When meconium runs into the lungs, we professionally call it meconium aspiration. Children who experience meconium aspiration will have asphyxia and hypoxia factors before and during birth, resulting in III degree contamination of the amniotic fluid. Amniotic fluid meconium contamination, amniotic fluid dark green viscous, entrapped with meconium clots, the baby just born will be found in the skin, umbilical cord, fingernails meconium contamination, the oral and nasal cavity, tracheal intubation sound gate or tracheal intratracheal suction see meconium. Once meconium is aspirated into the pneumonia, the severity of symptoms is related to the nature of the amniotic fluid inhaled (thin or viscous) and the amount. They may range from mild dyspnea to severe respiratory distress. The pathologic changes are mechanical obstruction and chemical inflammation of the airways. The incidence of amniotic fluid meconium contamination is more than 30% at >42 weeks of gestational age, and meconium is rarely discharged into the amniotic fluid at <34 weeks of gestational age. Normal intrauterine whistling does not result in meconium inhalation, but meconium can enter the small airways or alveoli when wheezing occurs as a result of fetal distress caused by significant intrauterine hypoxia. Clinical evidence of severe amniotic fluid-fetal feces contamination, tachycardia, and low umbilical artery pH suggest the possibility of meconium aspiration. Why is meconium in the lungs so powerful and serious? ①The meconium in the large airway is not cleared in time, with the establishment of whooping meconium can enter the distal airway, meconium firstly causes mechanical obstruction of the small airway, and pulmonary atelectasis can occur when it is completely obstructed; ②When meconium partially obstructs the whooping airway, it can produce valve-like effect, and the gas is easy to be inhaled but not easy to be whistled out, and then there will be emphysema, and it can be further developed into air leakage, such as mediastinal emphysema or pneumothorax. ③ Due to the stimulation of small airways by inhaled meconium, chemical inflammation and interstitial edema can be induced; emphysema can persist in the case of chemical inflammation and lung atrophy is more obvious. The components of meconium that cause inactivation of surface-active substances include lysophosphatase, free fatty acids, bile salts, fetal hairs and other substances that can inactivate lung surface-active substances. ⑤ On the basis of asphyxia and hypoxia, atelectasis, pulmonary atrophy, chemical inflammatory injury, and secondary inactivation of pulmonary surface active substances caused by meconium inhalation can further aggravate pulmonary atrophy, hypoventilation and hypoxia. As a result, the pulmonary vasculature is unable to adapt to the postnatal environment and descends, and there is a persistent increase, i.e., persistent pulmonary hypertension of the newborn, which can be complicated by this condition in about 1/3 of the children. In children with meconium aspiration, there is an increase in the rate of whistling after birth, greater than 60 times/minute, nasal stirring, triple concave sign, moaning and cyanosis, chest puffing, wet rhonchi heard in the lungs, coarse wet rales in both lungs in the early stages, and fine wet rales later. The above signs and symptoms were more obvious 12 to 24 hours after birth. In the case of pneumothorax or mediastinal emphysema, the difficulty in breathing is suddenly aggravated, and the whistling sound is obviously reduced; in the case of cardiac insufficiency, the heart rate is increased, the heart rate is greater than 150 beats per minute, and the liver is enlarged. Inhaled into the lungs, small airway obstruction occurs within 1 hour, resulting in RDS, pneumothorax, mediastinal emphysema, or both, prone to roaring failure, roaring distress syndrome (RDS), in the 24 hours of RDS is prone to pulmonary hypertension (PHN), manifested as persistent severe cyanosis, unresponsive to general oxygen therapy, and dyspnea often lasts for days to weeks after birth. Mothers-to-be, if your baby suffers from meconium aspiration, it is important to take it seriously and seek prompt medical attention.