[Simplified technique to calculate foetal weight from ultrasonic foetometric data (author's transl)].

Evaluation of more than 1500 cases has shown that real foetal weight can be calculated on the basis of mean thorax diameter, if linear ultrasonic measures are used. Addition of more parameters will render calculation more sophisticated and complex, though gain in accuracy will be unimportant. Accuracy depends not only on biological variation but even more on precise measurement by the examiner. An aid for more convenient calculation is described.