title: Preeclampsia in pregnancies with and without diabetes: the associations with placental weight. A population study of 655 842 pregnancies.
abstract: BACKGROUND
  Women with diabetes are at increased risk of preeclampsia, and women with diabetes tend to deliver placentas and offspring that are large-for-gestational-age. We therefore studied placental weight in preeclamptic pregnancies according to maternal diabetes status.
  
  
  METHODS
  Information on all singleton births from 1999 through 2010 (n = 655 842) were obtained from the Medical Birth Registry of Norway. We used z-scores of placental weight to adjust for differences in gestational age at birth between deliveries, and compared the distribution of placental weight z-scores, in deciles, in preeclamptic pregnancies with and without diabetes, and in non-preeclamptic pregnancies with and without diabetes.
  
  
  RESULTS
  Overall, the prevalence of preeclampsia was higher in pregnancies with diabetes than in pregnancies without diabetes (9.9% vs. 3.6%). Among preeclamptic pregnancies, having a placental weight in the highest decile was nearly three times more frequent (28.8%) in pregnancies with diabetes than in pregnancies without diabetes (9.8%). In the lowest decile, preeclamptic pregnancies with diabetes were underrepresented (7.5%), and preeclamptic pregnancies without diabetes were overrepresented (13.6%). Among pregnancies with preterm delivery, the above patterns were more pronounced, with 30.1% of the placentas in in preeclamptic pregnancies with diabetes in the highest decile, and 19.5% of the placentas in preeclamptic pregnancies without diabetes in the lowest decile.
  
  
  CONCLUSIONS
  These results suggest that women with diabetes who develop preeclampsia have a higher placental weight than other women with preeclampsia or non-preeclamptic women.
authors.affiliation: Department of Obstetrics and Gynecology, Akershus University Hospital, Lørenskog, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Johanne
authors.identifier: http://orcid.org/0000-0002-7267-638X
authors.initials: J
authors.lastname: Dypvik
authors.affiliation: Department of Obstetrics and Gynecology, Akershus University Hospital, Lørenskog, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Ellen M
authors.identifier: http://orcid.org/0000-0001-7446-9539
authors.initials: EM
authors.lastname: Strøm-Roum
authors.affiliation: Department of Obstetrics and Gynecology, Akershus University Hospital, Lørenskog, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Camilla
authors.identifier: http://orcid.org/0000-0002-4708-3267
authors.initials: C
authors.lastname: Haavaldsen
authors.affiliation: Department of Public Health, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Lars J
authors.identifier: http://orcid.org/0000-0003-2333-5252
authors.initials: LJ
authors.lastname: Vatten
authors.affiliation: Department of Obstetrics and Gynecology, Akershus University Hospital, Lørenskog, Norway.|Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Anne
authors.identifier: http://orcid.org/0000-0002-2756-1583
authors.initials: A
authors.lastname: Eskild
mesh_terms: D000328:Adult; D016640:Diabetes, Gestational / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D009664:Norway / Q000453:epidemiology; D009929:Organ Size; D010920:Placenta / Q000033:anatomy & histology*; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D015995:Prevalence; D012042:Registries; D012307:Risk Factors
keywords: Placental weight; diabetes; population study; preeclampsia; pregnancy