Special Care of Low Birth Weight Babies

Definitions

Low Birth Weight (LBW): Birth weight less than 2500 grams.

Very Low Birth Weight (VLBW): Birth weight less than 1500 grams.

Extremely Low Birth Weight (ELBW): Birth weight less than 1000 grams.

Preterm: Babies born before 37 weeks of pregnancy are called preterm or premature. A normal pregnancy lasts about 40 weeks.

Extremely preterm: Baby born before 28 weeks of gestation.

Very preterm: Baby born at 28 – 32 weeks of gestation.

Moderate to late preterm: Baby born at 32 – 37 weeks of gestation.

Why low birth weight babies need special care?

Low birth weight babies have a high risk of death or life-long neurological complications because of complications of prematurity.

Premature babies have an increased risk of:

  • Hypothermia
  • Respiratory distress
  • Apnea
  • Hypoglycemia
  • Feeding difficulties
  • Infections
  • Jaundice
  • Intracranial hemorrhage

Why are preterm babies prone to hypothermia?

1.  High surface area : weight ratio

  • Skin surface area : weight ratio of a preterm baby is 4 times higher as compared to adults.
  • Baby loses heat by skin surface. So, a high skin surface area : weight ratio means higher heat losses by skin surface.

2.  Immature skin

  • Increases evaporative heat losses multiple times.

3.  Less subcutaneous fat

  • This means less insulation and less fuel for heat generation.

4.  Less capability to metabolize fat to produce heat

5.  Decreased glycogen store

  • Glycogen is the fuel for heat generation. Low birth weight babies have less glycogen storage.

6.  Poor feeding because of immature sucking-swallowing coordination

7.  Associated problems

  • Infection, respiratory distress etc.

How does hypothermia harm the baby?

  • As compared to normothermic newborns, the risk of mortality is 1.7 times higher in mild hypothermic newborns and 4.66 times higher in moderately hypothermic newborns. In preterm newborns, every 1°C decrease in axillary temperature doubles the risk of mortality (Mullany et al. 2010).
  • Moderate hypothermia is associated with a higher risk of intraventricular hemorrhage (IVH). Moderate and severe hypothermia is associated with an increased risk of death (Miller et al. 2011).

How to avoid hypothermia in preterm newborns?

  1. Warm delivery room and nursery (temperature more than 28°C).
  2. Immediate and prolonged skin-to-skin contact after delivery in stable preterms. Learn more.
  3. Immediate drying with a pre-warmed sterile towel.
  4. Plastic wrapping below the neck in babies less than 28 weeks gestation.
  5. Initiate early breastfeeding in stable preterms over 34 weeks gestation.
  6. Multilayered clothing with cap, socks, mittens, and covering. Learn more.
  7.  Warm transport: either with skin-to-skin contact or transport incubator.

What causes respiratory distress in preterm babies?

1.  Respiratory Distress Syndrome (RDS)

  • Surfactant produced by type 2 alveolar cells in fetal lungs makes a thin layer in alveoli preventing the collapse of alveoli during expiration.
  • Preterm newborns have low levels of surfactant. These newborns present with respiratory distress since birth in form of grunting, tachypnea, chest retractions, nasal flaring, and cyanosis.
  • Chest X-ray shows homogeneous reticulogranular infiltrates with air bronchogram.

 

Chest X-ray in Respiratory Distress Syndrome

2.  Transient Tachypnea of Newborn (TTN)

  • Fetal lungs are filled with fluid. This fluid clears when the baby takes the first breath.
  • Amiloride-sensitive epithelial sodium channels transport this fluid from alveoli to interstitial spaces. Reduced number of these epithelial sodium channels in preterm newborns cause transient tachypnea of newborn.
  • Chest X-ray shows bilateral alveolar and interstitial edema with fluid in the interlobar fissure. These X-ray findings and clinical symptoms usually resolve within 24 hours.
transient tachypnea of newborn
Chest X-ray in Transient Tachypnea of Newborn. Case courtesy of Assoc Prof Frank Gaillard, Radiopaedia.org

3.  Persistent Pulmonary Hypertension (PPHN)

  • Associated with respiratory distress syndrome, transient tachypnea of newborn, meconium aspiration syndrome, perinatal asphyxia, pneumonia, sepsis, oligohydramnios, congenital diaphragmatic hernia, polycythemia.
  • Increased resistance of pulmonary vessels causes right-to-left shunting via patent foramen ovale and patent ductus arteriosus.
  • Clinically, differential cyanosis may be present: a saturation difference of more than 5 – 10% between the right upper limb and lower limbs if shunting is via PDA. No difference in saturation if shunting is via PFO.
  • Labile hypoxemia: On the same respiratory support, newborns with PPHN show significant changes in oxygen saturation. This happens because the volume of right-to-left shunt depends on a balance between pulmonary vascular resistance and systemic blood pressure.

