BGDA Practical 12 - Neonatal

From Embryology
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Practical 12: Embryo to Fetus | Second Trimester | Third Trimester | Birth | Neonatal | Abnormalities


Introduction

Newborn.jpg

The neonatal period (birth to 1 month) is a time of extensive and ongoing system transition from uterine environment to external world, this includes the initial period after birth which is referred to as the perinatal period.

It would seem obvious to say that development does not stop at birth. In fact many systems (cardiovascular, respiratory, gastrointestinal, homeostasis) undergo significant changes at birth, and many others (neural) have not yet completed their development. Note this current project focuses on prenatal development, so postnatal content is not as detailed.

Newborn Homoeostasis

Brown adipose tissue

Newborn has to establish new functioning systems in a balanced and regulated manner (homoeostasis).

  • lung function
  • circulatory changes
  • thermoregulation
  • endocrine function
  • nutrition
  • gastrointestinal tract function
  • waste
  • kidney function

Glucocorticoids - have an important role in the preparation for birth, including involvement in lung and cardiac development, and the maturation of enzymes in a variety of pathways.

Puerperium - The six weeks following parturition (birth) when maternal reproductive organs and physiology return to pre-pregnant state.


Respiration

Neonatal rib orientation
  • Lungs at birth collapsed and fluid-filled - replaced with air by powerful inspiratory movement and absorption through the alveoli
  • Lung epithelia has to rapidly change from its prenatal secretory function to that of fluid absorption.
    • initiated by a late fetal change in alveolar epithelial cell (AEC) chloride and fluid secretion to sodium and fluid absorption.
    • absorption requires sodium-potassium ATPase (Na-K-ATPase) together with apical sodium entry mechanisms (Epithelial Sodium Channels, ENaC)
    • Fetal thyroid hormone is thought to have a hormonal role in this developmental switch
  • These changes and pressure also lead to the pulmonary sytem becoming activated and changes in the circulatory shunting that existed before birth.
  • During the late fetal period regular fetal breathing movements (FBM) also occur preparing both the skeletomuscular system and lungs mechanically for respiration.
  • Respiratory Rate is higher than adult (30 breaths/minute).
  • Rib Orientation - Infant rib is virtually horizontal, allowing diaphragmatic breathing only. Adult rib orientation is oblique (both anterior and lateral views), allows for pump-handle and bucket handle types of inspiration.

Links: Respiratory System Development

Cardiovascular

  • Umbilical Vasculature - The umbilical blood vessel cavity is lost postnatally over the course of weeks to months after birth. The adult anatomical remnant of the umbilical vein between the umbilicus and liver is the ligamentum teres.
  • Foramen Ovale - two separate forms of foramen ovale closure; functional and structural. Functional closure begins at the first breath and is rapid. Structural (anatomical) closure is much slower and generally occurs before the end of the first year.
  • Ductus Arteriosus - a direct connection between the pulmonary trunk and the dorsal aorta. Postnatal closure occurs initially by by smooth muscle contraction and begins at the first breath and is rapid, completed within the first day (about 15 hr after birth). Anatomical closure is much slower occuring by 2–3 weeks after birth (33% of infants), by 2 months (90% of infants) and by 1 year (99% of infants). The adult anatomical remnant of the ductus arteriosus is the ligamentum arteriosum.
  • Ductus Venosus - connects portal and umbilical blood to the inferior vena cava. Functional closure occurs postnatally within hours. Structural closure commences days after birth and completes by 18 to 20 days. The adult anatomical remnant of the ductus venosus is the ligamentum venosum (a dorsal fissure on the liver).
Fetal circulation 01 icon.jpg Neonatal circulation 01 icon.jpg Atrial Septal Defect.jpg Patent Ductus Arteriosus.jpg
Fetal Circulation Neonatal Circulation Atrial Septal Defect Patent Ductus Arteriosus

Neonatal Testing

Apgar Test

Apgar Test

A historic neonatal test designed by Dr Virginia Apgar used in nearly all maternity clinics to assess the newborn infants well being assigned scores for each of 5 indicators: Heart Rate, Respiratory Effort, Reflex Irritability, Muscle Tone, Colour Measured at one and five minutes after birth the Score values are totalled for all indicators: 7-10 is considered normal, 4-7 may require resuscitative measures, 3 and below require immediate resuscitation. In recent years there has been some controversy of the relevance and accuracy of some of the criteria used in this test, though many feel it is still an invaluable initial assessment tool particularly where medical services are limited.

