Evaluation of femur/foot and humerus/foot ratios by transvaginal sonography between 62 and 116 days of gestation.

ABSTRACT

OBJECTIVE: The objective was to construct nomograms of femur/foot length and humerus/foot length ratios in early pregnancy by transvaginal sonography. METHODS: In the period 1994-2000, 1,008 singleton pregnant patients were examined from 62 to 116 days of gestation using transvaginal high-resolution ultrasound technique. As a part of biometric survey femur, humerus and foot length were recorded and evaluated as ratio at each gestational age. The distribution of the residuals for the different ratios is also described. RESULTS: A significant correlation was demonstrated between femur and foot length (R2=0.984; p<0.0001) and between humerus and foot length (R2=0.983; p<0.0001). The femur/foot length and humerus foot/length ratios were approximately 1 throughout this period of gestation with a narrow range. CONCLUSION: The presented data obtained in early pregnancy by transvaginal scan offer normative measurements of femur/foot length and humerus foot/length ratios which may be useful in the prenatal diagnosis of congenital syndromes that include skeletal maldevelopment.