Transient tachypnea - newbornTTN; Wet lungs - newborns; Retained fetal lung fluid; Transient RDS; Prolonged transition; Neonatal - transient tachypnea
Transient tachypnea of the newborn (TTN) is a breathing disorder seen shortly after delivery, most often in early term or late preterm babies.
- Transient means it is short-lived (most often less than 48 hours).
- Tachypnea means rapid breathing (faster than most newborns, who normally breathe 40 to 60 times per minute).
As the baby grows in the womb, the lungs make a special fluid. This fluid fills the baby's lungs and helps them grow. When the baby is born at term, hormones released during labor tell the lungs to stop making this special fluid. The baby's lungs start removing or reabsorbing it.
The first few breaths a baby takes after delivery fill the lungs with air and help to clear most of the remaining lung fluid.
Leftover fluid in the lungs causes the baby to breathe rapidly. It is harder for the small air sacs of the lungs to stay open.
TTN is more likely to occur in babies who are:
- Born before 38 completed weeks gestation (preterm, or early term)
- Delivered by C-section, especially if labor has not already started
- Born to a mother with diabetes or asthma
Newborns with TTN have breathing problems soon after birth, usually starting within 1 to 2 hours.
- Bluish skin color (cyanosis)
- Rapid breathing, which may occur with noises such as grunting
- Flaring nostrils or movements between the ribs or breastbone known as retractions
Exams and Tests
The mother's pregnancy and labor history are important to make the diagnosis.
Tests performed on the baby may include:
- Blood count and blood culture to rule out infection
- Chest x-ray to rule out other causes of breathing problems
- Blood gas to check levels of carbon dioxide and oxygen
- Continuous monitoring of the baby's oxygen levels, breathing, and heart rate
The diagnosis of TTN is most often made after the baby is monitored for 2 or 3 days. If the condition goes away in that time, it is considered to be transient.
Your baby will be given oxygen, and sometimes CPAP (continuous positive airway pressure) as well, to keep the blood oxygen level and breathing rate stable. Your baby will often need the most support within a few hours after birth and will usually begin to improve after that. Most infants with TTN improve in less than 24 to 48 hours, but some will need help for a few days.
Very rapid breathing usually means a baby is unable to eat. Fluids and nutrients will be given through a vein until your baby improves. Your baby may also receive antibiotics until the health care team is sure there is no infection. Sometimes, babies with TTN will need help with breathing or feeding for a week or more, usually if they are premature.
The condition most often goes away within 48 to 72 hours after delivery. In most cases, babies who have had TTN have no further problems from the condition. They will not need special care or follow-up other than their routine checkups. However, there is some evidence that babies with TTN may be at a higher risk for wheezing problems later in infancy.
Late preterm or early term babies (born more than 2 to 6 weeks before their due date) who have been delivered by C-section without labor may be at risk for a more severe form known as "malignant TTN."
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Crowley MA. Neonatal respiratory disorders. In: Martin RJ, Fanaroff AA, Walsh MC, eds. Fanaroff and Martin's Neonatal-Perinatal Medicine: Diseases of the Fetus and Infant. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 66.
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