title: Differing causes of pregnancy loss in type 1 and type 2 diabetes.
abstract: OBJECTIVE
  Women with type 2 and type 1 diabetes have differing risk factors for pregnancy loss. We compared the rates and causes of pregnancy loss in women with type 1 and type 2 diabetes.
  
  
  METHODS
  We utilized prospectively collected data on all pregnancies in a 20-year period (1986-2005) from a single center with a high prevalence of type 2 diabetes. Pregnancy losses included terminations for medical reasons and deaths up to 1 month postpartum but not spontaneous pregnancy losses <20 weeks' gestation.
  
  
  RESULTS
  There were 870 pregnancies in women with known diabetes (330 with type 1 and 540 with type 2 diabetes) and 325 in women with diabetes diagnosed in pregnancy but persisting postpartum (97% type 2 diabetes). The rate of pregnancy loss was similar in type 1 and type 2 diabetes (2.6 vs. 3.7%, P = 0.39), but the causes of pregnancy loss differed. In type 1 diabetes >75% were attributable to major congenital anomalies or prematurity; in type 2 diabetes >75% were attributable to stillbirth or chorioamnionitis (P = 0.017). Women with type 2 and type 1 diabetes had similar A1C at presentation and near term, but the former were older (P < 0.001) and more obese (P < 0.0001).
  
  
  CONCLUSIONS
  There are significant differences in the main causes of pregnancy loss in women with type 1 and type 2 diabetes. The higher rates of stillbirth in women with type 2 diabetes, suggest that other features, such as obesity, contribute significantly to pregnancy losses.
authors.affiliation: Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand. t.cundy@auckland.ac.nz
authors.forename: Tim
authors.initials: T
authors.lastname: Cundy
authors.forename: Greg
authors.initials: G
authors.lastname: Gamble
authors.forename: Leonie
authors.initials: L
authors.lastname: Neale
authors.forename: Rose
authors.initials: R
authors.lastname: Elder
authors.forename: Paul
authors.initials: P
authors.lastname: McPherson
authors.forename: Patrick
authors.initials: P
authors.lastname: Henley
authors.forename: Janet
authors.initials: J
authors.lastname: Rowan
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D005260:Female; D005865:Gestational Age; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology
chemical_list: D006442:Glycated Hemoglobin