[Ultrasonic size of fetal crump-rump length in first trimester of pregnancy. Accuracy of gestational age assessment (author's transl)].

The fetal crown rump length was measureed by means of pulsed ultrasound. The normal values between 49 and 94 days from the onset of the last menstrual period were determined in 72 patients. Statistical analysis showed a good correlation between gestationnal age and fetal crown rump length. The usefulness of this measure is so demonstrated: assessment of gestational age, within few days.