What is the role of blood test for infants?

Many mothers do not understand the purpose of having their babies’ blood drawn for examination. In fact, this is a kind of health screening, which is to timely discover and understand the two diseases of infant phenylketonuria and hypothyroidism. Because these two diseases, if they are not treated promptly and effectively, will cause great harm to the baby, so it is necessary to draw enough blood for examination to detect and treat them early.

1. Heel blood screening

Heel blood tests are mainly used to check for phenylketonuria (PKU) and hypothyroidism (CH). If these two diseases are not treated in time, they can cause severe intellectual disability in the baby. However, if they are discovered, diagnosed and treated early in the neonatal period, serious harm to the baby can be avoided.

2. Collection Methods

Heel blood sampling should be done within 3 to 7 days after birth and the newborn should be fully breastfed. For those who do not have blood drawn for various reasons (premature babies, low birth weight babies, those discharged early, etc.), the blood should be drawn no later than 20 days after birth. Newborn disease screening is done by collecting heel blood from the newborn at the delivery hospital (the blood is dropped onto a special paper and the blood spot is then sent to the Newborn Disease Screening Center for testing).

1. Hold the sole of your foot with your left hand;

2. When drawing blood, squeeze the sole of the foot with your left hand, and at the same time, hold the calf on the same side with your right hand, using moderate force and relaxing intermittently;

3. Use the index and middle fingers of your left hand to clamp the calf from the popliteal fossa along the small saphenous vein and push down to the ankle joint to clamp and collect blood and prevent blood from reflux.

4. Warm your feet and let the blood flow out naturally without squeezing;

5. After taking a bath, use a warm towel to apply heat to the blood collection point;

6. In addition to routine blood collection, blood should be collected from newborns after regular breastfeeding, bathing, and alcohol heel massage.

3. Test content

Phenylketonuria Phenylketonuria (PKU) is an autosomal recessive genetic disease. It is named because the baby has phenylalanine metabolism disorder, which causes a large amount of phenylpyruvate and other metabolites to be excreted in the urine. Phenylalanine is one of the essential amino acids for the human body. After being taken into the body through food, part of it is used by the body for protein synthesis, and the rest is converted into other substances. Phenylalanine in the baby's body cannot be metabolized normally and accumulates in the body, causing damage to the central nervous system and a series of pathological changes. Signs of illness: The baby will gradually develop hair turning from black to yellow, skin turning white, and eye irises becoming lighter, and will also have neurological abnormalities such as increased muscle tone, abnormal gait, slight tremors in the hands, and repetitive limb movements.