title: Fetal sex-related differences in maternal serum alpha-fetoprotein during the second trimester of pregnancy.
abstract: In an analysis of data gathered from routine maternal serum alpha-fetoprotein screening, we determined that the sex of the fetus is significantly correlated with differences in maternal serum alpha-fetoprotein concentration during the second trimester of pregnancy. Between the fifteenth and nineteenth gestational weeks, the mean maternal serum alpha-fetoprotein level is significantly higher for the male fetus than for the female fetus. There was no difference, however, in the rate of increase in maternal serum alpha-fetoprotein concentration with time between male and female fetuses during the weeks of gestation that were studied. No apparent cause for these observations has been demonstrated.
mesh_terms: D001835:Body Weight; D005260:Female; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D008297:Male; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis; D012016:Reference Values; D012189:Retrospective Studies; D012306:Risk; D012732:Sex Determination Analysis; D012737:Sex Factors; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000509:alpha-Fetoproteins