The preterm babies are those who are born before 37 weeks of gestation and are underweight due to shorter duration of full term gestation. Feeding is one of the major challenges in the care of the low birth weight babies. Goal of feeding the preterm is to achieve a growth rate that approaches the normal growth rate of the fetus in utero.
Low birth weight babies are born with a birth weight less than 2500g. The incidence of low birth weight babies in India is 30 percent. Low Birth Weight (LBW) neonates are more prone to continuous infections and have neuro developmental handicaps. India accounts for 10 lakh neonatal deaths every year due to low birth weight.
A pre-pregnancy weight of less than 40kg serves as a useful cut off to predict women who will deliver low birth weight babies. Infants who start with the initial handicap of low birth weight in spite of their being full term (Small for Gestational Age, SGA)may continue to be malnourished later in life.
The possible reasons for low birth weight of babies are low maternal body mass index, low age at marriage, small stature, low gain in weight during pregnancy, low maternal nutritional status with respect to iron and folic acid and shorter duration of full term gestation.
The preterm is at a disadvantage in many aspects of nutrition. The problems facing the preterm babies are poor sucking and swallowing reflexes, relatively high caloric requirement with small stomach capacity or decreased absorption of essential nutrients. The preterm babies lack adequate stores of brown fat and therefore are vulnerable to become hypothermic.
In critically ill infants, it is common to initiate parenteral nutrition with minimal macronutrients and to advance as tolerated to meet estimated needs for growth. Initially premature infants require parental nutrition and take several days to reach enteral feedings.
Calories; the caloric need of non-growing preterm babies during the first week of life are 60K cal/kg/day. After the first one or two weeks of life, most preterm babies require 120-150Kcal /kg/day to maintain satisfactory growth. High calories may be necessary in babies who are not gaining weight, post-operative patients and extreme preterms.
Fluids, the need of preterm babies are relatively high during the first week of life. The intake of fluids varies from 90-100 ml/kg/day for 7-10 days. Additional fluids may be required when the baby is under the phototherapy or a radiant warmer.
Carbohydrate; preterm babies can tolerate 50 percent of the calories in the form of carbohydrates. Very low birth weight babies may have difficulty in tolerating the lactose, the first few days. Glucose polymers are well tolerated.
Protein; preterm babies require 3-4gof protein per kilogram of body weight for rapid growth. Excess of protein may lead to metabolic problems of acidosis and hyperammonemia. Human milk contains mainly whey protein which is better utilized. Certain amino acids essential for the preterm cystine, taurine, alanine and arginine. These are present in breast milk.
Fat; malabsorption and steatorrhoea (the excretion of abnormal quantities of fat with the feces owing to reduced absorption of fat by the intestine) can occur in preterms due to reduced amounts of pancreatic lipase.
About 40-50 percent of calories in the preterm diet should be available from fats. Very low birth weight babies poorly digest and absorb saturated triglycerides. Vegetable oils containing unsaturated long chain fatty acids are better absorbed. Better still are medium chain triglyceride because their digestion and absorption are not dependent on bile salts level.
Minerals and Vitamins; Calcium and Phosphorus supplements may be needed to prevent rickets or osteopenia in preterms. Iron deficiency can occur by 6-12 weeks and hence 2.5mg/kg/day of iron starting from 6-8 weeks of age may be given. Zinc supplement increases weight gain.
All low birth weight babies should receive vitamin supplementation in addition to the amount present in human milk. This is because
Premature infants are born with low body stores of vitamins.
Their growth rates are rapid
Their gastro intestinal absorption is low, and
Their daily intake of milk feedings is initially low
This article is written and submitted to The E Today by Shrushti Mehta.
We thank her for her research and analysis and hope to see the awareness about health and nutrition being spread ahead to larger mass of our citizens.