Apgar Score Calculation[1] PMID 13083014
Indicator Score 0 Score 1 Score 2
Activity
(muscle tone)
Limp; no movement Some flexion of arms and legs Active motion
Pulse
(heart rate)
No heart rate Fewer than 100 beats per minute At least 100 beats per minute
Grimace
(reflex response)
No response to airways being suctioned Grimace during suctioning Grimace and pull away, cough, or sneeze during suctioning
Appearance
(color)
The baby's whole body is completely bluish-gray or pale Good color in body with bluish hands or feet Good color all over
Respiration
(breathing)
Not breathing Weak cry; may sound like whimpering, slow or irregular breathing Good, strong cry; normal rate and effort of breathing
Apgar test - Measured at one and five minutes after birth, the score values are totalled for all indicators:
7 to 10 is considered normal; 4 to 7 may require resuscitative measures; 3 and below require immediate resuscitation.


Links: Apgar test

Bloodspot Test or Guthrie Test

Guthrie card

A blood screening test developed by Dr Robert Guthrie (1916-95) at University of Buffalo. The test is carried out on neonatal (newborn) blood detecting markers for a variety of known disorders (phenylketonuria (PKU), hypothyroidism and cystic fibrosis). In NSW and Victoria, the Guthrie Cards are currently stored indefinitely.

R GUTHRIE, A SUSI A SIMPLE PHENYLALANINE METHOD FOR DETECTING PHENYLKETONURIA IN LARGE POPULATIONS OF NEWBORN INFANTS. Pediatrics: 1963, 32;338-43 PubMed 14063511


NSW Newborn Screening Programme

Each year test more than 90,000 babies and detects about 90 who need urgent assessment and treatment.

  • Phenylketonuria (PKU) - 1 in 10,000 live births (about 10 babies per year). PKU causes high blood levels of phenylalanine and severe intellectual disability. A diet low in phenylalanine, started in the first two to three weeks results in normal development.
  • Primary congenital hypothyroidism - 1 in 3,500 live births (about 26 babies per year). It is caused by the absence or abnormal formation or function of the thyroid gland. This causes growth and intellectual disability if not treated. Medication with thyroid hormone started early, results in normal growth and development.
  • Cystic Fibrosis (CF) - 1 in 2,500 live births (about 34 babies per year). Without treatment babies develop chest infections and often have very serious failure to thrive. Early institution of treatment greatly improves the health of babies with CF. Newborn bloodspot screening detects about 95% of babies with CF but also detects a few babies who may only be healthy carriers. For these babies a sweat test at about six weeks of age determines whether the baby has CF or is a healthy carrier.
  • Galactosaemia - 1 in 40,000 births (about 1-3 cases per year). Babies cannot process galactose, a component of lactose. Life-threatening liver failure and infections can occur. A galactose-free diet instituted in the first week is life saving.
  • Rarer metabolic disorders - Some fatty acid, organic acid and other amino acid defects can now be detected using Tandem Mass Spectrometry. These much rarer metabolic disorders affect about 15 – 18 babies per year. Early detection is important as diet and medications can treat most of these disorders. Without appropriate management they can cause severe disability or death.

Genetics services in NSW - coordinated by the NSW Genetics Service Advisory Committee, which is supported by the Statewide Services Development Branch of the Strategic Development Division, NSW Department of Health. (Information from NSW Health - Newborn Bloodspot Screening Policy 13-Nov-2006)


Links: Guthrie test | NSW Genetics Health


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Practical 12: Embryo to Fetus | Second Trimester | Third Trimester | Birth | Neonatal | Abnormalities


Additional Information

Additional Information - Content shown under this heading is not part of the material covered in this class. It is provided for those students who would like to know about some concepts or current research in topics related to the current class page.

Links: Birth | Postnatal Development | Puberty Development


Neonatal Neural Exam

Link=Neural_Exam_Movies#Newborn Link=Neural_Exam_Movies#Newborn_Abnormal

The collapsed tables below link to a number of short videos that demonstrate simple assessments of the postnatal developing nervous system.

Normal Newborn Neural Exam Movies  
Normal Newborn Neural Exam Movies

The newborn neuromuscular system can be initially assessed by 6 quick tests (posture, square window, arm recoil, popliteal angle, scarf sign and heel to ear). The following short videos show clinical examination of these assessments and a number of neonatal reflexes.

Later developmental assessment includes behaviour, reflexes (primitive and postural), muscular tone, and motor (gross, fine, co-ordination).

