The femur 65mm at 38 weeks of pregnancy is short, which may be caused by congenital genetic factors, slow development, calcium deficiency, etc. Pregnant women need to eat food with high calcium content and monitor the growth and development of the fetus on a regular basis. 1. Inherited genetic factors: short femur may be caused by genetic factors of the fetus is small in stature, can be improved by strengthening nutrition and exercise. 2. Slow development: If the slow development of the fetus is caused by the malnutrition of pregnant women, pregnant women need to strengthen nutrition, eat a balanced diet, and regular monitoring. 3. Calcium deficiency: If the short femur is caused by calcium deficiency, pregnant women need to pay attention to calcium supplementation, you can drink milk every day, eat more eggs, meat or take some calcium tablets under the guidance of the doctor. It is recommended that pregnant women pay attention to balanced nutrition during pregnancy, happy mood, pay attention to rest, regular obstetric examination, if there is a short femur, it is recommended to seek medical attention in time.