Summary: This study supported only physiological variables for the use of the Neuman Systems Model. The results from this study can be implemented into preconception care services as perinatal primary prevention for women who plan to get pregnant to reduce avoidable risks. The results can also be used in PNC services as secondary prevention, for women who are already pregnant, to provide appropriate treatment of symptoms. This study may help to reduce the incidence of LBW in Thailand by educating nurses to assess, identify, implement, and teach Thai women to promote their maternal/fetal system stability.