4.  Apnea of prematurity

  • When a baby stops breathing for 15 – 20 seconds or more; or the baby stops breathing for less than 15 seconds along with bradycardia or oxygen desaturation, it is called apnea. It is a frequent problem of preterms less than 34 weeks gestation because:
  • Central chemoreceptors are present in the medulla and initiate breathing when CO2 levels increase. But this response is impaired in preterm newborns, causing apnea.
  • Peripheral chemoreceptors present in the carotid body stimulates breathing when oxygen levels (PaO2) decreases. PaO2 before birth is ~ 25 mm Hg. This increases to ~ 90 mm Hg when the baby is born. Because of this change, peripheral chemoreceptors are silenced for a while.
  • When any fluid goes into the larynx, laryngeal chemoreflex is activated and causes apnea to prevent aspiration. In preterm newborns, this reflex is exaggerated and causes apnea whenever the baby is fed or have a gastroesophageal reflex.
  • Preterm babies show increased response to inhibitory neurotransmitters like GABA and adenosine which inhibits respiration.
  • Preterm newborns have a poor pharyngeal tone which can cause obstruction, leading to apnea.

How to treat respiratory distress in a preterm baby?

1.  Start Continuous Positive Airway Pressure (CPAP) immediately after birth

  • CPAP gives an end-expiratory pressure to the baby’s lungs. This eases the force needed by the baby to breathe.
  • CPAP is the best support for a preterm newborn with respiratory distress or apnea. It decreases the risk of intubation and the incidence of bronchopulmonary dysplasia in preterm babies.
  • Babies receiving early CPAP immediately after birth have a lower incidence of respiratory failure and shorter duration of ventilation as compared to newborns receiving early surfactant treatment (SUPPORT Study, 2010).

2.  When to give surfactant?

  • If the baby is intubated and needs positive pressure ventilation within the first 48 hours of life, or
  • the baby needs a FiO2 greater than 40% to maintain saturation of more than 88%, give surfactant.
How to give surfactant?

Less Invasive Surfactant Administration (LISA)

  1. In LISA, we do not intubate the baby with an endotracheal tube. Instead, we intubate with a small-bore catheter (3-5Fr nasogastric tube or umbilical catheter). Such a baby does not need positive pressure ventilation and continues normal respiration during surfactant instillation.
  2. Use this method to give surfactant without intubation in babies who are breathing spontaneously.
  3. What do you need? Surfactant, syringe, 5Fr nasogastric tube or 3-5Fr umbilical catheter as a tracheal catheter, laryngoscope with size 0 or 00 blades, small Magill forceps, sterile sheet, and gloves.
  4. How to give surfactant by LISA?
    • Place a nasogastric tube and aspirate gastric contents. Leave the nasogastric tube in place – it will help guide your tracheal catheter.
    • Maintain a sterile area and wear sterile gloves. Load surfactant into the syringe.
    • With Magill forceps, hold the tracheal catheter 2.5 cm away from its end.
    • Pass this tracheal catheter into the larynx 1.5 – 2 cm below the vocal cords under the laryngoscope view. Now carefully withdraw Magill forceps and laryngoscope taking care that the catheter should not be withdrawn from the trachea.
    • Instill the surfactant slowly over 5 minutes while allowing the baby to breathe spontaneously.
    • Watch for apnea, bradycardia, or desaturation during surfactant instillation.

INtubation-SURfactant-Extubation (INSURE)

  1. Even if we intubate the baby to give surfactant, we can extubate once the surfactant is instilled and the baby is breathing spontaneously.
  2. This approach still avoids the complications of prolonged ventilation.

