生兒出生頭圍異常(<32公分)的危險對比值較沒職業暴露者高 (OR=13.48, 95% C.I=1.54-118.24)。研究結果顯示母親的職業暴露、魚攝取量與胎便金屬濃度，特別是汞和砷會影響新生兒生長狀況。

[ 英文摘要 ]

Background: Meconium is a matrix that can be obtained easily and noninvasively and is representative of a wide period of exposure in the fetus during gestation. Objectives: The objective of this study was to investigate the relationships between the metal concentrations (lead, cadmium, mercury and arsenic) in meconium, lifestyle of mothers, and infant growth. Methods: A total of 198 mother-infant pairs residing in the city of HsinChu were recruited for the study between December 2006 and April 2007. Meconium specimens were collected from 198 healthy newborn infants (108 males, 90 females). The mothers were interviewed face-to-face by a trained interviewer after delivery in which information pertaining to the mother’s sociodemographic characteristics, occupation, pregnancy and reproductive history, fish intake, other lifestyle characteristics, and the baby’s sex, gestational age, birth weight, head circumference and height at birth were collected. Lead, cadmium, and arsenic were determined by ICP-MS. Mercury concentrations were determined by a mercury analysis system. Results: The geometric mean concentrations of toxic metals in the meconium were as follows: Pb: 11.69±2.10 ppb dry weight wt, Cd: 13.59 ±7.65 ppb dry wt; Hg: 79.21 ±7.33 ppb dry wt and As: 23.45±50.5 ppb dry wt. Meconium lead concentration was significantly higher in those infants whose mothers were aboriginal and primiparous. Meconium mecury concentration was significantly higher in those infants whose mothers consumed Sashimi (raw fish) before pregnancy. The infant’s body weights decreased with alcohol consumption of mothers and with fish intake reached statistical significance. The head circumference of infants is significantly lower in those mothers who with occupational exposure and alcohol consumption than those mothers who with no occupational exposure and alcohol consumption during pregnancy. Analysis showed that age (older) and alcohol consumption of mothers had affected the gesation week.The infants who increased 10 ppb meconium arsenic concentration had higher risk of lower head circumference (< 32 cm) and the odds ratio was 4.55 (95% CI=1.08-18.38) after adjusting occupational exposure and meconium mercury concentration. The infants whose mothers with occupational exposure had higher risk of lower head circumference (< 32 cm) than those with not (OR=13.48, 95% C.I=1.54-118.24) after adjusting meconium mercury and arsenic concentrations. Conclusion: The occupational exposure of mothers, fish intake, and metal concentrations in meconium (mercury and arsenic) had affected the infant growth.