Serum iron, zinc, folacin and vitamin B-12 in pregnant and non-pregnant adolescents

Iron status, blood folacin, vitamin B-12 and zinc were compared for 32 pregnant adolescents and 19 agematched non-pregnant controls. Blood samples were collected during the second and third trimesters (approximately 22 and 34 weeks gestation) and 6 to 8 weeks post-partum from the pregnant subjects and once from the controls. Second trimester pregnant subjects had significantly lower erythrocyte counts (p<0.001), hemoglobin (p<0.001), hematocrit (p<0.001) and serum B-12 levels (p<0.05) compared to the values noted in nonpregnant control subjects. Serum and red blood cell folacin values were significantly higher in pregnant subjects during the second trimester than values in control subjects (p<0.05 and p<0.001, respectively). Erythrocyte count, hemoglobin, hematocrit and serum B-12 were all significantly increased at post-partum as compared to the third trimester period (p<0.05 for all measures). Serum iron and transferrin saturation all decreased significantly between the second and third trimesters (p<0.05), then increased significantly from third trimester to post-partum (p<0.05). Total iron binding capacity (TIBC) showed no significant change between the second and third trimesters, but decreased significantly between third trimester and post-partum (p<0.05). The data indicate this sample of pregnant adolescents is not at significant risk for deficiencies of iron, zinc, folacin or B-12.