title: Maternal and fetal serum transformed alpha-fetoprotein levels in normal pregnancy.
abstract: OBJECTIVE
  To evaluate transformed alpha-fetoprotein (t-AFP) (a new molecular conformation of alpha-fetoprotein) levels in maternal serum and fetal serum in normal pregnancy.
  
  
  METHODS
  Prospective longitudinal study. Fifty pregnant women were studied in two groups: 25 were evaluated in each trimester of pregnancy and near term (12, 20, 32 and 36 weeks) and the other 25 were evaluated at the time of planned cesarean section at term. In the first group, maternal serum t-AFP was measured and in the second group, maternal and fetal serum t-AFP were analyzed.
  
  
  RESULTS
  Maternal serum t-AFP levels (medians) were 14.73 ng/mL in the first trimester, 28.29 ng/mL in the second trimester, 30.45 ng/mL in the early third trimester and 8.06 ng/mL in late pregnancy. t-AFP levels were significantly higher in maternal than in fetal serum (P < 0.001). There were no significant correlations between AFP and t-AFP levels in maternal versus fetal serum.
  
  
  CONCLUSIONS
  t-AFP increases during pregnancy until the early third trimester and then falls before delivery. t-AFP levels are higher in maternal than in fetal serum which suggests that native AFP is transformed to t-AFP either in the mother or in the placenta.
authors.affiliation: Department of Obstetrics and Gynaecology, University Hospital Puerta del Mar, Cádiz, Spain. fgonzalezb@sego.es
authors.forename: Fernando
authors.initials: F
authors.lastname: González-Bugatto
authors.forename: Esther
authors.initials: E
authors.lastname: Foncubierta
authors.forename: Maria de los Angeles
authors.initials: Mde L
authors.lastname: Bailén
authors.forename: Sebastián
authors.initials: S
authors.lastname: Illanes
authors.forename: Blas
authors.initials: B
authors.lastname: Hervías-Vivancos
authors.forename: José L
authors.initials: JL
authors.lastname: Bartha
mesh_terms: D000328:Adult; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D011247:Pregnancy / Q000097:blood*; D017434:Protein Structure, Tertiary; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000737:chemistry
chemical_list: D000509:alpha-Fetoproteins