title: Uterine contraction frequency before and after successful tocolytic therapy for preterm uterine contractions.
abstract: OBJECTIVE
  To examine the association between prelabor uterine contraction frequency (UCF) and the success of tocolytic therapy for preterm labor (PTL).
  
  
  METHODS
  Eleven centers conducted a prospective, observational study of UCF recorded between 22(0/7) and 36(6/7) weeks' gestational age or until delivery > or = 2 times/d on > or = 2 d/wk in women with singleton pregnancies with and without risk factors for preterm birth. Uterine contraction data obtained from patients diagnosed with PTL allowed comparison of mean UCF both before and after an acute episode of PTL treated with either intravenous, subcutaneous or oral tocolysis. The signed rank test was used to analyze differences in UCF before and after tocolytic therapy and between women who were or were not successfully treated with a labor-inhibiting agent.
  
  
  RESULTS
  Of 454 enrolled women, 128 were diagnosed with PTL, and 74 were successfully treated with a labor-inhibiting agent. The mean UCF preceding PTL was not different between those women successfully treated and those who delivered as a consequence of the PTL episode. There was no difference (P = .653) in mean UCF between the week before PTL (UCF 0.60 +/- 0.8, median 0.30) and the first week of monitoring after successful tocolysis (UCF 0.82 +/- 1.4, median 0.27).
  
  
  CONCLUSIONS
  The mean UCF immediately preceding PTL does not predict tocolytic success or failure.
authors.affiliation: Department of Obstetrics and Gynecology, Medical University of South Carolina, 96 Jonathan Lucas Street, Suite 634, P.O. Box 250619, Charleston, SC 29425, USA. newmanr@musc.edu
authors.forename: Roger B
authors.initials: RB
authors.lastname: Newman
authors.forename: Francee
authors.initials: F
authors.lastname: Johnson
authors.forename: Anita
authors.initials: A
authors.lastname: Das
authors.forename: Robert L
authors.initials: RL
authors.lastname: Goldenberg
authors.forename: Melissa
authors.initials: M
authors.lastname: Swain
authors.forename: Atef
authors.initials: A
authors.lastname: Moawad
authors.forename: Baha M
authors.initials: BM
authors.lastname: Sibai
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Menachem
authors.initials: M
authors.lastname: Miodovnik
authors.forename: Richard H
authors.initials: RH
authors.lastname: Paul
authors.forename: Mitchell P
authors.initials: MP
authors.lastname: Dombrowski
authors.forename: Beth A
authors.initials: BA
authors.lastname: Collins Sharp
authors.forename: Molly
authors.initials: M
authors.lastname: Fischer
mesh_terms: D000328:Adult; D000407:Alabama; D002140:California; D016022:Case-Control Studies; D002641:Chicago; D015331:Cohort Studies; D004219:District of Columbia; D005260:Female; D005865:Gestational Age; D006801:Humans; D008396:Maryland; D008824:Michigan; D009657:North Carolina; D007752:Obstetric Labor, Premature / Q000517:prevention & control*; D009820:Ohio; D010414:Pennsylvania; D011247:Pregnancy; D011446:Prospective Studies; D013022:South Carolina; D013714:Tennessee; D015149:Tocolytic Agents / Q000008:administration & dosage*; D014590:Uterine Contraction / Q000502:physiology*
chemical_list: D015149:Tocolytic Agents