Normal Newborn Neural Exam Movies

Newborn Behaviour
Newborn-normal-behaviour.jpg
 ‎‎Behaviour
Page | Play
Newborn n 02.jpg
 ‎‎Cranial Nerves
Page | Play
Newborn Tone
Newborn n 03.jpg
 ‎‎Resting Posture
Page | Play
Newborn n 04.jpg
‎‎ Tone Upper Limb
Page | Play
Newborn n 05.jpg
‎‎ Arm Traction
Page | Play
Newborn n 06.jpg
 ‎‎Arm Recoil
Page | Play
Newborn n 07.jpg
 ‎‎Scarf Sign
Page | Play
Newborn n 08.jpg
 ‎‎Hand Position
Page | Play
Newborn n 09.jpg
 ‎‎Lower Limb
Page | Play
Newborn n 10.jpg
 ‎‎Leg Traction
Page | Play
Newborn n 11.jpg
 ‎‎Leg Recoil
Page | Play
Newborn n 12.jpg
 ‎‎Popliteal Angle
Page | Play
Newborn n 13.jpg
 ‎‎Heel to Ear
Page | Play
Newborn n 14.jpg
 ‎‎Neck Tone
Page | Play
Newborn n 15.jpg
 ‎‎Head Lag
Page | Play
Newborn n 16.jpg
 ‎‎Head Control
Page | Play
Newborn Positions
Newborn n 17.jpg
 ‎‎Prone Position
Page | Play
Newborn n 18.jpg
 ‎‎Ventral Suspend
Page | Play
Newborn n 19.jpg
 ‎‎Vertical Suspend
Page | Play
Newborn Reflexes
Newborn n 20.jpg
 ‎‎Tendon Reflexes
Page | Play
Newborn n 21.jpg
 ‎‎Plantar Reflex
Page | Play
Newborn n 22.jpg
 ‎‎Reflex Suck,Root
Page | Play
Newborn n 23.jpg
 ‎‎Moro Reflex
Page | Play
Newborn n 24.jpg
 ‎‎Galant Reflex
Page | Play
Newborn n 25.jpg
 ‎‎Stepping Reflex
Page | Play
Newborn n 26.jpg
 ‎‎Grasp Reflex
Page | Play
Newborn Head
Newborn n 27.jpg
‎‎ Head Shape
Page | Play
Newborn n 28.jpg
‎‎Head Circumference
Page | Play
Neural Exam Movies: normal behaviour | cranial nerves | Newborn Tone - resting posture | upper extremity‎ | arm traction | arm recoil | scarf sign | hand position | lower extremity | leg traction‎ | leg recoil‎‎ | popliteal angle‎ | heel to ear | neck tone | head lag‎ | head control | Newborn Positions - prone | ventral suspension | vertical suspension | Newborn Reflexes - deep tendon reflexes | plantar reflex‎ | suck, root | Moro | Galant | stepping‎ | grasp | Newborn Head - head shape and sutures‎ | head circumference‎ | Neonatal Diagnosis


Abnormal Newborn Neural Exam Movies  
Abnormal Newborn Neural Exam Movies

The newborn neuromuscular system can be initially assessed by 6 quick tests (posture, square window, arm recoil, popliteal angle, scarf sign and heel to ear). The following short videos show clinical examination of these assessments and a number of neonatal reflexes.

Later developmental assessment includes behaviour, reflexes (primitive and postural), muscular tone, and motor (gross, fine, co-ordination).

Newborn Behaviour

Newborn ab 01.jpg
 ‎‎Behaviour
Page | Play
Newborn ab 02.jpg
 ‎‎Cranial Nerves
Page | Play

Newborn Tone

Newborn ab 03.jpg
 ‎‎Resting Posture
Page | Play
Newborn ab 04.jpg
 ‎‎Upper Limb
Page | Play
Newborn ab 05.jpg
 ‎‎Arm Traction
Page | Play
Newborn ab 06.jpg
 ‎‎Arm Recoil
Page | Play
Newborn ab 07.jpg
 ‎‎Scarf Sign
Page | Play
Newborn ab 08.jpg
 ‎‎Hand Position
Page | Play
Newborn ab 09.jpg
 ‎‎Lower Limb
Page | Play
Newborn ab 10.jpg
 ‎‎Leg Traction
Page | Play
Newborn ab 11.jpg
 ‎‎Leg Recoil
Page | Play
Newborn ab 12.jpg
 ‎‎Popliteal Angle
Page | Play
Newborn ab 13.jpg
 ‎‎Heel to Ear
Page | Play
Newborn ab 14.jpg
 ‎‎Neck Tone
Page | Play
Newborn ab 15.jpg
 ‎‎Head Lag
Page | Play
Newborn ab 16.jpg
 ‎‎Head Control
Page | Play


