title: In pregnant women who smoke, caffeine consumption is associated with an increased level of homocysteine.
abstract: OBJECTIVE
  To investigate whether maternal caffeine consumption is associated with increased maternal homocysteine (Hcy) levels in uncomplicated pregnancies.
  
  
  METHODS
  Ninety-two pregnant women were randomly selected, and maternal serum levels of folate, vitamin B(12), and Hcy at gestational weeks 17 and 33 were measured. Caffeine consumption was estimated from dietary records collected at the same gestational ages.
  
  
  RESULTS
  In women who smoked, Hcy levels were associated with caffeine consumption both in gestational weeks 17 and 33 and with folate at week 33. Consumption of one cup of coffee was associated with an increase in maternal Hcy of 0.26 micromol/l at week 17 and 0.69 micromol/l at week 33, indicating that one extra cup (150 ml) of coffee per day may increase Hcy by 5--10% in pregnant smokers. In non-smokers, caffeine consumption was not associated with Hcy levels.
  
  
  CONCLUSIONS
  In uncomplicated pregnancies, maternal caffeine consumption early in the second and in the third trimester is associated with increased maternal Hcy levels in women who smoked, but not in non-smokers.
authors.affiliation: Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway. sven.carlsen@medisin.ntnu.no
authors.forename: Sven M
authors.initials: SM
authors.lastname: Carlsen
authors.forename: Geir
authors.initials: G
authors.lastname: Jacobsen
authors.forename: Lars
authors.initials: L
authors.lastname: Vatten
authors.forename: Pål
authors.initials: P
authors.lastname: Romundstad
mesh_terms: D002110:Caffeine / Q000008:administration & dosage*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003069:Coffee / Q000009:adverse effects; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D012907:Smoking / Q000097:blood*; D013662:Tea / Q000009:adverse effects; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D000697:Central Nervous System Stimulants; D003069:Coffee; D013662:Tea; D006710:Homocysteine; D002110:Caffeine; D014805:Vitamin B 12