ABSTRACT
<p><b>OBJECTIVE</b>To explore the relationship between multi-trace elements levels in hair and human neural tube defects as well as other risk factors.</p><p><b>METHODS</b>Using 88 paired cases and controls, an 1:1 matched case control study was carried out. The study subjects were collected from the China-U. S. Collaborative Project on Neural Tube Defects Prevention and Birth Defects Surveillance System. Risk factors were obtained by field investigation with standardized questionnaires and hair trace elements levels were determined by AAS and ICP-MS methods. Microwave digestion was used to digest hair samples. The detected elements would include three groups, namely nutritional elements: Cr, Mn, Cu, Zn, Co, Mo; toxic elements: Pb, As, Cd, Hg; and Lanthanons: Y, La, Pr, Nd. Cox Proportional Hazard Regression Model was used to perform risk factors analysis.</p><p><b>RESULTS</b>Pregnancy fever appeared to be a risk factor of neural tube defects (OR = 6.525, P = 0.034) while hair zinc level (OR = 0.541 microg/100 g, P = 0.02) and times of prenatal physical examination (OR = 0.634, P < 0.001) served as two protective factors appeared in the last model.</p><p><b>CONCLUSION</b>Zinc deficiency might serve as a risk factor for human neural tube defects, suggesting that the avoidance of pregnancy infection together with more periodical prenatal physical examination might reduce the incidence of neural tube defects.</p>