title: Impact of high maternal hemoglobin at first antenatal visit on pregnancy outcomes: a cohort study.
abstract: OBJECTIVE
  To determine whether high maternal hemoglobin (Hb) at first antenatal visit is associated with adverse pregnancy outcomes.
  
  
  METHODS
  A retrospective cohort study was conducted in 920 singleton pregnancies who started their antenatal booking in the first trimester (<or=14 weeks' gestation). Women with first-visit high Hb levels (>125 g/L) were matched 1:1 with those who had normal Hb values (110-124 g/L) according to age group and parity. Adverse pregnancy outcomes including preeclampsia, gestational diabetes mellitus (GDM), preterm delivery, low birth weight (LBW), and small for gestational age (SGA) infants between both groups were compared.
  
  
  RESULTS
  Complete obstetric records of 426 and 448 women who had high and normal Hb levels, respectively, were studied. By uni- and multivariable analyses, women with high Hb levels had significantly higher rates of preeclampsia and GDM than those with normal Hb levels; their adjusted relative risks were 3.8 (95% confidence interval [CI]; 2.0, 7.1) and 3.3 (95% CI; 1.8, 6.0), respectively. Rates of preterm delivery, low birth weight, and small for gestational age infants between the two groups were not significantly different.
  
  
  CONCLUSIONS
  Our findings suggest that high Hb in the first trimester is associated with subsequent preeclampsia and GDM.
authors.affiliation: Department of Obstetrics and Gynecology, Bangkok Metropolitan Administration Medical College and Vajira Hospital, Bangkok, Thailand. chadakarn_pt@yahoo.com
authors.forename: Chadakarn
authors.initials: C
authors.lastname: Phaloprakarn
authors.forename: Siriwan
authors.initials: S
authors.lastname: Tangjitgamol
mesh_terms: D000328:Adult; D015331:Cohort Studies; D016640:Diabetes, Gestational / Q000097:blood*; D005260:Female; D006454:Hemoglobins / Q000032:analysis* / Q000378:metabolism*; D006801:Humans; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First / Q000097:blood*; D011295:Prenatal Care; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D006454:Hemoglobins