title: Accuracy of absence of fetal breathing movements in predicting preterm birth: a systematic review.
abstract: OBJECTIVE
  To determine the accuracy with which the absence of fetal breathing movements on ultrasound examination predicts spontaneous preterm birth in women with threatened preterm labor.
  
  
  METHODS
  Data sources included Medline, Embase, Pascal, Biosis, Cochrane Library, Medion, National Research Register, SciSearch, conference papers, and manual searching of bibliographies of known primary and review articles. A study was selected if it used absence of fetal breathing movements on ultrasound to predict spontaneous preterm birth in women with threatened preterm labor but before advanced cervical dilatation. Two reviewers independently selected studies and extracted data on their characteristics, quality and accuracy. Accuracy data were used to form 2 x 2 contingency tables with birth within 48 h and within 7 days of testing as the reference standards. Likelihood ratios for a positive test (LR+) and negative test (LR-) were calculated as a measure of accuracy.
  
  
  RESULTS
  There were eight studies, which included a total of 328 women, evaluating the accuracy of absence of fetal breathing movements in predicting spontaneous preterm birth in women with threatened preterm labor. There were differences in the methodological quality among the included studies. All were lacking in one or more item that make up an ideal test accuracy study. For women presenting with threatened preterm labor, meta-analysis showed a summary LR+ of 14.80 (95% CI, 6.30-34.79) with a corresponding summary LR- of 0.46 (95% CI, 0.36-0.58) for predicting preterm birth within 7 days, and summary LR+ of 7.84 (95% CI, 1.12-54.99) and summary LR- of 0.25 (95% CI, 0.13-0.48) for predicting preterm birth within 48 h of testing.
  
  
  CONCLUSIONS
  Absence of fetal breathing movements has the potential to be a useful test in predicting preterm birth both within 7 days and within 48 h of testing. However, the available studies were deficient in their sample size and quality of methodology. Future research should be undertaken to evaluate this technology and to address the methodological deficiencies.
authors.affiliation: Department of Obstetrics and Gynaecology, Birmingham Women's Hospital, University of York, UK. h.honest@bham.ac.uk
authors.forename: H
authors.initials: H
authors.lastname: Honest
authors.forename: L M
authors.initials: LM
authors.lastname: Bachmann
authors.forename: R
authors.initials: R
authors.lastname: Sengupta
authors.forename: J K
authors.initials: JK
authors.lastname: Gupta
authors.forename: J
authors.initials: J
authors.lastname: Kleijnen
authors.forename: K S
authors.initials: KS
authors.lastname: Khan
mesh_terms: D005260:Female; D005333:Fetus / Q000503:physiopathology*; D006801:Humans; D016247:Information Storage and Retrieval; D016013:Likelihood Functions; D007752:Obstetric Labor, Premature / Q000175:diagnosis*; D011247:Pregnancy; D012119:Respiration; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal