Work Activity in Pregnancy, Preventive Measures, and the Risk of Preterm Delivery

• Published in: American journal of epidemiology Vol. 166; no. 8; pp. 951 - 965
• Main Authors: Croteau, Agathe, Marcoux, Sylvie, Brisson, Chantal
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 15.10.2007; Oxford Publishing Limited (England)
• Subjects: Adult; Analysis. Health state; Biological and medical sciences; Case-Control Studies; Epidemiology; Female; General aspects; Humans; maternal exposure; Medical sciences; Miscellaneous; Obstetric Labor, Premature - epidemiology; Obstetric Labor, Premature - prevention & control; occupational exposure; Occupational medicine; Occupations - statistics & numerical data; Odds Ratio; posture; Pregnancy; pregnancy outcome; premature birth; Prevention and actions; psychological; Public health. Hygiene; Public health. Hygiene-occupational medicine; Quebec - epidemiology; Retrospective Studies; Risk Assessment; Risk Factors; stress; Surveys and Questionnaires; vibration; Women, Working; work schedule tolerance; Quebec; Canada, Quebec; maternal exposure; premature birth; work schedule tolerance; posture; stress, psychological; pregnancy outcome; vibration; occupational exposure; Human; Pregnancy disorders; Premature delivery; Activity; Risk; Occupational exposure; Posture; Pregnancy; Prevention; Mother; Prematurity; maternal exposure; occupational exposure; posture; pregnancy outcome; premature birth; stress; Risk factor; Work; psychological; vibration; work schedule tolerance; Female; Woman; Occupational medicine
• ISSN: 0002-9262; 1476-6256
• DOI: 10.1093/aje/kwm171

The objective of this case-control study was to evaluate whether occupational conditions during pregnancy are associated with preterm delivery (PTD). Women whose work conditions changed following the use of a legally justified preventive measure (withdrawal from work or job reassignment) were also compared with those whose work conditions did not change. Cases (n = 1,242) and controls (n = 4,513) were selected from 43,898 women who had single livebirths between January 1997 and March 1999 in Québec, Canada. They were interviewed by telephone after delivery. Results showed association of PTD with demanding posture for at least 3 hours per day, whole-body vibrations, high job strain combined with low or moderate social support, and a cumulative index composed of nine occupational conditions. The adjusted odds ratio increased from 1.0 to 2.0 for PTD (ptrend < 0.0001) and from 1.0 to 2.7 for very PTD (<34 weeks; ptrend = 0.0015) as the number of conditions increased from zero to four or more. The associations for PTD and very PTD with most of the above-mentioned work conditions were weaker when exposures were eliminated following recourse to a legally justified preventive measure. This study provides relevant information on the possible influence of preventive measures on the risk of PTD in pregnant workers.