What are Preterm Infants?

Live babies born before 37 weeks of gestation are called premature or immature. Most of her birth weight is below 2500g, and her head circumference is below 33cm. Its organ function and adaptability are worse than those of term infants, and special care should be given to premature infants. Those whose birth weight is reduced to less than the 10th percentile of the normal weight of the gestational age or less than two standard deviations below the mean due to insufficient placental function and other factors are referred to as infants less than gestational age (small children, poorly mature children). The birth weights below 2500g are collectively referred to as low-weight infants, and those with birth weights below 1500g are referred to as very low-weight infants, which include premature infants and those younger than the gestational age.

Basic Information

Also known as

Immature

English name

prematureinfant; preterminfant

Visiting department

Obstetrics and Gynecology

Contagious

no

Causes of Premature Infants

Since the mechanism that causes the onset of childbirth is still not fully understood, there are still many unknowns about the cause of premature birth. In the analysis of clinical records, most of the causes of preterm birth are:

1. Hypertension during pregnancy.

2. Early water rupture, early placental detachment, or placenta previa.

3. Multiple pregnancy or polyhydramnios.

4. Chronic diseases, such as heart disease, kidney disease, nephritis, liver disease, diabetes, severe tuberculosis, endocrine disorders (such as habitual preterm birth), malnutrition, etc.

5. Anemia and severe hemolytic disease.

6. Acute infectious diseases are accompanied by high fever.

7. Uterine tumors, endometritis and laxity of the cervix.

8. Pelvic and spinal deformities, twin or fetal malformations, premature rupture of amniotic membrane, abnormal umbilical cord, and excessive amniotic fluid.

9. Acute or chronic poisoning.

10. Intense emotional fluctuations or overwork.

11. Accidental injury or surgery.

Clinical manifestations of premature infants

1. The more premature babies, the thinner and softer the skin, the more water in the tissues, the dents, the red color, the less subcutaneous fat, the less muscles, the shorter nails, the longer the fetal hair on the trunk and the more head It is small and short, with a large head, wide cardia, flat ear shells and the skull, soft thorax, areola-like spots, edges not protruding, and small or inaccessible breasts. The abdomen is bloated and the scrotum develops poorly. The testicles of male preterm infants are often in the outer groin and gradually fall into the scrotum during development. The more premature a woman is, the more the labia will separate and protrude. There are fewer wrinkles on the soles of the hands and feet.

2. Body temperature regulation: Difficult and unstable, the use of its heat production is limited, less muscle, low tension, can not change posture to reduce the area of heat loss. On the other hand, due to immature sweat glands, sweating dysfunction, and high body temperature are also prone to occur.

3. Weak resistance: Very weak resistance to various infections, even minor infections can cause serious consequences such as sepsis.

4. Premature infants breath quickly and shallowly, and often have irregular intermittent breathing or apnea. Crying is very small, often bruising.

5. Premature babies are weak in sucking and swallowing, and the sphincter of the cardia is loose, which easily causes cough, vomiting, diarrhea, and abdominal distension.

6. When trauma, hypoxia, infection, and coagulation are impaired, bleeding is often easy and heavy. Brain blood vessels are particularly vulnerable to bleeding. Sometimes unexplained pulmonary hemorrhage can occur.

7. Preterm infants have a poor combination and excretion of bilirubin, and their physiological jaundice lasts longer and is heavier than term infants.

8. Due to immature liver and liver dysfunction in premature babies, the prothrombin factor V, factor VII and factor X are lower than those in term infants, so the coagulation mechanism is not sound and bleeding is easy.

9. The storage of iron and vitamins A and D is reduced, which is easy to get this kind of nutritional deficiency.

10. The function of making liver glycogen into blood sugar is reduced, so blood sugar is prone to be too low when shocked. The function of synthetic protein is not good, and edema can be formed due to low plasma protein.

11. Because the glomeruli and tubules are immature, the glomerular filtration rate is low, and the clearance rates of urea, chlorine, potassium, and phosphorus are also low, and proteinuria is more common. Premature babies lose more weight after birth and are prone to acid-base imbalance due to infection, vomiting, diarrhea, and changes in ambient temperature.

12. The center is immature, with weak crying, little activity, low muscle tone, and insignificant nerve reflexes. The reflexes such as coughing, sucking, and swallowing are all poor.

13. The weight gain of premature infants is greater than that of term infants. The term infants at 1 year old weigh approximately three times as much as those at birth, and 1501-2000g preterm infants can weigh 5 and a half times at birth when they are 1 year old. 1001 1500g can reach 7 times.

