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Transient Tachypnea of the Newborn

(Neonatal Wet Lung Syndrome)


Arcangela Lattari Balest

, MD, University of Pittsburgh, School of Medicine

Last full review/revision Jul 2021| Content last modified Jul 2021
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Transient tachypnea of the newborn is transient respiratory distress caused by delayed resorption of fetal lung fluid. Symptoms and signs include tachypnea, retractions, grunting, and nasal flaring. Diagnosis is suspected when there is respiratory distress shortly after birth and is confirmed by chest x-ray. Treatment is supportive care and oxygen.

Extensive physiologic changes accompany the birth process, sometimes unmasking conditions that posed no problem during intrauterine life. For that reason, a person with neonatal resuscitation skills must attend each birth. Gestational age and growth parameters help identify the risk of neonatal pathology.

Transient tachypnea of the newborn affects premature infants, term infants delivered by elective cesarean delivery without labor, and infants born with respiratory depression, all of whom may have delayed clearance of fetal lung fluid. Part of the cause is immaturity of the sodium channels in lung epithelial cells; these channels are responsible for absorbing sodium (and thus water) from the alveoli. (Mechanisms for normal resorption of fetal lung fluid are discussed in Neonatal pulmonary function.) Other risk factors include macrosomia, maternal diabetes and/or asthma, lower gestational age, and male sex.

Symptoms and Signs

Transient tachypnea of the newborn is suspected when the infant develops respiratory distress shortly after birth.

Symptoms of transient tachypnea of the newborn include tachypnea, intracostal and subcostal retractions, grunting, nasal flaring, and possible cyanosis.


  • Chest x-ray

  • Complete blood count (CBC) and blood cultures

Pneumonia, respiratory distress syndrome, and sepsis may have similar manifestations, so chest x-ray, CBC, and blood cultures usually are done. Chest x-ray shows normally inflated or hyperinflated lungs with streaky perihilar markings, giving the appearance of a shaggy heart border while the periphery of the lungs is clear. Fluid is often seen in the lung fissures.

If initial findings are indeterminate or suggest infection, antibiotics (eg, ampicillin, gentamicin) are given while awaiting culture results.


  • Oxygen

Recovery usually occurs within 2 to 3 days.

Treatment of transient tachypnea of the newborn is supportive and involves giving oxygen and monitoring arterial blood gases or pulse oximetry.

Less frequently, infants with transient tachypnea of the newborn (TTN) may require continuous positive airway pressure (CPAP) and occasionally even mechanical ventilation.

A small number of infants with TTN may develop persistent pulmonary hypertension or pneumothorax.

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