Physical Activity Pattern and Personal-Social Factors of Mothers During Pregnancy And Infant Birth Weight Based On MET Scale: A Case-Control Study

BACKGROUND: Low birth weight is one of the most important public health issues in developing and developed countries and identifying its etiology is important for prevention. OBJECTIVES: Considering the unknown impact of physical activity on low birth weight, this research was conducted to investigate the relationship between physical activity and low birth weight. PATIENTS AND METHODS: This research was conducted using a case-control design. The control group was made of 500 women with normal birth weight infants and the case group included 250 women with low birth weight infants from the selected hospitals in city of Tehran. The information was gathered using a researcher-made questionnaire which was prepared for determining the relationship between mothers’ lifestyle during pregnancy and infants' low birth weight using social determinants of health approach. In this questionnaire, scope of physical activity was investigated in three groups of athletic activities, activities at home and leisure activities. Activity intensity was determined using MET scale and the data were analyzed in SPSS software using independent t-test, Chi-square and logistic regression. RESULTS: In the present research, based on the results of multiple logistic regression test, an increase in the time spent on sport activities (OR = 2.20) and home activities (OR =1.44) (P = 0.003) was accompanied by increased chance of giving birth to low birth weight infants; in contrast, one hour increase of leisure activities decreased the probability of low birth weight infants by 0.32 (P = 0.008). CONCLUSIONS: An increase in the time spent on sport and home activities, even after considering other influential factors, was related to low birth weight.