14. Premature infants have less IgG from the mother's placenta, insufficient autoimmune and antibody IgA, D, E, G, and M synthesis, low complement levels, and lack of opsonin in the serum, so their resistance to infection is weak and it is easy to cause septicemia.

Premature baby check

Blood glucose test

Related blood glucose tests can be performed to check whether premature infants are complicated by hypoglycemia or hyperglycemia.

2. EEG examination

Some premature babies are prone to intraventricular hemorrhage or softening of white matter around the ventricle, which can be confirmed by EEG.

3.CT inspection

You can observe whether there are signs of intracranial lesions in preterm infants.

4. Detection of antigen antibodies.

5. Blood test

These include white blood cell counts, neutrophil counts, hemoglobin concentrations, and red blood cell counts, as well as blood electrolytes and blood pH. Infectious hemograms appear, white blood cell counts and neutrophils increase; when there is blood loss or anemia, the hemoglobin concentration and red blood cell counts decrease; when abnormal conditions occur, attention should be paid to the presence of hypoxemia and hyperphosphatemia.

6. Chest radiograph

Check the respiratory system for abnormalities. Know your lungs.

Complications in preterm infants

1. Clinical manifestations are bruising, apnea, drowsiness, convulsions, screaming, muscle weakness and abnormal eye movements.

2. About 7% of preterm infants develop intraventricular hemorrhage (IVH) or periventricular white matter softening (PVL).

3. There is often anemia. Due to insufficient iron storage in preterm infants, serum iron levels have dropped sharply after 1 month. Development is too fast and requires increased blood volume, but the hematopoietic function is poor, failing to keep up with the rate of weight gain.

4. Less storage of calcium, phosphorus and vitamin D. Poor ability to absorb fat and fat-soluble vitamins. Because the growth is too fast, the general supply of calcium and phosphorus often cannot meet the needs.

5. Premature infants have poor temperature regulation, relatively large body surface area, thin skin, rich blood vessels, and easy to dissipate heat, while the amount of brown fat is small and other factors make them susceptible to scleredema.

6. Inhalation of high concentration of oxygen can increase arterial blood oxygen tension to 13.3kPa (10mmHg) or more, which causes spasm of retinal blood vessels, leading to retinal ischemic damage, fibrous tissue proliferation and blindness. When premature babies must use oxygen, pay attention to the appropriate oxygen concentration and time.

Premature infant treatment

Premature babies must be kept warm when they are born, and their movements must be light and fast during handling. Cold exposure often causes irretrievable complications, and the temperature in the delivery room must be maintained at about 25 ° C. In order to prevent suffocation, it is best not to use anesthesia and sedative drugs that affect the fetal respiratory center during the labor process. When the fetal head is delivered, first squeeze out the mucus in the fetal mouth and nasal cavity. Those who are not cleared can be sucked off with a sterile suction tube when the fetuses are all delivered, and an endotracheal tube can be used if necessary. Do not use gauze in your mouth to avoid rubbing the mucous membrane and promoting infection. If you have difficulty breathing or bruising, give oxygen in time. After the umbilical cord is broken, gently wipe off excess fetal fat under the neck, underarms, and groin with disinfected vegetable oil gauze, and then wrap it with cloth. Use 0.25% chloramphenicol or 0.5% neomycin eye drops to prevent conjunctivitis. After the treatment is ready, transfer it to the incubator for premature babies whose temperature has been adjusted as soon as possible. The cure standard is that premature babies are generally in good condition, have good breast-feeding conditions, have weighed about 2,300 g, have no symptoms of anemia and other nutritional deficiencies, and can be discharged when the normal body temperature can be maintained at an indoor temperature of 21 to 24 ° C.

Premature infant care

Nursing method

Newborn premature infants should be quiet for 4 hours after entering the room, head side to side, so that the mucus in the mouth flows outwards, and then change the position lightly every 2 to 3 hours. Measure body temperature once every 4 hours. The difference between daily maximum temperature and minimum temperature should not exceed 1 . If it has been stabilized more than 3 times between 36 and 37 ° C, it can be changed to 1 test each morning and afternoon. If the body temperature is higher than 37 ° C or lower than 36 ° C, it needs to be measured every 4 hours. The use of oxygen is limited to those who have difficulty breathing or bruising and are in poor condition. Do not use oxygen as a routine. Usually after a few hours of oxygen, the bruising disappears and the breathing can stop when it is normal. For example, premature babies weighing less than 1000g can last 1 day and night. Continuous oxygen is best not to exceed 3 days. It is contraindicated that the oxygen is too high, the concentration is too high, and the time is too long, so as not to damage the eyes and lungs of the baby. Babies who are prone to cyanosis during feeding can be given oxygen inhalation for several minutes before and after feeding.

