[Use of the new East German percentiles in the classification of newborn infants].

Re-classifying the newborns treated in the NICU of the University of Greifswald between 1983 and 1987, according to the percentiles (birthweight and length) of Lubchenco and the new standards recommended for the GDR after a data sampling in 1985, identic results could be found for the number of LGA using the 90th percentile. Certainly until the 34th week of gestation (but probably also thereafter), using the 10th percentile of the GDR standard, a to high rate (greater than 20%) of SGA infants could be found, whereas the range of birthweights of our own patients fitted exactly the distribution found by Lubchenco. The reason might be an underrepresentation of lifeborn VLBW infants in the GDR sample due to differences of the definitions used for the assessment of lifeborns and stillborns/fetal loss. Therefore, for practical use of the new standards as criterion for classifying AGA/SGA newborns until the 34th week of gestation the 5th percentile is recommended. A reevaluation of the distribution of birthweight in the GDR population is proposed including even-dead newborns in the data sampling.