title: Outcomes of pregnancies affected by hemoglobin H disease.
abstract: OBJECTIVE
  To determine the outcomes of pregnancies affected by hemoglobin H (HbH) disease.
  
  
  METHODS
  A retrospective cohort study was conducted with 120 women with singleton pregnancies complicated by HbH disease only. The controls-to-cases ratio was 2:1.
  
  
  RESULTS
  Maternal outcomes were similar in the 2 groups. The incidences of fetal growth restriction (relative risk [RR], 2.4; 95% confidence interval [CI], 1.60-3.50), preterm birth (RR, 1.4; 95% CI, 1.03-1.96), and low birth weight (RR, 1.9; 95% CI, 1.46-2.56) were significantly higher in the study than in the control group. The perinatal mortality rate was slightly higher in the study group.
  
  
  CONCLUSIONS
  In spite of attempts to keep hemoglobin levels sufficiently high (>7.0 g/dL), pregnancies with HbH disease were significantly associated with increased risks of fetal growth restriction, preterm birth, and low birth weight.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. ttongson@mail.med.cmu.ac.th
authors.forename: Theera
authors.initials: T
authors.lastname: Tongsong
authors.forename: Kasemsri
authors.initials: K
authors.lastname: Srisupundit
authors.forename: Suchaya
authors.initials: S
authors.lastname: Luewan
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology* / Q000209:etiology; D006446:Hemoglobin E; D006801:Humans; D015994:Incidence; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D054238:Perinatal Mortality; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000453:epidemiology*; D011256:Pregnancy Outcome / Q000453:epidemiology*; D018566:Pregnancy, High-Risk / Q000502:physiology; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D012306:Risk; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult; D017085:alpha-Thalassemia / Q000150:complications* / Q000453:epidemiology
chemical_list: D006446:Hemoglobin E