2. Notes

Premature babies are bathed only after the umbilical cord has come off and the wound has healed. When not bathing, scrub the upper body in the incubator, wrap the upper body, and then hold it out to clean the buttocks. Those who weigh less than 1000-1500g can use disinfected vegetable oil or talcum powder to gently rub the wrinkles to protect the skin. Focus on the following three points in nursing:

(1) Keep warm Because premature babies have difficulty adjusting the body temperature, the temperature and humidity requirements in nursing are very important.

(2) Proper feeding Because premature babies grow faster, proper feeding is more important than full-term babies. Feeding time after birth: Generally, premature babies can be fed with sugar water 2 to 4 hours after birth, try feeding 1-2 times without vomiting, and change the milk solution 6 to 8 hours later. Those who have had bruising, dyspnea, low body weight, or who have been produced by surgery, can use intravenous infusion of 10% glucose solution, or use whole veins and some high-nutrition solutions, and then change to oral administration after the situation improves. The feeding interval can be arranged according to different body weights. It is fed once per hour under 1000g, 1.5 hours for 1001 to 1500g, 2 hours for 1501 to 2000g, and 3 times for 2001 to 2500g. Nights can be extended appropriately. If the intake is insufficient, the general situation is poor, the sucking power is poor, and the baby with poor stomach appetite is easy to vomit, it is advisable to use a small number of times during the day and night. Feeding method: According to the specific situation of premature babies. Feed breast milk directly . This method can be tried if you have a large birth weight and have the ability to suck. Bottle feeding can only be used for premature babies who are heavier and have sucking power. With a small bottle, the milk does not turn cold easily. The rubber nipple should be soft, with 2 to 3 openings, and the size should be the degree that the milk can drip out when inverted. Too fast to flow, too late to swallow, easy to cause suffocation; Too slow to flow, sucking effort, easy to make tired and refuse to eat. Gastric tube feeding is suitable for premature babies with poor sucking and swallowing ability and low body weight. If the gestational week is less than 32 weeks and the weight is less than 1,500g, enter various amino acids and lipids similar to human milk, 10% glucose, various vitamins and electrolytes, and do not exceed 3 days. For those with gastrointestinal malformations, temporary inability to feed after surgery, or severe inadequate intake of respiratory diseases, low birth weight infants, etc., external jugular veins of the digestive tract can also be used to supplement nutrition. Breast milk is most appropriate for feeding premature babies. Mothers should be encouraged to maintain breast milk. In the case of insufficient breast milk, artificial feeding with preterm infant formula can also be considered. Preterm infants have the best digestion and absorption of sugar, followed by protein, and have the worst digestion and absorption of fat. Therefore, semi-skimmed milk is ideal.

3. prevent infection

Premature babies should have air-conditioning equipment to maintain constant temperature, humidity and fresh air. After birth, sleep sideways to the right to prevent inhalation of vomitus. Frequently change the supine position to help the lungs circulate and prevent pneumonia. Generally you can turn to the right after feeding, and turn to the left after changing the diaper. When feeding with a bottle, it is best to hold your head, back or hold it with your left hand. After feeding, pat your back to belch and lie on your side. It is advisable to lie up semi-sitting horizontally for a short time to prevent the milk from sucking into the respiratory tract or vomiting into the external ear canal to cause infection. Once an infection is found, the child should be isolated.

Premature infant prevention

1. Premature birth is the main cause of morbidity and death of newborns, and most of the various causes of premature birth are maternal factors. Except for congenital reproductive malformations, most of them can be prevented through pregnancy care.

2. Prenatal examinations should be taken seriously, especially early and appropriate perinatal care for those at high risk. For example, to prevent and control pregnancy-induced hypertension syndrome, reduce the incidence of early placental ablation, find early treatment after placenta previa, and correct anemia. For pregnant women with heart disease, we must strengthen management, popularize common health care during pregnancy, and have preventive measures such as avoiding infection.

3. Use labor release method to block premature delivery and provide enough time to use glucocorticoids to promote lung maturity etc.