Foundations Practical - Neonatal

Newborn Infant

Newborn

Some essential systems come online, others continue to develop.

The neonatal period is about the transition from an interuterine placenta and maternally supported life to life to relatively independent life in the external environment.

In developing a broad understanding of the neonatal period you need to think about the two different environments and the effects of loss of placental support. Also remember that substantial postnatal development still has to occur postnatally in the musculoskeletal, nervous and immune systems.

Birth

The median duration of gestation for first births from assumed ovulation to delivery was 274 days (just over 39 weeks). For multiple births, the median duration of pregnancy was 269 days (38.4 weeks).

Newborn Homoeostasis

Guthrie card

The newborn has to establish:

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

Birth Weight

The primary causes of VLBW are premature birth (born <37 weeks gestation, and often <30 weeks) and intrauterine growth restriction (IUGR), usually due to problems with placenta, maternal health, or to birth defects. Many VLBW babies with IUGR are preterm and thus are both physically small and physiologically immature.

Birth weight (grams)	less 500	500 – 999	1,000 – 1,499	1,500 – 1,999	2,000 – 2,499	2,500 – 2,999	3,000 – 3,499	3,500 – 3,999	4,000 – 4,499	4,500 – 4,999	5,000 or more
Classification	Extremely Low Birth Weight		Very Low Birth Weight	Low Birth Weight		Normal Birth Weight			High Birth Weight

Australian Birth

Australia’s mothers and babies (2009) Report

Assisted reproductive technology in Australia and New Zealand (2009) Report

Now briefly consider the current Australian trends in birth and the new reproductive technologies available.

Assisted reproductive technology in Australia and New Zealand

• Assisted reproductive technology in Australia and New Zealand 2009. 9 Nov 2011
  • In 2009, there were 70,541 assisted reproductive technology (ART) treatment cycles undertaken in Australian and New Zealand.
  • Of these cycles, 17.2% resulted in a live delivery (the birth of at least one liveborn baby).
  • In total, 13,114 liveborn babies were born following ART treatment in 2009.
  • The most important trend in ART treatment has been the increase of single embryo transfer, from 48.3% in 2005 to 69.7% in 2009.
  • This trend has resulted in significant reduction of multiple delivery rate from 14.1% in 2005 to 8.2% in 2009. (More? Assisted Reproductive Technology)

Maternal Changes

• Puerperium - six weeks following birth, maternal reproductive organs and physiology return to pre-pregnancy state.
• Involution - process of tissue catabolism of uterus.
• Lochia - uterine (placental) discharge, blood plus mucous, continues for about 4 weeks.
• Mammary - glandular development and function.

Development does not finish at Birth

Postnatal brain weight increase

Many systems continue to grow and differentiate after birth, in particular neural, sensory, respiratory, renal, endocrine and genital.

Newborn Brain Changes

Complex and ongoing processes of neurological development continue postnatally. This can be seen at the very basic level by simply measuring the increase in overall brain weight.

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Foundations Practical: Introduction | Week 1 and 2 | Week 3 and 4 | Week 1 to 8 | Week 9 to 36 | Neonatal | Critical Periods | Additional Resources | Quiz

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers

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Cite this page: Hill, M.A. (2024, April 19) Embryology Foundations Practical - Neonatal. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Foundations_Practical_-_Neonatal

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G