3.  Antenatal corticosteroids

  • Give antenatal corticosteroids to pregnant women between 24 – 34 weeks gestation if delivery is imminent within 7 days.
  • Do not give in women having chorioamnionitis expecting imminent preterm birth.
  • Give either:
    • Dexamethasone 6 mg IM every 12 hourly for 2 days (total 24 mg), OR
    • Betamethasone 12 mg IM every 24 hourly for 2 days (total 24 mg).
  • If preterm delivery does not occur within 7 days and is expected to happen within the next 7 days, repeat this course.
  • In preterm newborns, antenatal corticosteroids decrease respiratory distress syndrome, intracranial hemorrhage, necrotizing enterocolitis, and neonatal sepsis.

4.  Ventilator strategy in preterm newborns

  1. Delivery room:
    • If positive pressure ventilation is needed, give low inspiratory pressure to prevent overdistention of lungs which causes lung injury.
    • Use a flow-inflating bag or T-piece resuscitator to maintain positive end-expiratory pressure (PEEP).
  2. Mechanical ventilation in NICU:
    • Start with pressure-controlled ventilation (PCV) set to deliver a tidal volume of 4-6 mL/kg. Set an inspiratory time between 0.3 – 0.4 seconds and positive end-expiratory pressure (PEEP) of 5-6 cm H2O.
    • Adjust FiO2 to maintain a target oxygen saturation of 90-94%.

5.  Use methylxanthines (caffeine, aminophylline, theophylline) for apnea of prematurity

  • Methylxanthines stimulate central chemoreceptors – increase their CO2 sensitivity; induce bronchodilation and improve diaphragmatic function.
  • We give caffeine in preterm newborns less than 34 weeks gestation with respiratory distress or apnea. We continue caffeine until 33-34 weeks gestation and the baby is apnea free.

How to identify silent hypoglycemia in low birth weight newborns?

  1. Hypoglycemia is defined as blood glucose levels of less than 45 mg/dL.
  2. Low birth weight babies have a high risk of hypoglycemia for up to 10 days after birth because:
    • they have low glycogen stores,
    • many have feeding difficulties,
    • mothers receive antenatal corticosteroids for fetal lung maturity.
  3. Brain cells get their energy from glucose. Hypoglycemia kills brain cells – and this damage is irreversible.
  4. Recognize newborns at risk of hypoglycemia – screen all low birth weight newborns, large for gestation babies, and infant of diabetic mothers for the first 24 hours after birth.
  5. Give first feed within 30 minutes of birth in stable low birth weight newborns, check blood glucose 1 hour after birth, 2 hours after birth (prefeed), 4-6 hours after birth (prefeed), and 6 hourly thereafter if all glucose readings are normal and the baby is feeding well.
  6. Blood glucose screening plans can vary from baby to baby depending upon the degree of prematurity and intrauterine growth restriction.
  7. Stable newborns over 1800 grams are usually shifted to mother for exclusive breastfeeding. Check their blood glucose bedside and sensitize the parents to identify and report any symptoms of hypoglycemia immediately.
  8. Signs of hypoglycemia: jitteriness, cyanosis, seizures, apnea, tachypnea, weak or high-pitched cry, lethargy, poor feeding, or a staring look.
  9. If blood glucose levels are less than 45 mg/dL on glucometer, send a lab sample in sodium fluoride vial and manage according to protocol.
Blood glucose screening in high risk newborns
Blood glucose screening in high risk newborns

How to fulfill the nutritional needs of low birth weight newborns?

What is the problem?

  • Low birth weight babies have poor coordination of sucking, swallowing, and decreased ability to generate sufficient pressure during sucking.
  • Poor feeding causes dehydration and hypoglycemia.

How to give IV fluids in preterm low birth weight babies?

  • A newborn uses ~60 Kcal/kg energy daily. And for a weight gain of ~15 g/kg/day, the baby needs an additional 70 Kcal/kg/day. So, for proper growth, the baby needs a total of 120 – 130 Kcal/kg/day.
  • Also, the baby needs carbohydrates, proteins, and fat to grow properly.
  • What does the baby get from IV fluids?
    • 100 mL of dextrose containing IV fluids like Dextrose 10%, Isolyte P 10% gives 10 g dextrose (carbohydrate), and 40 Kcal energy.
    • 100 mL of an amino acid (10%) solution gives 10 g protein and 40 Kcal energy.
    • 100 mL of intralipid (20%) emulsion gives 20 g fat and gives 180 Kcal energy.

