Neonatal disease screening refers to the screening of certain congenital diseases and hereditary diseases in the neonatal period for early diagnosis and treatment to avoid irreversible physical and intellectual developmental disorders. Such diseases often lack specific symptoms in the neonatal period or even in the small infant period, and once the symptoms appear, irreversible damage has been formed, losing the opportunity for treatment; while in the neonatal period there are biochemical and metabolic changes in the blood, so early diagnosis can be made in the neonatal period with laboratory tests. Newborn disease screening is an important element of modern preventive medicine, has far-reaching and positive significance to eugenics, improve the quality of the birth population, and is also one of the important measures to fundamentally reduce the high incidence of birth defects. Birth defects are the general term for various structural malformations and functional abnormalities present at birth due to congenital, hereditary and adverse environmental factors. There is a wide range of birth defects and the total incidence is about 5%. In Guangdong Province, the incidence of birth defects is 10% due to the high prevalence of thalassemia and G-6-PD deficiency. Birth defects are found in all systems of the body, and according to the World Health Organization classification, there are 20 common types of birth defects, including those visible to the naked eye and those not visible to the naked eye. Among them, congenital inherited metabolic diseases and hearing impairment are invisible to the naked eye and functionally abnormal birth defects. The target diseases for newborn screening generally meet the following conditions: (1) a certain incidence; (2) serious harm; (3) no specific symptoms in the early stage; (4) treatable; (5) screening methods are simple, effective, inexpensive, and suitable for large-scale implementation; (6) the economic situation and health technology strength of the country or region to determine the type of screening disease. Neonatal tandem mass spectrometry screening: It can analyze dozens of metabolites in one specimen within 2 minutes, which can achieve the requirement of “one experiment to detect multiple diseases”. It also improves the accuracy and efficiency of experiments. Tandem mass spectrometry has the potential to become a routine diagnostic tool for genetic metabolic disorders. Why do we need to screen newborns for diseases? Some parents think: We are both healthy and have no genetic disorders, is it necessary to screen our child for newborn diseases? We think it is necessary. Because newborn screening is mainly for metabolic and recessive genetic disorders, just because the couple is healthy does not mean that the next generation will be healthy. Also the only way to prevent and treat these diseases at this time is early detection and early treatment. In the case of children with congenital hypothyroidism (the incidence of the disease is 1:4000), if treatment is started within one month after birth, the intelligence is completely normal; within three months, the intelligence is basically normal; after six months, the intelligence of some patients is backward. If a child with phenylketonuria (the incidence of the disease is 1:8000-1:17000) is treated within three months after birth, mental retardation can be largely avoided. The earlier the treatment, the better the prognosis. Therefore, the responsibility of carrying out newborn disease screening is great and should never be taken lightly. At present, China’s newborn disease screening mainly includes: 1, phenylketonuria (PKU); 2, congenital hypothyroidism (CH); 3, glucose-6-phosphate dehydrogenase (G-6-PD) deficiency; 4, newborn hearing screening. Guangzhou has extended the range of newborn screening diseases to six, including thalassemia, congenital adrenocortical hyperplasia and galactosemia, in addition to the 1-3 mentioned above. With the help of tandem mass spectrometry screening technology, the number of congenital metabolic diseases that can be screened for can be increased to 50. Moreover, the screening center provides free treatment for children diagnosed with phenylketonuria until the age of 18, galactosemia until the age of 6, and maple diabetes until the age of 18. Screening precautions: 1. Blood collection should be done after 72 hours of adequate breastfeeding after birth, or after a minimum of 6 breastfeeding sessions. False negatives for screening for phenylketonuria can occur without breastfeeding, i.e., without protein loading. Blood specimens taken 72 hours after birth can also avoid physiological thyrotropic hormone (TSH) rise and reduce false positives for screening for congenital hypothyroidism. 2. If your child is screened for newborn diseases in the hospital, you will no longer be notified if the screening result is normal, but only reported to the hospital where the blood was collected (generally, if you do not receive the notification after one month, it is indicated that the screening result is normal). Since screening is different from diagnosis, its sensitivity is about 95%, therefore, if the screening result is suspicious, you will be notified immediately in the shortest time and fastest speed. For Phenylketonuria and congenital hypothyroidism with suspicious results, you should be notified by the blood collection hospital for review and the government will be responsible for giving free treatment; for G-6-PD deficiency with suspicious results, you will be notified by the blood collection hospital to confirm the diagnosis at the local maternal and child health center. 3. When parents receive the notification for review, they must review the test on time and must not take it lightly. If you do not confirm the diagnosis on time after receiving the notification, you will be responsible for the consequences. Specially remind you to fill in your contact address and phone number clearly and accurately so that you can get the fastest contact. For the sake of the healthy growth of the next generation and the happiness of your family, please actively cooperate with the hospital to do a good job of newborn screening.