After pregnancy, women suffer from the discomfort during the whole pregnancy period, and finally get to the due date and meet the conditions for full-term delivery. Some mothers can’t bear it. When they have the idea of facing the puerpera, doctors often suggest that the fetus stay in the stomach for a few more days. But some mothers still insist on giving birth ahead of time, and even eloquently say: isn’t it full-term at 37 weeks? Since full-term, any time can be born. < / P > < p > in theory, those fetuses born at 37-42 weeks of gestational age are full-term infants, their organs have been mature, their body length and weight have also been mature, fully meeting the production conditions. < / P > < p > the medical community in the United States further shortens the time range of full-term infants, and believes that newborns born between 39 and 41 weeks are truly full-term infants. < / P > < p > American scientists found that infants born at 39 weeks of age are slightly behind in development, mainly reflected in breathing, hearing and learning cognitive ability. < / P > < p > and the main reason for this result is that the key development of the brain is in the second two weeks of pregnancy, that is, 37-39 weeks. Those children born after 39 weeks mean that their IQ, understanding ability and cognitive ability will be better. < / P > < p > near the third trimester, the risk of premature birth will increase. Clinically, the fetus that is more than 28 weeks pregnant but less than 37 weeks is called “premature infant”. < / P > < p > there are many reasons for premature birth, of which 70-80% are spontaneous premature birth, which is caused by some improper behaviors of pregnant mothers. So the closer to the third trimester, the more attention should be paid to every aspect of life. < / P > < p > the prenatal examination in the third trimester can not only monitor the condition of the fetus, but also know the delivery mode and intrauterine situation of the pregnant women in the near future, so that the doctors can better help the pregnant women in the delivery. < / P > < p > in addition, excessive diet in late pregnancy can also lead to abnormal uterine contractions and premature delivery. Therefore, the closer pregnant women are to late pregnancy, they should be more strict in diet and pay attention to balanced nutrition intake to meet their own and fetal nutritional needs. < / P > < p > these pathological diseases will be transmitted to the fetus through the mother, and then lead to premature delivery, so pregnant women in the third trimester should pay more attention to their own health management to avoid gynecological diseases. < / P > < p > in the third trimester of pregnancy, the fetus often develops almost completely in length and weight, and even the head of the fetus has entered the basin. At this time, if the fetus is in the same room, it is easy to damage the amniotic membrane, resulting in the breakage of amniotic membrane, leading to the occurrence of premature delivery. < / P > < p > the influence of pregnant mother’s emotion on the fetus during the whole pregnancy period can not be ignored. There was once a report that a pregnant mother in the third trimester of pregnancy was watching a performance when she suddenly burst out laughing, which directly led to premature birth. < / P > < p > from this point of view, it is not bad emotions that lead to fetal abnormalities. Some sudden fluctuations will impact the body and cause premature birth. < / P > < p > frequent touching the pregnant belly will lead to abnormal uterine contraction, especially in the late pregnancy, the uterus is stretched by the fetus, which is extremely sensitive. In the process of touching the pregnant belly, the pregnant mother will cause uterine contraction, leading to premature delivery. After pregnancy, do not let the wife do these five kinds of housework, the husband should be responsible for it, otherwise it is easy to hurt the fetus!