Objectives This study was designed to establish new reference charts for
BPD (biparietal diameter), OFD (occipitofrontal diameter), HC (head
circumference), CM (cisterna magna), TCD (transverse cerebellar diameter), PCV
(posterior cerebral ventricle), AC (abdominal circumference), FL (femur length),
and HL (humerus length) and extend known charts to 42 weeks of gestation. These
new charts were compared to studies carried out by Snijders and Nicolaides, the
INTERGROWTH 21st Project, and the WHO Fetal Growth Charts.
Methods In this retrospective cross-sectional single-center study of
12,972 low-risk pregnancies, biometric data between the 15th and 42nd weeks of
gestation were evaluated. Only one examination per pregnancy was selected for
statistical analysis. Descriptive analysis for the 5th, 50th, and 95th quantile
was performed for each parameter as listed above. Regression models were used to
fit the mean and the SD at each gestational age.
Results Initially the reference curves for BPD, OFD, HC, AC, FL, and HL
show a linear increase, which changes into a cubic increase towards the end of
pregnancy. The results of this study show statistically noticeable differences
from the percentile curves of the studies listed above.
Conclusions The percentile curves in this study differ from the commonly
used ones. The presented standard curves can be used as a reference in prenatal
diagnostics.