Late pregnancy is small one week is pregnancy week accounting error, nutritional factors and other reasons, generally have no effect, if it is caused by fetal factors, will affect the normal development of the fetus. 1. Wrong accounting of gestational weeks, the first thing to do is to recheck the gestational weeks of the fetus during pregnancy, such as the phenomenon of the fetus weighing less than one week due to the wrong accounting of gestational weeks, recheck and then assess. 2. Nutritional factors, pregnant women partial eclipse, pregnancy vomiting and intake of protein, vitamins and trace elements insufficient and other nutritional factors caused by small fetus, need to adjust the dietary structure, strengthen the nutrition, the growth and development of the fetus will have less impact. 3. Fetal factors, fetal genetic or chromosomal abnormalities, structural abnormalities and other diseases of the fetus may also appear in the phenomenon of small-sized fetus week, usually combined with other malformations, this situation is not normal, will affect the normal development of the fetus. If the fetus is small in late pregnancy, it is recommended to consult a doctor in time, improve the examination, actively search for the cause of the disease, improve the circulation of the placenta, strengthen the monitoring of the fetus, and terminate the pregnancy at the right time.