title: Hemoglobin köln and pregnancy.
abstract: BACKGROUND
  Patients with hemoglobin Köln usually present with a mild hemolytic anemia characterized by reticulocytosis, splenomegaly, and elevated circulating bilirubin and lactate dehydrogenase levels. There have been no previous reports of whether these characteristics change during pregnancy and whether pregnancy provides any specific concerns for patients with hemoglobin Köln.
  
  
  METHODS
  A 36-year-old woman of Chinese origin with a twin pregnancy had an uneventful antenatal course except for the presence of thrombocytopenia that was not completely investigated. During elective repeat Caesarean section, it was noted that the woman had a low SpO2 on pulse oximetry despite a normal arterial oxygen tension from arterial blood gas measurement. Subsequent investigations identified the woman as a heterozygous carrier for hemoglobin Köln.
  
  
  CONCLUSIONS
  Women with hemoglobin Köln who become pregnant require close monitoring of the maternal platelet count and an awareness of the falsely low SpO2 on pulse oximetry to ensure a favourable outcome.
authors.affiliation: Department of Obstetrics and Gynaecology, North York General Hospital, University of Toronto, Toronto ON.
authors.forename: Vincent Y T
authors.initials: VYT
authors.lastname: Cheung
authors.affiliation: Department of Internal Medicine, North York General Hospital, University of Toronto, Toronto ON.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Silverman
mesh_terms: D000328:Adult; D002353:Carrier State; D005260:Female; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000235:genetics*; D011272:Pregnancy, Multiple; D013921:Thrombocytopenia / Q000235:genetics*; D014427:Twins
chemical_list: D006455:Hemoglobins, Abnormal; C034409:hemoglobin Koln; D010100:Oxygen