Transient Tachypnea of the Newborn Workup

Updated: Dec 23, 2020
  • Author: Siva Subramanian, MD, FAAP; Chief Editor: Ted Rosenkrantz, MD  more...
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Laboratory Studies

The following studies are indicated in transient tachypnea of the newborn (TTN).

Arterial blood gas (ABG)

An ABG assessment is important to ascertain the degree of gas exchange and acid-base balance.

Consider an intraarterial catheter, such as an umbilical artery catheter, if the infant's inspired fraction of oxygen exceeds 40%.

Hypoventilation is very uncommon, and partial carbon dioxide tensions are usually normal because of the tachypnea. However, a rising carbon dioxide tension in an infant with tachypnea may be a sign of fatigue and impending respiratory failure or a complication such as a pneumothorax.

Pulse oximetry

Continuously monitor infants with pulse oximetry for assessment of oxygenation.

Pulse oximetry allows the clinician to adjust the level of oxygen support needed to maintain appropriate saturation.

Persistently increased oxygen requirement (FiO 2 >40%) may be an indication for surfactant replacement.

Other tests

Few biochemical markers have been shown to be effective in predicting the severity of transient tachypnea of the newborn, such as lactate, lactate dehydrogenase (LDH), [21] and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP). [22]

Levels of ischemia-modified albumin (IMA) appear to have potential as markers for predicting transient tachypnea of the newborn and disease severity. A study of 47 infants with this condition found significantly higher levels in infants with transient tachypnea of the newborn relative to control infants without respiratory symptoms, as well as in infants on nasal continuous positive airway pressure (CPAP) compared to those on supplemental oxygen therapy. [23]


Imaging Studies

Chest radiography

Chest radiography is the diagnostic standard for transient tachypnea of the newborn.

The characteristic findings include prominent perihilar streaking, which correlates with the engorgement of the lymphatic system with retained lung fluid, and fluid in the fissures. Small pleural effusions may be seen. Patchy infiltrates have also been described.

Follow-up chest radiography may be necessary if the clinical history suggests meconium aspiration syndrome or neonatal pneumonia or if respiratory status worsens.

Lung ultrasonography

One study showed the utility of lung sonogram in diagnosing transient tachypnea of the newborn with sensitivity and specificity of 100%. Copetti et al described the sonographic landmark finding of transient tachypnea of the newborn as “double lung point”. [24]

Lung ultrasonography appears to be useful in neonates with suspected or confirmed coronavirus disease 2019 (COVID-19). In a 2020 study that comprised data from 27 infants, investigators reported the following findings [25] :

  • Infants who had pulmonary symptoms but were negative for COVID-19 presented with transient tachypnea of the newborn and respiratory distress syndrome.
  • In these COVID-19-negative infants, lung ultrasonography some showed a pattern with A lines, few B lines, a thin linear pleural line, and no pleural effusion (normal), whereas others showed coalescent B lines and areas of opacity.
  • Of infants positive for COVID-19, the lung sonograms in two revealed several coalescent B lines, pleural thickening, and areas of opacity.


Echocardiogram is warranted in an infant with persistent tachypnea for more than 5-6 days to rule out congenital cardiac anomalies and cardiac function.