Boys born less than 6 pounds may be physiological phenomenon, malnutrition, pregnant mothers suffering from diseases, short gestational age and so on have a relationship. 1. Physiological phenomenon: it may be a normal range, belonging to physiological phenomenon, it is recommended not to worry too much, pay attention to the development of the child at a later stage. 2. Malnutrition: During pregnancy, pregnant mothers need to consume high protein and vitamin foods that are easy to digest. But also to prevent anemia, calcium deficiency and other conditions, if the pregnant mother picky eating, partiality and long-term unhealthy diet may cause maternal and fetal malnutrition, the birth of a boy less than 6 pounds of the situation. 3. Pregnant mothers suffer from diseases: If the pregnant mother has a disease, it may also cause the child to be born with a low birth weight, such as heart disease, gestational diabetes, nephritis and so on. 4. Short gestational age: the normal gestational age is 38 to 42 weeks, the shorter the gestational age, the earlier the birth, the lighter the child’s weight. Boys born less than 6 pounds may also have other reasons, if the child has other abnormal symptoms, should go to the hospital in time to visit the doctor to clarify the cause of the disease, under the guidance of the doctor for treatment.