Ocupación materna, duración de la gestación y bajo peso al nacimiento

objective: to assess the association between maternal occupation during pregnancy with the presence of low birth weight and preterm delivery. method: the sample consisted of 1,341,686 preterm infants and 1,217,897 low birth weight infants in spain (1996-2000) with valid information on maternal occupation from the national registry of births. maternal occupation was the main exposure variable coded according to groups of occupation (cno-79) and outcomes were low birth weight (<2500g) and preterm birth (<37 weeks). crude and adjusted odds ratios (or) and 95% confidence interval (ci) were calculated through the maximum verisimilitude method. results: the highest prevalence of preterm infants was found in mothers working in agriculture (10.8%) and the lowest in professional women (6.6%). the highest prevalence of low birth weight was observed in the women working in the services sector (3.5%) and manual workers in industry and construction (3.4%) while the lowest prevalence was found in professional women (2.5%). women working in agriculture had a higher risk of preterm birth than professional women (aor=1.68; 95%ci: 1.57-1.80). the risk of low birth weight was higher in women working in the service sector (aor=1.36; 95%ci: 1.30-1.42), housewives (aor=1.30; 95%ci: 1.28-1.38), agricultural laborers (aor=1.29; 95%ci: 1.14-1.44) and manual workers in industry and construction (aor=1.29; 95%ci: 1.21-1.36). conclusions: the results of this study suggest that belonging to certain occupational groups during pregnancy could affect the risk of low birth weight and preterm birth.