The development of the fetus: By the 31st week of pregnancy, the fetus has repeatedly practiced opening and closing its eyes, and can distinguish darkness and light to a certain extent. However, fetal vision cannot yet see very far like adults, and the visual field generally does not exceed 20~30cm. When there is a bright light outside the abdomen, the fetus\’ head will turn to the bright light and it will reach out to touch the bright light. Related articles: Prenatal education for your baby in the 30th week of pregnancy. At this time, the fetal lungs and digestive system are almost completely formed. The amount of amniotic fluid also increases. However, from this point on, the fetus becomes larger and the space in the uterus becomes narrower, causing the amount of amniotic fluid to slowly decrease. The fetus fully inflates its lungs in the amniotic fluid and continuously exhales and inhales in preparation for breathing after birth. The diaphragm can be seen moving through ultrasound. The fetus takes in water from the amniotic fluid and then excretes it in urine. At this time, the pregnant mother\’s body changes, and the ligaments supporting the waist relax, causing the pregnant mother to feel low back pain again. In addition, in order to support the increasingly heavy abdomen, the shoulders and body naturally lean back. The shoulders are prone to fatigue and will cause pain over time. Moreover, the shoulders have to support increasingly larger breasts. The closer to delivery, the more painful the shoulder will be. In order to reduce pain, pregnant mothers can perform appropriate exercises such as gymnastics to improve blood circulation. Massaging your shoulders is also an effective method. At this time, pregnant mothers will experience urinary incontinence, and urine will flow out unknowingly when sneezing or laughing loudly. This is caused by the uterus pressing on the bladder. It is a common phenomenon among pregnant mothers and there is no need to worry too much. Most urinary incontinence occurs after the 30th week of pregnancy when the abdomen gradually becomes larger, and will disappear naturally after delivery. Do not hold in your urine normally. Use sanitary napkins when symptoms are severe.