title: Reevaluating the relationship between prenatal employment and birth outcomes: a policy-relevant application of propensity score matching.
abstract: BACKGROUND
  Prior research shows an association between prenatal employment characteristics and adverse birth outcomes, but suffers methodological challenges in disentangling women's employment choices from birth outcomes, and little U.S.-based prior research compares outcomes for employed women with those not employed. This study assessed the effect of prenatal employment status on birth outcomes.
  
  
  METHODS
  With data from the Listening to Mothers II survey, conducted among a nationally representative sample of women who delivered a singleton baby in a U.S. hospital in 2005 (n = 1,573), we used propensity score matching to reduce potential selection bias. Primary outcomes were low birth weight (<2,500 g) and preterm birth (gestational age <37 weeks). Exposure was prenatal employment status (full time, part time, not employed). We conducted separate outcomes analyses for each matched cohort using multivariable regression models.
  
  
  RESULTS
  Comparing full-time employees with women who were not employed, full-time employment was not causally associated with preterm birth (adjusted odds ratio [AOR], 1.37; p = .47) or low birth weight (AOR, 0.73; p = .41). Results were similar comparing full- and part-time workers. Consistent with prior research, Black women, regardless of employment status, had increased odds of low birth weight compared with White women (AOR, 5.07; p = .002).
  
  
  CONCLUSIONS
  Prenatal employment does not independently contribute to preterm births or low birth weight after accounting for characteristics of women with different employment statuses. Efforts to improve birth outcomes should focus on the characteristics of pregnant women (employed or not) that render them vulnerable.
authors.affiliation: Division of Health Policy and Management, University of Minnesota School of Public Health, Minneapolis, Minnesota 55455, USA. katybkoz@gmail.com
authors.forename: Katy B
authors.initials: KB
authors.lastname: Kozhimannil
authors.forename: Laura B
authors.initials: LB
authors.lastname: Attanasio
authors.forename: Patricia M
authors.initials: PM
authors.lastname: McGovern
authors.forename: Dwenda K
authors.initials: DK
authors.lastname: Gjerdingen
authors.forename: Pamela Jo
authors.initials: PJ
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D004651:Employment / Q000706:statistics & numerical data*; D005260:Female; D005865:Gestational Age; D006291:Health Policy; D006306:Health Surveys; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D016015:Logistic Models; D015999:Multivariate Analysis; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011295:Prenatal Care; D015995:Prevalence; D057216:Propensity Score; D012307:Risk Factors; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology; D014931:Women, Working; D055815:Young Adult