In this lecture, we’re going to
discuss delivery of the newborn,
how newborns are resuscitated and TTN
or transient tachypnea of the newborn.
Let’s go over the epidemiology
of newborns in the U.S.
There are 4 million births per year.
Ten percent of infants
who are born require
some sort of intervention
at birth to keep them going
and 1% require frank
So we’re doing a lot of
infant resuscitation in U.S.
Let’s keep in mind the fetal circulation.
Here, you can see a picture of it here
and I won’t go through it in detail,
but what’s key is remembering that these
children at their very first breath
are dramatically altering the way
blood flows through their heart.
They’re closing off their
patent ductus arteriosus
and they’re reversing flow so that they can
now suddenly adopt the adult circulation.
This is one of the most miraculous engineering
feats in the history of the world.
So we need to guide them
through this transition,
so that they’ll maintain a healthy state
as blood flow is dramatically reversed
through closing of the patent foramen ovale
and closing of the ductus arteriosus.
So let’s go through that physiology.
The patient has their first breath.
This causes a rapid expansion of the lungs.
Now, molecular pumps turn on and
rapidly pull fluid out of the airspace
through osmosis and into the
interstitium of the lungs.
Remember, while in utero, their
lungs were filled with fluid.
In fact, they even manufactured a tiny
percentage of that amniotic fluid.
Now, suddenly, they
must be emptied.
Oxygen causes a rapid dilatation
of the pulmonary arteries,
thus decreasing pulmonary
This leads to the
sympathetic nervous system
which thus increases systemic
vascular resistance through stress.
And that discrepancy,
the differences in vascular resistance
result in the transformation
from a fetal to an adult
The patent ductus arteriosus closes,
the patent foramen ovale closes and
those close over the first 1-2 days,
which sort of seal in this
new permanent architecture.
So occasionally kids will
need resuscitation at birth.
There are many potential risk
factors for needing resuscitation.
Patients who are twins, triplets or
otherwise have multiple gestations
are at increase risk for
If a mother has an infection
around the time of delivery,
that certainly can
increase the risk.
If the mother received
magnesium for a preterm labor,
that baby will have a decreased motor tone
and thus will need likely a resuscitation.
Maternal substance abuse increases
risk and need for resuscitation.
There can also be some
problems with labor
that can increase the risk
and need for resuscitation.
Breech presentation, a failure to progress
may result in distress in the infant.
Infants with nuchal cords may
have decreased vascular perfusion
prior to delivery and
may need resuscitation.
Infants who are stressed
will often have meconium
in the amniotic fluid
prior to being delivered.
Those infants are then at
increased need for resuscitation,
not only because they were
stressed and thus produce meconium
but also because meconium can get
into the lungs and cause pneumonitis.
Likewise in mothers who had
chorioamnionitis at the time of delivery,
those infants may be in distress
and certainly if there was placental
abruption or placenta previa
or some other problem like that,
these infants would be at increased
risk for needing resuscitation.
In cases where some previous risk factor
for needing resuscitation occurs,
the obstetrician may decide to have the
pediatrician come down to the delivery room
to assist with the
resuscitation, just in case.
When the pediatrician arrives,
they have to obtain information
about the prenatal history and
delivery so they know what’s going on.
The pediatrician should assess the
room and make sure it’s ready to go,
make sure the warmer is
active and plugged in.
Make sure there are clean, dry cloths
available for drying out the baby
and make sure there is suction
available and airway equipment
in the unfortunate need for true
resuscitation or intubation.
Pediatrician should know the gestational
age and the estimated weight in advance.
This is because any difference there
may be of clues as to what’s going on.
In general, as that baby is first
being handed to the pediatrician,
the pediatrician is asking
themselves three critical questions.
These are really important.
One, is the infant full-term?
A premature baby is going
to be managed differently.
Two, does the infant, when they’re handed
to the pediatrician, have good tone?
Is the infant floppy or
they’re all balled up?
All balled up is good.
And is the infant already crying?
If an infant is handed off to the
pediatrician as full-term with good tone
and if that infant is crying by the time they
make it across the room to the pediatrician,
there is very low likelihood of
needing to do resuscitation.
The pediatrician’s role can
be to dry off the infant,
to do some basic tasks such
as vitamin K inoculation,
swaddle the baby and hand that
baby right off to the mother.
If on the other hand, one
of these questions is true,
the infant is not full-term,
the infant has poor tone or the
infant is not crying or breathing,
we can expect the resuscitation.