2- NEWBORN high risk newborn

Newborn Development and Physiology

Stages of Growth and Development

  • Prenatal Period (Conception to Birth)

  • Early Childhood

    • Toddler (1-3 years)

    • Pre-school (4-5 years)

  • Middle Childhood

    • School Age (6-12 years)

  • Later Childhood

    • Prepubertal (10-12 years)

    • Adolescence (13-18 years)

Prenatal Stages of Development

  • Germinal Stage (Conception to 2 weeks GA)

  • Embryonic Stage (2-8 weeks GA)

  • Fetal Stage (8-40 weeks GA)

    • Key weeks highlighted: 5 days, 7 weeks, 10 weeks, 14 weeks, 20 weeks, 36-38 weeks GA

Infancy

  • Infancy (% Birth-12 months)

    • Newborn (1st 72 hrs - 1 week)

    • Neonatal (Birth-27 or 28 days)

Physiological Changes in Pregnancy

  • Oxygen Supply: Maternal blood flow increases to one-third; fetal respiratory and heart rates increase by 40%.

  • Nutrition: Provided via placental circulation and amniotic fluid swallowing.

  • Fetal Heart Rate: Audible by 10 weeks via Doppler stethoscope.

  • Temperature Regulation: Maintained by the amniotic fluid.

  • Elimination: Feces are not expelled until birth.

  • Safety: Embryos vulnerable to teratogens.

Transition from Intrauterine to Extrauterine Life

  • The cutting of the umbilical cord marks this transition.

  • Neonates often resemble patients recovering from anesthesia.

Newborn Classification

  • Pre-term (PR): < 37 completed weeks

  • Full-term (F): 38-41 completed weeks

  • Post-term (PO): ≥ 42 weeks

Physiological Adjustments Post-Birth

Respiratory Adjustments

  • Chemical Factors: Triggered by changes in O2 and CO2 levels.

  • Tactile Stimulation: Caused by birth canal and handling.

  • Thermal Stimulus: Sudden temperature drop post-birth activates respiratory center.

  • Pulmonary Perfusion: Adjustments include capillary erection and alveolar expansion.

Circulatory Adjustments

  • Prenatal vs. Postnatal Circulation: Adjustments involve the closure of the ductus venosus, foramen ovale, and ductus arteriosus.

Thermoregulation

  • Newborns are at high risk for hypothermia due to:

    • Large surface area for heat loss.

    • Immaturity of subcutaneous fat.

    • Heat production through non-shivering thermogenesis (e.g., brown adipose tissue).

Gastrointestinal System

  • Newborns have limited abilities to digest and absorb food.

    • Enzymatic deficiencies lead to challenges with fat digestion.

    • Jaundice may arise due to immature liver function.

  • Meconium: First stool described as black and sticky, typically occurs within the first 24-48 hours.

Renal System

  • Functionally immature, expected urine output between 200-300 ml at 1st week, must void within 24 hours post-birth.

Integumentary System

  • Skin structures present but immature. Sebaceous glands active due to maternal hormone influence.

Neurological System

  • CNS development is sufficient to support extrauterine life. Most reflexes are primitive.

High-Risk Newborns

  • Defined as having a higher than average chance of morbidity or mortality, regardless of gestational age or birth weight.

  • Classification: Based on birth weight (LBW, VLBW, ELBW) and gestational age.

Nursing Care for High-Risk Newborns

  • Focused on management of hydration, thermoregulation, nutritionally fortified feeding, and infection prevention.

Hyperbilirubinemia (Jaundice)

  • Causes include physiological factors, breast milk factors, hemolytic disease, etc.

  • Therapeutic Management: Involves phototherapy, hydration, and blood transfusion in severe cases.

  • Prevention includes early feeding and monitoring bilirubin levels.

Conclusion

  • Newborns undergo significant physiological adjustments at birth, and understanding these processes is crucial for providing care and recognizing high-risk conditions.