There may be measurement errors in fetal femur shortening, and there is no need to worry too much when the range is not large. In addition, there may be nutritional deficiency, genetic factors, etc. The main points for reference are as follows: 1, measurement error: the location, angle and different examining doctors may cause certain errors. If the difference between the measured value and the average value is large, it is recommended to recheck; 2. Nutritional deficiency: when the nutritional intake of pregnant women is unbalanced, it may lead to fetal growth retardation, thus manifesting as short femur, it is recommended to adjust the diet structure and actively supplement high quality protein and vitamins. Foods rich in high quality protein include eggs, milk, meat, fish, and soy products, and foods rich in vitamins include egg yolk, carrots, pumpkin, etc.; 3, genetic factors: due to genetic factors leading to congenital short femur of the fetus, it will have a certain impact on the height of the baby after birth. It is recommended to take proper calcium supplement during pregnancy, and after the baby is born, breastfeeding mothers are recommended to eat moderate amount of food with high calcium content every day, such as milk, soy products, dark green vegetables, etc. Non-breastfeeding is recommended to choose milk powder with high calcium content; 4, chromosomal abnormalities: fetal short femur is related to chromosomal abnormalities such as 21-trisomy karyotype and 18-trisomy karyotype, which is one of the ultrasound soft indicators to evaluate fetal chromosomal abnormalities. If pregnant women have abnormal ultrasound results at 17-20 weeks, they can combine Down’s syndrome screening and amniocentesis chromosome test to help improve the accuracy of diagnosis; 5. Other: If pregnant women have gestational hypertension, diabetes and other diseases, or their own bad habits lead to, such as smoking and drinking, can also cause fetal dysplasia and short femur, and should be actively treated under the guidance of a specialist. Adopt good living habits. Pregnant women should be aware that the femur is only one of the indicators to monitor the development of the fetus in the uterus, and should be combined with other indicators to analyze the development of the fetus.