Anthropometric assessment of nutritional status in pregnant women: a reference table of weight-for-height by week of pregnancy.

A reference table of weight-for-height by week of pregnancy has been devised on theoretical grounds, based on the premises that the average increment of weight during pregnancy is 20% of the prepregnant weight and that almost all the increment takes place linearly during the 2nd and 3rd trimesters of pregnancy. The table was tested with retrospective clinic and hospital data. The results show a good correlation between the weight-for-height at different stages of pregnancy as a percentage of the reference table and the birth weight of the offsprings. This reference table can be a useful tool to assess the nutritional status of pregnant women and, within limits, to "predict" the chances of delivering a low birth weight infant.