title: Impact of pregnancy on primary dysmenorrhea.
abstract: OBJECTIVE
  Because it has been observed that dysmenorrhea can improve after childbirth, this investigation was intended to quantify the impact of both gestational length and mode of delivery on primary dysmenorrhea.
  
  
  METHODS
  This is an 8-year prospective observational study. Patients with a history of dysmenorrhea who later gave birth were evaluated for improvement on the severity of dysmenorrhea, with use of visual analogue scale (VAS), and Likert-type scale.
  
  
  RESULTS
  Final analysis involved 3694 patients. Women who had spontaneous delivery would have significantly more improvement than women with cesarean delivery per VAS (term delivery, 51 vs. 33, P<0.001; preterm delivery, 17 vs. 10, P<0.001). For first delivery, patients in the spontaneous delivery subgroup were the most likely to have improvement in severity of dysmenorrhea. For second delivery, only patients in the spontaneous delivery subgroup had statistically significant improvement.
  
  
  CONCLUSIONS
  Both length of gestation and mode of delivery have an impact on primary dysmenorrhea. The most significant improvement occurred after the first delivery.
authors.affiliation: Division of General Gynecology, Department of Obstetrics and Gynecology, Veterans General Hospital, Taipei, Taiwan. cmjuang@yahoo.com.tw
authors.forename: Chi-Mou
authors.initials: CM
authors.lastname: Juang
authors.forename: Ming-Shien
authors.initials: MS
authors.lastname: Yen
authors.forename: Nae-Fong
authors.initials: NF
authors.lastname: Twu
authors.forename: Huann-Cheng
authors.initials: HC
authors.lastname: Horng
authors.forename: Hung-Chuan
authors.initials: HC
authors.lastname: Yu
authors.forename: Chih-Yao
authors.initials: CY
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D036861:Delivery, Obstetric / Q000379:methods*; D004412:Dysmenorrhea / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008423:Maternal Age; D007752:Obstetric Labor, Premature; D010147:Pain Measurement; D010298:Parity; D011247:Pregnancy / Q000502:physiology*; D047928:Premature Birth; D011336:Probability; D011379:Prognosis; D011788:Quality of Life; D018570:Risk Assessment; D012720:Severity of Illness Index