What are regulations on technical guidelines for newborn screening in Vietnam?

What are regulations on technical guidelines for newborn screening in Vietnam?

Pursuant to Clause 1, Article 9 of the Technical and Professional Guidelines for newborn screening, diagnosis and treatment promulgated together with Decision 1807/QD-BYT in 2020 regulating newborn screening for the group of diseases by technical screening test on dried blood samples as follows:

1. Group of diseases screened by testing technique on dried blood samples

a) Subjects

- Newborns aged from 24 hours to 72 hours.

- The best time to take a newborn blood sample is 48 hours after birth. Newborns who leave the obstetric facility sooner than 24 hours after birth, need a blood sample before leaving the obstetric facility.

- If the child needs a blood transfusion, a screening blood sample should be taken before the transfusion.

b) Method

- Medical examination and treatment establishments use the technique of taking blood from newborns and blotting them on specialized blotting paper, preserving and transporting them to medical examination and treatment establishments that provide newborn screening testing services (referred to as newborn screening facility).

- Newborn screening facility uses testing technique on dry blood samples to screen for diseases (Congenital hypothyroidism, Congenital adrenal hyperplasia, G6PD dehydrogenase, some inborn metabolic disorders of amino acids, organic acids, fatty acid oxidation, cytolytic storage diseases and other genetic diseases).

c) Procedure for performing screening

- Take a blood sample from the infant's heel.

+ Use standard absorbent paper samples with expiry date.

+ Fill in all pre-printed information on the card before taking a blood sample (especially specifying the address and phone number to contact the family when it is necessary to notify the screening test results).

- Preserve and transport dried blood samples to newborn screening facilities.

+ After taking a newborn blood sample, the blood blotting card must be allowed to dry naturally at room temperature for at least 4 hours on a flat and impervious surface; must not be exposed to heat sources and directly exposed to sunlight; avoid near any odorous substances such as paints, varnishes, aerosols or bug sprays; Do not touch and contaminate the blood drops on the blotting paper.

+ Staggered blood blotting cards ensure that the dried blood cells in adjacent samples do not come into contact with each other and are placed in a moisture-proof envelope.

Blood blotting cards should be sent for screening tests within 24 hours of blood sampling.

+ Transport the dry blood blotting card to the newborn screening facility by post or other means.

- Screening test

Diseases currently screened for newborns and tests used in screening:

+ Congenital hypothyroidism: quantitative test of TSH (Thyroid Stimulating Hormone) in the dry blotting card for screening.

+ Congenital adrenal hyperplasia: quantitative test 17-OHP (17- Hydroxyprogesterone) in a dry blotting card for screening.

+ Deficiency of G6PD enzyme (Glucose 6-Phosphate Dehydrogenase enzyme): measure G6PD enzyme activity in dry blotting card for screening.

+ Some congenital metabolic disorders of amino acids, organic acids, fatty acid oxidation, cytolytic storage diseases and other genetic diseases.

- Notification of screening results

+ In case of low-risk screening test results, the newborn screening facility shall notify the management agency of the test results monthly, and at the same time notify the test results to the medical examination and treatment facility. take a blood sample from an infant to respond to the child's parent or guardian. In the event that a parent or guardian of a child being screened makes a request, the newborn screening facility is responsible for responding directly.

+ In case of high-risk screening test results, the newborn screening establishment must immediately notify and advise the test results to the parents or guardians of the child for diagnosis according to regulations; and at the same time notify management agencies and medical examination and treatment establishments to take blood samples from newborns for coordination in settlement.

The procedure is shown in Diagram 4. Newborn screening and diagnosis of diseases by screening technique on dried blood samples

What are regulations on screening diseases using other techniques in newborn screening in Vietnam? 

