title: Birthweight with gestation and maternal characteristics in live births and stillbirths.
abstract: OBJECTIVE
  To establish a normal range of birthweight with gestational age (GA) at delivery and examine the contribution of maternal characteristics in defining growth restriction in stillbirths.
  
  
  METHODS
  In 69,895 normal singleton pregnancies, regression analysis was used to determine the association of birthweight with GA and maternal characteristics. The proportion of 290 stillbirths classified as small for GA depending on inclusion or exclusion of maternal characteristics was determined.
  
  
  RESULTS
  In normal pregnancies, there was a polynomial association between birthweight and GA. Birthweight increased with maternal weight, height and parity and was lower in Africans and South Asians than in Caucasians. Birthweight for GA was reduced in antepartum stillbirths (n = 243; p < 0.0001) but not in intrapartum stillbirths (n = 47; p = 0.334). There was no significant difference in the proportion of antepartum stillbirths with birthweight below the 10th percentile when birthweight was corrected for GA only compared to correction for GA and maternal characteristics (53.1 vs. 54.3%). The birthweight was below the 10th percentile in 71.8% of antepartum stillbirths at <32 weeks' gestation, in 47.2% at 33-36 weeks and in 31.5% at ≥37 weeks.
  
  
  CONCLUSIONS
  Correction of birthweight for maternal characteristics does not alter the proportion of stillbirths that are small for GA.
authors: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, London, UK.
authors: Leona C Y
authors: LC
authors: Poon
authors: Nicola
authors: N
authors: Volpe
authors: Brunella
authors: B
authors: Muto
authors: Argyro
authors: A
authors: Syngelaki
authors: Kypros H
authors: KH
authors: Nicolaides
mesh_terms: D001724:Birth Weight; D044383:Black People; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D050498:Live Birth / Q000453:epidemiology* / Q000208:ethnology; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000503:physiopathology*; D011263:Pregnancy Trimester, Third; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D050497:Stillbirth / Q000453:epidemiology* / Q000208:ethnology; D016216:Ultrasonography, Prenatal; D006113:United Kingdom / Q000453:epidemiology