title: Short and long interpregnancy intervals: correlates and variations by pregnancy timing among U.S. women.
abstract: BACKGROUND
  Short and long interpregnancy intervals are associated with adverse health outcomes. Little is known about the correlates of short and long interpregnancy intervals in the general population, and whether correlates vary by pregnancy intention.
  
  
  METHODS
  Data on 10,236 pregnancies following a live birth were drawn from the 1995, 2002 and 2006-2010 waves of the National Survey of Family Growth. Logistic regression was used to assess characteristics associated with women's reporting short interpregnancy intervals (less than 12 months) and long intervals (greater than 60 months). Analyses were stratified by whether women considered their pregnancies well timed or mistimed.
  
  
  RESULTS
  Thirty-one percent of pregnancies following short intervals and 47% following long intervals were well timed. Among well-timed pregnancies only, the odds of short intervals were elevated if women had been 35 or older, rather than aged 20-29, at last pregnancy (odds ratio, 2.3); if their prior infant had died (10.6); or if they had wanted their prior pregnancy sooner than it had occurred (2.2). Overall, the odds of long intervals were higher among minority groups than among whites (1.4-1.6) and were lower among women who had been 30 or older at prior pregnancy than among those who had been in their 20s (0.1-0.5); they increased with level of family income. Correlates of long intervals generally varied little by intention.
  
  
  CONCLUSIONS
  Although the majority of pregnancies at short intervals are unintended, specific subsets of women have elevated odds of intending short interpregnancy intervals.
authors.affiliation: adjunct associate research scientist, Department of Psychiatry, Columbia University, New York. kc2497@columbia.edu.
authors.forename: Keely
authors.initials: K
authors.lastname: Cheslack Postava
authors.forename: Alix S
authors.initials: AS
authors.lastname: Winter
mesh_terms: D017677:Age Distribution; D001294:Attitude to Health; D001721:Birth Intervals / Q000706:statistics & numerical data*; D005260:Female; D006304:Health Status; D006801:Humans; D008423:Maternal Age; D008913:Minority Groups / Q000706:statistics & numerical data; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome / Q000453:epidemiology*; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D016387:Women's Health / Q000706:statistics & numerical data*