title: Provisional recommended weight limits for manual lifting during pregnancy.
abstract: OBJECTIVE
  The National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (RNLE) was adapted to derive recommended weight limits (RWLs) for pregnant workers and to develop corresponding guidelines for clinicians.
  
  
  BACKGROUND
  In the past three decades there has been a large increase in the number of women employed outside the home and remaining in the workforce during pregnancy. Practical authoritative guidelines based on accumulated evidence are needed to inform allowable work activity levels for healthy pregnant workers.
  
  
  METHODS
  Empirically based lifting criteria established by NIOSH to reduce the risk of overexertion injuries in the general U.S. working population were evaluated for application to pregnant workers. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Decision logic and supporting literature are presented, along with computational details.
  
  
  RESULTS
  Provisional RWLs for pregnant workers were derived from the RNLE, along with guidelines for clinicians. The guidelines advise against pregnant workers lifting below midshin and overhead.
  
  
  CONCLUSIONS
  Based on our review of the available evidence, we present lifting thresholds that most pregnant workers with uncomplicated pregnancies should be able to perform without increased risk of adverse maternal and fetal health consequences. Except for restrictions involving lifting from the floor and overhead, the provisional guidelines presented are compatible with NIOSH lifting recommendations adopted in the early 1990s for the general working population.
  
  
  CONCLUSIONS
  Implementation of these provisional guidelines could protect millions of female workers in the workplace from fetal and maternal lifting-related health problems.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Waters
authors.forename: Leslie A
authors.initials: LA
authors.lastname: MacDonald
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Hudock
authors.forename: Donald E
authors.initials: DE
authors.lastname: Goddard
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D017408:Guidelines as Topic; D006801:Humans; D017770:Lifting / Q000009:adverse effects*; D009314:National Institute for Occupational Safety and Health, U.S.; D009784:Occupational Diseases / Q000453:epidemiology / Q000517:prevention & control*; D011247:Pregnancy; D012307:Risk Factors; D014481:United States / Q000453:epidemiology