Maternal leisure-time physical activities are not determinant risk factors of low birthweight babies: A cross-sectional study of 1,714 pregnant women.

There is a general recognition of the role of low birthweight (LBW) as a major determinant of infant mortality rates. Since the rate of LBW has been increasing over the past fifteen years in Japan, we decided to ascertain the risk factors related to it, and also to verify whether or not maternal leisure-time physical activities including sports activities, before pregnancy and during gestation, affected the rate of LBW babies. In our study of the 2,682 questionnaires delivered within a year to the Municipal Health Centers of the three cities chosen for this study, 1,714 questionnaires were analyzed. The results in a univariate analysis showed that maternal height, pre-pregnancy weight, length of gestation, smoking, hospitalization before the 37th week of gestation, a history of LBW, and occupational activities were significantly associated with LBW. In logistic regression analyses, mothers of smaller stature, less pre-pregnancy weight, less length of gestation and mothers who were, furthermore, hospitalized before the 37th week of gestation, smoked, had previously delivered a LBW baby or had experienced stressful events during pregnancy were more likely to have LBW babies. The results showed that maternal leisure-time physical activities before and/or during pregnancy had no bearing on the delivery of a LBW baby.