Transient tachypnea of the newborn (TTN, TTNB, or "Transitory tachypnea of newborn") is a respiratory problem that can be seen in the newborn shortly after delivery

Childbirth

Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...

. Amongst causes of respiratory distress in term neonates, it is the commonest . It consists of a period of rapid breathing (higher than the normal range of 40-60 times per minute). It is likely due to retained lung

Lung

The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...

 fluid, and common in 35+ week gestation babies who are delivered by caesarian section without labor. Usually, this condition resolves over 24-48 hours. Treatment is supportive and may include supplemental oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

 and antibiotic

Antibiotic

An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

s. The chest X-Ray

X-ray

X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

 shows hyperinflation of the lungs including prominent pulmonary vascular markings, flattening of the diaphragm

Thoracic diaphragm

In the anatomy of mammals, the thoracic diaphragm, or simply the diaphragm , is a sheet of internal skeletal muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in respiration...

, and fluid in the horizontal fissure of the right lung.

Pathophysiology

1. Due to the higher incidence of TTN in newborns delivered by caesarean section, it has been postulated that TTN could result from a delayed absorption of fetal lung fluid from the pulmonary lymphatic system. The increased fluid in the lungs leads to increased airway resistance and reduced lung compliance. It is thought this could be from lower levels of circulating catecholamine
   Catecholamine
   Catecholamines are molecules that have a catechol nucleus consisting of benzene with two hydroxyl side groups and a side-chain amine. They include dopamine, as well as the "fight-or-flight" hormones adrenaline and noradrenaline released by the adrenal medulla of the adrenal glands in response to...
   
   s after a caesarean section, which are believed to be necessary to alter the function of the ENaC channel to absorb excess fluid from the lungs.
2. Pulmonary immaturity has also been proposed as a causative factor. Levels of phosphatidylglycerol
   Phosphatidylglycerol
   Phosphatidylglycerol is a glycerophospholipid found in pulmonary surfactant.The general structure of phosphatidylglycerol consists of a L-glycerol 3-phosphate backbone ester-bonded to either saturated or unsaturated fatty acids on carbons 1 and 2. The head group substituent glycerol is bonded...
   
   (an indicator of lung maturity) were found to be negative in certain newborns.
3. Mild surfactant deficiency has also been suggested as a causative factor.

Clinical evaluation

TTN is a diagnosis of exclusion as it is a benign condition that can have symptoms and signs similar to more serious conditions, such as respiratory distress syndrome . A chest X-ray may show a radiopaque line - fluid - in the horizontal fissure of the right lung, fluid inflitrate throughout alveoli or fluid in individual lung lobes.