Tachypnea

For some newborns, the breaths during those first hours of life are more rapid and labored than normal because of a condition called transient tachypnea of the newborn (TTN). About 1% to 2% of all newborns develop TTN, a lung condition that usually subsides within a few days with treatment.

Although babies born with TTN need special monitoring and treatment while in the hospital, afterwards they typically make a full recovery, and the TTN has no lasting effect on growth and development.

What Is Transient Tachypnea of the Newborn?

Before birth, the lungs of the fetus are filled with 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 baby passes through the birth canal, some of the fluid inside the baby's lungs is "squeezed" out. After the 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 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 the baby breathes faster and harder to compensate. TTN is also called "wet lungs" or type II respiratory distress syndrome. Doctors usually can diagnose TTN usually in the hours after birth. The condition typically lasts between 24 to 72 hours.

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What Causes Transient Tachypnea of the Newborn?

It is not possible to detect whether a child will have TTN before the baby is born. TTN occurs in both premature and full-term infants. Premature babies tend to have TTN because their lungs are not yet fully developed.

Newborns at higher risk for TTN include those who are:
  • delivered by cesarean section
  • born to mothers who smoked during pregnancy
  • born to mothers with diabetes
  • small for gestational age (small at birth)
Delivery by cesarean section increases the risk for 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. So these babies tend to have more fluid than normal 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.

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Signs and Symptoms of TTN

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.

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How Is TTN 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 the heel to check for signs of infection.
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How Is TTN Treated?

As with any newborn who has a breathing problem, infants diagnosed with TTN are closely observed and monitored. Sometimes they'll be admitted to the neonatal intensive care unit (NICU) for extra care. The babies are typically attached to monitors so that heart rate, breathing rate, and oxygen levels can be closely watched.

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 oxygen mask or under a plastic oxygen 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 the baby's nose to help keep the lungs open as he or she breathes.

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 he or 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, the breathing in infants with TTN typically improves and returns to normal, and within 72 hours, all symptoms of TTN typically dissipate altogether.

If fluid persists in a baby's lung beyond that time, than doctors will likely look into other medical problems which may be causing the condition.

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Bringing Your Baby Home

After babies with TTN receive special monitoring and treatment in the hospital, they usually recover fully and are at no increased risk for other respiratory conditions, or other health problems.

Even though you won't have to worry about TTN after the third day of life, it's a good idea to stay aware of the signs of respiratory distress so you can call your child's doctor if you suspect a problem. If your baby has trouble breathing, appears blue, or if the skin pulls in between the ribs or under the ribcage during rapid or labored breathing, it's important to call your child's doctor or emergency services (911) right away.

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Information obtained from National Institute of Health
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