title: Post-term birth as a response to environmental stress : The case of September 11, 2001.
abstract: OBJECTIVE
  Despite growing interest in the role of maternal psychosocial stress as a determinant of preterm birth, no existing work has examined the relation between maternal stress and post-term birth (≥42 weeks). We hypothesize that prolonging gestation past term may represent an adaptive strategy to a suboptimal environment.
  
  
  METHODS
  We examined the relationship between exposure to the September 2001 terrorist attacks and odds of post-term birth in California. We calculated the expected odds of post-term birth among conception cohorts of singleton gestations in California between October 1996 and November 2005. We used time series analysis to test for higher than expected odds of post-term birth among the 10 cohorts exposed to the attacks of September 2001 (those conceived from December 2000 to September 2001).
  
  
  RESULTS
  The observed odds of post-term delivery among gestations at 33-36 weeks in September 2001 were higher than statistically expected for all race/ethnic and sex groups.
  
  
  CONCLUSIONS
  Our finding that odds of post-term birth were higher than expected among pregnancies exposed to the September 2001 terrorist attacks in late gestation provides initial support for the hypothesis that exposure to a psychosocial stress during pregnancy may result in prolonged gestation.
authors.affiliation: Department of Epidemiology and Biostatistics, Michigan State University, 909 Fee Rd. Rm. 601B, East Lansing, MI 48823, USA; School of Public Health, University of California, Berkeley, 50 University Hall #7360, Berkeley, CA 94720, USA; Department of Demography, University of California, Berkeley, 2232 Piedmont Ave, Berkeley, CA 94720, USA. cmargerisonzilko@epi.msu.edu.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Margerison-Zilko
authors.affiliation: Department of Epidemiology and Biostatistics, Michigan State University, 909 Fee Rd. Rm. 601B, East Lansing, MI 48823, USA; School of Public Health, University of California, Berkeley, 50 University Hall #7360, Berkeley, CA 94720, USA; Department of Demography, University of California, Berkeley, 2232 Piedmont Ave, Berkeley, CA 94720, USA.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Goodman
authors.affiliation: Department of Epidemiology and Biostatistics, Michigan State University, 909 Fee Rd. Rm. 601B, East Lansing, MI 48823, USA; School of Public Health, University of California, Berkeley, 50 University Hall #7360, Berkeley, CA 94720, USA; Department of Demography, University of California, Berkeley, 2232 Piedmont Ave, Berkeley, CA 94720, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Anderson
authors.affiliation: Department of Epidemiology and Biostatistics, Michigan State University, 909 Fee Rd. Rm. 601B, East Lansing, MI 48823, USA; School of Public Health, University of California, Berkeley, 50 University Hall #7360, Berkeley, CA 94720, USA; Department of Demography, University of California, Berkeley, 2232 Piedmont Ave, Berkeley, CA 94720, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Gemmill
authors.affiliation: Department of Epidemiology and Biostatistics, Michigan State University, 909 Fee Rd. Rm. 601B, East Lansing, MI 48823, USA; School of Public Health, University of California, Berkeley, 50 University Hall #7360, Berkeley, CA 94720, USA; Department of Demography, University of California, Berkeley, 2232 Piedmont Ave, Berkeley, CA 94720, USA.
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Catalano
keywords: critical window; parent–offspring conflict; growth; gestation; pregnancy; post-term; pre-term