Case scenario: A preterm 1400 gram newborn on day 6 of life is kept NPO since birth and on IV fluids @ 155 mL/kg/day (total 155 x 1.4 = 217 mL). How can we fulfill the nutritional needs of this baby on IV fluids?

Step 1: Start amino acids from day 1

  • Low birth weight babies need ~3.5 g/kg/day proteins. We need to supplement this protein in IV fluids if the baby is kept NPO.
  • Start amino acids (10%) 2 g/kg/day on day 1 and increase 0.5 g/kg everyday to a maximum of 3-4 g/kg/day
  • IV Fluid composition of this baby on day 5:
    • Amino acids (10%) 3 g/kg/day: 1.4 x 30 = 42 mL
    • Isolyte P 10%: 217 mL – 42 mL – drug fluid (~15 mL) = 160 mL
  • Energy gained from amino acids = 16.8 Kcal
  • Energy gained from carbohydrates = 16 g x 4 Kcal/g = 64 Kcal
  • Total energy from IV fluids = 64 + 16.8 = 80.8 Kcal: 57.7 Kcal/kg/day
  • The baby gets just the maintenance energy from dextrose and amino acid combination. To give more energy, and to fulfill the need for essential fatty acids, we need to give lipids.

Step 2: Start intralipids via a separate IV line if the baby is expected to be NPO for a longer time

  • We start lipids in newborns who are expected to remain NPO for longer than 10-15 days.
  • Give lipids via a syringe infusion pump via a separate IV line – preferably central line, but can be given via a peripheral line.
  • Give continuous IV infusion over 24 hours.
  • If we give Isolyte P 10% + Amino acids @ 3 g/kg/day + Lipids @ 2 g/kg/day, baby will get:
    • Amino acids (10%) 3 g/kg/day: 1.4 x 30 = 42 mL (4.2 g protein)
    • Lipids (20%) @ 2 g/kg/day: 1.4 x 10 = 14 mL (2.8 g fat)
    • Isolyte P 10%: 217 mL – 42 mL – 14 mL – drug fluid (~15 mL) = 146 mL (14.6 g dextrose)
  • Energy gained from amino acids = 4.2 x 4 = 16.8 Kcal
  • Energy gained from lipids = 2.8 x 9 = 25.2 Kcal
  • Energy gained from dextrose = 14.6 x 4 = 58.4 Kcal
  • Total 100.4 Kcal: 71.7 Kcal/kg/day
  • This extra energy will be used in the growth of the baby.
  • But we don’t start lipids in every newborn since birth, because we are afraid of the risk of sepsis, respiratory distress, and cholestatic jaundice associated with lipid infusion.
  • We start oral feeds as soon as possible.

How to start early oral feeds in preterm low birth weight newborns?

  1. Many preterm newborns cannot breastfeed right after birth.
  2. Preterm newborns can successfully breastfeed only after a gestational age of 35 weeks or a weight of 2500 grams.
  3. We start feeds via an orogastric tube soon after birth in preterm babies.


