[Intrauterine growth--normal curves for gestational age]

We calculated new birthweight, length and head circumference standards for caucasian boys and girls between 26 and 43 weeks gestation from 28,126 singleton live births at our hospital between 1980 and 1985. Only stillbirths and infants with serious congenital abnormalities were excluded, whereas babies born to mothers suffering from complications known to affect fetal size were considered part of the population to which standards will be applied and thus remained included. The standards were determined from centiles for each gestational week independent of the mode of distribution of the data. The centiles were then "smoothed" using a Hanningfilter. The descriptive analysis showed a skew to the left of all our data and a steep distribution pattern so that the assumption of a normal distribution is incorrect. Comparison with mean values and standard deviations computed from the same data revealed considerable deviations from our results.