title: The predictive value of first trimester fetal volume measurements, a prospective cohort study.
abstract: OBJECTIVE
  To determine if fetal volume (FV) measurements with three-dimensional ultrasound in the first trimester of pregnancy can detect the fetus at risk for preterm birth and/or low birth weight.
  
  
  METHODS
  In this prospective cohort study, 538 participants were included during the routine first trimester ultrasound examination. Volume measurements were performed with VOCAL (9°). Firstly, the relation between FV and gestational age for a set of participants with normal pregnancies (training set), was assessed using multiple linear regression analysis, which was then used to determine the expected normal values. Secondly, for a new set of participants with normal pregnancies and a set of participants with complicated pregnancies (preterm birth and/or low birth weight), i.e. the validation set, the observed fetal volumes (FVobserved) were compared with their expected normal values (FVexpected) and expressed as a percentage of the expected normal value. The difference in mean percentage was then assessed with independent-samples t-test. Finally, logistic regression analysis was applied to the validation set to analyze the ability to predict the pregnancy outcome with FV calculation.
  
  
  RESULTS
  Linear regression analysis of FV as a predictor of preterm birth and/or low birth weight did not result in significant (p=0.630 and 0.290, respectively) or clinical relevant results (standardized effect sizes of 0.061 and 0.179, respectively). The predicting quality was also very low (AUC=0.508 and 0.545 respectively).
  
  
  CONCLUSIONS
  Fetal volume measurements in the first trimester of pregnancy are not useful as a prognostic tool for predicting pregnancies of high risk for preterm birth or a low birth weight.
authors.affiliation: Department of Gynecology and Obstetrics, Atrium Medical Centre, Heerlen, The Netherlands. n.smeets@atriummc.nl
authors.forename: Nicol A C
authors.initials: NA
authors.lastname: Smeets
authors.forename: Bjorn
authors.initials: B
authors.lastname: Winkens
authors.forename: Marc
authors.initials: M
authors.lastname: Prudon
authors.forename: Joost van
authors.initials: Jv
authors.lastname: de Ven
authors.forename: Vera P J
authors.initials: VP
authors.lastname: Gondrie
authors.forename: Frank
authors.initials: F
authors.lastname: van Deursen
authors.forename: S Guid
authors.initials: SG
authors.lastname: Oei
mesh_terms: D019540:Area Under Curve; D015331:Cohort Studies; D005260:Female; D005333:Fetus; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D016014:Linear Models; D008137:Longitudinal Studies; D009426:Netherlands; D011237:Predictive Value of Tests; D011247:Pregnancy; D047928:Premature Birth / Q000175:diagnosis*; D011446:Prospective Studies