Transient Tachypnea of the Newborn
What is it?
Before birth, the lungs of the fetus are filled
with amniotic fluid. While a fetus is inside of
its mother, it does not use its lungs to breathe -
all its oxygen comes from the blood vessels of the
placenta.
During the birthing process, as a
soon-to-be-born baby passes through the birth
canal, some of the fluid inside the baby's lungs
is "squeezed" out. After birth, during
the first breaths that a newborn takes, the lungs
fill with air and more fluid is pushed out of the
lungs. Any remaining fluid is then coughed out or
gradually absorbed into the body through the
bloodstream.
In infants with TTN, however, there is extra
fluid present in the lungs or the fluid in the
lungs is absorbed too slowly. As a result, it is
more difficult for the baby to take in oxygen
properly, and she breathes faster and harder to
compensate. TTN is also called "wet
lungs" or type II respiratory distress
syndrome.
TTN usually is noted soon after birth and lasts
between 24 to 72 hours.
Who gets it?
About 1% to 2% of all newborns develop TTN, a
lung condition that usually subsides within a few
days with treatment.
What Causes it?
It is not possible for doctors to pinpoint
which babies will have TTN before birth. No one
knows the exact reason why some babies are unable
to clear their lungs effectively.
Doctors have found that race isn't a factor in
whether a baby has TTN - the condition is equally
present in all ethnicities. TTN occurs in both
premature and full-term infants, although the risk
is greater for preemies.
Newborns at higher risk for TTN include those
who are:
- premature
- delivered by cesarean section
- born to mothers who smoked during pregnancy
- born to mothers with diabetes
- small for gestational age (small at birth)
Why does the type of labor and delivery a woman
has determine the newborn's risk for developing
TTN? Because during vaginal births, especially
with full-term babies, the pressure of passing
through the birth canal squeezes some of the fluid
out of the lungs. Babies who are small or
premature or who are delivered via rapid vaginal
deliveries or cesarean births don't experience the
usual squeezing that occurs with a more routine
vaginal birth. These babies have more fluid than
normal present in their lungs when they take their
first breaths.
Some doctors have suggested that in babies with
TTN, the release of the hormone epinephrine is
inhibited during labor. In normal births,
epinephrine aids in the clearing of fluids from
the lungs. When a smaller amount of epinephrine is
released, babies are less effective at clearing
the fluid from the lungs.
What are the symptoms?
Symptoms of TTN include:
- rapid, labored breathing (tachypnea) of more
than 60 breaths a minute
- grunting or moaning sounds when the baby
exhales
- flaring nostrils or head bobbing
- retractions (when the skin pulls in between
the ribs or under the ribcage during rapid or
labored breathing)
- cyanosis (when the skin turns a bluish color)
around the mouth and nose
Other than the above symptoms, infants who have
TTN will look fairly healthy.
How is it diagnosed?
Because TTN has symptoms that are initially
similar to more severe newborn respiratory
problems such as pneumonia or persistent pulmonary
hypertension, doctors usually use chest X-rays in
addition to physical examination to make a
diagnosis. Doctors may also use other indicators
to make a diagnosis of TTN:
- If an infant has TTN, the X-ray picture of
the lungs will appear streaked, and fluid will
usually be seen. The X-ray will otherwise appear
fairly normal.
- Pulse-oximetry monitoring, which is when a
small piece of tape containing an oxygen sensor
is placed around a baby's foot or toe and
connected to a monitor, can aid in diagnosis.
This tells doctors how well the lungs are
sending oxygen to the blood and is also useful
in monitoring TTN.
- A complete blood count (CBC) may also be
drawn from one of the baby's veins or her
heel to check for signs of infection.
What is the treatment?
As with any newborn who has a breathing
problem, infants who are diagnosed with TTN are
closely observed and monitored. Sometimes they
will be admitted to the NICU
for extra care. The baby will be attached to a
monitor so heart rate, breathing rate, and oxygen
levels can be closely watched from minute to
minute.
- Some babies with TTN are simply monitored to
ensure that their breathing rates slow down and
their oxygen levels remain normal. Sometimes
they may need to receive extra oxygen through a
mask or under a plastic hood (called a "headbox").
- If a baby struggles to breathe in oxygen,
even while under an oxygen hood, continuous
positive airway pressure (CPAP) is sometimes
used to keep air flowing through the lungs. With
CPAP, a baby wears a special oxygen cannula (a
type of tubing that is placed directly into the
baby's nose) and a machine continuously pushes a
stream of pressurized air into her nose to help
keep her lungs open as she breathes on her own.
- In the most severe cases of TTN, a baby would
need ventilator support, but this is rare.
Nutrition can be a problem if an infant is
breathing so fast that she can't suck, swallow,
and breathe simultaneously. Intravenous (IV)
fluids provide hydration and will prevent the
infant's blood sugar from dipping to dangerously
low levels. If your baby has TTN and you want to
breast-feed, talk to your doctor or a nurse about
maintaining your milk supply by using a breast
pump while your infant receives IV fluids.
Within 24 to 48 hours, an infant with TTN
should improve and breathing should return to what
is normal for a newborn. Within 72 hours, all
symptoms of TTN should disappear.
Self Care Tips
Although your child will receive special
monitoring and treatment while in the hospital,
once you bring your baby home, she is not at
increased risk for other respiratory problems. In
addition, your baby's growth and development will
be unaffected by TTN.
Even though you won't have to worry about TTN
after the third day of life, you should always be
aware of the signs of respiratory distress so that
you can call your child's doctor if you suspect a
problem. If your baby or child has trouble
breathing, appears blue, or if her skin pulls in
between the ribs or under the ribcage during rapid
or labored breathing, call your child's doctor or
emergency services (911) immediately.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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