Pursuant to Clause 2, Article 9 of the Technical and Professional Guidelines for newborn screening, diagnosis and treatment promulgated together with Decision 1807/QD-BYT in 2020, the group of diseases screened using other techniques in newborn screening is specified as follows:

2. Screening disease group using other techniques

2.1. Screening for congenital hearing loss

a) Subjects: Newborns aged between 24 hours and 48 hours or right before discharge if discharged before 24 hours after birth.

b) Methods: Screening by automatic cochlear acoustic measurement (OAE: Otoacoustis Emission) technique - AOAE (there are 2 types of automatic OAE machines, TE OAE or DP OAE) or multi - sensory automatic brain (ABR: Auditory Brainstem Response) - AABR.

c) Procedure for performing screening

Newborns sleep deeply in a soundproof room, the technician inserts the earplugs into the transducer, gently inserts the earplugs into the child's outer ear canal, turns on the meter, the meter automatically measures.

Result session:

- The result is P (Pass) - “Pass”: currently, the results of screening children do not suspect hearing loss (specificity > 95%).

- If the first measurement result is R (Refer) - “Failed” (1st Referer) for 1 ear or both ears, the patient needs to schedule a second measurement after 1 month.

If the first screening with OAE, the second screening with OAE and ABR.

If first screening with ABR, then second screening with OAE and ABR.

- If the measurement is repeated a second time, the result is “Pass” which is the same as in the child without suspicion of hearing loss (specificity > 95%).

- If the second re-measurement is “Failed” (2nd Referer): the child is suspected of hearing loss, give 1 ear or both ears. Children need to be transferred to the otolaryngology department of hospitals that are capable of doing intensive hearing tests such as measuring ABR, ASSR to be able to accurately answer whether the child has a hearing loss or not, the level of hearing loss and the level of hearing loss. intervention direction. The diagnosis of hearing (ABR test, ASSR) should be measured before 3 months of age. If the child has hearing loss, it is necessary to intervene before 6 months of age.

The process is shown in Figure 5. Screening for congenital hearing loss.

2.2. Screening for congenital heart disease

a) Subjects: Newborns aged between 24 hours and 48 hours or right before discharge if discharged before 24 hours after birth.

b) Method: measurement of blood oxygen saturation through the skin.

Using percutaneous oxygen saturation measurement in congenital heart disease screening, newborns are measured in their right hand and foot (right or left) for the purposes of: (1) assessing SpO₂ anterior to the ductus arteriosus and posterior to the ductus arteriosus; (2) assessment of persistent pulmonary hypertension in neonates.

The method of measuring blood oxygen saturation through the skin in combination with clinical examination helps guide the diagnosis of: (a) cyanotic congenital heart disease; (b) tubular-dependent systemic circulatory congenital heart disease and (c) congenital heart disease requiring emergency management but due to adaptive cyanosis difficult to detect with the naked eye.

c) Procedure for performing screening

Newborns aged between 24 hours and 48 hours who are screened for congenital heart disease will have their transcutaneous oxygen saturation measured with an oximeter. The measurement location is the right hand and foot (right or left) of the child. The oxygen saturation meter is permitted by the Ministry of Health to be used in medical examination and treatment facilities and must use a sensor that can be used in screening for congenital heart defects in infants (confirmed by the manufacturer).

The results of measurement of blood oxygen saturation through the skin are classified and considered as follows:

- Passed results: if oxygen saturation 95 % in right hand and foot (right or left) and saturation difference between 2 measurement sites 3 %, at any measurement of the process screening. Stop filtering.

- Unsatisfactory results:

Case not reached A: oxygen saturation in right hand and foot (right or left) < 90% at any time of screening. Early referral to a pediatric cardiologist.

Case B: oxygen saturation < 95% in right hand and foot (right or left) or saturation difference between 2 sites > 3%, at any time of sieving filter.

+ If the child has an unsatisfactory result as in case B, during the first screening, continue to measure a second time one hour after the first measurement.

+ If the second screening results are not satisfactory as in case B, continue to measure for a third time one hour after the second measurement.

+ If the third screening results are not as satisfactory as in case B, the child should be referred to a pediatric cardiologist soon.

During the screening process, it is necessary to pay attention to the clinical condition of the child, if there is an abnormal heart sound (bruise), it is necessary to consult a pediatrician soon.

The procedure is shown in Figure 6. Screening for congenital heart disease by transcutaneous oxygen saturation measurement.

Best Regards!