title: [Study on the Hemoglobin levels among the Tibetan pregnant women in rural Lhasa].
abstract: OBJECTIVE
  To understand the level of hemoglobin (Hb) and determine the risk factors of Hb concentration among the Tibetan pregnant women in rural Lhasa.
  
  
  METHODS
  Between August 2008 and May 2011, a hospital-based study was conducted among 1 530 Tibetan pregnant women after getting their informed consent in agricultural and pastoral areas in maternity clinic or hospital in city, county and township level of Lhasa. Their blood samples were tested and related socio-demographic information was collected. Blood was collected on tip of finger and the Hb concentration was measured using B-Hemoglobin photometer. American Centers for Disease Control and Prevention(CDC) method was used to adjust the Hb measurements based on altitude for estimating the prevalence of anemia. Anemia was assessed according to WHO criteria. A hemoglobin concentration of less than 110 g/L in a pregnant woman was considered an indication of anemia.
  
  
  RESULTS
  From August 2008 to May 2011, 1 530 Tibetan pregnant women living at (3 716.4 ± 69.1) m above sea level in rural Lhasa were examined. The findings indicated that average Hb concentration was (122.0 ± 17.5) g/L; the Hb concentration of 1(st), 2(nd) and 3(rd) trimester were (125.5 ± 18.0), (122.5 ± 16.9) and (120.6 ± 17.4) g/L, respectively. The Hb concentration of pregnant women decreased with the increase of gestational age(P < 0.05). Based onCDC method and the adjusted Hb level, the prevalence of anemia in pregnant women were 85.6% (1 310/1 530), the prevalence of anemia of 1(st), 2(nd), and 3(rd)rd trimester were 79.5% (206/259) , 86.1% (395/459)and 87.3% (698/800), respectively (P < 0.05) . The rate of moderate and severe anemia were 46.7% (612/1 310) among pregnant women. Multiple linear regression analysis showed that high Hb level was associated significantly with low family income status (β = 2.74, 95%CI:1.73-3.74), no bad habits (drinking or smoking) (β = 7.34, 95%CI:4.87-9.81) and fewer times of pregnancies(β = -1.62, 95%CI:-2.93--0.31) after adjusting for potential confounding factors.
  
  
  CONCLUSIONS
  Hb concentration level in pregnancy was rather low in rural Lhasa. The increase of family income, reduction the intervals of pregnancies and no bad habits might benefit for the improvement of Hb level of pregnant women in this region.
authors.affiliation: School of Public Health, Xi'an Jiaotong University & Health Science Center/Nutrition and Food Safety Engineering Research Center of Shaanxi Province, Xi'an 710061, China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Kang
authors.forename: Fangzhen
authors.initials: F
authors.lastname: Li
authors.forename: Shaonong
authors.initials: S
authors.lastname: Dang
authors.affiliation: Email: yanhonge@mail.xjtu.edu.
authors.forename: Hong
authors.initials: H
authors.lastname: Yan
authors.forename: Lingxia
authors.initials: L
authors.lastname: Zeng
authors.forename: Yue
authors.initials: Y
authors.lastname: Cheng
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Yuxue
authors.initials: Y
authors.lastname: Bi
mesh_terms: D000531:Altitude; D000740:Anemia; D003710:Demography; D005260:Female; D006454:Hemoglobins; D006801:Humans; D007182:Income; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000453:epidemiology*; D011264:Pregnancy Trimesters; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population; D012959:Socioeconomic Factors; D018609:Tibet
chemical_list: D006454:Hemoglobins; C020622:hemoglobin B