Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Wikipedia.
an infant born before the expiration of the complete term of pregnancy; such an infant weighs between 1,000 and 2,500 g and is 37 to 46 cm long. After birth, the premature infant remains in the fetal position, with his spine bent and his arms and legs pressed to his trunk. The head is large in comparison with the trunk, and the fontanelles and cranial sutures are open. The neck is thin and long. The limbs are long and have short nails that do not always reach the edges of the nail bed. The skin is wrinkled and folded, and the trunk is profusely covered with lanugo. In extremely premature infants, the lanugo covers the face. The umbilical ring is located in the lower part of the abdomen. The subcutaneous fat and the muscles are poorly developed. Respiration is rapid, superficial, feeble, and irregular; sometimes there is temporary cessation of breathing. The pulse is weak and averages 120 to 140 beats per minute; during crying or feeding the frequency increases significantly. The sucking and, in some infants, the swallowing reflexes are weakly expressed or completely absent. In girls the genital cleft is open; in boys the scrotum may be empty, and the testes may be located in the inguinal canals or in the abdominal cavity. Underdevelopment of the central nervous system produces inadequate thermoregulation, respiratory insufficiency, and twitching of the facial musculature. Initial weight loss fluctuates between 130 and 200 g; weight is often restored between the 12th and 20th day of life. Anemia often develops at the end of the second month.
Premature infants characteristically gain weight rapidly during the first year of life. By 2 1/2 to three months of age the infants double their weight at birth, and by four to six months of age, they have tripled it. By the time the infants are one year old, their weight is four to six times greater than at birth, and their height has increased 24 to 29 cm. When the child is three years old, its weight and height approach those of three-year-olds who were full-term births. (Heavier premature infants reach normal body measurements at age 1 1/2.) The nervous and mental development in premature infants is characterized by retardation in motor, speech, and other abilities by 1 1/2 to two months in comparison with full-term infants.
Because the body of a premature infant is marked by the rapid exhaustion of physiological processes, a strict regimen requiring regulation of temperature, light, sound, and other stimuli, as well as adherence to rules of asepsis and antisepsis, should be observed in the first two months of life. Premature infants weighing less than 1,500–1,700 g require special hospital care. To ensure adaptation to the new environment, the infant is kept in a closed incubator for the first two to four weeks and sometimes even longer; if an incubator is not available, the infant is kept warm with hot-water bags.
Because of the small volume of his stomach, the infant is fed ten to 12 times a day during the first days of life; the number of feedings later decreases to seven daily. The caloric value of food in the first days after birth is from 30 to 60 calories (cal) per kg of newborn weight (1 cal = 4.19 joules), by the seventh or eighth day 70–80 cal per kg, and by the tenth to 14th day 100–120 cal per kg. At one month of age the infant must receive 135–40 cal per kg of weight (about 200 g of milk per kg of weight).
Infants weighing less than 1,200–1,300 g should be fed through a catheter during the first 1 1/2 to two weeks of life even if the sucking reflex is present. This is because the infant would expend too much energy sucking. A polyethylene catheter may be left in the stomach for three or four days; sometimes a pipette is used for feeding the premature infant. If the infant is not in an incubator, oxygen is given before and after feeding. When the infant reaches a weight of approximately 1,700 g, it may be breast-fed.
Multiple vitamins are strongly recommended. Vitamin D is prescribed at the end of the first month (in the third week of life). Natural fruit and vegetable juices are introduced when the infant is two months old—beginning with two or three drops and increasing the dosage to 15–20 g at three months of age and to 50–60 g at six months of age.
REFERENCESSpravochnik pediatra. Moscow, 1966.
Nedonoshennye deti. Sofia, 1971.
E. CH. NOVIKOVA