A femur length of less than 2 sd represents a fetus with a current developmental delay. It is shorter than 2 standard deviations of normal fetal development of the same age and sex. Representing fetal dysplasia, it may be related to gestational hypertension or poor nutrition, it is best to complete a series of macro-anatomical examination to clarify the cause of the disease, and timely correction of the nutritional status, to avoid fetal dysplasia, which affects the health. Pay attention to rest, eat a balanced diet and don’t be picky about what you eat. Regular checkups and ultrasound of the fetus should be conducted to clarify the nutritional status.