Foetal growth from 50 to 150 days of gestation.

Weight and several linear measurements have been related to postmenstrual age in a series of fresh, apparently normal foetuses, ranging in age from 8 to 21 weeks. Although the correlation between these variables and age was high, the prediction of foetal age from such measurements can never be precise, due in part to difficulties inherent in the concept of postmenstrual age. The average relationships agreed in general with those in previous reports, including those based on spontaneous abortion material.