[Levels of hemoglobin concentration and anemia during pregnancy in Lhasa].
To investigate the distribution of hemoglobin(Hb) and prevalence of anemia in pregnant women living in the Tibetan Plateau area. Random sampling method was used and fingertip blood sample was tested. Related sociodemographic information was collected. We adjusted the hemoglobin measurements based on the different levies of altitude, using three different methods from CDC, Dilren's and Dallman's to estimate the prevalence rates of anemia. Three hundred and eighty pregnant women were included. The mean Hb was 127.6 g/L. Tibetan had a lower Hb (126.6 g/L) than people from other ethnicities (134.6 g/L) with rural pregnant women having a higher Hb (130.4 g/L) than that of urban ones (125.9 g/L). After controlling the gestational age, results remained the same. Different method used for correction of hemoglobin would cause different prevalence rates of anemia which were all higher than the pre-adjusted prevalence rates: 70.0% for CDC method, 77.9% for Dilren's method and 41.3% for Dallman's method respectively. After analyzing the erythrocyte parameters, we could not conclude that population in our study was under the early stage of the iron deficiency anemia. Higher altitude could affect the levels of hemoglobin concentration significantly. Currently adopted hemoglobin correction methods might not be suitable for Tibetan pregnant women. We suggested that it was imperative to establish a relationship between altitude and hemoglobin of Tibetan women during pregnancy in order to correctly evaluate the prevalence of anemia.