title: Umbilical venous leptin concentration and gender in newborns.
abstract: OBJECTIVE
  To investigate the relationship between umbilical venous leptin concentration and gender in 20 pairs of newborns matched 1:1 for birth weight and gestational age at sampling.
  
  
  METHODS
  Blood samples were obtained from 40 women at delivery, identified as having an uncomplicated pregnancy. Umbilical venous blood samples were obtained from their newborns (20 males and 20 females) at birth. Specimens were analyzed using a human leptin 125-I radioimmunoassay.
  
  
  RESULTS
  Fetal leptin correlated positively with birth weight (rs = 0.541; P < .001). Umbilical venous leptin concentrations in female newborns (median: 10.7 ng/mL, range: 3.5-34.4 ng/mL) were significantly higher (P = .028) than in male newborns (median: 7.7 ng/mL, range: 2.0-19.3 ng/mL). There was no significant correlation between maternal and fetal leptin concentrations. Multiple logistic regression analysis revealed birth weight and gender to be independent factors influencing fetal cord leptin.
  
  
  CONCLUSIONS
  Our results suggest that in the fetus, as in children and adults, gender and weight are the major determinants of circulating leptin levels.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Gynecology, University of Vienna Medical School,Vienna, Austria. thomas.laml@akh-wien.ac.at
authors.forename: T
authors.initials: T
authors.lastname: Laml
authors.forename: O
authors.initials: O
authors.lastname: Preyer
authors.forename: I
authors.initials: I
authors.lastname: Schulz-Lobmeyr
authors.forename: E
authors.initials: E
authors.lastname: Ruecklinger
authors.forename: B W
authors.initials: BW
authors.lastname: Hartmann
authors.forename: P
authors.initials: P
authors.lastname: Wagenbichler
mesh_terms: D000328:Adult; D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D020738:Leptin / Q000032:analysis*; D016015:Logistic Models; D008297:Male; D012727:Sex Characteristics; D014471:Umbilical Veins
chemical_list: D020738:Leptin