This is the 3650th article of Da Medical Care
Newborn disease screening is the detection of certain congenital diseases that seriously affect physical and mental health early after birth, and appropriate intervention and treatment are given so that the child's health status and life ability reach or are close to the level of normal people.
Human beings are great and fragile, and human newborns cannot survive without the care of their parents and relatives, but kittens and puppies are born running on their own to find food. In ancient and modern China and abroad, raising children is a major event to ensure the prosperity of families, countries and societies, and newborn disease screening is one of the important measures to "protect children's health and improve the quality of life". Therefore, as doctors and parents, we must correctly and actively face the screening of newborn diseases and understand the types and methods of screening.
I. Regulations and principles for newborn disease screening
Most babies with congenital genetic disorders lack specific manifestations before screening, and generally do not develop the clinical symptoms inherent in the disease until 6 months later, which are getting worse. Once the clinical symptoms of the disease appear, it indicates that the disease has entered an advanced stage, and even if it is treated, functional defects such as mental retardation will be difficult to recover and become irreparable lifelong disability.
Newborn disease screening, most of them are group screening for some congenital diseases that are seriously harmful in the neonatal period by means of checking peripheral blood, and finding children from healthy people as soon as possible and giving early intervention and treatment methods, with the purpose of avoiding damage to important organs such as heart, liver, kidney, brain and abnormal growth and development of children due to metabolic abnormalities. Newborn disease screening is a tertiary preventive measure for birth defects, which is an important means to reduce birth defects, promote children's health, and improve the quality of the birth population. With the development of social economy and culture, the screening coverage rate of newborn diseases in various countries in the world is getting higher and higher, and developed countries such as Europe and the United States have approached 100%.
The Maternal and Infant Health Care Law, which was implemented in 1995, placed newborn disease screening in a very important position, clearly stating: "Health care institutions should carry out screening for congenital hypothyroidism and phenylketonuria and other diseases of newborns and put forward treatment opinions." In 2004 issued the "Neonatal Disease Screening Technical Specifications" (revised and republished in 2010), in 2009 issued the "Neonatal Disease Screening Management Measures", in order to make the newborn disease screening work more practical and standardized, the provinces and cities have also formulated the corresponding screening routines and implementation documents according to local characteristics, the types of universal screening are different, but they are increasing year by year.
The formulation principles of newborn disease screening types and projects need to consider the incidence of diseases, the feasibility of screening technologies, the promotion of screening technologies, and whether the diseases screened can be treated, etc. Internationally recognized types of diseases that can be screened need to meet the following three conditions:
There is a certain incidence, but there is a lack of specific symptoms in the early stages;
The harm is serious, but early detection can be treated;
There are reliable screening methods that are suitable for large-scale screening.
Second, the types of newborn disease screening
In 1974, the European Conference recommended 20 diseases as a project type for newborn disease screening, including phenylketonuria (PKU), maple glycuria, histisineemia, and galactosemia.
In 2006, the Neonatal Screening Expert Group of the American Medical Genetics Society assessed the severity of 84 existing neonatal congenital diseases, and divided them into 29 primary screening diseases in the first category, 25 secondary screening diseases in the second category and not easy to screen diseases at this stage according to the conditions of screening technology, diagnosis, differential diagnosis and treatment.
At present, the screening coverage rate of neonatal diseases in mainland China has exceeded 50%, and the types of newborn disease screening in Shanghai, Beijing and other regions are 6 types: phenylketonuria (PKU); congenital hypothyroidism (CH); glucose-6-phosphate dehydrogenase (G6PD) deficiency disease; congenital adrenal hyperplasia (CAH); congenital heart disease; hearing screening.
Recently, with the development of science and technology, some hospitals have begun to try tandem mass spectrometry technology for newborn screening of other amino acids, organic acids, fatty acids and other rare genetic metabolic diseases.
3. Blood collection methods for newborn disease screening
1． Screening targets All live births of newborns who are 72 hours old and have been breastfed at least 6 to 8 times.
2. Time of blood collection At least 6-8 breastfeeding sessions during the 72nd hours of the baby's birth.
3. Blood collection filter paper Blood collection filter paper is a texture, thickness, water absorption, water permeability and other quite uniform special cotton high-quality filter paper, in order to ensure the quality of screening and the comparability of international screening materials, the requirements must be consistent with the standard filter paper, most of the newborn disease screening centers choose filter paper is the internationally recognized American Schleicher & Schuell 903 special filter paper.
4. Blood collection site Mostly choose the inside or outside of the infant's heel.
5. Blood collection operation methods and procedures
Massage or apply warm compresses to the baby's heel to make it blood-filled.
After alcohol disinfection, puncture with a disposable blood collection needle about 2-4 mm deep, discard the first drop of blood and drop the extruded blood on a specific filter paper so that it fully penetrates into the back of the filter paper.
Each newborn is required to collect 3 blood spots, each of which should be ≥ 10 mm in diameter.
6. Preservation and delivery of blood samples Blood filter paper pieces are dried in the shade at room temperature and delivered to the screening center within the specified time, or temporarily put into paper bags and stored in a refrigerator at 2 to 10 ° C.
7. Fill in the blood collection card Fill in all the items on the blood collection card one by one, and cannot miss the items. The handwriting should be clear and the writing should be standardized.
Fourth, the test method of newborn disease screening
1. Screening method of phenylketonuria (PKU) With the development of experimental diagnostic technology, most screening laboratories in China have adopted fluorescence analysis (full quantitative) for PKU screening, and very few still use the traditional Guthrie bacterial inhibition method (semi-quantitative), and also use high performance liquid chromatography.
2. Screening methods for congenital hypothyroidism (CH) Most screening institutions use enzyme-linked immunoassay, enzyme immunofluorescence and other methods.
3. Tandem mass spectrometry technology has been adopted in developed countries for more than 10 years, which can screen about 25 kinds of hereditary metabolic defects including amino acids, organic acids, fatty acid metabolism disorders, etc., and the screening efficiency is high.
V. Treatment of the results of newborn disease screening
Each screening center has a special person responsible for the screening results of neonatal diseases, which can be divided into the following three situations to treat differently.
1. If the test result is negative, the city and county management centers are generally notified.
2. For positive suspicious cases, a review will be conducted.
3. If it is still positive after the re-examination, it needs to be fed back to the city and county center, and the city and county center should cooperate with the recall (or follow-up), review and diagnosis of positive cases.
6. Case tracking of newborn disease screening
For children diagnosed with newborn disease screening, there are special medical institutions to track and evaluate the cases, and according to the different requirements of different diseases, timely give long-term and correct drug treatment or diet control, so that the children can achieve a relatively normal survival condition, which is the purpose and social effect of newborn disease screening.
Excerpted from the author's original popular science book "Solving Common Diseases in Pediatrics" (by Xu Lingmin)
Author: Qingpu Branch, Zhongshan Hospital, Fudan University
Pediatrics Xu Lingmin Chief Physician