Transient tachypnea of the newborn
- Karen E Johnson, MD
Karen E Johnson, MD
- Associate Professor
- Baylor College of Medicine
Transient tachypnea of the newborn (TTN) is a parenchymal lung disorder characterized by pulmonary edema resulting from delayed resorption and clearance of fetal alveolar fluid . TTN is a common cause of respiratory distress in the immediate newborn period. In a review of 33,289 term deliveries (37 to 42 weeks), the incidence of TTN was 5.7 per 1000 births . Although thought to be a benign, self-limited condition, there are increasing data to suggest that TTN increases a newborn's risk for developing a wheezing syndrome early in life .
The process of clearing fetal alveolar fluid begins before term birth and continues through labor and after delivery. During late gestation, in response to increased concentrations of catecholamines and other hormones, the mature lung epithelium switches from actively secreting chloride and liquid into the air spaces to actively reabsorbing sodium and liquid (figure 1) [4,5]. Increased oxygen tension at birth enhances the capacity of the epithelium to transport sodium and increases gene expression of the epithelial sodium channel . Reduced gene expression of this channel contributes to the inability of immature lungs to switch from fluid secretion to absorption and can be upregulated by glucocorticoids .
Passive resorption of liquid also occurs after birth because of differences among the oncotic pressure of air spaces, interstitium, and blood vessels. The majority of water transport across the apical membrane is thought to occur through aquaporin 5 (AQP5) water channels .
Delayed resorption of fetal lung fluid is thought to be the underlying cause of TTN. Fluid fills the air spaces and moves into the interstitium, where it pools in perivascular tissues and interlobar fissures until it is eventually cleared by the lymphatics or absorbed into small blood vessels. The excess lung water in TTN results in decreased pulmonary compliance. Tachypnea develops to compensate for the increased work of breathing associated with reduced compliance. In addition, accumulation of fluid in the peribronchiolar lymphatics and interstitium promotes partial collapse of the bronchioles with subsequent air trapping. Continued perfusion of poorly ventilated alveoli leads to hypoxemia, and alveolar edema reduces ventilation, sometimes resulting in hypercapnia.
In one study, the expression of AQP5 was greater in patients with TTN than in those with respiratory distress syndrome (RDS) or controls. This finding suggests that upregulation of AQP5 increases reabsorption of postnatal lung fluid, which contributes to the quick resolution of symptoms in infants with TTN .
- Avery ME, Gatewood OB, Brumley G. Transient tachypnea of newborn. Possible delayed resorption of fluid at birth. Am J Dis Child 1966; 111:380.
- Morrison JJ, Rennie JM, Milton PJ. Neonatal respiratory morbidity and mode of delivery at term: influence of timing of elective caesarean section. Br J Obstet Gynaecol 1995; 102:101.
- Liem JJ, Huq SI, Ekuma O, et al. Transient tachypnea of the newborn may be an early clinical manifestation of wheezing symptoms. J Pediatr 2007; 151:29.
- Bland RD, Nielson DW. Developmental changes in lung epithelial ion transport and liquid movement. Annu Rev Physiol 1992; 54:373.
- O'Brodovich HM. Immature epithelial Na+ channel expression is one of the pathogenetic mechanisms leading to human neonatal respiratory distress syndrome. Proc Assoc Am Physicians 1996; 108:345.
- Li Y, Marcoux MO, Gineste M, et al. Expression of water and ion transporters in tracheal aspirates from neonates with respiratory distress. Acta Paediatr 2009; 98:1729.
- Machado LU, Fiori HH, Baldisserotto M, et al. Surfactant deficiency in transient tachypnea of the newborn. J Pediatr 2011; 159:750.
- Isik DU, Bas AY, Demirel N, et al. Increased asymmetric dimethylarginine levels in severe transient tachypnea of the newborn. J Perinatol 2016; 36:459.
- Levine EM, Ghai V, Barton JJ, Strom CM. Mode of delivery and risk of respiratory diseases in newborns. Obstet Gynecol 2001; 97:439.
- Tutdibi E, Gries K, Bücheler M, et al. Impact of labor on outcomes in transient tachypnea of the newborn: population-based study. Pediatrics 2010; 125:e577.
- Kolås T, Saugstad OD, Daltveit AK, et al. Planned cesarean versus planned vaginal delivery at term: comparison of newborn infant outcomes. Am J Obstet Gynecol 2006; 195:1538.
- Persson B, Hanson U. Neonatal morbidities in gestational diabetes mellitus. Diabetes Care 1998; 21 Suppl 2:B79.
- Pinter E, Peyman JA, Snow K, et al. Effects of maternal diabetes on fetal rat lung ion transport. Contribution of alveolar and bronchiolar epithelial cells to Na+,K(+)-ATPase expression. J Clin Invest 1991; 87:821.
- Demissie K, Marcella SW, Breckenridge MB, Rhoads GG. Maternal asthma and transient tachypnea of the newborn. Pediatrics 1998; 102:84.
- Birnkrant DJ, Picone C, Markowitz W, et al. Association of transient tachypnea of the newborn and childhood asthma. Pediatr Pulmonol 2006; 41:978.
- Liu J, Chen XX, Li XW, et al. Lung Ultrasonography to Diagnose Transient Tachypnea of the Newborn. Chest 2016; 149:1269.
- Onal EE, Dilmen U, Adam B, et al. Serum atrial natriuretic peptide levels in infants with transient tachypnea of the newborn. J Matern Fetal Neonatal Med 2005; 17:145.
- Kuo CY, Chou YH, Lien R, Yang PH. Study of plasma endothelin-1 concentrations in Taiwanese neonates with respiratory distress. Chang Gung Med J 2001; 24:239.
- Wiswell TE, Rawlings JS, Smith FR, Goo ED. Effect of furosemide on the clinical course of transient tachypnea of the newborn. Pediatrics 1985; 75:908.
- Kassab M, Khriesat WM, Bawadi H, Anabrees J. Furosemide for transient tachypnoea of the newborn. Cochrane Database Syst Rev 2013; :CD003064.
- Stroustrup A, Trasande L, Holzman IR. Randomized controlled trial of restrictive fluid management in transient tachypnea of the newborn. J Pediatr 2012; 160:38.
- Kassab M, Khriesat WM, Anabrees J. Diuretics for transient tachypnoea of the newborn. Cochrane Database Syst Rev 2015; :CD003064.