Maternal Hair Zinc and Neural Tube Defects: No Evidence of an Association from a Case-Control Study in Western Australia

Abstract

In a case-control study of isolated neural tube defects in Western Australia, zinc was estimated by flame spectrophotometry in post-partum hair specimens from 54 mothers of infants with neural tube defects, and from 128 mothers of normal infants. The distribution of the estimates of zinc was divided into quartiles. Using the lowest quartile as the reference group, the crude odds ratios (and their 95% confidence intervals) for quartiles two through four were 1.07 (0.44, 2.59), 1.02 (0.41, 2.56), and 0.70 (0.28, 1.73). Adjustment for several potential confounding variables (parental country of birth, social class, previous pregnancy outcome, interval between previous and index pregnancy, pregnancy order, and interval from birth to interview) made little difference to the odds ratios. This study provides no evidence of an association between post-partum, maternal hair zinc and of fspring with neural tube defects.