title: Preterm birth and subsequent risk of type 2 diabetes in black women.
abstract: BACKGROUND
  Gestational diabetes is a precursor to type 2 diabetes. Little is known about the relation of other common pregnancy complications, such as preterm birth, to risk of type 2 diabetes.
  
  
  METHODS
  We assessed preterm birth in relation to incident type 2 diabetes among 31,101 participants from the Black Women's Health Study. Preterm birth, defined as <37 weeks gestation, was reported at baseline (1995) and on subsequent biennial follow-up questionnaires. Self-reported type 2 diabetes diagnoses were ascertained on biennial questionnaires through 2009. We used Cox proportional hazards models to calculate incidence rate ratios (IRRs) and 95% confidence intervals (CIs), adjusting for potential confounders.
  
  
  RESULTS
  At baseline, 5162 participants (19%) reported a history of giving birth preterm, of which 16% occurred at <32 weeks gestation. A total of 3261 cases of type 2 diabetes were ascertained during follow-up. Ever having had a preterm birth was associated with a 20% increased risk (95% CI = 1.11-1.31) after adjusting for age at first birth, family history of diabetes, education, respondent having been born preterm, and body mass index. Gestational age <32 weeks was associated with the greatest risk (IRR = 1.27 [95% CI = 1.06-1.51]). Among women without a history of gestational diabetes, the IRR for type 2 diabetes among women who ever had a preterm birth was 1.17 (1.07-1.28).
  
  
  CONCLUSIONS
  Preterm birth was associated with an increased type 2 diabetes risk in black mothers, independent of gestational diabetes.
authors.affiliation: From the aDepartment of Medicine, Division of Women's Health, Connors Center for Women's Health and Gender Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; bSlone Epidemiology Center at Boston University, Boston, MA; and cDepartment of Epidemiology, Harvard School of Public Health, Boston, MA.
authors.forename: Tamarra
authors.initials: T
authors.lastname: James-Todd
authors.forename: Lauren
authors.initials: L
authors.lastname: Wise
authors.forename: Deborah
authors.initials: D
authors.lastname: Boggs
authors.forename: Janet
authors.initials: J
authors.lastname: Rich-Edwards
authors.forename: Lynn
authors.initials: L
authors.lastname: Rosenberg
authors.forename: Julie
authors.initials: J
authors.lastname: Palmer
mesh_terms: D000328:Adult; D001741:Black or African American / Q000235:genetics*; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics*; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D011247:Pregnancy; D047928:Premature Birth; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology