OBJECTIVES Many pregnant women have musculoskeletal complaints, the onset and aggravation of which are thought to be associated with their activity or work postures. The purpose of this paper was to obtain more insight into the influence of pregnancy on the load of the musculoskeletal system at work to provide a better basis for preventing complaints.

METHODS To this end, literature pertinent to a model called "work load of the musculoskeletal system" was reviewed. The model was developed to describe how work contributes to musculoskeletal complaints.

RESULTS It was found that pregnancy causes changes in a worker's characteristics. These changes can lead to changes in the work situation, activity pattern, and postural characteristics and possibly result in a change in work load. In addition, physical changes such as weight gain increase the work load in a given posture. The load-bearing capacity of the musculoskeletal system decreases due to pregnancy.

CONCLUSIONS The changes in load and the decrease in load-bearing capacity singly or simultaneously increase the risk of musculoskeletal complaints. The multifactorial cause of musculoskeletal complaints during pregnancy reveals various possibilities for prevention.