title: [Heaviness of the work measured by energy expenditure during pregnancy and its effect on birth weight].
abstract: OBJECTIVE
  Maternal work during pregnancy, especially with high work-related physical exertion, is still considered one of the most prevalent risk factors of negative pregnancy outcome.
  
  
  METHODS
  Nofer Institute of Occupational Medicine has recently completed a study of women working in polish greenhouses. The greenhouse is a very good environment to measure the energy expenditure during work. That's why the women working for a period of at least 2 years in greenhouses in Poland were asked to participate in the project. We classified pregnancies of women on the basis of energy expenditure during mother's work into three groups: light work (200-700 kcal/shift); moderate work (701-1000 kcal/shift); and heavy work (1001-1200 kcal/shift).
  
  
  RESULTS
  The study among women working in greenhouse revealed that the mean birth weight of infants whose mothers worked in greenhouse with heavy wok (work expenditure >1000 kcal/shift) during pregnancy was 177 g. lower, than that of those whose mothers worked out of greenhouse with light work (light work <700 kcal/shift) (p=0.05).
  
  
  CONCLUSIONS
  The results suggest the necessity to inform pregnant women about the potential negative influence of heavy work on pregnancy outcome.
authors.affiliation: Zakład Epidemiologii Srodowiskowej, kierownik, Instytut Medycyny Pracy w Lodzi. joannaj@imp.lodz.pl
authors.forename: Joanna
authors.initials: J
authors.lastname: Jurewicz
authors.forename: Wojciech
authors.initials: W
authors.lastname: Hanke
authors.forename: Teresa
authors.initials: T
authors.lastname: Makowiec-Dabrowska
authors.forename: Jarosław
authors.initials: J
authors.lastname: Kalinka
mesh_terms: D000328:Adult; D000382:Agricultural Workers' Diseases / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D005082:Physical Exertion; D011044:Poland; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome / Q000453:epidemiology; D012494:Sampling Studies; D014931:Women, Working / Q000706:statistics & numerical data*; D014937:Work / Q000706:statistics & numerical data; D016526:Workload / Q000706:statistics & numerical data