The neonatal phase is the period that stretches from directly after birth and encompasses the first two to four weeks in the life of the child.
Contrary to most parents’ descriptions, newborns are not exactly pretty – they have a swollen bluish and reddish face, a broad flat nose, swollen eyelids and ears that seem somewhat misplaced. Sometimes the shape of the face is misshapened due to the long path down the birth channel. The little body is covered in a white substance, vernix caseosa, which protects the baby from infection and dries off in a few days. Some babies are still covered in fine hair, lanugo, which falls out during the first month. Newborns exhibit prominent external sex organs and both sexes’ nipples are swollen due to high amounts of estrogen in the mother’s blood before giving birth.
In addition to these features, the body proportions of newborns differ substantially from the proportion of an adult body.
The head makes up one fourth of the total body in contrast with the eighth of an adult’s. The neck muscles are not able to keep the head up at this point in time.
The average weight of a newborn varies between 2.5 and 4.5kg, with most weighing between 3 and 3.5kg. Girls tend to weigh less than boys at birth and firstborns tend to be lighter than siblings.
Most parents experience that their infants lose up to 10% of their body weight in the first couple of days in hospital, but will regain it with a week or two once feeding is established. Boys tend to be taller than their counterparts, with the average length being around 45 to 56cm. A newborn baby’s heartbeat varies between 120 and 150 beats per minute, going up when stressed and down when resting.
The apgar-scale is used to evaluate an infant at birth. This evaluation gets done twice – one minute after birth and again 5 minutes after birth.
A: Appearance (Colour)
G: Grimace (Reflex irritability)
P: Pulse (Heartbeat)
A: Activity (Muscle tone)
R: Respiration (Breathing)
Each of these aspects gets scored as zero, one or two, with zero being the worst score and two the best score. The scores get combined with a maximum score of ten. Most babies score 7 or more. A score of 4 is indicative of further evaluation and treatment.