Criteria for considering studies for this review

We will include randomized controlled trials (RCTs), quasi‐randomized controlled trials, and cluster‐randomized trials.

We will exclude cross‐over trials.

We will include infants that meet the following criteria.

Born at 34 weeks’ gestational age or more

Less than three days of age

Suffering from transient tachypnea of the newborn, defined as the presence of respiratory distress starting within six hours after birth, with::

X‐ray findings such as increased lung volumes with flat diaphragms, mild cardiomegaly, and prominent vascular markings in a sunburst pattern originating at the hilum; or

a normal chest X‐ray with no other apparent reason for respiratory distress (we plan to exclude infants with pneumonia, surfactant deficiency, aspiration syndromes, congenital diaphragmatic hernia, pneumothorax or congenital heart disease).

If necessary, we will contact the authors of studies to ascertain details of their enrolled population so we can determine whether the study should be included in our review.

We will include any type of corticosteroids, e.g. dexamethasone, budesonide, beclomethasone dipropionate, flunisolide, fluticasone propionate betamethasone, hydrocortisone, or others.

We will include any dose, mode of administration and duration of therapy in this review. Our comparisons will be as follows.

Corticosteroids versus no treatment or placebo

Systemic corticosteroids versus no treatment or placebo (comparison 1)

Inhaled corticosteroids versus no treatment or placebo (comparison 2)

Head‐to‐head comparison of different corticosteroids

One type of systemic steroid versus another type of systemic steroid (comparison 3)

One type of inhaled steroid versus another type of inhaled steroid (comparison 4)

Inhaled corticosteroids versus other inhaled corticosteroids (comparison 5)

Since TTN begins in the very first hours of life and its course is self‐limited, we will included trials in which the intervention was started within the first 72 hours of life.

We will investigate the effects of different corticosteroid preparations (e.g. dexamethasone, budesonide, beclomethasone dipropionate, flunisolide, fluticasone propionate, betamethasone, hydrocortisone) in the subgroup analysis (see Subgroup analysis and investigation of heterogeneity).

Need for nasal continuous positive airway pressure (yes/no)

Need for mechanical ventilation (yes/no)

Duration of hospital stay (days)

Duration of supplemental oxygen therapy (hours)

Duration of mechanical ventilation (hours)

Pneumothorax (anytime after intervention) (diagnosis on chest X‐ray)

Culture‐proven sepsis (anytime after intervention) (yes/no)

Initiation of oral feeding (days)

Duration of tachypnea, defined as number of hours with respiratory rate greater than 60 breaths per minute

Silverman or Downes' score greater than 6 (indicative of impending respiratory failure) (yes/no), 24 and 48 hours after study entry (Silverman 1956; Wood 1972)

Silverman or Downes' score greater than 4 (indicative of moderate distress) (yes/no), 24 and 48 hours after study entry

Persistent pulmonary hypertension diagnosed clinically, with or without at least one of the following echocardiographic findings: high right ventricular systolic pressure, right to left or bidirectional shunt at the patent foramen ovale or patent ductus arteriosus, severe tricuspid regurgitation (anytime after intervention)

Hyperglycemia, defined as blood glucose greater than 10 millimoles per liter (mmol/L) during the course of intervention

Gastrointestinal bleed, defined as presence of bloody nasogastric or orogastric aspirate (anytime after intervention)

Hypertension, defined as systolic or diastolic blood pressure more than two standard deviations (SDs) above the mean for the infant’s gestational and postnatal age (Zubrow 1995) during the course of intervention

Major neurodevelopmental disability: cerebral palsy, developmental delay (Bayley Mental Developmental Index (Bayley 1993; Bayley 2006) or Griffiths Mental Development Scale (Griffiths 1954) assessment more than two SDs below the mean), intellectual impairment (intelligence quotient (IQ) more than two SDs below the mean), blindness (vision less than 6/60 in both eyes), or sensorineural deafness requiring amplification (Jacobs 2013). We plan to assess data separately for children aged 18 to 24 months and those aged three to five years.