  4. We ask the mother to start expressing her breast milk soon after delivery. We feed this expressed breast milk to her newborn via an orogastric tube.
  5. If the baby is on vasopressor support or having significant respiratory distress or internal bleeding (disseminated intravascular coagulation) or necrotizing enterocolitis, we withhold feeds and store this expressed breast milk in a deep freezer (-20°C).
  6. We give minimal enteral nutrition as soon as baby’s condition stabilizes. Minimal enteral nutrition is small quantities of feeds (10-20 mL/kg/day) given 3-4 hourly which keeps the gut functional. It does not increase the risk of necrotizing enterocolitis.
  7. If the newborn is less than 30 weeks (1200 g), we start giving IV fluids and start minimal enteral nutrition as soon as stable. We increase daily feeds by 30-40 mL/kg/day and according to baby’s tolerance.
  8. If the baby is over 30 weeks of gestation (more than 1200 g) and stable, we start with full feeds by orogastric tube immediately after birth.
  9. We take abdominal girth before initiating feeds and recheck when the abdomen is appearing full or bowel loops are visible. If prefeed abdominal girth increases by more than 2 cm and prefeed gastric aspirates are more than 25% of last feed, we withhold feeds until abdominal distention is resolved and bowel sounds are normal.
  10. If the abdomen is shiny or tense, we stop feeds immediately and investigate for necrotizing enterocolitis.
  11. Oral care with colostrum: In babies kept NPO because of shock, sepsis, or necrotizing enterocolitis, we apply colostrum inside the oral cavity. There is some evidence that it improves baby’s immunity.
  12. Suthi (paladai) or spoon-feeding:
    • Most neurologically normal babies start accepting feeds by spoon (also called as suthi or paladai) by 32-33 weeks gestation (or weight over 1500 g).
    • We start giving some feeds by suthi once the baby is over 1400 g and stable. Most of the feeds are given by an orogastric tube initially.
    • We advance suthi feeds according to the acceptance and vigor of the baby.
    • Learn more about suthi (paladai) feeding here.
  13. Non-nutritive sucking: When the baby sucks over the mother’s empty breasts and does not receive any milk from it, is called non-nutritive sucking. We start non-nutritive sucking in preterm newborns once the baby is over 1400 grams and stable. It improves sucking coordination and oral-motor tone.
  14. Donor Human Milk:
    • Mother’s milk protects from necrotizing enterocolitis – a life-threatening gut infection in preterm newborns.
    • Giving formula milk or other top milk increases the risk of necrotizing enterocolitis by up to 10 times.
    • When the mother is not available (critically ill or admitted somewhere else), donor human milk must be given to save the newborn.
    • Helping mothers express their breast milk immediately after birth is the key to successful breastfeeding and saving the lives of preterm babies admitted to the hospital.
    • Learn more about the principles of Human Milk Banking.
  15. Tube assisted breastfeeding (supplemental nursing):
    • Case scenario: A preterm 1200 g newborn was born at 30 weeks gestation and initiated expressed breast milk by orogastric tube right after birth. The mother started expressing her breast milk immediately after birth and expressed every 2 hourly in the day and 3 hourly in the night, so her breast milk supply is good. The baby was started on suthi feeding 3 weeks after birth. Suthi (spoon) feeds were gradually increased to full feeds by 34 weeks gestation (4 weeks after birth). Non-nutritive sucking was started by 33 weeks of gestation. We usually discharge the baby when the baby starts accepting full feeds by suthi. But this baby came to us at our Lactation Management Center “Jeevan Dhara” and the baby’s current weight was 80 g less than discharge weight from the hospital.
      • Step 1: Checking mother’s milk supply: We use hospital-grade breast pumps to help mothers express breast milk. Milk production of this mother was good.
      • Step 2: Checking the attachment of baby while breastfeeding: The baby had a poor latch.
      • Many preterm babies need help latching on to breasts once they could breastfeed. It does not come naturally to them as it does for full-term babies because preterm babies have been fed with suthi spoon for too long.
      • Non-nutritive sucking is an easy way to improve sucking coordination but it may not be sufficient. The baby needs a stimulus (feed) to coordinate sucking with swallowing and respiration.
      • Tube assisted breastfeeding (supplemental nursing) helps preterm babies learn to latch-on to breasts.
Tube assisted breastfeeding or supplemental nursing in neonates
Tube assisted breastfeeding (supplemental nursing) helps when baby cannot latch properly because of nipple problem or immature reflexes. Mother’s expressed breast milk is slowly trickled via a tube affixed to mother’s nipple which the baby suckles to get milk.

Why are low birth weight babies at high risk of infections?

  • Low birth weight babies have low cellular and humoral immunity.
  • Low birth weight babies are at higher risk of hospital-acquired infections because they have a longer hospital stay, need for prolonged IV lines, longer parenteral nutrition, and need for mechanical ventilation.
  • Infections increase the risk of bronchopulmonary dysplasia and brain injury.

How to avoid infections in low birth weight newborns?

