Clavicular measurement: a new biometric parameter for fetal evaluation.

Fetal clavicular length was measured sonographically in 85 fetuses with gestational ages ranging from 15 to 40 weeks. Biparietal diameter (BPD) and femur length (FL) were also measured. A linear correlation was found between clavicular length and gestational age (coefficient of correlation = 0.81). A simple relation was found: The gestational age in weeks is approximately equal to the length of the clavicle as expressed in millimeters. The measurement of clavicular length can be a useful parameter for the estimation of gestational age and in the detection of congenital anomalies that affect the clavicles. Clavicular measurements may also prove useful in the detection of macrosomic fetuses at high risk for obstructed labor or shoulder dystocia.