Materials and Methods: Participants comprised 100 pregnant women (age, 20-30 years). Posture control was assessed during the second and third trimesters using 2 stabilometers to measure the ability to control upright posture. During the third trimester, participants were asked to complete a self-administered questionnaire on falls.

Results: Data were obtained from 82 subjects after excluding dropouts. Ten fallers were identified, resulting in a fall incidence of 12%. The fall group showed a 9.9% increase in abdominal girth from the second to third trimester, significantly greater than the 6.9% in the non-fall group. In the fall group, the rectangular area in the back, left and right was larger from the second trimester. In the third trimester, the stability limits of the fall group were significantly smaller than in the non-fall group.

Conclusions: The loosening of joints from second trimester and declines in equilibrium function and an abrupt increase in abdominal girth may cause shifts in recognition of how the body moves, such as estimation errors, thereby causing falls. For pregnant women, guidance, exercises promoting awareness of fall prevention, and accurate perception of the body need to be incorporated in the exercise from the second trimester.