The parents of babies often come to the clinic and say that the doctor at the outside clinic says that the baby’s fetal phlegm is caused by the incomplete aspiration of the lungs at birth, and that they take a special pill for fetal phlegm. Is it true? From the perspective of modern medicine, there is no such thing as fetal phlegm. 1, such as the baby at birth if not sucked clean amniotic fluid, may lead to aspiration pneumonia in newborns. At that time, coughing, shortness of breath and other conditions, must be hospitalized. The birth canal has some pathogens with a long incubation period such as, for example, chlamydia, and the infection may appear only after 2-4 weeks with cough and other respiratory symptoms. If these are said to be fetal phlegm, it still makes sense; 2. However, the vast majority of what is called fetal phlegm is phlegm in the throat, which, after examination, is commonly congenital laryngeal wheezing. Congenital laryngeal wheezing, laryngeal wheezing occurs in young children due to soft and flaccid laryngeal tissue, tissue collapse during inspiration, narrowing of the laryngeal cavity into a live flap-like tremor, also known as laryngeal cartilage softening. It may be caused by malnutrition during pregnancy, fetal calcium deficiency, oversized and soft epiglottis cartilage, or inspiratory arytenoid cartilage prolapse. The baby is born with normal breathing and gradually develops laryngeal tinnitus 2 to 4 weeks after birth. It is mostly persistent or intermittently aggravated. Laryngeal tinnitus occurs only during the inspiratory phase and may be accompanied by inspiratory dyspnea. It may be accompanied by the inspiratory trigeminal sign, i.e., a depression in the suprasternal fossa, supraclavicular fossa, and subclavian process during inspiration. There are also cases in which laryngeal tinnitus is not usually obvious but occurs immediately after slight stimulation. Some of them are position-related, aggravated when lying on the back and lighter when lying prone or on the side. The cry is not hoarse. Most children are in good general condition, and if the symptoms are not severe, the laryngeal gap will gradually increase with age and the laryngeal cartilage will develop well, and the disease usually resolves itself by 1 to 2 years of age. Note: The disease will be aggravated by upper respiratory tract infection, so usually more sunshine, more outdoor activities to enhance the physical fitness of the child, to avoid respiratory tract infection and laryngeal spasm, aggravating laryngeal obstruction. In a few children with severe clinical manifestations, it may lead to funnel chest or chicken chest due to respiratory distress and long-term oxygen deprivation, because the lung function is affected, some children may have an enlarged heart, and sometimes surgery is required for severe cases. Occasionally, tracheotomy is required for severe laryngeal obstruction. Other rare congenital abnormalities of the larynx and trachea such as laryngeal webbing, laryngeal fissures, and cartilage softening of the trachea also have laryngeal tinnitus and phlegm in the throat. These are also not what fetal phlegm oh.