title: Placental weight and birthweight: does the association differ between pregnancies with and without preeclampsia?
abstract: OBJECTIVE
  Placental weight and infant birthweight may be markers of different types of preeclampsia. We studied birthweight within placental weight percentiles in pregnancies with and without preeclampsia.
  
  
  METHODS
  This was a population study of 317,688 singleton births.
  
  
  RESULTS
  Within the lowest 10% of placental weight, 36% of the offspring were small for gestational age (SGA) in preeclamptic pregnancies and 14% in normotensive pregnancies (relative risk, 2.6; 95% confidence interval, 2.4-2.8). Risk of SGA subsided with increasing placental weight and was negligible at >50th percentile. At low placental weights, large for gestational age (LGA) offspring were nearly nonexistent; however, at >70th percentile, LGA occurred more often in pregnancies with preeclampsia. Within the highest 10% of placental weight, 20.7% of the infants were LGA in the preeclampsia group, and 15.3% of the infants were LGA in pregnancies without preeclampsia (relative risk, 1.4; 95% confidence interval, 1.2-1.5).
  
  
  CONCLUSIONS
  In pregnancies with small placentas, the offspring were more often SGA in preeclamptic pregnancies and more often LGA at high placental weights. The results support the hypothesis that preeclampsia may represent different diseases, depending on placental size and infant birthweight.
authors.affiliation: Department of Obstetrics and Gynecology and Medical Faculty Division, University of Oslo, and Akershus University Hospital, Lørenskog, Oslo, Norway.
authors.forename: Anne
authors.initials: A
authors.lastname: Eskild
authors.forename: Pål R
authors.initials: PR
authors.lastname: Romundstad
authors.forename: Lars J
authors.initials: LJ
authors.lastname: Vatten
mesh_terms: D001724:Birth Weight; D005260:Female; D006801:Humans; D009929:Organ Size; D010920:Placenta / Q000473:pathology*; D011225:Pre-Eclampsia / Q000473:pathology*; D011247:Pregnancy