title: Serum zinc levels of cord blood: relation to birth weight and gestational period.
abstract: BACKGROUND
  Zn-deficiency has been associated with numerous alterations during pregnancy including low birth weight; however, the research relating neonatal zinc status and birth weight has not produced reliable results.
  
  
  OBJECTIVE
  To compare the serum Zn-levels of cord blood in healthy newborns and low birth weight newborns, and to assess a possible relationship between zinc concentration and neonatal birth weight and gestational age.
  
  
  METHODS
  123 newborns divided in "study group" (n=50) with <2500g birth weight neonates and "control group" (n=73) with ≥2500g birth weight neonates were enrolled. Study group was subdivided according to gestational age in preterm (<37 weeks) and full-term (≥37 weeks). Serum cord blood samples were collected and the Zn-levels were analyzed using flame Atomic Absorption Spectrophotometry method and the result was expressed in μmol/L. The Zn-levels were compared between the groups (Mann-Whitney-U test) and the Zn-levels were correlated with the birth weight and gestational age (Spearman's rank correlations).
  
  
  RESULTS
  Statistically significant low positive correlation between Zn-levels and birth weight (ρ=0.283; p=0.005) was found. No statistically significant difference between Zn-levels of study and control groups [17.00±0.43 vs. 18.16±0.32 (p=0.053)] was found. Statistically significant low positive correlation between Zn-levels and gestational age (ρ=0.351; p=0.001) was found. No statistically significant difference between Zn-levels of preterm as compare to full-term newborns [16.33±0.42 vs. 18.43±0.93 (p=0.079)] was found. Zn-level of preterm subgroup was significantly lower compared to control group (p=0.001).
  
  
  CONCLUSIONS
  Despite low birth weight preterm neonates had significantly lower serum zinc levels of cord blood than healthy term neonates, the correlation between cord blood zinc levels and birth weight and gestational age was lower. The results are not enough to relate the change in cord blood zinc concentration to the birth weight values or gestational period. In relation to complicated pregnancies, further studies regarding zinc levels in blood in our population are required.
authors.affiliation: Biomedical Research Center, Medical College of Villa Clara, Cuba. Electronic address: tahirygh@ucm.vcl.sld.cu.
authors.forename: Tahiry
authors.initials: T
authors.lastname: Gómez
authors.affiliation: Biomedical Research Center, Medical College of Villa Clara, Cuba.
authors.forename: Leticia
authors.initials: L
authors.lastname: Bequer
authors.affiliation: Las Villas Central University, Cuba.
authors.forename: Angel
authors.initials: A
authors.lastname: Mollineda
authors.affiliation: Biomedical Research Center, Medical College of Villa Clara, Cuba.
authors.forename: Olga
authors.initials: O
authors.lastname: González
authors.affiliation: Biomedical Research Center, Medical College of Villa Clara, Cuba.
authors.forename: Mireisy
authors.initials: M
authors.lastname: Diaz
authors.affiliation: Biomedical Research Center, Medical College of Villa Clara, Cuba.
authors.forename: Douglas
authors.initials: D
authors.lastname: Fernández
mesh_terms: D000328:Adult; D001724:Birth Weight; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D018709:Statistics, Nonparametric; D015032:Zinc / Q000097:blood*
chemical_list: D015032:Zinc
keywords: Birth weight; Gestational age; Serum zinc; Umbilical cord