[Antenatal assessment of fetal maturity--a comparison of ultrasound-cephalometry and radiology (author's transl)].

334 ultrasound-cephalometries and 231 X-ray fetographies were performed for antenatal assessment of fetal maturity as well as for exact estimation of gestational age in women with unknown date of donfinement. The accurance of the predictions was compared. Ultrasound-cephalometry gave best results when performed until the 20th week of gestation. A correct prediction was obtained in 80.4% of cases. After the 20th week of gestation, the accuracy of prediction decreased. Radiology on the contrary gave optimal results at the end of pregnancy. A correct prediction of the date of confinement was obtained in 73.8% of cases, when the X-ray fetography was performed between the 37th and 40th week of gestation. At the end of gestation radiography should be performed, if there is a discrepancy between ultrasound and clinical estimation or if ultrasound-cephalometry was not carried out in early pregnancy--especially if induction of labour is necessary.