title: The influence of smoking on uterine bleeding during sequential oral hormone therapy.
abstract: OBJECTIVE
  To study the influence of smoking on uterine bleeding patterns during sequentially administered oral hormone therapy (HT).
  
  
  METHODS
  Using a post-hoc strategy, we included four sequential oral HT groups from two studies. The therapies consisted of estradiol from days 1 to 28 (estradiol or estradiol valerate) and progestogen (levonorgestrel or gestodene) on days 17-28. A total of 111 healthy, early postmenopausal women (38 smokers and 73 non-smokers) followed for 2 years were included in the analyses. Uterine bleeding data were collected from bleeding calendars.
  
  
  RESULTS
  On the regimen containing levonorgestrel, smoking women had a cyclical bleeding significantly earlier than non-smoking women (about 2 days' difference). Moreover, smoking women had significantly longer bleeding than non-smoking women (about 1 day in difference). This was in contrast to the three regimens containing gestodene, where smoking seemed to have far less influence on uterine bleeding.
  
  
  CONCLUSIONS
  On a regimen containing levonorgestrel, smokers exhibit an earlier and longer uterine bleeding than do non-smokers. This is in contrast to regimens containing gestodene, where smoking women are less likely to differ from non-smoking women with regard to bleeding. This indicates that smoking influences progestogen metabolism, and that this influence may vary with different progestogens. Further studies are needed.
authors: Center for Clinical & Basic Research, Ballerup, Denmark.
authors: N H
authors: NH
authors: Bjarnason
authors: I
authors: I
authors: Byrjalsen
authors: H L
authors: HL
authors: Jørgensen
authors: C
authors: C
authors: Christiansen
mesh_terms: D000284:Administration, Oral; D003270:Contraceptive Agents / Q000008:administration & dosage; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D016912:Levonorgestrel / Q000008:administration & dosage / Q000097:blood; D008875:Middle Aged; D009652:Norpregnenes / Q000008:administration & dosage / Q000097:blood; D017698:Postmenopause / Q000502:physiology; D016032:Randomized Controlled Trials as Topic; D012907:Smoking / Q000503:physiopathology*; D014592:Uterine Hemorrhage / Q000503:physiopathology*
chemical_list: D003270:Contraceptive Agents; D009652:Norpregnenes; C033273:Gestodene; D004958:Estradiol; D016912:Levonorgestrel