THE STUDY OF RELATION BETWEEN THE GESTATIONAL AGE OF HUMAN FETUSES AND THE DIAPHYSEAL LENGTH OF FEMUR USING ULTRASONOGRAPHY

Address for Correspondence: Dr Chaithra Rao B R Assistant Professor, Department of Anatomy, Sapthagiri Institute of Medical Sciences and Research Centre, No 15, chikkasandra, Hesarghatta main road, Bangalore560090, Karnataka. India. Ph+919916667709 Fax080283933404 E-Mail: chaithra.rao5@gmail.com Background and Objectives: Presently the most effective way to date pregnancy is by the use of ultrasound. The diaphyseal length of femur can be used as an additional parameter to estimate gestational age. The objective is to evaluate of the diaphyseal length of femur as a parameter to estimate the gestational age of the fetus at the time of examination. Materials and Methods: It is a Prospective cross sectional study done on 152 antenatal women. Antenatal women of all gestational age from 15 to 40 weeks of gestation from the District of Dharwad, age ranging from 20 to 30 yrs were included. Subjects with maternal disease known to affect normal fetal growth such as chronic hypertension, gestational diabetes mellitus, anemia, hypothyroidism, etc. and history of recurrent miscarriages and of chronic medications, multiple gestations or other complications such as fetal growth restriction, preeclampsia, pregnancy induced hypertension, placenta previa, or major fetal abnormalities were excluded. The diaphyseal length of femur was measured by an experienced Ultrasonographer in a standardized manner. The study establishes the relationship of the diaphyseal length of femur in centimeters, with the advancing gestational age in weeks. We obtained correlation of the diaphyseal lengths of femur with the gestational age from 15 to 40 weeks. Results: It was observed that the diaphyseal length of femur gradually increased from 15 weeks to 40 weeks of gestation. Normograms of diaphyseal lengths of femur can be constructed by the formula derived by this study for this particular geographical area. These normograms can be used to determine whether a given diaphyseal length of femur is normal or abnormal for a particular gestational age. Conclusion: The relationship between the diaphyseal length of femur and the gestational age is linear and direct. The measurement of the diaphyseal lengths of femur (in cm) can be an important additional parameter for estimating gestational age along with other parameters.