Low Birth Weight and Prematurity

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Definitions & Classifications - Tiny Tots Tagged

Gestational Age (GA) Categories:

CategoryGA (weeks)
Preterm<37
Late Preterm34 to 36 6/7 wks
Moderately Preterm32 to 33 6/7 wks
Very Preterm (VPT)<32 wks
Extremely Preterm (EPT)<28 wks
Term37 to 41 6/7 wks
Post-term≥42 wks
CategoryBW (g)
---------------------------------------------
Low Birth Weight (LBW)<2500
Very Low Birth Weight (VLBW)<1500
Extremely Low Birth Weight (ELBW)<1000
  • Small for Gestational Age (SGA): BW <10th percentile for GA.

    ⭐ SGA infants (BW <10th percentile for GA) face ↑ perinatal morbidity & mortality vs. AGA infants, even if not LBW.

  • Appropriate for Gestational Age (AGA): BW 10th-90th percentile for GA.
  • Large for Gestational Age (LGA): BW >90th percentile for GA.
  • Intrauterine Growth Restriction (IUGR): Pathological fetal growth restriction, often leading to SGA.

Fenton Preterm Growth Chart for Boys

Etiology & Risk Factors - Preemie Triggers

  • Maternal Factors:
    • Previous preterm birth (PTB) - strongest risk
    • Multiple gestation (twins, triplets)
    • Uterine/cervical issues: incompetent cervix, fibroids, Müllerian anomalies, short cervix (<25 mm)
    • Infections: UTI, BV, chorioamnionitis, periodontal disease
    • Chronic illness: HTN, DM, renal, thyroid, autoimmune
    • Preeclampsia, eclampsia
    • Placental: abruption, previa, insufficiency
    • Polyhydramnios/Oligohydramnios
    • Age: <18 or >35 yrs
    • Low SES, poor nutrition, stress
    • Substance abuse (smoking, alcohol, illicit drugs)
    • Short interpregnancy interval (<18 months)
  • Fetal Factors:
    • IUGR, macrosomia (rarely)
    • Congenital anomalies
    • Fetal distress, hydrops
  • Iatrogenic Preterm Delivery (medically indicated)

Risk Factors for Preterm Birth and Nutritional Support

⭐ Prior preterm birth is the single most important risk factor for subsequent preterm birth, increasing the risk by 2-3 times.

Complications of Prematurity - Fragile Fighters' Foes

  • Respiratory:
    • RDS (Surfactant deficiency; ground glass CXR)
    • BPD (O₂ need at 36wks PMA / 28d postnatal)
    • Apnea of Prematurity (>20s pause)
  • Neurological:
    • IVH (Germinal matrix; Grades I-IV; US screen)
    • PVL (White matter injury; ↑CP risk)
    • ROP (Screen <32wks / <1500g; Zones I-III, Stages 1-5)
  • Gastrointestinal:
    • NEC (Bowel necrosis; pneumatosis intestinalis)
    • Feeding intolerance
  • Cardiovascular:
    • PDA (Continuous murmur)
    • Hypotension
  • Hematologic/Metabolic:
    • Anemia, Hyperbilirubinemia
    • Hypoglycemia, Hypocalcemia, Hypothermia
  • Infectious:
    • Sepsis (Immature immunity)
  • Long-term: Neurodevelopmental delay, growth failure.

Complications of Prematurity

IVH is most common in infants <1500g or <32 weeks gestation, typically occurring in the first 72 hours of life.

Management Strategies - Little Lives Lifelines

  • Antenatal (Threatened PTL):

    • ACS: Betamethasone (12mg IM x2, 24h apart) or Dexamethasone (6mg IM x4, 12h apart) for PTL <34 wks (up to 36+6 if no prior).
    • Tocolysis (Nifedipine): Delays delivery 48h for ACS.
    • $MgSO_4$: Neuroprotection if PTL <32 wks (4g load, 1g/hr).
  • Delivery Room ("Golden Hour"):

    • Warmth (23-25°C), radiant warmer, poly-wrap (VLBW/ELBW).
    • Delayed Cord Clamping (30-60s).
    • Respiratory: CPAP/intubation; surfactant (RDS).
  • Postnatal:

    • KMC: Skin-to-skin, early breastfeeding.
    • Nutrition: Trophic feeds (human milk), fortification (VLBW), PN prn.
    • Respiratory: Target $SpO_2$ 90-95%; caffeine (apnea).
    • Screen: IVH (US), ROP. Infection control.

⭐ Antenatal $MgSO_4$ for PTL <32 weeks significantly reduces cerebral palsy risk.

High‑Yield Points - ⚡ Biggest Takeaways

  • LBW < 2500g; VLBW < 1500g; ELBW < 1000g. Prematurity is birth < 37 weeks.
  • Key complications: RDS, IVH, NEC, ROP, PDA, sepsis, long-term neurodevelopmental delay.
  • Antenatal corticosteroids (given 24-34 weeks gestation) reduce RDS, IVH, and neonatal mortality.
  • Exogenous surfactant is vital for RDS management in preterm infants.
  • Kangaroo Mother Care (KMC) significantly improves survival and outcomes in LBW infants.
  • Common causes of prematurity: PPROM, maternal infections (e.g., UTI, chorioamnionitis), multiple gestation.

Practice Questions: Low Birth Weight and Prematurity

Test your understanding with these related questions

According to neonatal resuscitation protocol, how much oxygen to give in a term neonate with apnea and bradycardia initially?

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Flashcards: Low Birth Weight and Prematurity

1/5

Doderlein's bacilli are present in newborn females' vagina and then disappear after _____ days

TAP TO REVEAL ANSWER

Doderlein's bacilli are present in newborn females' vagina and then disappear after _____ days

10-14

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