Studies on basal metabolism during pregnancy and after delivery. 1. On the basal metabolism in the normal pregnancy.

For the study on the basal metabolism (B.M.) during pregnancy, this of 117 normal pregnant women was determined.1. The difference of B.M. by age was not observed between twenties and thirties.2. There was no difference of B.M. between those who bore babies of weighting 2, 501 to 3, 000g and those of 3, 501 to 4, 000g.3. The average calorie per hour per square meter for each month of pregnancy fluctuated somewhat, however, an equation of regression line was found as y=0.82x+33.63. B.M. of the pregnant was increased by 10-11% for the 3rd and the 4th month, 6% for the 5th, 24% for the 9th and 10th to the standard B.M. value. There was a small dip in the 5th month, and it was supposed that hormonal factors were responsible for this dip. The increase of B.M. during the latter period of pregnancy was considered to be due to the increasing mass of active protoplasmic tissue, which consists in large part of the fetal tissues and in lesser part of maternal ones.4. By the monthly determination of B.M., it was revealed that the average calories per hour per kilogram body weight for each pregnant month were rather constant. By statistical analysis, this constant was found to be 1.09.5. The body weight in the 10th month of pregnancy increased about 20% to that before pregnancy.From this research, it becomes easy to calculate B.M. and for this calculation, B.M. is designated conveniently as calories per hour per kilogram body weight. This may be useful to calculate the individual and periodical requirements of nutrients.