title: Pregnancy intentions-a complex construct and call for new measures.
abstract: OBJECTIVE
  To estimate the prevalence of unintended pregnancies under relaxed assumptions regarding birth control use compared with a traditional constructed measure.
  
  
  METHODS
  Cross-sectional survey.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Nationally representative sample of U.S. women aged 15-44 years.
  
  
  METHODS
  None.
  
  
  METHODS
  Prevalence of intended and unintended pregnancies as estimated by [1] a traditional constructed measure from the National Survey of Family Growth (NSFG), and [2] a constructed measure relaxing assumptions regarding birth control use, reasons for nonuse, and pregnancy timing.
  
  
  RESULTS
  The prevalence of unintended pregnancies was 6% higher using the traditional constructed measure as compared with the approach with relaxed assumptions (NSFG: 44%, 95% confidence interval [CI] 41, 46; new construct 38%, 95% CI, 36, 41). Using the NSFG approach, only 92% of women who stopped birth control to become pregnant and 0 women who were not using contraceptives at the time of the pregnancy and reported that they did not mind getting pregnant were classified as having intended pregnancies, compared with 100% using the new construct.
  
  
  CONCLUSIONS
  Current measures of pregnancy intention may overestimate rates of unintended pregnancy, with over 340,000 pregnancies in the United States misclassified as unintended using the current approach, corresponding to an estimated savings of $678 million in public health-care expenditures. Current constructs make assumptions that may not reflect contemporary reproductive practices, so improved measures are needed.
authors.affiliation: Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland. Electronic address: mumfords@mail.nih.gov.
authors.forename: Sunni L
authors.initials: SL
authors.lastname: Mumford
authors.affiliation: Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Sapra
authors.affiliation: Population Dynamics Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland.
authors.forename: Rosalind B
authors.initials: RB
authors.lastname: King
authors.affiliation: Glotech, Inc., Rockville, Maryland.
authors.forename: Jean Fredo
authors.initials: JF
authors.lastname: Louis
authors.affiliation: Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland.
authors.forename: Germaine M
authors.initials: GM
authors.lastname: Buck Louis
mesh_terms: D000293:Adolescent; D000328:Adult; D003267:Contraception / Q000379:methods*; D003268:Contraception Behavior; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D033182:Intention; D008875:Middle Aged; D011247:Pregnancy; D018873:Pregnancy Rate; D049168:Pregnancy, Unplanned / Q000523:psychology*; D011275:Pregnancy, Unwanted / Q000523:psychology*; D011795:Surveys and Questionnaires; D013997:Time Factors; D014481:United States; D055815:Young Adult
keywords: Pregnancy intentions; unintended; unplanned pregnancy