Nurses Guide to Neonatal Procedures Anigrace S Kalaimathi
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Sizing and Estimating Gestational Age of an Infant1

  1. What is gestational age and sizing?
It is a way of assuring the maturity and size of a newborn at the time of birth. It helps to anticipate the problems a baby may develop.
  1. How is gestational aging and sizing done?
By using Dubawitz chart the gestational age of the baby is assessed. Sizing is done by weighing the baby soon after delivery and then using a special graph to relate weight to gestational age.
  1. How does it help to take care of the baby?
On completion of examination of the baby, you know two aspects;
  • The baby's gestational age in weeks
  • The baby's weight
    • If the baby is the Appropriate weight for Gestational Age, they are called AGA babies.
    • Some babies will be Small for Gestational Age; this means smaller than you would anticipate for this gestational age. They are called SGA babies. They need special care.
    • Other babies will be Large for Gestational Age; this means they are larger than you would anticipate for their gestational age. They are called as LGA babies.
and also you will know if the baby is pre-term, term or post-term.2
  1. Why do you assess gestational age?
Babies who are preterm (less than 37 weeks), term (37 to 42 weeks) or post-term (> 42 weeks) have certain characteristic problems. Babies who are SGA or LGA also have certain characteristic problems. So, by knowing gestational age problems can be anticipated and prevented or treated promptly.
  1. When do you assess gestational age in infants?
Preferably on all babies, but certainly for:
  • babies less than 2500 gm
  • babies greater than 4000 gm
  • babies who are too ill (after stabilization of the baby's condition)
  • babies who are born to mothers who are sick during pregnancy or abnormal labor.
  • babies who are preterm or post-term by dates.
  1. What do you anticipate when a baby is preterm?
The preterm babies have certain characteristic problems. They are:
Respiratory Distress
If the baby is having difficulty in breathing it may be due to RDS. Also termed as HMD (hyaline membrane disease). This problem comes from immature lungs and may lead to low blood oxygen which in turn may cause brain damage.
  • evaluate respirations.
Very preterm babies will have low sugar stores and may become hypoglycemic. If this is not corrected baby may develop brain damage.
  • do blood sugar tests.3
The preterm baby can become cold very easily. Just the right environmental temperature is needed so the baby does not need to use extra energy to keep warm.
  • use appropriate neutral thermal environment
  • take temperature frequently
  • minimize conductive, convective, evaporative and radiant heat loss.
Feeding Difficulties
A preterm baby may be able to suck but not be able to coordinate sucking with breathing and swallowing. If the baby cannot coordinate these actions, milk may go in to the lungs instead of the stomach. Babies who are less than 32-34 weeks gestational age often cannot coordinate sucking, swallowing, and breathing.
  • feed by oro or nasogastric tube and IV fluids.
The preterm babies may have a low blood pressure from loss of blood at the time of delivery, from an infection, or from having too much acid in the blood.
  • take blood pressure measurements.
Preterm babies may have a low RBC count than other babies. It may be important to give blood transfusion to preterms.
  • Check Hb.
Preterm babies are frequently jaundiced because their livers are 4immature and do not help to get rid of bilirubin, jaundice in preterms may lead to brain damage.
  • observe for jaundice
  • check SBR.
Preterm babies may develop apneic attacks.
  • So continuously monitor heart rate and respiratory rate by hooking the baby to cardiac monitors.
  1. What do you think when a baby is post-term?
These babies have some typical problems;
  1. Asphyxia
  2. RDS
  3. Hypoglycemia—post-term babies have outgrown their mothers placenta and have low sugar stores. They are likely to develop hypoglycemia and this may lead to brain damage.
  1. What special problems you can anticipate in extremely preterm baby?
Very small babies usually less than < 1000 gm has special problems related to extreme prematurity.
Respiratory Distress
The very small baby likely to get RDS, because of small size and also have more problems than usual in clearing lung secretions. Small babies tire easily and quickly even a mild RDS can lead to low blood oxygen and high CO2. Majority of them need assisted ventilation.
  • observe respirations
  • monitor blood gases.5
More prone for this because of low sugar storage and stress also will lead to hypoglycemia.
Very tiny babies, when given IV fluids may develop hyperglycemia. High blood sugar may cause an increase in urine glucose and may result in excessive fluid loss in urine.
So glucose monitoring is very important.
  • monitor blood glucose
  • monitor urine glucose.
The very preterm baby can become cold easily and quickly even a slight cold stress in the tiny baby can cause the baby to become sick or can worsen.
  • * Temperature control in a tiny baby is extremely important.
Great care must be taken from the moment they are born. They are best cared initially under radiant warmers with servo control.
  • use radiant warmer with servo control
  • take temperature frequently
  • minimize conductive, convective, evaporative and radiant heat loss.
Fluid Therapy
Tiny babies, even if they are not sick should not be fed by mouth or tube. They should have IV fluids because these babies have thin skin and a large surface area to weight ratio, they lose a great amount of fluid through their skin. ELBW babies fluid requirements are greater than for a larger babies, they require extra fluid to prevent dehydration.6
  • weigh the baby
  • do not feed by mouth or tube
  • start IV fluids
  • place a plastic wrap covering over the baby who are under radiant warmers. This helps to reduce water losses and maintains temperature.
The ELBW baby's blood pressure may dangerously low. So monitor blood pressure frequently. Correct hypotension slowly.
ELBW baby's may have a lower RBC count because their blood volume is small (< 90 ml). So even small amounts of blood drawn for lab tests may make the baby anemic.
  • check Hb
  • withdraw smallest volumes of blood for lab test and record amount withdrawn.
  • observe for jaundice
  • if jaundice appears check SBR levels frequently
  • initiate phototherapy at lower levels of SBR.
The ELBW baby has 100 percent chance to develop apnea.
  • monitor heart and respiratory rate.
  • investigate the cause for apnea
  • assist baby's ventilation if apnea is severe.
Intracranial Hemorrhage
Very tiny babies are more likely to develop bleeding in the brain or in the ventricles, this can cause brain damage. Possible causes 7for this may be sudden changes in blood pressure, rapid infusions of volume expanders, rapid infusions of high concentrated glucose and pneumothorax.
The best way to prevent IC hemorrhage is to handle the baby gently and avoid sudden changes in fluid volume.
  • monitor Hb and hematocrit
  • handle the baby gently
  • avoid sudden changes in fluid management and other care practices.
Retinopathy of Prematurity
The ELBW baby is at greater risk of developing some degree of ROP, an eye condition that can progress to total blindness. Causes for ROP are extreme prematurity, high blood oxygen levels and prolonged oxygen treatments.
  • monitor ABG
  • watch the inspired oxygen concentration and avoid excessive blood oxygen levels
  • at 6 to 8 weeks of age perform eye examination.
Post Test
Select one best answer for each question (unless otherwise instructed).
  1. True or False—a very tiny baby without RDS may require endotracheal intubation and assisted ventilation.
  1. In which one of the following ROP most likely to develop?
  1. Preterms8
  2. SGA baby
  3. LGA baby
  4. ELBW baby
  1. Which one of the following problems is the preterm infant at highest risk of developing?
  1. Apnea
  2. Congenital malformations
  3. Hypercalcemia
  4. Hyperthermia
  1. True or False—all babies weighing 3500 gm are term babies
  1. Preterm babies are those whose gestational age is less than
  1. 35 weeks
  2. 37 weeks
  3. 40 weeks
  4. 42 weeks