title: Fetal fibronectin versus cervical length as predictors of preterm birth in twin pregnancy with or without 17-hydroxyprogesterone caproate.
abstract: OBJECTIVE
  The objective of this study was to compare cervicovaginal fetal fibronectin (FFN) versus transvaginal sonographic cervical length as predictors of preterm birth in twin pregnancy and to test whether 17-hydroxyprogesterone caproate (17OHPc) modifies the predictive value of FFN.
  
  
  METHODS
  Secondary analysis of a randomized trial of 17OHPc versus placebo in dichorionic-diamniotic twins, analyzing the subset with screening FFN (N = 198) and/or cervical length (N = 214) at 24 to 26 weeks of gestation.
  
  
  RESULTS
  Positive FFN was found in 7%, cervical length ≤ 25 mm in 8%, and both positive FFN and cervical length ≤ 25 mm in 3%. Birth < 32, < 34, and < 37 weeks occurred in 8, 30, and 67%, respectively. In logistic regression analysis controlling for FFN, cervical length, prior preterm birth, and treatment group, positive FFN was significantly associated with birth < 30 and < 32 weeks (odds ratio 55.0 [95% confidence interval 5.2-582], 18.1 [3.3-99], respectively, p < 0.001 for both) but cervical length ≤ 25 mm was not (odds ratio 0.1 [0.002-1.6], 0.6 [0.1-4.3]).
  
  
  CONCLUSIONS
  Positive FFN was stronger than cervical length ≤ 25 mm in predicting early preterm birth in twins, regardless of 17OHPc use. Treatment with 17OHPc did not appear to alter the predictive value of FFN.
authors.affiliation: The Center for Research, Education, and Quality, Mednax, Inc., Sunrise, Florida.
authors.forename: C Andrew
authors.initials: CA
authors.lastname: Combs
authors.affiliation: The Center for Research, Education, and Quality, Mednax, Inc., Sunrise, Florida.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Garite
authors.affiliation: The Center for Research, Education, and Quality, Mednax, Inc., Sunrise, Florida.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Maurel
authors.affiliation: Axistat, Inc., San Francisco, California.
authors.forename: Anita
authors.initials: A
authors.lastname: Das
mesh_terms: D000077713:17 alpha-Hydroxyprogesterone Caproate; D000328:Adult; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000737:chemistry* / Q000000981:diagnostic imaging*; D004965:Estrogen Antagonists / Q000627:therapeutic use; D005260:Female; D005353:Fibronectins / Q000032:analysis*; D005865:Gestational Age; D006801:Humans; D006908:Hydroxyprogesterones / Q000627:therapeutic use; D011237:Predictive Value of Tests; D011247:Pregnancy; D059285:Pregnancy, Twin; D047928:Premature Birth / Q000175:diagnosis* / Q000517:prevention & control; D016216:Ultrasonography, Prenatal; D014621:Vagina / Q000737:chemistry*
chemical_list: D004965:Estrogen Antagonists; C403421:FFN protein, human; D005353:Fibronectins; D006908:Hydroxyprogesterones; D000077713:17 alpha-Hydroxyprogesterone Caproate