Newborn Positions

Newborn ab 17.jpg
 ‎‎Prone Position
Page | Play
Newborn ab 18.jpg
 ‎‎Ventral Suspend
Page | Play
Newborn ab 19.jpg
 ‎‎Vertical Suspend
Page | Play

Newborn Reflexes

Newborn ab 20.jpg
 ‎‎Tendon Reflexes
Page | Play
Newborn ab 21.jpg
 ‎‎Plantar Reflex
Page | Play
Newborn ab 22.jpg
 ‎‎Reflex Suck,Root
Page | Play
Newborn ab 23.jpg
 ‎‎Moro Reflex
Page | Play
Newborn ab 24.jpg
 ‎‎Galant
Page | Play
Newborn ab 25.jpg
 ‎‎Stepping Reflex
Page | Play
Newborn ab 26.jpg
 ‎‎Grasp Reflex
Page | Play


Newborn Head

Newborn ab 27.jpg
 ‎‎Head Shape
Page | Play
Newborn ab 28.jpg
‎‎Head Circumference
Page | Play



Newborn Abnormal Links: behaviour | cranial nerves | Newborn Tone - resting posture | upper extremity‎ | arm traction | arm recoil | scarf sign | hand position | lower extremity | leg traction‎ | leg recoil‎‎ | popliteal angle‎ | heel to ear | neck tone | head lag‎ | head control | Newborn Positions - prone | ventral suspension | vertical suspension | Newborn Reflexes - deep tendon reflexes | plantar reflex‎ | suck, root | Moro | Galant | stepping‎ | grasp | Newborn Head - head shape and sutures‎ | head circumference‎



Immunisation

Australian Child Immunisation Programs 2013  
Age Vaccine
Birth
  • Hepatitis B (hepB)a
2 months
  • Hepatitis B, diphtheria, tetanus, acellular pertussis (whooping cough), Haemophilus influenzae type b, inactivated poliomyelitis (polio) (hepB-DTPa-Hib-IPV)
  • Pneumococcal conjugate (13vPCV)
  • Rotavirus
4 months
  • Hepatitis B, diphtheria, tetanus, acellular pertussis (whooping cough), Haemophilus influenzae type b, inactivated poliomyelitis (polio) (hepB-DTPa-Hib-IPV)
  • Pneumococcal conjugate (13vPCV)
  • Rotavirus
6 months
  • Hepatitis B, diphtheria, tetanus, acellular pertussis (whooping cough), Haemophilus influenzae type b, inactivated poliomyelitis (polio) (hepB-DTPa-Hib-IPV)
  • Pneumococcal conjugate (13vPCV)
  • Rotavirusb
12 months
  • Haemophilus influenzae type b (Hib)
  • Meningococcal C (MenCCV)

  • Measles, mumps and rubella (MMR)
18 months
  • Varicella (chickenpox)
4 years
  • Diphtheria, tetanus, acellular pertussis (whooping cough) and inactivated poliomyelitis (polio) (DTPa-IPV)
  • Measles, mumps and rubella (MMR)
  Notes: Information provided for educational purposes only. Postnatal - Vaccination | Immunise Australia Program

a Hepatitis B vaccine: should be given to all infants as soon as practicable after birth. The greatest benefit is if given within 24 hours, and must be given within 7 days.

b Rotavirus vaccine: third dose of vaccine is dependent on vaccine brand used.

  Source: Australian Immunisation Handbook 10th edition (April 2013).[2] National Immunisation Program Schedule From 1 February 2013 to 30 June 2013 PDF Immunise Australia Program.



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Cite this page: Hill, M.A. 2017 Embryology BGDA Practical 12 - Neonatal. Retrieved September 20, 2017, from https://embryology.med.unsw.edu.au/embryology/index.php/BGDA_Practical_12_-_Neonatal

What Links Here?
© Dr Mark Hill 2017, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G
  1. V APGAR A proposal for a new method of evaluation of the newborn infant. Curr Res Anesth Analg: 1953, 32(4);260-7 PubMed 13083014
  2. Australian Immunisation Handbook 10th edition (April 2013) Immunise Australia Program