Background and Aim: One of the important changes during pregnancy is weight gaining of pregnant women that is one of reliable indicators of nutrition controlling. Pregnancy weight gain is measured by the rate of Body Mass Index (BMI) before pregnancy and standard criteria of American Institute of Medicine (IOM). This study was designed to evaluate the pattern of weight gain in pregnant women referred to health centers of Birjand.

  Materials and Methods: This descriptive- analytic study was performed in 2007 on 347 healthy pregnant women who referred to health centers of Birjand in 2007. BMI before pregnancy was recorded for all mothers, and repeated at regular visits, at least between 3^rd to 9^th months of pregnancy. Mothers who suffered from pregnancy induced hypertension, gestational diabetes, abnormal swelling and signs of preeclampsia or those with multigestational pregnancy were excluded from the study. Body weight during different months of pregnancy, were retrieved from information on pregnant women care in the health centers. The data were analyzed by SPSS using relevant statistical tests at the significant level of P<0.05.

  Results: The mean weight gain in the third quarter was 5.34±2.79 Kg, and during the whole of pregnancy was 10.46±4 Kg. Weight gain in mothers with BMI less than 19.8 was 10.86±3.88 Kg, mothers with 19.829, was 8.77±3.57Kg. Significant correlation was observed between weight gain during pregnancy and BMI before pregnancy (P=0.009), maternal age (P<0.001), and birth weight (P<0.05). Moreover, a significant correlation was seen between the mean weight gain and rank of birth baby (P=0.002), and level of mother's education (P=0.004).

  Conclusion: Weight gain during pregnancy among pregnant women in Birjand is lower than the standard of IOM, which may be due to nutrition factors or maternal care during pregnancy.