[Prenatal sex determination using ultrasound]

The fetal urogenital region could be visualized by single routine sonography after the 20th gestational week in 66.4 per cent, after the 24th one in 74.4 per cent (n = 1002). Compared with the true sex of 875 children after birth 90.2 per cent of the girls and 75.9 per cent of the boys were determined correctly during pregnancy. The prenatal prognosis of a boy was confirmed in 90.3 per cent, of a girl only in 75.7 per cent. Multiple examinations make raise perceptibility and certainty. These differences and possible consequences in practice are discussed. In twin pregnancies final statements could not be afforded because of the more difficult conditions.