  1. Use antibiotics wisely
    • Start with first-line antibiotics when needed.
    •  Avoid using cephalosporins as first-line antibiotics – they cause resistance.
    •  Keep an idea of prevalent pathogens in the nursery by analyzing blood culture reports – draft your antibiotic policy according to prevalent pathogens and their resistance pattern.
    •  Avoid revising antibiotics frequently – if your baby is not responding to higher antibiotics at first, also check for non-infective causes of deterioration, e.g., patent ductus arteriosus, intraventricular hemorrhage, dyselectrolytemia, persistent pulmonary hypertension, pneumothorax, iatrogenic dehydration, etc.
  2. Extensive hand-washing policy
    • Washing your hands before touching every newborn in the nursery is the best time-tested intervention to prevent hospital-acquired infections.
    • Sanitizing hands with alcohol-based sanitizer using all the steps of hand-washing is the preferred alternative if hand washing could not be done every time.
  3. Strict asepsis during all invasive procedures, especially IV cannulation, blood sampling, and blood glucose monitoring; because these are more frequently repeated.
  4. Minimize sampling – use cluster sampling
    • List all non-essential routine samplings for each baby and take samples during cannula change without any additional pricks.
  5. Early initiation and advancement of feeding – use expressed breast milk
  6. Prophylactic fluconazole in extremely low birth weight newborns in nurseries where fungal infection is prevalent
  7. Initiate kangaroo care as soon as the baby is ready

This article outlines the need for special care in preterm low birth weight newborns. Summarizing, take care to maintain a normal temperature; give continuous positive airway pressure (CPAP) and start caffeine immediately after birth if the baby has respiratory distress; monitor blood glucose levels until the baby is on full oral feeds and normoglycemic; start feeds early and advance aggressively according to tolerance, and maintain strict asepsis in the nursery.

We will discuss the management of complications and follow-up care of preterm low birth weight newborns in upcoming articles. I welcome inputs from all doctors and nurses involved in newborn care – I will incorporate it in this article to improve it. If you have questions or comments, be sure to ask it in the comment section or mail me: [email protected].

References:

  1. Miller SS, Lee HC, Gould JB. Hypothermia in very low birth weight infants: distribution, risk factors and outcomes. J Perinatol. 2011 Apr;31 Suppl 1:S49-56. doi: 10.1038/jp.2010.177. PMID: 21448204.
  2. Mullany LC, Katz J, Khatry SK, LeClerq SC, Darmstadt GL, Tielsch JM. Risk of Mortality Associated With Neonatal Hypothermia in Southern Nepal. Arch Pediatr Adolesc Med. 2010;164(7):650–656. doi:10.1001/archpediatrics.2010.103
  3. Gyamfi-Bannerman C, Thom EA, Blackwell SC, Tita AT, Reddy UM, Saade GR, Rouse DJ, McKenna DS, Clark EA, Thorp JM Jr, Chien EK, Peaceman AM, Gibbs RS, Swamy GK, Norton ME, Casey BM, Caritis SN, Tolosa JE, Sorokin Y, VanDorsten JP, Jain L; NICHD Maternal–Fetal Medicine Units Network. Antenatal Betamethasone for Women at Risk for Late Preterm Delivery. N Engl J Med. 2016 Apr 7;374(14):1311-20. doi: 10.1056/NEJMoa1516783. Epub 2016 Feb 4. PMID: 26842679; PMCID: PMC4823164.
  4. SUPPORT Study Group of the Eunice Kennedy Shriver NICHD Neonatal Research Network
  5. WHO recommendations to improve preterm birth outcomes.
  6. Clinical Report: Postnatal Glucose Homeostasis in Late-Preterm and Term Infants. Pediatrics. 2011;127(3):575–579.

Recent Articles

IV Fluid Charting In Newborns Weighing More Than 1000 grams

IV fluid charting in newborns weighing more than 1000 grams

Special Care of Low Birth Weight Babies

Low birth weight babies need special care because of the high risks of death and morbidity associated with preterm birth.

Hypernatremic Dehydration In Newborns

Diagnosis and treatment of hypernatremic dehydration in newborns with an easy calculator to estimate fluid and electrolyte deficit.

Empiric Antibiotic Therapy In Newborn Care Units

This article summarizes an empiric antibiotic therapy with referenced doses of commonly used antibiotics and drugs in newborn care units

IAP Undergradute Quiz

Pre-divisional Round of IAP Undergraduate Quiz