Abstract: Aim of the stud; To verify the correlation between abdominal Aorta Length in the fetus and gestational in weeks between 34- 40 weeks Type of study; Case Control Methods; a healthy pregnant women were chosen who’s age between 15-40 years all are primigravida and conceived within 3 months of marriage. They were between 34- 40 weeks in gestation. Their last menstrual period was know and recorded in addition all were scheduled for ultrasound examination for measurement of the abdominal aorta length, femoral length and biparietal diameter. Result; a highly significant correlation was found between abdominal aorta and biparietal diameter and femoral length . In addition a highly significant correlation was found between gestational age calculated by their LMP and abdominal aorta. In addition a highly significant correlation was found between gestational age and abdominal aorta length. A non linear exponential equation was constructed with lowest mean of sum of squares=1, and coefficient of correlation= 0.97 between abdominal aorta length and gestational age in weeks. From this equation a reference table built which contains value for the abdominal aorta between 34- 40 weeks for 1,2.5,5,10,90,95, and 99 centiles. After the building of this table further 35 women were taken for assessment of this table. Only 2 were miss calculated, the Kappa Cohen coefficient=0.93 Conclusion; a table by which the gestational age can be calculated between 34-40 weeks by measuring the abdominal aorta. However under no circumstances this table may be used apart from assessment applications. Further studies are required to verify its accuracy