examining the methods of measuring the womb height and mother's abdomen circumference to estimate baby's weight at the birth time in term mothers referred to maternities in isfahan during 2007-08

background: this research aimed to examine the methods of measuring the womb height and mother's abdomen circumference to estimate infant's weight at birth time. methods: in this cross-sectional descriptive-correlative research, 1070 mothers with term pregnancy (and their infants) who referred to isfahan maternities were assessed. questionnaire, demographic data form, patient's medical files and standard meter and scales for adults and infants were the data collection tools. data were analyzed using spss software. results: there was a significant relation between womb height and infant's weight at birth time, also between mother's abdomen circumference and baby's weight at birth time categorized by the number of childbirths, age of gestation, condition of infant's head engagement, body mass index, and mother's bulk (p < 0.05). the correlation coefficient of womb height and mother's abdomen circumference in estimating baby's weight at birth time were not statistically different. besides, the positive and negative prediction value of these two methods for determining the weight of infants with less than 2.5 kilos or more than 4 kilos are the same. finally a formula was achieved to estimate baby's weight: birth weight = - 2.203 + 0.035 (womb height) + 0.012 (abdomen circumference) + 0.012 (duration of gestation) - 0.114 (infant's head engagement) + 0.043 (size of bulk) conclusion: it is suggested that the personnel of maternities especially in disadvantaged parts of the society learn the correct method of measuring mother's abdomen circumference and womb height and estimate baby's weight using achieved model to improve mother's and baby's health.