Twin gestations require different normal values than singleton pregnancies.
The aim of this study was to define percentiles of birth weight, length an
d head circumference for twin pregnancies according to gestational age. 80
000 twins born at 21 to 42 weeks' gestation between 1990 and 1995 in German
y of German citizens were analyzed. Percentiles were calculated from cumula
tive frequencies. The advantage of twin-specific percentiles are discussed.