title: Measurement of fetal fat in utero in normal and diabetic pregnancies using magnetic resonance imaging.
abstract: OBJECTIVE
  To assess the reliability of magnetic resonance imaging (MRI) to measure fetal fat volume in utero, and to study fetal growth in women with and without diabetes in view of the increased prevalence of macrosomia in the former.
  
  
  METHODS
  We studied 26 pregnant women, 14 with pre-gestational diabetes and 12 non-diabetic controls. Fetal assessment took place at 24 weeks' gestation and again at 34 weeks by standard ultrasound biometry followed by MRI at 1.5 T. Fetal fat volume was determined from T1-weighted water-suppressed images using a semi-automated approach based on pixel intensity and taking into account partial volume effects. Fetal volume was also determined from the MRI images. Fetal weight was calculated using published fat and lean tissue densities.
  
  
  RESULTS
  There was little fetal fat at 24 weeks' gestation, but at 34 weeks the fetal fat content was considerably higher in the women with diabetes, with a mean fat content of 1090 ± 417 cm(3) compared with 541 ± 348 cm(3) in the controls (P = 0.006). Measurements of fetal fat volume showed low intra- and interobserver variability at 34 weeks, with intraclass correlation coefficients consistently above 0.99. Birth-weight centile correlated with fetal fat volume (R(2)  = 0.496, P < 0.001), percentage of fetal fat (R(2)  = 0.362, P = 0.008) and calculated fetal weight (R(2)  = 0.492, P < 0.001) at 34 weeks.
  
  
  CONCLUSIONS
  MRI appears to be a promising tool for the determination of fetal fat, body composition and weight in utero during the third trimester of pregnancy.
authors.affiliation: Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, UK.
authors.forename: D
authors.initials: D
authors.lastname: Anblagan
authors.forename: R
authors.initials: R
authors.lastname: Deshpande
authors.forename: N W
authors.initials: NW
authors.lastname: Jones
authors.forename: C
authors.initials: C
authors.lastname: Costigan
authors.forename: G
authors.initials: G
authors.lastname: Bugg
authors.forename: N
authors.initials: N
authors.lastname: Raine-Fenning
authors.forename: P A
authors.initials: PA
authors.lastname: Gowland
authors.forename: P
authors.initials: P
authors.lastname: Mansell
mesh_terms: D000273:Adipose Tissue / Q000502:physiology*; D000328:Adult; D001823:Body Composition / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D020567:Fetal Weight / Q000502:physiology*; D005333:Fetus / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011254:Pregnancy in Diabetics; D015203:Reproducibility of Results
keywords: body composition; diabetes; fat; fetus; magnetic resonance imaging; pregnancy